Spray Granulator: The Ultimate FAQ Guide

If you have any question about spray granulator, you will find the answer right here.

Whether you want to learn about design, features, applications, advantages, parts or working principle – this guide has all information you need about spray granulator.

Let’s dive right in.

What is a Spray Granulator?

Spray granulator is a machine that transforms water-containing suspension, melt or paste into a granule.

It performs the granulation and drying processes simultaneously, forming dust-free and easy to manage granules.

Spray Granulator

Spray Granulator

A spray granulator is a machine you employ in a particle’s granulation by covering it in multiple layers.

You achieve the layered construct when fragments of matter dissolve in a liquid dry upon spraying into a fluidized bed.

Consequently, you achieve granule formation that is rigid and condensed with minimal dust and outstanding physical structure.

In using a spray granulator, you employ a liquid mater that carries your particles.

You disperse this solid-liquid containment through a nozzle onto the seed in the fluidized bed as a spray.

The liquid quickly evaporates, leaving behind the solid particles on the seed’s surface in the form of a layer.

You achieve a multi-layer formation by repeating this process many times.

You can alter the particles’ size, liquid, and solid content to facilitating granule formation when using a spray granulator.

Using a fluidized bed, you can use a spray granulator to develop seeds with consistent granule formation.

These granules typically possess a high bulk density with reduced dust levels.

Using a spray granulator allows you to make consistent granules with an equal distribution of particles.

You also retain a liquid remnant with admirable flow qualities with reduced dust presence.

When you use a spray granulator with a fluidized bed, you can achieve the granulation and drying process concurrently.

In this case, you refer to your granulator as a fluidized bed spray granulator and dryer.

What Granulation Method do you Employ in a Spray Granulator?

You select the granulation method by considering the material properties of the substances you intend to granulate.

Additionally, the characteristics you desire for your end product will also determine the granulation method you employ.

The granulation method you employ with a spray granulator is wet granulation, where you use a binder and dissolved solid material.

In wet granulation, you form granules through an agglomeration process to combine a liquid agent and dissolved particles.

The agglomeration process in wet granulation uses steam or water as the liquid agent employed as a binding solution.

The liquid has to be non-toxic, allowing consumption without harm, especially when used for the pharmaceutical purpose as dosage.

Aside from water, you can use ethanol as your liquid binding agent or even isopropanol.

Furthermore, you can use a combination of these liquids to extract a fluid with desired properties for your granulation purposes.

Spraying the solution on your seed in the fluidized bed evaporates the liquid agent leaving behind the dissolved particles as granules.

During the granulation process, the powder and liquid agent interaction dictate the granules’ features from wet granulation.

How is Granulation Conducted by the Spray Granulator?

Spray Granulation process

Spray Granulation process

The spray granulator employs the wet granulation process, where you use a liquid agent to dissolve the particles for granule formation.

The liquid agent typically contains binders that are adhesive to impart cohesion between the particles while forming granules.

In preparing the solution, you add the fine powder you desire to granulate to a liquid solution such as water.

You combine the two substances in the required measure to achieve a suspension, solution, or paste.

Using a solution is preferable due to its impressive granule formation qualities compared to other binding forms.

You fill up the spray granulator with this solution, ready for the granulation process through spraying.

The spray granulator subjects the solution under pressure during release to initiate the particle dispersion.

A nozzle enables the solution to exit from the granulator in a stream while influencing some granular characteristics.

You typically position the desired seed in a fluid bed where the granulation process occurs.

The fluid bed enables the evaporation process to eliminate the liquid agent leaving behind the desired powder in granules.

You can also use other specialized equipment to dewater the solution other than a fluid bed.

The granulation process and the drying process occur simultaneously, leaving behind even granules with minimal dust.

When using a spray granulator, you achieve particles with homogeneous characteristics related to the shape and size.

These particles form through the accumulation of the small particles to form large particles called granules hence granulation.

Why Should you Use a Spray Granulator?

Spray granulator is a popular piece of equipment for undertaking the granulation process of converting small powder particles into larger granules.

You employ the wet granulation method with a spray granulator, allowing you to achieve granules with consistent shape and size.

Some of the advantages of using a spray granulator include:

  • Granulation using a spray granulator allows you to inhibit the powder constituents’ disintegration when making tablets or during storage.
  • When you use a spray granulator, you reduce dust formation, especially in the tablet-making process.
  • Granules formation using a spray granulator allows you to present more appealing products by influencing their shape and size.
  • When you use a spray granulator, you augment the flowability of the powder combination.
  • Granulation using spray granulator minimizes product adulteration through dust formation, which is potentially hazardous.
  • When using a spray granulator to make dosages in tablet form, you enhance the compression properties.

What are the Granulation Mechanisms of a Spray Granulator?

When using a spray granulator, the granulation process occurs in phases that influence the final granule characteristics.

You can realize the development of these phases separately during granulation using a spray granulator or at the same time.

Nevertheless, you discover that particular mechanisms can be prevalent in certain processes or when using a particular equipment.

These mechanisms are as follows:

Wetting and Nucleation

The wetting and nucleation phase is the foremost mechanism in the formation of granules using a spray granulator.

Here, you form nuclei in the bed by inducing wetting on the particles using the granulating liquid.

Different factors affect the wetting and nucleation mechanism, including distributing the solution during spraying and its constituents.

Nucleation involves merging particles in a pre-granulation process as you disburse the solution into the fluidized bed.


Coalescence features the formation of granules by the amalgamation of saturated powder particles and formed nuclei.

You can observe a granule pair combining during coalescence to form a bigger granule.


You observe consolidation of granules in the fluidized bed that results in even larger sizes of granules.

You find consolidation results from the movement of particles in the bed induced by force enabling compaction.

The extent of particle movement in the bed and resistance to the applied external force determines the level of granular consolidation.

Consolidation influences your granules’ porosity and, consequently, their strength, rigidity, and ability to dissolve.


Attrition refers to the breakage of a granule resulting in the multiplication of granules.

These granules then coalesce with other granules enveloping the original granule.

How do you Make Tablets Using a Spray Granulator?

You find the spray granulator useful in the tablet-making process used for dosage purposes.

Using the spray granulator, you employ wet granulation to consistently make tablets in defined sizes and shapes.

The following steps are necessary when making tablets using the spray granulator:

Determining the Appropriate Measures of the Tablet Ingredients

Here, you determine and measure the materials and excipients you need to make the dosage form in the required quantities.

Such ingredients include the granulating agent, plant extract, diluent, and agitator.

You then mix these ingredients and excipients to achieve a powder formation.

You can use different equipment to enable the mixing process, including the rotating drum and planetary bowl.

Employing powder materials with identical physical properties increases your efficiency in obtaining a perfect mix.

You can employ sugar or starch-based extracts alongside salts such as sulfates and phosphates of calcium for diluents.

Lactose finds popular use as an excipient due to its availability, ability to dissolve easily, and congruency with drug extracts.

