Process and equipment for producing organic fertilizer by composting livestock and poultry manure

organic fertilizer production equipment

Iorganic fertilizer production equipment. Traditional livestock and poultry manure composting fermentation is mainly based on natural fermentation. Which has the disadvantages of long cycles, incomplete fermentation, large pollution, strong odor, etc. The labor intensity of pure manpower production of organic fertilizer is high. The working environment is bad, and the labor efficiency is low. It is difficult to adapt to the current social development situation of high labor costs and efficient production. And it is also difficult to adapt to the development of modern ecological cycle agriculture and efficient animal husbandry. Therefore, it will become particularly necessary to accelerate the “machine replacement”. In the field of organic fertilizer fermentation industry and improve the level of organic fertilizer production equipment.

Composting treatment technology

Livestock and poultry manure are generally treated in two forms: liquid manure and solid manure. The treatment methods of liquid manure include anaerobic fermentation technology and natural biological treatment technology. And the main treatment method of solid manure is composting treatment. Composting refers to the process of mineralizing, humifying, and harmless (killing pathogens, insect eggs, weed seeds, etc. Organic matter through high-temperature fermentation under the action of microorganisms to become decomposed fertilizer.
The whole process can be summarized into three links: raw material pretreatment, aerobic fermentation, and granulation. Raw material pretreatment includes solid-liquid separation. Auxiliary material crushing, and adjustment of raw material moisture content, carbon-nitrogen ratio, and pH value. Aerobic fermentation includes measures such as turning and ventilation, which can supplement oxygen, control temperature, dissipate moisture, and restore porosity. Granulation is a systematic project. Around the core of granulation, there are crushing, batching, mixing, and other processes, and drying, screening, cooling, and other processes.

Raw material pretreatment and equipment
organic fertilizer production equipment

Raw material pretreatment is mainly to prepare fermentation raw materials that meet the requirements of aerobic fermentation. Its main processes include solid-liquid separation of livestock and poultry manure. crushing of auxiliary materials, and mixing ratio of various raw materials.
2.1 Solid-liquid separation equipment
The raw material for composting is solid manure. The source of solid manure is dry manure and solid matter separated from “water-bubble manure” by the solid-liquid separation method. To achieve solid-liquid separation, mechanical separation is the most widely used and has the best separation effect. Mechanical separation equipment can be divided into four types: screening separation, centrifugal separation, filter press separation, and screw extrusion separation.
1) Screening and separation machinery:

The screening machinery used for separating livestock and poultry manure mainly includes inclined plate screens and vibrating screens. The inclined plate screen with a wedge-shaped cross-section of the screen bar is used for manure separation and has the characteristics of a simple structure and no clogging. However, the solid matter removal rate is low, generally less than 25%.
2) Centrifugal separation machinery:

The centrifugal solid-liquid separators used for livestock and poultry manure mainly include filtering centrifuges and horizontal spiral centrifuges. The advantages of centrifuges are fast separation speed and high separation efficiency. The disadvantages are large investment, complex structure, and high energy consumption.
3) Filter press separation machinery:

The filter press has the advantages of large processing capacity, simple operation and management. Low filter cake moisture content, no vibration, no noise, and low energy consumption. Because it uses a filter belt to separate solids and liquids, to prevent the filter belt from clogging. High-pressure water is required to continuously flush, increasing the amount of sewage treatment, and the cost is high.
4) Screw extrusion separation machinery:

The screw extrusion separator is a relatively new solid-liquid separation equipment. And is currently the most widely used equipment for solid-liquid separation of livestock and poultry manure. Its defect is that the raw manure water needs to be stirred evenly with a stirrer before separation. So that a large amount of solid organic matter in the manure water is dissolved in the water, making the post-treatment of wastewater extremely difficult. And the final treated water is difficult to meet the discharge standard.
Because of some existing deficiencies, a new solid-liquid separator can be studied and designed to improve the separation mechanism. Prevent the manure liquid from directly rushing into the separation system, enhance the anti-blocking property of the screen, greatly improve the working efficiency and separation effect of the equipment, and reduce the solid moisture content.
2.2 Crushing equipment
The fermentation process of livestock and poultry manure requires the addition of certain auxiliary materials straws, branches, rice husks, corn cobs, etc. To obtain the auxiliary material particle size suitable for aerobic composting fermentation. The auxiliary material needs to be crushed, so crushing equipment is needed. There are three main types of equipment for crushing commonly used materials. Hammer crusher, large and small grass choppers, and branch crusher. The hammer mill has good versatility. When working, the material enters the crushing chamber from the feed port.

