Ring Die Pelleting Machine

Equipment Introduction

The dual-die pelleting machine, also known as a ring die pelleting machine, is a crucial piece of equipment in modern fertilizer production. A dual-die pelleting machine combines the advantages of both ring and flat dies into one granulation unit, boasting powerful granulation capabilities. Its main features include high efficiency, ease of operation, and long service life. Compared to traditional single-die granulation equipment, the dual-die structure effectively integrates the advantages of both processes, meeting the granulation needs of various material types.

This equipment is widely used in bio-organic fertilizer, compound fertilizer, feed, and other pellet processing industries. It can process powdered materials into smooth, moderately hard pellets, improving pellet quality and flowability, and facilitating storage and transportation.

The dual-die pelleting machine is a highly efficient bio-fertilizer processing device integrating forced feeding, secondary mixing, and combined ring and flat die pelleting machine.

Technological Breakthrough: It not only possesses the high output and aesthetically pleasing pellets of a ring die granulator but also the strong adaptability of a flat die pelleting machine to high-fiber and high-moisture materials.

Market value: One machine is equivalent to a combination of a mixer, a ring die machine, and a flat die machine, which significantly reduces the user's equipment procurement costs and factory space requirements.

Equipment Structure and Composition

I. Core Component System

II. Five Major Functional Systems

1. Feeding System: Mechanical forced feeding or gravity vertical feeding, equipped with frequency conversion speed regulation.

2. Conditioning System: Steam conditioning to improve material granulation characteristics.

3. Granulation System: Core working area of ​​ring die + pressure roller extrusion molding.

4. Adjustment Mechanism: Die-roller gap adjustment (key parameter 0.1-0.3mm), pressure roller limit screws.

5. Lubrication System: Automatic lubrication pipeline to ensure good lubrication of pressure rollers and bearings.

III. Features of Dual-Die Integrated Structure

"Dual-Die" Core Meaning:

1. Ring Die Mode: The ring die rotates, and the pressure roller, as the driven wheel, follows the rotation, and the material is squeezed into the die hole between the die rollers.

2. Flat Die Mode: The flat die plate or the pressure roller rotates, and the material falls vertically into the pressing area to be extruded and molded.

3. Integrated Machine Design: The two modes are integrated into the same main unit, equivalent to two granulators working simultaneously, doubling the production capacity.

Equipment Working Principle

The working logic of the dual-die pelleting machine is called "step-by-step compaction process":

Distribution Stage: Material is evenly spread in the granulation chamber by a rotating forced feeder.

Pre-compression Stage: The material first passes through the flat die area, where air is expelled under the rotation of the pressure rollers, initially increasing the material density.

Forming Stage: The pre-compressed material is forcibly pushed into the aperture of the annular die. Due to the strong friction and reaction forces within the aperture, the material undergoes physical deformation under extremely high pressure, eventually overflowing through the orifice.

Cutting Stage: An external adjustable cutter cuts the long strip of material into uniformly sized cylindrical particles according to customer needs.

Dual-Mold Synergistic Technology

After entering the feeder, the material undergoes secondary mixing (adjusting moisture content) and then falls into the granulation chamber.

Flat Die Area Pre-compression: The material undergoes initial compression to increase density.

Annular Die Area Forming: High pressure forces the material into the annular die aperture, utilizing frictional heat and extrusion pressure to achieve physical deformation, ultimately cutting it into granules by the cutter.

Low temperature rise characteristic: The process design keeps the temperature rise of the particles below 30℃, which maximizes the protection of the activity of effective bacteria in the bio-organic fertilizer.

Fermentation and Granulation Process of the Equipment

I. Fermentation Process of the Equipment

The dual-die pelleting machine can process fermented organic fertilizer raw materials. Typical fermentation steps include composting in fermentation tanks, turning, and maturation. Fully fermented materials need to be crushed before entering the granulator to maintain particle uniformity. The dual-die pelleting machine/ring die pelleting machine itself does not directly participate in the fermentation process, but in organic fertilizer production lines, fermentation is a pre-granulation step.

1. Key Points of Fermentation Process

Organic waste (livestock manure, straw, etc.) must first undergo composting and fermentation.

During fermentation, a turning machine is used to regularly turn the compost pile to provide sufficient oxygen.

The fermentation system includes a feeding conveyor, mixer, dedicated turning machine, oxygen supply system, and automatic control system.

2. Impact of Fermentation on Granulation

The degree of fermentation directly affects the granulation effect.

The moisture content of the fermented material must be controlled within the range required by the equipment (20%-50%).

The advantage of the dual-mold granulator is that the wet material after fermentation can be directly fed into the machine for granulation without pre-drying.

3. Seamless Integration of Fermentation and Granulation

In a complete organic fertilizer production line, the fermentation system and the granulation system are closely integrated. After fermentation, the material is screened and crushed before directly entering the granulation process, reducing intermediate transfer links.

II. Granulation Process of the Equipment

Cold Granulation: Suitable for processes requiring low-temperature production.

Hot Granulation: Extrusion molding at a suitable temperature, suitable for producing exposed granules.