Alternatively, microcrystalline cellulose is a viable option as it readily compacts with consistent results alongside being highly compatible with medicinal substances.

You have different selections for your agitators in preparing the powder, including PVP and various starch extracts.

These disintegrants provide a balance for the binding effect resulting from the compaction employed in tablet formation.

Preparation of the Wet Matter

You form the wet matter for your tablets making process by adding the binding liquid to the powder mix.

The solution allows you to create a damp mass that the spray granulator can disperse.

The binding liquid consists of a binder agent and a fluid such as water, alcohol, or isopropanol mixed in adequate proportions.

You determine a proper mix when you obtain a solid mass upon applying pressure to a fistful of the mixture.

Having an inadequate binding agent in your solution results in low adhesion leading to soft and defective tablets.

When you employ more binding agents than you need, your tablets become harder with a low dissolution rate.

The tablets you require are susceptible to active solutions; you can employ a neutral solution or a dry binding agent.

You can also employ additives such as colors and flavors to enhance your granulation properties.


The spray granulator screens the damp mass using almost a dozen mesh screens in preparation for wet granulation.

You observe the outcome as a uniformly spread granule formation on a bed thanks to the punctured meshwork’s extrusion process.


A spray granulator makes wet granules by depositing them on a bed or tray in an even manner.

You can use an oven to dry the granules by closely monitoring the temperature.

You need to ensure your temperature is less than 55 0C, so you achieve granules with similar weight parameters.

The dosage formulation’s active excipient dictates the temperature value and how long you sustain the drying process.

Furthermore, the moisture present in the granules guides the process to achieve the desired moisture content.

Instead of an oven, you can employ a fluidized bed-dryer with a spray granulator.

Granule Sizing

Upon drying, you size the granules by subjecting them to a screening process similar to that in wet granule formation.

You observe that your punch size influences the granule size and using screens with a mesh size of up to 20.

Granule Lubrication

Before the lubrication process, you sift the granules on a sieve with 250 mesh to obtain large and small granules.

Subsequently, you apply a lubricant of another sieve with a mesh size of 200.

You gel the small granules with the lubricant first before including the large granules.

You achieve the desired lubrication effect when you employ a lubricant no more than five percent of the granular weight.

When lubricating granules using a spray lubricant, you can use plant-based hydrogenated oil and calcium or magnesium stearates.

You can also use wax, talc, some starch derivatives, and stearic acid.

Tablet Compression

Upon successfully forming granules using the spray granulator, you proceed to the tablet-making process through granular compression.

You use a punch and die system to compress the granules into a tablet.

You can enhance your tablet’s features, such as taste and dissolution rate, by applying a coating.

Coating application should employ substances that are non-toxic as it defeats the medicinal purpose of dosage.

Spray Granulation Machine

Spray Granulation Machine

What are Some of the Products you can Make Using a Spray Granulator?

You can use the spray granulator to manufacture the following products in the granular form:

  • Different sauces of flavors from different plant extracts.
  • Concentrates and hydrolysates of building blocks such as proteins.
  • Coffee extracted from coffee berries.
  • Both organic and inorganic salts derivatives.
  • Stevia and other plant extracts.
  • Inorganic fertilizers, pesticides, organic acids, and coloring agents.
  • Detergents, processed minerals, and ceramics.

Where do you Employ the Spray Granulator?

Here are some of the industries that use spray granulator:

Pharmaceutical Industry

You can use the spray granulator in making dosage forms of medicine before tableting.

Tablets you form from the granulation process using a spray granulator are then delivered for a prescription.

Food Processing

The spray granulator is useful in processing various food substances from plant extracts such as leaves, barks, and seeds.

You can use a spray granulator to make coffee, milk powder, food flavorings, and spice seasonings.

Chemical Industry

The spray granulator in the chemical industry finds various applications such as dye-making and making detergents and pigments.

You also find spray granulation employed in the processing of raw materials for use in other manufacturing endeavors.

What is a Fluidized Bed Spray Granulator?

Fluidized Bed Spray Granulator

Fluidized Bed Spray Granulator

A fluidized bed spray granulator encompasses a spray granulator with a fluidized bed construction for granulation and drying purposes.

The fluidized bed allows you to derive uniform and evenly spaced granules from concentrated solutions.

The fluidized bed spray granulator is the go-to equipment for granulating pharmaceutical products.

However, you can employ the fluidized bed spray granulator in other industries by configuring the desired outcome equipment.

With a fluidized bed spray granulator, you can achieve a triple-action of mixing the formulation, granulating it, and drying.

Using this equipment in tablet making is popular due to consistency in granule formation with respect to size and shape.

You can also use the fluidized bed spray granulator for coating purposes, where you deposit layers of granules over a seed.

When using a fluidized bed spray granulator, you convert liquid formulations into granules with enhanced flowability and properties.

A fluidized bed spray granulator allows you to simplify the material for further processing.

Additionally, using this equipment allows you to package, transport, and store material easily by reducing volume.

Employing the fluidized bed spray granulator also allows you to present more chemicals in more stable forms.

You can use the fluidized bed spray granulator to process items susceptible to heat, such as proteins and active enzymes.

When using a fluidized bed spray granulator, you disperse solid substances in different liquid states to a fluidized bed.

A temperature differential induces an evaporation process that eliminates the liquid leaving behind the solid particles contained in the solution.

As you continue spraying the solution into the fluidized bed, you observe the formation of more particles.

These particles form as layers over each other coalescing to form dense and larger particles you refer to as granules.

You observe that when using a fluidized bed spray granulator, the drying process occurs concurrently with the granulating process.

You can remove formed granules from the bed, maintaining a constant particle count.

You determine granular characteristics such as moisture content, flowability, dissolution rate, flaking, and abrasion by varying the dispersion process.

Denser granules offer you better resistance to abrasion while reducing dust production allows you to achieve a high bulk density.

What are the Parts of a Fluidized Bed Spray Granulator?

When purchasing a fluidized bed spray granulator, you encounter such granulators with different designs and constructions.

However, you find certain parts on all fluidized bed spray granulators necessary for effective functioning despite the different designs.

Here are the main parts of the fluidized bed spray granulator:

  • The gas inlet chamber is otherwise known as the plenum. Air you employ for fluidization enters through this part.
  • Part for gas distribution.
  • Container holding product for granulation.
  • Chamber constructed to hold several filter bags.
  • Nozzle system for releasing the solution or binder and liquid mixture.

What are the Nozzle Designs you can Use for a Spray Granulator?

When using a spray granulator, you disperse the solution to the bed via a nozzle system.

The system allows you to control the granulation process by regulating the rate of flow.

Spray Nozzle

Spray Nozzle

There are four nozzle designs you can use with a spray granulator, including:

Pressure Nozzle

The pressure nozzle is characteristically unstable in its dispersal of the pressurized solution.

When using the pressure nozzle, the fluid burst interacts with the air and each other during release.

Rotating Nozzle

You use the rotating nozzle when you want to hasten the drying process.

The rotating nozzle releases the solution in very small bursts resulting in its alternative reference as the rotary atomizer.