First, the high-speed rotating rotor drives the hammer to hit and rub it. And then it is further hit and rubbed by the screen and tooth plate set around the crushing chamber to achieve crushing processing. When the particle size of the material is smaller than the diameter of the screen hole. It passes through the screen and is discharged from the discharge port. Waste after grain processing, such as rice husks and corn cobs, can achieve satisfactory results through the hammer mill. The grass cutter is powered by an electric motor or an internal combustion engine. The power is transmitted to the main shaft, and the gear at the other end of the main shaft transmits the speed-regulated power to the grass-pressing roller through a gearbox, a universal joint, etc.

When the material to be processed enters between the upper and lower grass-pressing rollers, it is clamped by the grass-pressing roller and sent to the cutting mechanism at a certain speed. After being chopped by the high-speed rotating tool, it is thrown out of the machine through the grass outlet. The straw after harvesting crops, because it contains long fibers, can be cut and crushed by the grass cutter to obtain a satisfactory particle size.

The branch crusher uses the high-speed relative movement between the movable toothed disc and the fixed toothed disc. The crushed material is crushed by the combined effects of tooth impact, friction, and mutual impact. The crushed material can be directly discharged from the grinding chamber of the main machine. And the particle size is obtained by replacing the mesh screen with different apertures. Various wood, wood scraps, branches, and twigs can be crushed by the branch crusher.
The improvement of the crushing equipment can start from the reasonable optimization of the cutting angle of the fixed knife. The optimization of the knife disc cutting speed, the blade parameters, and the arrangement of the blade and hammer on the knife disc. So that the crushing mechanism can quickly cut and knead a variety of materials. At the same time, increase the research on the feeding mechanism to solve the problem of difficult feeding and difficulty in entering the crushing chamber.
2.3 Mixing Equipment
Mixing refers to the process of evenly mixing solid feces, auxiliary materials. And various conditioners according to the pre-set formula ratio. Premixing the raw materials can make the required carbon-nitrogen ratio in the pile reach everywhere. Ensuring the survival and reproduction of microorganisms. According to the properties of the mixed materials, a double-axis gravity-free mixer should be used.

The horizontal cylinder of the machine is equipped with double-axis rotating blades in opposite directions. The blades are at a certain angle to stir the materials axially and radially in a circular manner so that the materials are quickly mixed and evenly mixed. The rotation speed of the reducer-driven shaft and the structure of the blades will weaken the gravity of the materials. Even if the materials have differences in specific gravity and particle size, they can achieve a good mixing effect under the rapid and violent tumbling and throwing of the staggered stirring blades. If the machine can automatically control the mixing time according to the properties of the raw materials, better results and efficiency can be achieved.

Fermentation equipment

The fermentation methods for making organic fertilizer from livestock and poultry manure include strip-stack fermentation. Tank fermentation, and tower heating fermentation. Strip-stack fermentation is a relatively primitive fermentation method with a long fermentation cycle. Average fermentation effect, and a large footprint. But the production process is simple, the equipment is easy to debug, and the cost is low. Tank fermentation has strong controllability, can effectively shorten the fermentation cycle. And has a good fermentation effect, but the civil engineering cost is relatively high. The equipment often needs to be customized, and the installation cost is high. Tower heating fermentation has stable sealing performance, strong mobility, good fermentation effect. And a cycle of generally less than one week, but the equipment investment cost is high.

Windrow fermentation equipment

Windrow fermentation equipment mainly refers to windrow compost turning machines. A windrow compost turning machine is a turning and throwing equipment suitable for windrow fermentation. Which generally requires a larger site. Windrow fermentation is piling materials into windrows of a certain height.

There is no need to build a fermentation tank. Through the turning and throwing action of the windrow compost turning machine, the natural wind is sent into the material pile from both sides of the material pile to provide oxygen and realize compost fermentation. Windrow compost turning machine is mainly composed of a turning and throwing device, walking drive tractor, transmission system, etc., and is mainly driven by an internal combustion engine.

