Large Wheel Compost Turning Machine

Equipment Overview

The large wheel compost turner (also known as a wheel-type compost turner or large wheel compost turning machine) is a large-scale compost turning device developed for large-span, high-depth fermentation tanks. It adopts a disc-type rotating turning structure, offering a wide turning area, sufficient penetration depth, and high operating efficiency. It is suitable for the large-scale fermentation needs of large organic fertilizer processing plants and centralized manure treatment bases, and is a core piece of equipment for modern organic fertilizer mass production.

This equipment differs from traditional spiral and  wheel-type compost turners. It relies on a large-diameter rotating disc combined with multiple sets of high-strength throwing blades for operation, resulting in a wider turning coverage and stronger material layer penetration in a single pass. It can thoroughly turn thick piles of material in one go, completely solving the industry problem of surface turning and bottom aeration. The equipment is suitable for trench-type fermentation and is a core piece of equipment for the industrialized harmless treatment of livestock farming, municipal waste, and municipal sewage sludge.

This equipment features a reasonable design structure, high efficiency, low energy consumption, high automation, and ease of use, making it a highly efficient model that is very popular with users.

Equipment Structure and Components

The large wheel compost turner mainly consists of the following five core components:

1. Power Transmission Device

Comprising a motor, reducer, bearing housing, and main shaft, this is the core device providing power to the compost turning disc. The motor directly transmits power to the reducer, which is connected to the main shaft of the turner, driving the disc to rotate. High-power plasma cutting technology is used in the manufacturing process to ensure that the steel beams do not deform and the cuts are smooth and easy to process. The main drive power is typically in the range of 18.5–55kW, with some large models reaching 115kW.

2. Walking Device

Comprising a walking motor, transmission gears, and walking wheels, this device enables longitudinal movement of the equipment on the fermentation tank. The walking motor power is commonly 5.5kW×2. During operation, the trolley travels along the length of the tank, while the auxiliary trolley moves left and right along the width of the tank, achieving full site coverage.

3. Hydraulic Lifting Device

Comprising a hydraulic pump station, solenoid valve body, hydraulic oil pipes, and hydraulic cylinder. The hydraulic system allows for automatic raising and lowering of the wheel, ensuring unobstructed movement of the equipment. Hydraulic cylinders control the wheel's lifting depth, adjusting its height according to ground conditions.

4. Turning Device (Wheel and Rake Teeth)

This device consists of a motor, reducer, wheel, and manganese steel toothed turning plates. The equipment uses an intermediate chain drive mechanism to drive two large diameter turning wheels symmetrically. The wheel diameter is generally between 1.5 and 3 meters. Alloy cutting teeth (usually high-chromium cast iron or tungsten carbide welded material) are installed on the wheel rims, cutting into the pile like milling cutters, scooping up the bottom material, throwing it into the air, and pushing it backward, achieving a three-in-one effect of oxygenation, crushing, and mixing.

5. Electrical Control System

Equipped with a fully automated electrical control system, centrally controlled by a control cabinet, it can achieve manual or automatic control functions. The equipment has a PLC control system and sensors to monitor parameters such as pile temperature, humidity, and oxygen content in real time. Limit switches provide safety and limit functions, allowing for unattended operation during equipment operation.

Working Principle of the Equipment

The working principle of the large wheel compost turner is based on the core requirements of aerobic fermentation—oxygen supply, turning, and mixing.

The working process is as follows: The equipment uses an intermediate chain drive mechanism to drive a large-diameter turning wheel. During operation, the bridge (main trolley) moves along the length of the fermentation tank, while the lateral trolley (small trolley) adjusts the wheel's position along the width of the tank. Hydraulic cylinders control the wheel's raising and lowering to a set depth, and the motor directly drives the wheel to rotate at high speed via a reducer.

The alloy cutting teeth on the wheel rim cut into the pile like milling cutters, lifting the material from the bottom of the fermentation tank to the top surface. During the wheel's rotation, the material is turned, stirred, and pushed backward a distance of 3-5 meters, achieving material displacement: the bottom material is turned to the surface for heat dissipation and aeration, while the surface material sinks back to the bottom to continue fermentation.