Airless Spray Nozzle

In an airless spray nozzle, you have a dual inlet system of the solution to the nozzle.

However, you have a single exit where the release occurs in the form of a single jet.

Gas Atomizing Nozzle

The gas atomizing nozzle employs a dual fluid system in disbursing the solution on the fluidized bed.

The gas atomizing nozzle employs compressed air to disperse the solution with a binder to the bed.

What Determines the Design of a Fluidized Bed Spray Granulator?

When constructing a fluidized bed spray granulator, you can have it such that the spray mechanism is at the top or bottom.

The construction of this spray granulator bears heavy similarity to a coating apparatus using almost similar compressed airspeeds.

However, with the granulator, you find the spray area’s location occupies a larger part of the base.

When using the fluidized bed granulator, you agitate the powder above the tray and release the binder solution from the nozzle system.

The location of the nozzles depends on the construction of the fluidized bed spray granulator.

The nozzles’ positioning is relative to the fluidized bed location, such that it is above or below.

The following factors influence the design of your granulator:

  • The methodology you employ in processing your binder solution.
  • Your choice of operation for the granulator between batch granulation and continuous granulation.
  • Your intended use of the equipment, whether it is granulating or coating.
  • The processing principle guides your spray granulator.

Why Should you Use a Fluidized Bed Spray Granulator?

You have different constructions and types of spray granulators available for your employment.

Your choice of the granulator depends on your expected application and the operation mode you select.

The common type of spray granulator used is fluidized bed spray granulator.

Some of the reasons of using fluidized bed spray granulator are:

  • The fluidized bed spray granulator can execute multiple operations, reducing the need for transfers.

Consequently, you save on time and costs associated with extra labor when you employ the fluidized bed spray granulator.

  • With a fluidized bed spray granulator, you experience a larger heat transfer compared to using a tray dryer.

The difference in the heat generation can be up to six times, rapidly increasing the drying process.

  • When using a fluidized-bed granulator, you can automate the processes to require low human input. You find automation possible by optimizing the granulator’s parameters.
  • The drying process in a fluidized bed spray granulator is uniform resulting in evenly sized granules. Consequently, you prevent mottling when you employ the fluidized bed spray dryer.

How are Fluidized Bed Spray Granulators Limited?

Every piece of equipment has observable limitations when operating, and the fluidized bed spray granulator is no exception.

A fluidized bed spray granulator allows you to form granules from pressurizing a binding solution over a powder-laden bed.

You find the following drawbacks in employing the fluidized bed spray granulator:

  • Acquiring a fluid bed spray granulator is costly.
  • You can use both the continuous and batch operation with a fluidized bed spray granulator.

However, the densification level achievable using the continuous process is not possible with the batch process.

  • The time taken in the granule formation process using the fluidized bed spray granulator is long. Consequently, you find the granule formation process to be slow with this equipment.
  • Using a fluidized bed spray granulator requires granulating fluid in excessive amounts. Therefore, you need to use plenty of raw material in the preparation of your granulating fluid.
  • When working with this equipment, you can experience several issues that affect the process. Common failings include demising, solvent explosion, filter clocking, and electrostatic charge release.
  • The granules formed by the fluidized bed spray granulator have low-density property.

What Factors Affect the Granulation Process Using the High Shear Spray Granulator?

The high-shear spray granulator includes a mixing tank, a motor-driven triple blade impeller, a chopper pair, and a discharge container.

You use the shear granulator for cooling or heating substances in the mixer by employing steam or cold fluid.

The granulation process using a high-shear granulator encompasses powder preparation and binder agent, and fluid addition.

You follow this by dampening the powder to initiate the nucleation process.

You observe the formation of granules as the powder densifies, resulting in attrition and breakage.

The triple blade impeller mixes the powder to the desired consistency and disperses the solution at high speeds.

You can have a vertical or horizontal high shear granulator determined by the main impellers’ location and rotary direction.

Furthermore, a vertical high shear granulator can be distinguished by the driving mechanism’s location above or below it.

Some of the factors affecting the granulation process using the high-shear granulator includes:

  • The individual properties of the excipients you employ in preparing your granulating fluid. These excipients determine the solution’s overall properties and eventually those of the formed granules.
  • The binding agent you employ will influence the granulation process. Additionally, the quantity of binder solution you use determines the granular characteristics.
  • The feedstock you are granulating determines the granulation process success when using a high shear granulator.
  • When using a high shear granulator, variables such as the impeller’s speed and the chopper affect the granulation process. Additionally, adding the granulating solution to the equipment and how much you add affect the process.

Parts of High Shear Granulator

Parts of High Shear Granulator

What are the Advantages and Disadvantages of the High Shear Spray Granulator?

When using the high shear granulation, you accrue benefits and encounter limitations from its use in the granulation process.

However, you still achieve the core mandate of granulation to acceptable standards when using the high shear granulator.

Here are some the benefits of using high shear granulator:

  • You only use a little amount of binder liquid when preparing the solution for high shear granulation.
  • The granulation process using the high shear granulator is fast, taking minimal time.
  • The drying sequence using the high shear granulator is short, requiring little time to remove excess moisture.
  • You achieve rigid granules using a high shear granulator with enhanced densification.
  • The high shear granulator is consistent in the production of granules with uniform size and shape.
  • Granulation using a high shear granulator has very little dust production, thereby prevent toxic effects to operators.
  • You can easily determine the end of the granulation process when using a high shear granulator.

However, some the main disadvantages of the high shear granulator include:

  • The compressibility of granules you produce using the high shear granulator is low compared to other granulator types.
  • You can only operate the high shear granulator within certain conditions and is thus inflexible.
  • Where your granules are excessively damp, you obtain oversized chunks of material formation.
  • The high shear granulator is not conducive for materials susceptible to high temperature and heat and can easily damage them.
  • The high shear granulator particles are delicate; the shear granulator’s mechanical operation can be damaging.

How does the Mechanical Agitator Granulator Compare to the Spray Granulator?

Mechanical agitator granulators generate low shear forces for granulation due to their reduced speeds during agitation, low volume, and pressure.

With these granulators, the material preparation involving excipients, binding agent, and liquid is done gently with low power motion.

Common features you observe with the mechanical agitator granulators include an extended production time with granules with low bulk density.

You, therefore, find granules formed by mechanical agitator granulators are highly compressible due to their porosity.

You have different designs for the mechanical agitator granulators stemming from their dissimilar constructions.

The shear induction method’s differences arise, including convection screw action, impeller rotation, or kneading maneuver.

Some of the common differences between the mechanical agitator granulator and the spray granulator are:

  • You find the quality of granules formed by the spray granulator superior by achieving a more spherical shape.
  • Dust production in spray granulators is minimal compared to mechanical agitator granulators lowering the risk of harm to operators.
  • You achieve a high granular bulk density with the spray granulators.

The low bulk density in granules produced by mechanical agitator granulators is due to the formed granules’ porosity.