Windrow fermentation has a poor heating effect due to the low material stacking height. Due to outdoor stacking fermentation, it is easily affected by seasons and rainy days. In addition, its exhaust pollution, odor, and seepage will bring environmental problems. Windrow compost turning machine is more suitable for pre-treatment of sticky materials, small-scale production, farm self-use fertilizer production, no fixed production site, or temporary production. Windrow compost turning machine should increase research on the self-adaptation of material height so that the equipment has an adaptive control function and enhances the ability of equipment to adapt to materials. Since it is a manned device, it should be equipped with a cockpit with air conditioning and an air filtration and purification system to improve the working environment.
Tank fermentation equipment
Tank fermentation equipment mainly refers to a tank turner. A tank turner is a turning equipment that matches the fermentation tank. Tracks are installed on the top of both sides of the fermentation tank, and the turner can run forward and backward on the track.

organic fertilizer production equipment

Generally, the tank turner is equipped with multiple tanks in one machine, and the transfer of the turner between the fermentation tanks can be achieved by a transfer machine. The tank turner is mainly composed of a frame, a turner device, a walking mechanism, a cable drum device, an electronic control system, etc., and is mainly driven by electricity. The tank fermentation system has the advantages of a small footprint, high composting depth (0.8~2.5 m), fast heating, and large processing capacity.

It is widely used in China and is the main turning equipment for livestock and poultry manure composting in my country. During the tank fermentation process, it can maintain and ensure the formation of a medium temperature-high temperature-medium temperature-high temperature alternation state, effectively shortening the fermentation cycle. A device for adding bacteria is set on the turner, which can spray evenly in proportion during the fermentation process. At the same time, ventilation pipes can be laid at the bottom of the trough to increase the ventilation volume. In addition, the equipment uses electricity, has no tail gas pollution, and odor and water seepage can also be effectively controlled. The trough-type composting machine is suitable for refined large-scale production, which is conducive to production management and production cost control.
The trough-type composting machine can be improved and studied in terms of walking safety, reliability of the composting system, adaptability to composting materials, and degree of automation of operation. The composting machine with high product efficiency, stable and reliable operation, durability, uniform composting, and good market reputation is produced.
Tower heating fermentation equipment
The tower heating fermentation equipment adopts closed operation. The livestock and poultry manure, auxiliary materials, bacterial agents, and reflux materials are mixed evenly in a certain proportion, and the moisture content reaches 60%~65% before entering the three-dimensional aerobic system.

By adjusting the moisture, oxygen content, and temperature changes of the raw materials, the materials are fully aerobic fermented, and decomposed. The heat released during the decomposition process can increase the temperature of the material itself, and the temperature can reach up to 80℃.

The moisture in the material is evaporated as the temperature rises, and some organic matter is decomposed, thereby reducing the volume of the material pile and achieving material reduction treatment. The equipment can be equipped with detection and control devices. Which can realize precise control of different fermentation stages during the fermentation process, which is conducive to the reproduction, expansion, fermentation, and decomposition of livestock and poultry manure of target biological bacteria.

The auxiliary heating of the equipment can ensure normal operation under low temperature environment. However, the fermentation tower has high requirements for manufacturing materials, and the manufacturing cost is correspondingly high. It is also equipped with automatic detection and control devices, and the maintenance cost is also high. The high cost is not in line with my country’s national conditions, and the usage is also decreasing. Customers do not use it much, and manufacturers do not produce it much. If the tower body fermentation equipment wants to achieve rapid development, it should work hard to reduce the price and achieve convenient operation, good maintenance, and low energy consumption.

Granulation and molding equipment

organic fertilizer production equipment
Granulation and molding is a unique link in China compared with Europe and the United States. Granular fertilizer has good commodity properties, will not automatically grade during storage and transportation, has slow release, and can create a granular structure for the soil.

At present, the main organic fertilizer granulation methods on the market are extrusion granulation and agglomeration granulation. The commonly used equipment for extrusion granulation is a double-roll extrusion granulator, which is a widely used granulator in organic fertilizer granulators.

It belongs to the extrusion sliding model and can continuously produce one-time roller-pressing molding. The material is added from the feed hopper, extruded by rollers. Demolded and pelletized, and then conveyed to the crushing and screening studio. Where the finished particles are screened and separated, and then the returned material is mixed with the new material and granulated.

organic fertilizer production equipment

In addition, there are flat die granulators and ring die granulators for extrusion granulation. The commonly used equipment for agglomeration granulation is the disc granulator and drum granulator. The disc granulator is a mature organic fertilizer granulation equipment. The granulation disc angle adopts an overall arc structure. The material entering the disc is sprayed with an appropriate amount of liquid by the atomizing nozzle, and the granulation disc rotates to form a granular product. After a certain amount is formed, it is thrown out with the inertia of the disc rotation. The granulation disc is equipped with three discharge ports for intermittent production operations. The drum granulator has a special structure inside the barrel. The material to be granulated is passed through the rotating motion of the barrel. Rolling and rotating in the barrel, and agglomerated into balls at a certain humidity and temperature to complete the ball-making process.