Flat Die Pelleting machine

Equipment Overview

A flat die pellet mill is a dry pelletizing machine based on extrusion molding technology that processes powdery or fibrous materials into cylindrical pellets. This equipment is mainly used in agricultural waste treatment, bio-organic fertilizer production, and feed processing. It uses extrusion molding technology to process powdery or fibrous materials into cylindrical pellets, featuring low investment costs and wide applicability. The flat die pellet mill can process various crop straws such as sawdust, rice husks, cotton stalks, cottonseed hulls, and weeds, as well as materials with low binding rates and difficult to form, such as household waste, waste plastics, and factory waste. It is also suitable for low-temperature pelleting of bio-fertilizers, organic fertilizers, and compound fertilizers. The equipment boasts a high pelleting rate, good pellet strength, low temperature rise during processing, and relatively simple operation, making it a popular choice in the organic fertilizer and feed production fields.

Overall structure and core components

The flat die pellet mill features a simple and compact structural design, primarily composed of the following core components:

(I) Flat Die Plate: This is the core forming component of the equipment, made of high-quality alloy steel through heat treatment, achieving a hardness of HRC50 or higher. The flat die has evenly distributed die holes, allowing for the selection of different hole diameters (e.g., Φ1.5-Φ20mm or 2mm, 4mm, 6mm, 8mm, 10mm, etc.) to produce pellets of different specifications. The die plate can be used in both directions, effectively extending its service life.

(II) Pressure Roller (Grinding Roller): This is the key component for applying extrusion pressure, featuring a large body and wide groove design for pressure resistance and wear resistance. The pressure roller employs a multiple evenly distributed structure, ensuring smooth operation, increasing the pressing area, and improving production efficiency. The flat die pellet mill adopts a "conical wheel flat die" structural design, with the pressure roller's ends aligned with the inner and outer rings of the die plate, avoiding misalignment friction, reducing resistance, and lowering kinetic energy loss.

(III) Transmission System: This includes a motor, reducer, and a belt drive mechanism or a two-stage worm gear transmission device. This equipment employs a two-stage transmission system using belts and worm gears, ensuring smooth operation and low noise. Feeding relies on the material's own gravity, effectively preventing blockages.

(IV) Pressure Adjustment Mechanism: Utilizing a screw-centered pressure adjustment structure, the die gap can be adjusted according to material characteristics, suitable for various materials and ensuring optimal pressing effect. It can be adjusted manually by rotation or automatically by hydraulic pressure.

(V) Cutting and Discharge Device: The formed columnar strips are cut into granules by a scraper. The length of the columnar granules can be controlled by adjusting the cutter. The equipment uses a unique tangential discharge method, effectively preventing granule breakage after forming.

(VI) Machine Body and Auxiliary Devices: The machine body is made of cast steel, robust and durable, equipped with heavy-duty thrust bearings to withstand large axial loads. The granulation chamber has an observation door for easy inspection, maintenance, and repair.

Applicable fields and industry coverage
Flat die pellet mills have a wide range of applications. In organic fertilizer production, they can produce (bio)organic fertilizer and organic-inorganic compound fertilizer pellets, suitable for pelleting organic waste such as livestock and poultry manure. In feed processing, they can directly press crushed materials such as corn, soybean meal, straw, grass, and rice husks into pelleted feed, suitable for processing pelleted feed for livestock and poultry such as pigs, horses, cattle, sheep, rabbits, chickens, ducks, and geese. In biomass fuel, they can produce biomass fuel pellets from sawdust, straw, etc. In waste treatment, they can process waste pellets from rubber and plastics. Furthermore, they can be used for the re-granulation of organic waste in industries such as pharmaceuticals and tobacco factories.

Types of available raw materials

The flat die pellet mill is highly adaptable to various raw materials. It can handle coarse fiber materials such as sawdust, rice husks, cotton stalks, cottonseed hulls, weeds, and other crop straws. It can also handle organic waste such as household garbage, waste plastics, and factory waste, which have low binding rates and are difficult to form. Furthermore, it can produce fertilizers such as bio-fertilizers, organic fertilizers, and compound fertilizers. Finally, it can process feed such as corn flour, soybean meal, wheat bran, and grass meal. The equipment has low requirements for raw material moisture content and fineness; the moisture content of the raw materials can be within the range of 20%-40%.

Operating principle and forming mechanism

The flat die pellet mill operates primarily on the principle of extrusion molding. Its workflow is as follows: The main motor drives a belt and pulley, transmitting power to the drive shaft via a reducer. The motor then drives the main shaft through a gearbox, which in turn drives the pressure rollers (grinding rollers) in a circular motion on a stationary flat die. Under the influence of gravity and a distribution device, the material is evenly spread on the die. The rotating pressure rollers continuously roll over the material layer, forcibly squeezing it into the die holes.

Within the die holes, the material undergoes compression, forming, and shaping processes: In the extrusion forming zone at the front of the die hole, it is subjected to high pressure, undergoing initial shaping before entering the shaping section. In this section, residual stress that is detrimental to shape retention is eliminated, and the granules are finally shaped. After being extruded from the die holes, the cylindrical material is cut by a rotating cutter into granules of a certain length, and finally discharged from the machine by a sweeping plate. The main shaft rotates at approximately 60 rpm, and the linear velocity of the pressure rollers is approximately 2.5 m/s, effectively removing gas from the material and increasing the product density.

Core Strengths and Unique Highlights

The flat die pellet mill has the following outstanding advantages: High pressure: The enlarged pressure rollers allow for larger bearings, enhancing their pressure resistance. Low temperature rise: The enlarged pressure rollers prevent the heat generated by extrusion friction from easily transferring to the bearing housing, ensuring the bearings operate at low temperatures and preventing lubricant leakage. Long service life: The enlarged pressure rollers can be repaired 2-3 times, extending service life and reducing production costs. Multi-functional: It can produce round bars, cubes, and pellets simply by changing the die, adapting to the compression molding of different materials. Dry inlet and dry outlet: No drying is required; it uses a differential gear and universal joint drive.

Target customer group

The main target groups for flat die pellet mills include: equipment procurement and production management personnel of small and medium-sized organic fertilizer production enterprises; operators of livestock and poultry farm manure resource utilization projects; heads of feed processing plants and farms; technicians of biomass fuel pellet production enterprises; small production entities such as agricultural cooperatives and family farms; and investors in organic waste treatment projects in industries such as pharmaceuticals and tobacco factories.