  • Granules formed by spray granulators achieve high flowability, unlike those by mechanical agitator granulators.

Furthermore, the granules do not break away easily with a highly rigid structure.

  • The granules you form using a mechanical agitator granulator have a wide distribution in size, unlike those by spray granulators.
  • You find it easier to screen, package, store, transport, and dose granules from a spray granulator.

What are Some of the Features of a Spray Granulator?

With the different designs available for the spray granulator, you require certain features to be common for them.

These features allow you to derive maximum useful employment of the equipment in granule formation and production.

You can find the following admirable features for your spray granulator:

  • Having a design in line with current Good Manufacturing Practices (cGMP).
  • A configuration allowing easy access for parts for effective cleaning procedures and removal of residue.
  • Equipment possessing impressive precision during mixing with short production times.
  • The amalgamation of the parts of a spray granulator in one unit with advanced integration.
  • Automatic functionality using an HMI control panel to issue instructions to PLCs.
  • Provision of a sampling pot with the product bowl.
  • Using atomization for the spraying mechanism ensuring the solution flow is precise.
  • Employing impellers with regulated speed to achieve the desired product mix and consistency.
  • Utilizing a filter for the air inlet prevents the entry of air-borne contaminants that can deteriorate product quality.

Do Spray Granulators Have Safety Features?

Safety features on a spray granulator ensure the equipment is not potentially harmful to operators when in use.

Having safety features is a requirement of OSHA for such equipment when employed for commercial use.

Some of the safety features provided for a spray granulator include:

  • Electrical parts of the spray granulator are inflammable to minimize fire occurrence in case of electrical faults.
  • You have an explosion guard around the granulator’s frame, which protects the operator in the event of an explosion.

An explosion can result from the interaction of materials in the mixing chamber and compressed air storage.

  • You find the spray granulator’s blower can cease operation with a drop in air pressure in the filtration unit.

How is Automation Useful on a Spray Granulator?

Automation in spray granulators involves employing programmable logic controllers in executing processes, eliminating the need for human input.

You feed instructions to the spray granulator via a control panel that guides the actions for the PLCs.

When using automation in spray granulators, you achieve the following:

  • Operating an automatic spray granulator is simple, requiring only program instructions while the PLCs execute them.

Consequently, you require reduced operating costs in the form of labor to constantly keep watch of operations.

  • Automation allows you to come up with more compact spray granulator designs with integrated features and units.

With automation, you only need to connect your granulator to a power source and compressed air, and you’re good to go.

  • Automation increases the efficiency of the granulation process using the spray granulator. The automated controls guide the mixing, agglomeration, and drying processes, achieving granule formation with the desired properties.
  • Using an automatic spray granulator, you benefit from increased flexibility as you can navigate between different processing options.

You can have two options with a large and small processing capacity to suit your granule formation endeavor.

  • Automatic spray granulator allows you to achieve precise control of processes such as temperature regulation. Some materials you employ in the granulation process are sensitive to high temperatures and heat, requiring precise control.
  • You can employ the automatic spray granulator for different applications by configuring program settings. Subsequently, you can use this granulator in food processing to make flavors and pharmaceutical use for dosage forms, among others.

What are the Components of a Spray Granulator Dryer?

The spray granulator consists of different components that you find essential in the granulation process.

You find these components each play a specific role in forming granules beginning with the mixing to the drying process.

Some major components of the spray granulator include:

Parts of Spray dryer

Parts of Spray dryer

i. Air Compression Unit

The granulation process employs compressed air as a fluid in the fluidization process, suspending the damp material.

The air compression unit allows the intake of air and subjects it to the required pressure during compression.

ii. Product Mixer

Before undertakings a granulation process, you prepare the solution by mixing raw ingredients with the excipients and binder agent.

You carry out the mixing process in the mixer via a rotating horizontal shaft with extensions.

iii. Exhaust Filter and Blower

The exhaust filter ensures any dust produced cannot cause harm by filtering it to a less toxic state.

The exhaust blower enables you to eliminate unwanted particles from the granulation process that can be contaminating.

iv. Control Panel

You use the control panel to set the desired parameters for your granulating process.

The control panel is an essential part when employing an automatic spray granulator.

v. Solution Delivery System

You need to transfer the solution from the mixing unit to the nozzles for dispersal into the fluidized bed.

The solution delivery system channels the solution to the nozzle compressed air-fluid release it.

vi. Spray Nozzle

You release the binding solution to the fluidized bed through the nozzle, which has four common designs.

The nozzle consists of a system with an inlet and outlet that disburses the solution in a spray.

vii. Distributor

The distributor ensures the fluidization process is constant with the production of stable and uniform granules.

Using poor distributors results in the formation of porous granules and a wide distribution size of granules.

What are the Influential Parameters you Control when Using a Spray Granulator Dryer?

A spray granulator dryer is a granulator that also has a drying mechanism in a single unit.

When using a spray granulator dryer, you do not need to carry out a separate drying process.

Instead, after the granulation process, your granulator dryer initiates a moisture elimination process without the need for other equipment.

You find many spray granulator dryers with enhanced controls to improve the efficiency of operation.

You can classify the parameters you control when using a spray granulator dryer into the following divisions:

Equipment Parameters

Equipment parameters are those whose control depends on the equipment employed.

Some of the parameters you identify as equipment parameters include:

  • The air distribution plate’s positioning determines the granulation pattern.
  • The apparatus design where you find more reliability when employing annular design.
  • The height of the nozzle relative to the tray influences the rate of drying during the atomization process.

Operating Parameters

Control of operating parameters depends on the prevalent processes during granulation and drying.

You also refer to operating parameters as process parameters, and they include:


When using a spray granulator dryer, the atmospheric temperature determines the drying rate of the granules.

You associate higher temperature values with an increasing rate of drying through an enhanced evaporation process.

Additionally, you also find the material properties of your ingredients influence the process temperature.

Some materials are sensitive to high temperatures and heat, which can destroy the active ingredients in them.


You will achieve an accelerated drying process with your spray granulator when operating in low humid conditions.

Therefore, you have to regulate the wetness of the air you allow through the inlet of your equipment.

Rate of Airflow

When subjecting the solution to a pressurized air release, you observe a direct relation between the drying and airflow rates.

However, you need to maintain the airflow rate at an optimum level for effective drying.

Product Parameters

The nature and qualities of the product define the product parameters.

Some of the product parameters for the spray granulator are:

  • Water content of the material is undergoing granulation.
  • Quantity of the material for every single process.
  • Physical characteristics of the material such as size and shape.

What are the Advantages of Using a Spray Granulator with a Dryer?

Using the spray granulator allows you to achieve uniformly shaped and sized granules during granulation.

However, you employ different equipment to execute the drying of the granules, known as a dryer.

The spray granulator dryer construction is such that you achieve granulation and drying without the need for extra equipment.