1. Key Process Parameters

The length-to-diameter ratio of the die hole, the die height, and the die rotation speed directly affect the pelletizing effect in the ring die structure. The die rotation speed must be designed reasonably; excessive speed will reduce the pellet forming rate, while insufficient speed will hinder pellet forming.

2. Key Points of Granulation Process for Different Materials

Application of Equipment in Production Lines

Dual-die pelleting machines/ring-die pelleting machines are typically used as core granulation equipment in organic fertilizer/compound fertilizer production lines, located after fermentation, crushing, and mixing processes, and before drying, cooling, and screening processes.

1. Typical Flow of an Organic Fertilizer Production Line

Raw material selection (animal manure, etc.) → Ingredient mixing → High-temperature microbial composting and fermentation → Semi-finished product screening and crushing → Dual-die/ring-die granulation → Drying → Cooling and screening → Metering and sealing → Finished product warehousing

2. Composition of Complete Equipment Sets

Complete production lines mainly consist of a fermentation system, a granulation system, a drying and cooling system, a deodorization and dust removal system, and a finished product packaging system. The fermentation system includes a feeding conveyor, a mixer, a dedicated turning machine, an oxygen supply system, and an automatic control system.

3. Unique Advantages of Dual-die Granulators

In the production line, dual-die pelleting machines integrate feeding, mixing, and granulation, reducing intermediate equipment. The dual-die modules can operate independently, switching as needed to avoid energy waste. The equipment supports continuous feeding and discharging, requiring no dedicated personnel; 1-2 people can complete the entire operation and maintenance process.

4. Construction Scale The construction scale of an organic fertilizer production line is generally 10,000-50,000 tons per year.

Operating Instructions and Precautions

Start-up Procedure: The start-up sequence is "Main Machine → Feeder → Material Feeding"; the shutdown sequence is the reverse.

Break-in Period Treatment: New molds must be circulated and extruded for 1-2 hours using an abrasive mixture of "machine oil + fine sand + sawdust" until the channels are smooth and mirror-like.

Operation Monitoring: Operators must closely monitor the ammeter. If the current suddenly increases, the feed should be immediately reduced using the feeder speed controller.

Equipment Maintenance Methods

1. Daily Maintenance

Removing Residual Material: Regularly remove residual material from the ring die cavity.

Lubrication: Before each shift, fill the lubrication gauges on the two roller eccentric shafts with lubricating oil.

Checking Clearance: Regularly check whether the clearance between the rollers and the inner wall of the ring die is within normal limits.

Checking Belts: Regularly check the tension of the V-belts and adjust them promptly.

Cleaning Equipment: Regularly clean the equipment exterior to remove dust and dirt.

2. Periodic Maintenance

Pressure Roller Bearings: Lubricate the pressure rollers every shift during the first week of operation; thereafter, after more than 10 shifts (8 hours per shift), the rollers need to be disassembled, and high-temperature grease should be applied to the bearings.

Gearbox: Replace the oil seal promptly if there is any oil leakage.

Bolt Inspection: Regularly check the tightness of the bolts.

New Ring Dies Require New Pressure Rollers: The pressure rollers must be loose at the beginning and tight at the end when fitting the ring die.

3. Precautions: 1. During granulation, the pressure roller must not come into contact with the die and run idle.

2. Do not allow the pellet mill to run idle for several minutes without material.

3. When installing the ring die, apply lubricant to the threads of the inner and outer fastening bolts, but be careful not to apply grease to the threads.

Common Equipment Problems and Solutions

Target Audience:

Livestock Farm Owners: Seeking solutions to environmental inspection pressures and the resource utilization of manure.

Agricultural Input Entrepreneurs: Looking for low-cost startup solutions in areas with abundant straw or medicinal herb residue resources.

Fertilizer Plant Upgrade Managers: Seeking more durable and upgraded products to replace inefficient and rapidly worn-out existing equipment.

Dual-die pelleting machines, with their low energy consumption, long lifespan, and versatility in handling various materials, are currently the mainstay in environmentally friendly fertilizer production.

Core advantages of dual-mode granulator

The dual-die pelleting machine represents a breakthrough innovation based on ring die technology—integrating both ring and flat die pelleting machine modules into one unit, allowing for flexible switching based on material characteristics. This design enables it to handle a wide range of raw materials, from highly moist and viscous materials to coarse fibrous materials, achieving a granulation rate of over 95% and reducing energy consumption per unit output by more than 30% compared to traditional equipment.

The equipment boasts a scientifically sound structure (three-in-one design), simple operation and maintenance (operable by ordinary workers), and a production capacity ranging from 0.5 tons/hour to over 8 tons/hour. With the continued advancement of policies promoting organic fertilizer substitution for chemical fertilizers, the resource utilization of agricultural waste, and biomass energy, the market demand for dual-die/ring die granulators will continue to grow due to their comprehensive advantages of high efficiency, energy saving, flexibility, and versatility.

Whether you are building a new organic fertilizer/compound fertilizer/feed production line and need a complete equipment solution, upgrading an existing production line and need equipment selection advice, or encountering difficulties in granulating highly moist and viscous materials and need technical support—we are always ready to provide you with professional and sincere service.