This process achieves three core functions: Oxygenation – ensuring full contact between the material and oxygen in the air, providing oxygen for aerobic microorganisms; Crushing – breaking up clumps of material, increasing the material's specific surface area; and Mixing – ensuring uniform mixing of the material, with consistent temperature, humidity, and nutrient distribution. Combined with variable frequency speed control, the walking speed and wheel rotation speed can be automatically matched according to the pile temperature curve. Through lateral and longitudinal movement, turning and turning can be achieved at any location within the site without dead angles. The wheeled turning machine can be customized with different spans to suit the width of the fermentation tank.

Applicable Raw Materials for the Equipment

The large wheel compost turner can process a variety of organic waste materials:

1. Livestock and Poultry Manure

It can process large quantities of chicken, pig, cow, and sheep manure produced by large-scale farms. The equipment's powerful turning ability can quickly break up compacted manure layers, and high-temperature fermentation kills pathogens, parasite eggs, and weed seeds, effectively removing odors.

2. Agricultural Crop Straw

Including corn stalks, wheat stalks, and rice stalks. The disc compost turner can crush and bale the straw and mix it evenly with other materials, promoting the degradation of cellulose and hemicellulose in the straw and converting it into organic fertilizer.

3. Industrial Organic Waste

Including distiller's grains from alcohol plants, filter mud and bagasse from sugar plants, and medicinal residue from traditional Chinese medicine plants. These materials have high moisture content and are easily perishable. Continuous turning can quickly reduce the moisture content and promote the growth of beneficial microorganisms.

4. Municipal Sludge

Large quantities of sludge produced by sewage treatment plants, after passing heavy metal content testing, can be fermented using the large disc compost turner. The turning process can reduce the sludge moisture content from approximately 80% to below 60%, stabilizing the sludge and eliminating odors.

5. Garden Waste

Including dead branches, fallen leaves, weeds, etc., generated during urban greening. It can be mixed with other organic matter for fermentation to produce humus-rich organic fertilizer.

6. Other Organic Waste

Including sugar factory filter mud, lees cake, sawdust, Chinese medicine residues, spent mushroom substrate, distiller's grains, etc.

Equipment Operation Method

(I) Pre-Trial Run Inspection

1. Check if the reducer and all lubrication points have sufficient lubricating oil.

2. Check the power supply voltage. The rated voltage is 380V, and the voltage drop should not be less than 10% (i.e., 340V) or more than 10% (i.e., 415V). Do not start the machine if it exceeds the range.

3. Check if the connections of the motor and electrical components are secure, and ground the motor with a wire for safety.

4. Check if all connections and bolts are secure. If any are loose, tighten and weld them firmly.

5. Check the material accumulation height.

(II) No-Load Trial Run

1. First, run the turning equipment. If the rotation direction is reversed, stop immediately and change the three-phase circuit connection to change the rotation direction.

2. While the equipment is running, listen for any abnormal noises from the reducer.

3. Touch the temperature of each bearing to see if it is within the temperature range.

4. Observe whether the rotating wheel rake teeth rub against the ground. If there is friction, adjust the wheel bolt angle.

No-load running sequence:

1. Start the power supply, turn on the trolley power and move it to the designated position, then stop.

2. 1. Pump station operation, lower the wheel disc

3. Start the main motor, the wheel disc rotates

4. Start the trolley, make the wheel disc contact the material, the trolley stops; the trolley starts and moves to one side, automatically cutting off power on the right side; start the trolley forward (the distance is related to the width of the material being turned and the depth of the trough) a specified distance and then stop; start another switch on the trolley, the trolley moves back

Stopping sequence:

1. Trolley power off

2. Main motor power off

3. Hydraulic cylinder operates, the wheel disc retracts to a horizontal position

4. Power off

(III) Load test run

1. First start the turning equipment, start the hydraulic lifting device, and place the wheel disc at the bottom of the fermentation tank

2. Depending on the ground level, if the overall level error of the same ground is less than 15 mm, the wheel disc can be controlled at about 30-50 mm off the ground

3. If the fermentation tank ground level cannot reach this level, the turning blades can only be controlled at more than 50 mm off the ground

4. After adjusting the wheel disc's position off the ground, adjust the equipment to the working walking speed for turning

5. During the turning process, careful observation is necessary. If the blades hit the ground, the turner should be lifted immediately to prevent damage to the equipment.