Some of the advantages of using a spray granulator are as follows:

  • The construction allows you to execute two processes using the same equipment without the need for extra apparatus. You, therefore, save on the cost of separately acquiring drying equipment when you use a spray granulator.
  • The continuity of the processes from granulation to drying enhances the moisture elimination rate. The granules formed interact more effectively with the air particles allowing a larger thermal transference.
  • By employing the integrated heat exchanger, you observe this equipment achieves elevated thermal efficiency levels.
  • Acquiring and maintaining a spray granulator dryer is cost-effective in the long run. By integrating the two operations in one machine, you only have one machine to maintain instead of two.
  • When using the spray granulator dryer, the integrated operations reduce the contact time you need to dry.
  • Operating and controlling processes in a spray granulator dryer is simple. When using a machine with automatic controls especially, you can easily obtain dry and uniform granules.

How is a Spray Granulator with a Dryer Limited?

While integrating the spray granulator with a dryer has its advantages, you will experience some drawbacks with this configuration.

The following are some of the limitations in employing a spray granulator dryer:

Laboratory Spray Dryer Granulator

Laboratory Spray Dryer Granulator

  • Using this granulator type records increased energy by agitating the seed in the tray. You note this process results in a large drop in pressure accompanying the high energy yield.
  • Leads to increased re-entry of gas in the equipment, altering the thermal efficiency. Consequently, you need to better manage the movement of gas in the granulator-dryer.
  • Where you have excess dampness of the feed material, you experience an inefficient fluidization process. As a result, the granulation and drying processes are highly inflexible, resulting in defective granules.
  • Some granulating machines require the removal of employed solvents, especially when they are organic-based before the drying process. When you have spray granulator integrated with a dryer, you cannot, therefore, use organic solvents.
  • The particle size distribution when employing a combined granulator and dryer of this type is wide. Therefore, this granulator type is not efficient where you require high consistency levels.
  • The drying process using a spray granulator-dryer immediately succeeds the granulation process. Therefore, the granules don’t settle, increasing the chances of attrition and the accumulation of fine lumps.
  • You face an increased risk of fire outbreaks or explosions when using this equipment with highly flammable material. Managing a separate dryer for the drying process of such materials is preferable.

What are the Features of a Good Spray Granulator with a Dryer?

When purchasing a spray granulator integrated with a dryer, there are certain features you have to identify for effective functionality.

The following highlight features ensure you derive the most for your equipment:

  • Your granulating equipment has to perpetuate a thermal transference with minimal energy use.
  • The equipment has to have the capacity to effectively carry out multiple functions without failure.
  • You should be able to execute both batch processing and continuous processing with your apparatus.
  • Your granulator machine’s build should be from material with high resistance to corrosion, such as stainless or carbon steel.
  • The cost of operating and maintaining the device needs to be low and manageable.
  • When operating, the machine has to be capable of initiating and withstanding vibrations to enhance productivity.

Is there a Difference Between a Spray Dryer and a Spray Granulator?

A spray granulator is a gadget that facilitates granule formation by enclosing a seed in several layers.

When using a spray granulator, dispersing the granulation fluid is via spray formation through a nozzle.

In making the granulation fluid of a spray granulator, you prepare the desired raw content into powder.

You then dissolve this powder into a liquid such as water or ethanol alongside a binding agent where needed.

You can employ either a continuous or batch process in granulation when using a spray granulator.

Granules form when the moisture in the granulating solution evaporates, leaving behind small particles which agglomerate to form granules.

Spray dryer is an equipment you use to remove excess moisture from granules or particles by employing hot gas.

When using a spray dryer, the process involves atomization and moisture elimination through hot air exposure.

Upon interacting the wet granules or powder with hot air, you separate the dry product and eliminate the air.

You can use nitrogen instead of air where the liquid solution you are evaporating is flammable, for instance, ethanol.

The spray dryer consists of different parts, including a feeder pump, atomizing unit, an air dispenser, and heater.

You conduct the drying process with an exhaust system to filter the air and eliminate hot air.

When using the spray dryer, the quality of the process depends on the dryer’s configuration and the method used.

Additionally, the material properties of the substances used in the granulation process influence the drying process’s success.

Can you Use Freeze-Drying with a Spray Granulator?

When using freeze-drying, you freeze the granulation product to alter the crystalline nature of ice.

You then transfer the frozen product to a vacuum, at which point you eliminate the water molecules via sublimation.

You further subject the product to another energy-intensive sublimation process at about 20 degrees Celsius and reduced air pressure.

In this case, you eliminate the bound ice crystals through sublimation by converting them to vapor.

You can use the freeze-drying process after spray granulation, where maintaining the product properties in a wet state is difficult.

You also use freeze-drying where preference is for a solid product and where you require special storage conditions.

Some products require up to five days to achieve the appropriate frozen state, depending on their characteristics.

However, freeze-drying is a long and costly process that is difficult to undertake for large product volumes.

What Granulation Type do you Use with a Spray Granulator?

There are two techniques available for you when undertaking granulation: dry granulation or wet granulation.

You begin both methods by employing milling operations to prepare the ingredients into powder form.

With dry granulation, you compact particles by employing pressure and are suitable where the product is susceptible to moisture presence.

You can employ dry granulation in two ways, namely slugging and roller compaction.

Using slugging, you use a powerful press machine for tableting, forming a large tablet called a slug.

In roller compaction, you employ a dual roller system, between which you subject the powder material to form a sheet.

In wet granulation, you employ a fluid to achieve a wet product from mixing dry ingredients with the desired properties.

Your granulating fluid needs to have high volatility for elimination via evaporation during the drying process.

Additionally, when taking drugs, the fluid must be non-toxic to allow consumption as a dosage form.

You can use water, ethanol, or isopropanol as your granulating fluid or in formulations containing two or all three.

Furthermore, you can use a binding agent to enhance particles’ adhesion during the agglomeration process of granulation.

You typically dissolve the binder in the granulating fluid to form a binder solution.

Water finds popular use as a granulating fluid since it is cheaply and widely available.

Additionally, water is inflammable, and as such, you face no danger of fire outbreak during the drying process.

However, water can affect the powder product’s material properties by causing hydrolysis where possible and influencing the stability of drugs.

Furthermore, eliminating water molecules during the drying process takes a long time compared to other granulating fluids.

Granulating fluids such as ethanol and isopropanol offer you better granule formation where the powder product is sensitive to water.

You also use such organic solvents to conduct a fast drying process with reduced heat exposure.

Consequently, you can achieve highly stable drugs when you employ organic solvents as granulating fluid.

However, these solvents’ flammability makes them inappropriate where the powder product is sensitive to heat or high temperatures.

When using the spray granulator, you employ wet granulation to form a solution capable of atomization.

The granulating fluid aids in dissolving the particles for granulation, allowing you to compact them during drying via evaporation.

What Spray Systems do you Employ in Spray Granulators?

When using the spray granulator, you have different configurations of the spray systems you can employ.

The major distinguishing factor with these systems is the location and positioning of the spray system.

Types of Spray Nozzle Position in Spray granulator

Types of Spray Nozzle Position in Spray granulator

Here are the main spray systems for spray granulators:

Top Spray System

The location and position of the top spray on a fluidized bed spray granulator are at the top.

