Granulation process and machine structure of double roller granulator

The working principle of the double roller granulator is that the belt and pulley are driven by the motor and transmitted to the driving shaft through the reducer, and they are synchronized with the passive shaft through the split gear and work in the opposite direction. The materials are added from the feeding hopper, extruded by rollers, demoulded into balls, and transported to the crushing screen studio to screen and separate the finished particles (balls), and then the returned materials are mixed with the new materials, and then granulated.

The whole double roller granulator is divided into four parts

1. Frame part: all working bodies of roller granulator are fixed on the frame. The frame of the double roller granulator is made of medium carbon steel plate and channel steel by welding. Through strict quality control and specific process requirements, the purpose of the machine is achieved. Lifting holes are set in the middle of the four corners of the frame for use in loading, unloading and transportation.
2. Transmission connection part: the motor drives the belt pulley, V-belt and reducer to drive the machine head. In addition, the chain wheel and chain constitute the transmission chain and transmit to the crushing and separating work part. The transmission reducer and the working part of the machine head are meshed and driven by nylon pin coupling.
3. Working part of the machine head: the transmission wheel is transmitted to the transmission roller shaft through the pin coupling. The synchronous operation of the pair of rollers is ensured by a pair of open gears, and both sides of the active and passive shafts.

Double roller granulator process flow:

1. The qualified raw materials are added into the mixer according to the proportion requirements and mixed evenly;
2. It is transported to the disc feeder to remove the iron substance in the material during the conveying process;
3. The materials in the disc feeder enter into the double roller granulator evenly, and the materials are forced to pass between the two pressure rollers and are squeezed into thin plates. The thin plates are broken into fragments by the coarse crusher under the pressure roller, and the materials on the screen continue to be broken and screened;
4. The semi-finished products are transported to the screening machine of finished products; the fine particles after screening are directly returned to the disc feeder; the large particles are crushed by the pulverizer and then returned to the disc feeder,
5. After screening, the qualified products are transported to the automatic packing scale for weighing, packaging and warehousing

Introduction to the characteristics of double roller granulator:

1) Compared with other methods, it does not need fuel oil, gas and other drying measures.

2) There is no need to add additional binder. Steam granulation is the common production method of compound fertilizer in China. Water vapor condenses and crystallizes between the material molecules and acts as an adhesive in the manufacturing process. But in the drying process, the water inside and on the surface of the particles must be driven out, otherwise the fertilizer is easy to stick and agglomerate in the storage process. However, dry granulation does not need additional additives, and only uses the intermolecular force of the material itself, which simplifies the process and reduces energy consumption.

3) The investment of double roller granulator is low, because the drying process is omitted, and the return ratio is low (accounting for about 15% of the total feed amount of the extruder), the process is simple and the investment is low.

4) At present, there are more than 20 kinds of materials successfully used in extrusion granulation: ammonium nitrate, urea, ammonium chloride, calcium nitrate, potassium chloride, potassium sulfate, etc.

Mainly including compound fertilizer production equipment, organic fertilizer production line equipment, double-roll press granulat