The working principle of the disc granulator in the fertilizer production line

The disc granulator machine is mainly used in the NPK fertilizer production line and organic fertilizer production line to produce various granular products; it’s also used in pharmaceutical products, fertilizers, feeds, etc. Adopting the overall arc structure, the granulation rate can reach above 93%. The granulation tray has three discharge ports, which facilitates intermittent production operations, greatly reduces labor intensity and improves labor efficiency.

disc granulator machine

Disc fertilizer granulator machine working principle:
The raw meal powder is uniformly wetted by the atomized water in the mixer to form a spherical core having a uniform particle size, and then fed into a ball plate for ball formation. The moisture of the ball should be controlled at 12-14%. Most of the water should be added in the twin-shaft mixer. Only a small amount of supplementary water is added to the ball plate, and the amount of water added is controlled to be about 0 to 3%. The dry powder granulation is directly added to the ball-forming plate, and the proper amount of water is sprayed. The raw material nucleus enters the spherical disk and is subjected to centrifugal force, friction and gravity in the disk, and moves along the parabola. Due to the cohesiveness and plasticity of the material, the cores are bonded to each other and gradually grow up during the movement. When the inclination angle of the ball disc, the height of the disc edge, the rotation speed and the moisture are constant, the balls of different particle sizes roll downward from the edge of the disc at different disengagement angles due to different gravity. During the continuous rolling process, the ball continuously discharges the water in the ball out of the surface. Due to the cohesiveness of the material and the natural volatilization of the surface liquid film, the ball has certain strength, and then the disk is rotated with the tilting of the disk. The sides are discharged out of the pan.

Disc granulator performance advantages:
1. The raw materials are suitable for a wide range of applications. They can be used for granulation of various raw materials such as compound fertilizer, medicine, chemical feed, coal, metallurgy, etc., and can produce various concentrations and various types (including organic fertilizer, inorganic fertilizer, and magnetic fertilizer etc.) of compound fertilizer.
2. The disc granulator is light in weight, low in height, and flexible in process;
3. The machine has simple structure, convenient adjustment and superior performance.
4. The use of unique unpowered combination scraper integration reduces auxiliary power consumption.

5, high ball formation rate, large rounded particle strength, intuitive operation, easy maintenance and so on.

Fertilizer granulator machine is the core equipment for fertilizer manufacturing process. As one of leading fertilizer machine manufacturers in China, in addition to the disc granulator, we also produce other types of fertilizer granulator machines, and other equipment such as compost turning machines, mixer machine, crusher machine, etc.

Other article for your reference:Chicken manure organic fertilizer production line

Production Advantage of NPK Compound Fertilizer with Double Roller Granulator

NPK compound fertilizer production mainly deals with raw materials in the state of powder, bulk, solution and molten liquid to produce particles with certain shape and size. Fertilizer granulator machine is an important equipment for compound fertilizer processing. Generally speaking, many parameters of fertilizer granulator can be adjusted, so it can adapt to a large range of raw materials.


Although many conventional compound fertilizer equipments still use wet granulation process to produce spherical pellet fertilizer, extrusion granulation process has many advantages, among which the most important is: low energy consumption of roller granulator NPK fertilizer production process, no need for liquid binder in granulation, many kinds of raw materials can be used, and the composition of raw materials is flexible. The function of roller fertilizer granulator is applicable to a wide range of large or small devices. Therefore, extrusion granulation NPK fertilizer production process has attracted more and more interest. Many fertilizer factories are considering dry extrusion NPK fertilizer production granulation process in construction.

In dry roller granulator equipment, the powder is applied force and compacted between two pairs of rollers. As with powder material, the quality requirement of roller granulator is reasonable formula, all kinds of components are complete and mixed evenly.In addition, the quality of particles produced by the double roller fertilizer granulator has the following two indicators:


  1. Hardness

Generally speaking, manufacturers usually want the particles to be harder. But whether from the point of view of use effect or manufacturing cost, it can not be said that the harder the better. The particle hardness produced by the double roller fertilizer granulator can be measured by the particle hardness meter and expressed by the pressure. According to the variety of materials, it is generally 0.06-0-12 MPa.


  1. Powdered rate

The method of determining the pulverization rate is to put a certain number of finished granules in a special pulverization rate measuring instrument, and turn them over at a prescribed speed in a prescribed time, and then determine the proportion of the powder transformed from granules in all materials. Generally, the powdered rate should not exceed 10% and the quality product should not exceed 5%.

Main Granulating Methods of NPK Compound Fertilizer Production

NPK fertilizer can supply many kinds of nutrients needed by crops at the same time. The economic benefit is obvious. The production cost can be reduced by using compound fertilizer.