When using the top spray system, you process the material in a mixing tank by mixing it with a granulation fluid.

You thereafter use compressed air to fluidize the product in a tray conducting the spraying process from above.

Consequently, you observe the direction of the granulating fluid is downwards relative to the nozzle position.

You find the top spray useful in the granulation process and succeeding drying of the granules and powder product.

When using the top spray system, the granulation processes typically remain the same without any modifications.

When using a top spray system, you can adjust the air temperature and volume used in the atomization process.

You can also improve the atomization efficiency by regulating the air pressure and the flow rate of granulating fluid.

You get smaller granules by employing higher air temperature and pressure of atomization when using the top spray.

Alternatively, when you increase the granulating fluid flow rate, you obtain larger and more rigid granules.

Consequently, you commonly use the top spray system for spray granulators with a fluidized bed dryer.

Additionally, when using water as your granulation fluid and a binding agent, the top spray system is more efficient.

Bottom Spray System

The location and positioning of the spray system are at the bottom.

During operation, heated air flows through the lower half of the granulator with the fluidized bed lifting the powder product.

While the particles’ movement in the bed occurs, the bottom spray releases the granulating fluid in a gust.

The atomization process is highly efficient, covering the entire particles uniformly, resulting in narrow granular size distribution.

With the spray system at the bottom, the atomizer’s distance and the particle are very small.

You find this contributes to the uniform fluidization process that precedes granulation, hence the high consistency in granular properties.

When using the bottom spray system, you can determine the granule formation’s properties by adjusting the process parameters.

You can achieve near-perfect granular formation by establishing the optimal values of the parameters like air temperature and atomizing pressure.

The air distribution plate also plays a role in the granulation process’s quality when employing the bottom spray.

You can use different sizes for your distribution plate in influencing the fluidization outcome.

When partitioning the spray granulator, you influence the distance between the particles and the nozzle.

Consequently, you influence the flow rate you require to achieve the consistency that determines the product’s density and granular size.

Tangential Spray System

You find the nozzle system employed on a tangential spray system positioned at the fluidized bed’s compartment side.

You can employ the tangential spray system with a fluidized bed spray granulator and coating purposes.

The tangential nozzle system utilizes a rotating variable disc which subjects the product to a centrifugal force during operation.

Also, the powder product in the tray also experiences a lift as air travels through the disk’s length.

Notwithstanding the two forces, you also observe the effect of gravitational force on the powder.

You regulate the centrifugal force by adjusting the disc’s rotational speed and the inlet’s airspeed and volume.

The combined action of these forces ensures the powder material’s granulation process in the tray is consistent.

The particles move about thanks to the centrifugal force while the air volume and speed alongside gravity determine to lift.

Using the tangential spray system, you achieve granules with a high bulk density and low susceptibility to fragmentation.

Furthermore, the granular size is large than average with enhanced compressibility when used in the tablet making process.

What are the Mechanism Stages when Using a Spray Granulator?

When undertaking the granulation using a spray granulator, the process undergoes three stages in granules formation including:


After preparing the granulation solution, you disperse this solution to a fluidized bed tray, for instance, in a gush.

You achieve an increased surface area to the mass ratio by employing an atomizer to disperse the fluid in many droplets.

An atomizer employs compressed air to subject the fluid to a disintegrating force via a nozzle system.

The nozzle opening influences the size of the droplets by instigating a pressure drop.


Agglomeration occurs in the tray over the particles after the atomization process disburses particles of the granulating fluid.

Where you have minimal wetness, you have the formation of bridges by the association of multiple particles.

You observe these fluid bridges result in the formation of a droplet that wholly encloses a granule.

The surface tension of the fluid determines the hydrostatic capacity of the droplet and its strength and structure.


Drying entails the elimination of water or liquid molecules to leave behind the dissolved powder particles.

While you have different drying methods for your particles, using heated gas finds common use after wet granulation.

You channel a stream of hot air over the tray containing the combined droplets to initiate an evaporation process.

The supply of hot air needs to consistently ensure moisture elimination simultaneously, resulting in uniform granular formation.

What affects the Particle Formation in Fluidized Bed Spray Granulator?

Using the fluidized bed spray granulator, you can use a batch or continuous process in conducting granulation.

A spray system enables particles’ formation using this granulator with a top or bottom spray system popular.

Top Spray Nozzle

Top Spray Nozzle

The following parameters influence the formation of particles using a spray granulator with a fluidized bed:

  • Water content in the feed material.
  • Rate of flow of the fluid during the spraying process.
  • Volume and flow rate of the compressed air that aids the disbursement of the granulating fluid.
  • Amount of pressure employed in the atomization process.

What Factors Affect the Effectiveness of Using a Spray Granulator?

The effectiveness of the granulation process using a spray granulator is influenced by the following factors:

  • Feed material and excipients you use during preparation.
  • Strength and quantity of the binding agent you employ.
  • the water quantity in the product mixture.
  • The quantity of shear employed in the granulating process.
  • The rate of moisture elimination in the drying process.

Can you Use Steam in a Spray Granulator?

Water finds common use as a granulating liquid due to its wide and cheap availability and inflammability.

You can also use organic solvents such as ethanol and isopropanol to dissolve your powder particles for granulation.

Conversely, you can use steam to dissolve your powder particle instead of water in a modified granulation process called steam granulation.

  • When using steam instead of water in the granulation process using a spray granulator, you obtain the following benefits:
  • You have a more uniform particle distribution with an enhanced rate of diffusion during particle formation.
  • When drying the particles, you achieve a better thermal balance.
  • The shape of the granules formed from steam granulation is more circular.
  • When using steam, you find the surface area larger, thus enhancing the dissolution rate of the particles.
  • Using steam reduces the time taken to undertake the granulation process, thus increasing the output per hour.
  • Steam has no adverse effects on the environment compared to organic solvents such as ethanol in the granulation process.
  • Furthermore, ingesting fumes by evaporating organic solvents can affect operators’ health, which is not possible with steam.
  • Steam granulation can be used for drug formation without any danger of toxic content for prescription users.
  • You do not have to implement sterilization methods when using steam granulation since steam is sterile by the nature.

What are the Wet Granulation Methods Possible with a Spray Granulator?

When using wet granulation, you mix the powder material you granulate with a liquid substance to dissolve it.

You use a binding agent as an adhesive to enhance the granules’ formation with the liquid forming a binding solution.

There are different wet granulation methods that you can undertake when using a spray granulator:

Reverse Wet Granulation

In reverse wet granulation, you employ water vapor as the binding agent rather than water in the conventional liquid state.

When using water vapor, you increase the diffusion rate due to the increased surface area created by water gas molecules.

Melt Granulation

In the melt type of wet granulation, you form the binding solution by melting a binder.

Binders you commonly employ for the melt granulation liquefy at around 50 0C to 90 0C.

When using melt granulation, you can first melt the binder before adding the desired powder particles to the liquefied formation.