(IV) Operating Precautions

1. The turning machine must be operated at the specified speed; exceeding the speed limit is prohibited.

2. Before shutting down the equipment, check for any accumulated material in front of the turning roller. When stopping the machine, avoid areas with accumulated material.

3. No one other than the machine operator may operate the machine.

4. No one may pass in front of or behind the turner during production. Warnings should be given before starting the machine.

5. No maintenance or lubrication should be performed during production.

Common equipment problems (symptoms → causes)

Application of the Equipment in the Production Line

The large wheel compost turner is the core equipment in the fermentation section of an organic fertilizer production line, located at the source of the entire production line.

1. Typical Organic Fertilizer Production Line Process Flow:

Raw material pretreatment → Fermentation tank composting → Disc compost turner fermentation → Composted material → Crushing → Batching and mixing → Granulation → Drying → Cooling → Screening → Coating → Packaging

2. Specific Positioning of the Large Disc Compost Turner in the Production Line:

Location: Fermentation section, trough-type fermentation tank

Function: Turning, crushing, oxygenating, and composting materials in the trough

Connection: Connects to the raw material batching and feeding system at the front end, and prepares the composted material for entry into the granulation section at the rear end.

3. Production Line Adaptability:

Suitable for aerobic fermentation, can be used with solar fermentation chambers, fermentation tanks, and transfer machines.

When used with a transfer machine, it can achieve multi-tank functionality.

The fermentation tanks it is paired with can discharge continuously or in batches.

High efficiency, stable operation, robust and durable, uniform turning and composting.

Fermentation Process of the Equipment

The large wheel compost turning machine serves the aerobic composting fermentation process, its core function being to provide sufficient oxygen for aerobic microorganisms.

1. Aerobic Fermentation Principle

Composting fermentation is a microbial-dominated exothermic process. The disc turner, through turning and tossing, ensures full contact between the material and air, providing oxygen for aerobic microorganisms and promoting the decomposition of organic matter. The turner also has a crushing function, significantly saving time and labor, and significantly improving production efficiency and product quality.

2. Fermentation Temperature Control

Temperature control is crucial in the fermentation process:

Suitable Temperature Range: 55–65℃ is the critical temperature for killing pathogens and weed seeds.

Excessively High Temperature (above 70℃): Beneficial microorganisms' activity decreases or even die, resulting in "compost burning."

Excessively Low Temperature: It is difficult to maintain the high-temperature period, prolonging the harmless treatment time.

Control Methods: Controlling the heat dissipation rate of the compost pile by adjusting the turning frequency and depth.

3. Fermentation Cycle

With continuous turning and oxygen supply from the large wheel compost turner, the compost pile temperature is balanced and stable, maintaining a stable sterilization temperature of 55–70℃. The entire fermentation and maturation cycle typically takes 20-25 days to complete harmless maturation, thoroughly killing insect eggs and pathogens, and meeting the standards for organic fertilizer raw materials. In some high-efficiency scenarios, the fermentation cycle can be shortened to 7-10 days.

4. Turning Frequency

The turning frequency needs precise control:

Too low a frequency: Heat accumulates inside the pile, with local temperatures exceeding 70℃, leading to "piling fire."

Too high a frequency: The pile temperature drops frequently, making it difficult to maintain a high temperature period.

Intelligent Control: Modern rotary turners integrate sensors and a PLC control system, which can automatically adjust the turning frequency and depth.

Target Users of the Large Wheel Compost Turner

1. Large-Scale Organic Fertilizer Production Enterprises: Enterprises planning to build or expand large-scale organic fertilizer production lines. The equipment is designed for large-span fermentation tanks and is suitable for the large-scale fermentation needs of large-scale organic fertilizer processing plants and centralized manure treatment bases.

2. Large-Scale Livestock Farms/Animal Huts: Livestock farms with tens of thousands of cattle, large pig farms, chicken farms, etc., that need to utilize large quantities of livestock and poultry manure resources. The equipment enables the harmless and resource-based recycling of livestock manure and agricultural solid waste.

3. Sludge and Waste Treatment Plants: Environmental protection enterprises that treat urban sludge, domestic waste, and other organic waste.