Compound fertilizer is not easy to agglomerate, easy to store and use, and is widely welcomed. How to select granulator for NPK fertilizer production line? Several main granulation methods are introduced here.


  1. Solid aggregate method

The basic monomer fertilizers such as urea, ammonium nitrate, ammonium chloride, ammonium sulfate, monoammonium phosphate, diammonium phosphate and potassium chloride are used as raw materials. After crushing to a certain fineness, the materials are agglomerated and granulated in a disc fertilizer granulator (or rotary drum granulator) by adding water and heating. NPK compound fertilizer products can be obtained by drying, cooling and sieving granules, which is also one of the widely used methods in the world.

This method has a wide range of raw materials, simple processing process, less investment, low production cost, flexibility, and raw materials are solid. Because it is a secondary process of basic fertilizer, there is almost no environmental pollution problem.


  1. Bulk blending method

According to the requirement of nutrient distribution ratio, mixed fertilizers with uniform nutrient distribution were prepared from various solid basic fertilizers of nitrogen, phosphorus and potassium without obvious chemical reaction, with basically identical granularity and roundness. The process of this method is simple and the investment cost is low, mainly use bulk blending mixer. It is a very practical and easy to promote method.

Bulk blending fertilizer has comprehensive nutrients, high concentration and flexible formula. It can be flexibly changed according to the different conditions of crop nutrition, soil fertility and yield level. The method is simple in processing, low in production cost and pollution-free.


  1. Extrusion method

Extrusion granulation is a dry granulation process in which solid materials are agglomerated by external pressure. Double roller press granulator is mainly used for granulation. The machine have two shaft with one fixed and the other can move, which can adjust the distance between the two shafts. And the granules will be extrude between the shafts.

Double Roller Press Granulator

Extrusion method of NPK fertilizer production has the following advantages:

(1) Drying and cooling processes are generally not needed in the production process, which can save investment and energy consumption.

(2) The operation is simple and there is no three wastes discharged during production.

(3) High-concentration compound fertilizer with lower concentration than general compound fertilizer can be produced. Organic fertilizer and other nutrients can also be added in production according to need. The production capacity of a single extruder is small. If large-scale production is needed, it can be combined with multiple units for factory production.

How to Choose Suitable Fertilizer Granulator Machine

Granulating fertilizer with granulator makes it easy to store and sow. It is beneficial to the even distribution of nutrients and slow release the fertilizer efficiency. Different types of fertilizers, different sizes and shapes of fertilizer particles, and different granulators are used.

We can choose the right fertilizer granulator machine according to the specific function of the machine.


Rotary Drum Granulator

Drum Granulator is a larger production version of the disc granulator, make the fertilizer powder into round particles. It is suitable for hot and cold granulation and high, medium and low concentrations of mass production of fertilizer. The shell of the machine uses special rubber slab lining or acid-resistant stainless lining board which realizes auto scar removal and de-tumor instead of traditional drawknife equipment.

Rotary Drum Granulator

Disc Fertilizer Granulator

Disc Granulator, also called pan granulator, not only produce organic fertilizer, but also compound fertilizer. The disc bottom adopts multiple steel plates which are firm, durable, not deforming. The granulator’s main gears adopt high temperature quenching technology, doubling the service life. Granulation rate reaches above 93%.

Flat Die Extrusion Pelleting Machine

Flat die extrusion pelleting machine is used for granulation to all kinds of organic matter after fermentation, break through the conventional organic prilling before granulation needs not to dry and crush the raw materials. Pelleting machine can direct burdening to work out cylindrical grain, has better granulation effect on fertilizers containing more straw, can save a lot of energy.


New Type Organic Fertilizer Granulator

This Organic Fertilizer Granulator is used for making granulation of organic matter after fermentation, dedicated to the production of organic fertilizer granules. After fermentation organics don’t need to dry, it process fertilizer powder into granules, the organic content can be high to 100%. The granulator have the feature of simple machine structure, easy operation and maintenance, low power consumption.


Double Roller Press Granulator

Double roller press granulator is often used to manufacture NPK compound fertilizer, such as ammonium choride, ammonium sulphate, ammonium nitrate, diamonium phosphate, potassium Sulphate, magnesium sulfate, magnesium silicate, zinc sulphate, phosphorus pentoxide, etc. This machine diameter of the ball can be made according to the requirement of the customers. The roller press granulator machine have two shaft with one fixed and the other can move, which can adjust the distance between the two shafts, the materials will be extrude between the shafts.

Double Roller Press Granulator


For more information on how to choose granulator machine, please contact us. We are a well-known fertilizer machine manufacturer in China. We have many years of rich experience and we will try our best to give you a detailed answer.