You can also use a binder in its solid state at the beginning of the process, after which it melts.

Batch Fluid Granulation

In batch fluid granulation, you extract a wet granulating fluid by combining acids and bicarbonate of sodium with the powder material.

Common acid strains you employ in this process include citric and tartaric acid.

When using the batch fluid, wet granulation, you subject the mixture you obtain to a heating process.

Using temperatures of about 93 to 104 degrees Celsius, you initiate an effervescent reaction in which you can add desired material.

What are Some of the Specifications of a Spray Granulator?

Manufacturers attach different specifications to their spray granulators, allowing you to identify their production capacities and capabilities.

You find specifications that allow you to make decisions regarding your budget and output.

Some common spray granulator specifications include:

  • Power rating is given in kilowatts with most machines having 5KW and more rating.
  • Granulating capacity of the machine provided in unit weight per batch.
  • Minimum amount of powder you can achieve with a sample given in grams.
  • Temperature the granulator can operate within given as a range in degrees Celsius.
  • Pressure of the compressed air you use in atomization provided in bars.
  • Quantity of material you can mix for a single batch in grams.
  • Nozzle system the spray granulator employs and the size of the orifice in millimeters.
  • Rate of airflow accommodated by the spray granulator given in cubic meters per hour.
  • Volume of the granulator’s main chamber provided in liters.
  • Mode of operation of the granulator with both automatic and manual machines available.
  • Control panel system and capabilities in controlling process parameters such as temperature, pressure, and frequency.

Top Spray Granulation Machine

Top Spray Granulation Machine

Why do you Require a FAT Test for your Spray Granulator?

AFactory Acceptance Test seeks to establish a spray granulator’s conformity and agreement to the original design.

When you conduct a FAT test for a spray granulator, you establish whether the processes and responses are as intended.

You typically carry out the FAT test at the manufacturing point before distribution to identify any related shortcomings.

Where you have such failings, you make corrections and document them for future observation.

When conducting a FAT, you need to delve deeper into a spray granulator’s features and functionality.

Consequently, you will not miss any inconsistencies or faults, damaging and expensive when uncaptured.

A FAT test is useful for both the manufacturers and users, ensuring they are not liable for any negligence.

Alternatively, users purchasing a FAT-certified spray granulator can expect to benefit from employing the equipment productively.

When you subject equipment to a FAT test, you make economic and time savings by addressing pending issues at the site.

You can quickly intervene by adjusting the factory’s equipment rather than having to recall and incur high return costs.

Using a FAT test, you can ensure the spray granulator’s safety features are according to the prevailing standards.

You find this important due to the difficulty in establishing the correctness of safety features until you observe a safety concern.

When you conduct a FAT test, you gain an impartial check on the spray granulator’s functional status.

Furthermore, you can determine its quality aspects and structural integrity before releasing it into the market.

Conducting a FAT allows you to make comparisons between the product and the design specifications.

You can identify any deviations from the design that affect the functionality and rectify them as a result.

When conducting a FAT test for a spray granulator, you determine its extent of operational capability.

You can identify within what temperature or humidity ranges the machine can effectively perform and provide guidance in that concern.

How do you Maintain a Spray Granulator?

Maintenance of a spray granulator involves the mechanisms and practices you undertake to ensure your equipment’s consistent use.

Subjecting your spray granulator to effective maintenance schedules can reward you with a long and useful life of service.

Some effective maintenance practices for your spray granulator include:

  • Effective maintenance begins with good housekeeping procedures such as cleaning parts of the spray granulator. You need to ensure the regrind is clean alongside the mixing chambers and the fluidized bed after every batch process.
  • Lubricating of the spray granulator’s rotary bearings using grease or heavy oil.

Lubrication reduces the wear and tear resulting from the frictional force created by the rotation movement.

  • Conveyor belt system enables rotational movement shown by the rotor blades in a spray granulator, with slacking as major concern.

You need to ensure the belts are tight to the required tension level to positively influence the rotation process.

  • The blades you employ in a spray granulator can wear off due to continuous chopping actions and become blunt.

Periodically checking these blades allows you to retool the blades by sharpening them to achieve effective functionality.

  • When sharpening the knives of the bed, you need to ensure the angle of sharpening is appropriate.

The knifing action occurs at a desired set angle from which any deviation results in inefficient knifing operations.

  • The rotor blades are worn out from sustained wear and tear; you need to replace them by sourcing new parts.

Factors affecting the wear of these blades include the number of operations and the type of materials you work on.

  • The spray granulator encompasses several safety switches and linkages which can result in grave damage if secured loosely.

Good maintenance requires you to check these features, ensuring their appropriate positioning and fixation.

  • When conducting maintenance schedules, keeping a record of the operations you conduct during maintenance is essential.

In these records, you need to indicate the date and kind of procedures undertaken and the parts repaired or replaced.

What Causes Spray Granulation to Fail?

Spray granulation involves the employment of a liquid and binding agent with powder particles to form a granulating fluid.

When using a spray granulator, you pay considerable attention to several parameters that ensure the process is successful.

When using a spray granulator, mishandling of these factors will cause the granulation process to fail:

Wrong Placement of the Air Distribution Plate

The air distribution plate allows you to establish a granulation pattern that is effective for your spray granulator.

When you wrongly position this plate, you encourage inconsistent airflow resulting in an ineffective granulation process.

Inappropriate Nozzle Height

Top Spray Nozzle

Top Spray Nozzle

The nozzle is a feature on the spray granulator that executes the dispersion of the granulating fluid.

You can have the nozzle at the top, bottom, or side, influencing the fluid dispersal and drying rate effectiveness.

Positioning the nozzles very far from the bed tray results in loss of particles and consequently low output.

Where the nozzles are too close to the bed results in an overconcentration of particles and an extended drying process.

Operating Temperature

When carrying out the granulation process, you need the optimal temperature to successfully execute the process.

Having excessively high temperatures hastens the drying process resulting in poor quality granules.

Furthermore, some of the ingredients you employ in the granulating fluid are sensitive to temperature changes.

Consequently, large temperature variations can alter the content matter of these substances diluting their effectiveness.

The Rate of Airflow

You find air used in compressed form to aid the dispersion of granulating fluid during the spraying process.

The airflow rate determines the volume of air you use for every compression action and consequently the pressure.

Where you employ a low airflow rate and pressure, you achieve ineffective granulation with excessive fluid waste.

Additionally, you undertake a difficult drying process with a high moisture content of the granules.

Humidity Levels

The spray granulator employs wet granulation, where you evaporate the granulating fluid containing desired particles.

An optimal humidity level is necessary for effective granulation to occur without excessive moisture content that extends the drying process.

Is there a Difference Between Prilling and Spray Granulation?

Prilling refers to the process you form large bursts of jet via submitting a melt substance through a nozzle system.

The nozzle system disperses the liquid jets into small individual particles of a pure form with more consistent sizing.

The spray granulation process creates large particles called granules from the accumulation of smaller particles after an evaporating process.