4. Large-Scale Agricultural Industrial Parks and Planting Bases: Agricultural operators pursuing large-scale, automated, and standardized organic fertilizer production.

5. Enterprises Seeking High-Efficiency Automated Production: The equipment is equipped with a fully automatic intelligent control system, supporting functions such as automatic walking, reciprocating turning, timed start/stop, and stepless speed regulation, enabling fully unattended automated operation. 6. Large projects requiring deep material layers: The equipment can easily handle ultra-high material layers of 2-3 meters, completing the entire process of deep material turning, material dispersal, oxygen supply and ventilation, and cooling of the stockpile in one go.

Equipment Selection Recommendations

I. Selection Based on Processing Capacity

1. Daily processing capacity 100-500 tons: Medium-sized disc compost turner (disc diameter 1.2-1.6 meters)

2. Daily processing capacity 500-2000 tons: Large disc compost turner (disc diameter 2.0-3.0 meters)

3. Turning efficiency requirement 150-400 m³/h: Select the corresponding model from the FDPZ series

II. Selection Based on Fermentation Tank Specifications

1. Fermentation tank width determines the required equipment span; a maximum span of 30 meters can be customized.

2. Fermentation tank depth determines the required turning depth; standard models turn to a depth of 1.0-2.7 meters.

3. Material pile height can reach 2-3 meters.

III. Selection Based on Material Characteristics

1. High-moisture, viscous materials (such as fresh livestock manure): Select a model with a large-diameter disc and high-strength blades.

2. For loose fibrous materials (such as straw): Choose models with anti-tangle design.

IV. Focus on Core Configurations

1. Disc Material: Thickened, wear-resistant, and corrosion-resistant material; impact-resistant, tangle-resistant, and corrosion-resistant.

2. Electrical Control System: Fully automatic intelligent control system, supporting unattended operation.

3. Hydraulic System: Stable and reliable hydraulic lifting device.

V. Comparison with Other Compost Turning Equipment:

1. Disc Compost Turner vs. Trench Compost Turner: Disc compost turners have a daily processing capacity of 500-2000 tons, high efficiency (1 turn ≈ 3 stirs), but higher energy consumption (30-75kW).

2. Disc Compost Turner vs. Tracked Compost Turner: Disc compost turning depth is limited by the disc diameter (typically 1.2-1.8 meters), with uniformity of 70%-75% in deep trench scenarios; disc compost turners are more suitable for large-span, fixed trench fermentation scenarios.

Safe Operating Procedures

1. Operators must not operate the compost turner after drinking alcohol, or when feeling unwell or unwell.

2. All tracks of the compost turner must be grounded to ensure safety.

3. Power must be disconnected when replacing cable trays or cables.

4. No one may pass in front of or behind the compost turner during production. Warnings should be given before starting the machine, and personnel must stay away from it.

5. No maintenance or lubrication should be performed during production.

6. The machine must travel at the specified speed during turning; exceeding the speed limit is prohibited.

7. Unauthorized operators are prohibited from operating the machine.

8. The traveling and lateral tracks must be parallel. Limit switches must be moisture-proof and sealed to withstand the high temperature and humidity fermentation environment.

9. Daily maintenance requires close monitoring of chain tension, hydraulic station oil quality, and wheel bearing temperature.

As a core piece of equipment in the fermentation section of large and medium-sized organic fertilizer production lines, the large wheel compost turner, with its advantages of large span, deep depth, high automation, and low energy consumption, has become the preferred fermentation equipment for large-scale organic fertilizer plants, large-scale livestock farms, and sludge treatment centers. Its ground-trough aerobic fermentation technology can convert organic raw materials such as livestock manure and agricultural waste into high-quality organic fertilizer within 15-30 days, achieving the dual goals of resource utilization and environmental protection.

During selection and use, users should choose the appropriate model based on the actual fermentation tank size, raw material quantity, site conditions, and budget, and strictly adhere to operating procedures and maintenance requirements to ensure safe, efficient, and long-term stable operation of the equipment. The large-disc compost turner features a reasonable design structure, high efficiency, low energy consumption, high degree of automation, ease of use, low cost, and wide application, making it a highly efficient machine that is popular among users.

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 granulation of high-moisture, sticky, or coarse-fiber materials and need technical support—we are always ready to provide you with professional and sincere service.