You atomize a liquid concentrate containing the dissolved form of particles, binder, and additives via a granulator system.

Some of the points of comparison between prilling and spray granulation include:

The Resulting Particle Size

Particles in both the prilling and spray granulation process are round-shaped with high flowability.

However, you observe distinct differences in the particles of these two processes.

With the prilling particles, the height of the nozzle greatly influences the size of the particles.

This results from the height affecting the time it takes to cool the droplets and, therefore, the ultimate size.

You can employ vibrations to the priller construction to influence the size of the particles.

When using vibrations, you limit the range of distribution of the particle sizes.

When using the spray granulator, you find the granulating time determines the size of the particles.

When you conduct a longer granulation process, you achieve larger granular formation.

Particle Strength

Granules formed via spray granulation have a stronger physical structure compared to particles from the prilling process.

The better strength performance results from an increased crushing capacity and the use of binder increasing particle adhesion.

Prilling employs no additives and starts to solidify soon after release as a droplet, increasing the chance of cavity creation.

You find this structural configuration stems from the cooling process occurring from the outside inwards.

The Purity Level of the Product

When conducting the prilling process, you use no additives on your melt, forming a solid particle that is pure.

During spray granulation, you add a binder to your granulating fluid to enhance adhesion affecting the purity level.

Cost of Conducting the Process

Employing spray granulation is expensive, costing up to triple what a prilling machine would.

In spray granulation, you have a host of different processes you undertake before achieving your granules.

A prilling machine typically involves a single-stage process where you force the melt through a nozzle to form droplets.

Furthermore, you can employ a natural draft to guide the cooling process in prilling.

Controlling the Process

Operations on a prilling machine are easier to handle compared to those on a spray granulator.

Additionally, most of the controls on a prilling machine are self-actuated, ranging from melting, temperature control, and airflow regulation.

Emissions Resulting from the Process

You experience increased emissions from employing prilling compared to spray granulation.

You note an increase in the evaporation levels when melting products with high vapor pressure during prilling.

The pure form of melts demands you treat the outlet gas before release or reuse during the prilling process.

The evaporating spray granulation process largely contributes to the observed emissions, whose effect can be minimized by employing non-organic solvents.

What are the Features of Continuous Spray Granulation?

Continuous spray granulation features a fluidized bed you employ to disturb the particles into an excited state.

You employ an upstream of air from an inlet source through the perforated fluidized-bed that lifts the particles.

You find this particle disturbance is what you refer to as the fluidized state.

Furthermore, the air you employ in the fluidization process using continuous spray granulation is responsible for thermal regulation.

When carrying out continuous spray granulation, you ensure your granulating fluid is an intense mixture possessing equal thermal distribution.

Consequently, when undertaking particle drying, you achieve simpler control and better material handling where the temperature is an issue.

You can use a spouted bed for your continuous spray granulation process to suit certain special conditions.

The spouted bed allows you to conduct the granulation process when you require defined temperature values and airflow rates.

While you can use both the fluidized or spouted bed with continuous spray granulation, the system mechanisms differ.

You employ different fluid approaches and dynamics, allowing you to come up with novel particulates.

How do you Achieve Optimal Atomization of Granulation Liquid?

Atomization is the process you employ compressed air to disperse granulating fluid to a bed in many small droplets.

You employ a nozzle system for the atomization process and alter the particle size by adjusting its opening.

You can also influence the atomization process by regulating the granulating fluid mix makeup and the airflow rate.

You employ the flow rate to determine the volume and pressure under which you subject the fluid.

Furthermore, when you employ inert gas such as helium for the atomization process, you achieve more spherical particles.

Having imperfect spheres helps in the agglomeration process as it increases the surface area for adhesion.

What Affects the Accumulation of Particles in Spray Granulation?

In spray granulation, particles accumulation is essential for the formation of granules after the drying process.

After disbursing the granulating fluid in the fluidized bed seed in small droplets via a nozzle, particle agglomeration occurs.

Pharmaceutical Granulating Machine

Pharmaceutical Granulating Machine

Factors affecting particle accumulation include:

Material Input

When preparing the granulating fluid, you employ different substances in its preparation, including excipients for drugs.

You employ different measures of the substances you use, each contributing to the overall particle characteristics and agglomeration ability.

Wetting Agent

The spray granulation process employs wet granulation to create granules from the accumulation of small powder particles.

In wet granulation, you employ a liquid substance to dissolve the desired particles for use in granulation.

You can use water or organic solvents like ethanol and isopropanol as wetting agents, with the former being inexpensive.

Organic solvents, however, offer you faster drying times and better particle dissolution.

Binder Agent

When preparing the granulating fluid, you can employ a binder agent alongside a wet medium to enhance the adhesion process.

Consequently, the adhesion qualities of the binder agent will determine the success of particle accumulation.


Particle accumulation when conducting spray granulation occurs during the drying process.

Therefore, the temperature parameter is essential in determining the rate of accumulation and adhesion of particles.

How does Batch Fluid Bed Compare to Continuous Fluid Bed?

When using a spray granulator, you can use a batch or continuous fluid bed configuration.

You find both of these configurations employ similar granulation procedures but with different production outcomes.

You use the batch fluid bed for achieving granulation with specific order quantities.

In the continuous fluid bed, the configuration is ideal for mass-producing granules at a low cost.

A continuous fluid bed has several air compartments with an independent control system allowing air in and out.

Consequently, you can determine the temperature and airflow rate parameters for each compartment.

You use the fluid batch bed when determining reduced amounts for granules of different formulations.

Therefore, employing a fluid batch bed makes sense when producing varied products in different quantities.

Batch configuration also suffices for the spray granulation process with many complex procedures.

However, its approach to this kind of processing is sequential, making it straightforward.

How do You Use Spray Granulators for Coating?

When using a spray granulator for coating processes, you can use the top spray or bottom spray design.

The top spray granulator is simple but with limited employment due to quality and thickness concerns.

The bottom spray nozzle system finds common use when employing the spray granulator for coating.

During the coating process, a flow of hot air travels across the granulating column’s bottom half.

When this happens, it subjects the particles to a frenzy upward direction; spraying occurs, coating individual particles.

You observe the coating process has an excellent and consistent finish on every particle.

The nozzle system’s integration with the fluid bed allows the nozzle easy access to the product for coating.

The spraying process during coating is hence efficient with the particles positioned not far from the nozzle.

When using a spray granulator for coating, you need to monitor process parameters for effective performance.

These parameters include the volume and pressure of air and temperature, and their control ensures an optimal process.

When using the bottom spray for your coating needs, you achieve an even consistent coating of high quality.

Additionally, the high-value molecular energy of the process presents inter-particle sticking with a complete evaporation process.

With the information in this guide, you can definitely choose the best spray granulator for all your applications.

At Pilotech, we design and manufacture a range of spray granulator machines.

Whether you want lab spray granulator or industrial grade spray granulator, Pilotech offers a perfect solution for you.

Contact us now for all your spray granulator needs.

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