Due to the consistently high temperatures in the southern region, it is more suitable to produce organic fertilizer from livestock and poultry manure through aerobic composting treatment. The traditional composting and fermentation of livestock and poultry manure mainly rely on natural fermentation, which has drawbacks such as long cycle, incomplete fermentation, high pollution, and heavy odor. The production of organic fertilizer by pure human labor has high labor intensity, harsh working environment, and low labor efficiency. It is difficult to adapt to the current social development situation of high labor costs and efficient production, as well as the development of modern ecological circular agriculture and efficient animal husbandry. Therefore, accelerating the "machine replacement" in the field of organic fertilizer fermentation equipment industry and improving the level of organic fertilizer production equipment will become particularly necessary.

1. Composting treatment technology

Animal manure is generally treated in two forms: liquid manure and solid manure. The treatment methods for liquid feces include anaerobic fermentation technology and natural biological treatment technology, while the main treatment method for solid feces is composting. Composting refers to the process in which organic matter is mineralized, humified, and rendered harmless (by killing pathogens, insect eggs, weed seeds, etc.) through high-temperature fermentation under the action of microorganisms, and becomes composted fertilizer.

The entire process can be summarized into three stages: raw material pretreatment, aerobic fermentation, and granulation molding. Raw material pretreatment includes solid-liquid separation, auxiliary material crushing, and adjustment of raw material moisture content, carbon nitrogen ratio, and pH value. The aerobic fermentation process includes measures such as flipping and ventilation, which play a role in supplementing oxygen, controlling temperature, dissipating moisture, and restoring porosity to the raw materials. Granulation molding is a systematic engineering process that revolves around the core of granulation molding. It involves processes such as crushing, batching, and mixing, followed by drying, screening, and cooling.

4) Spiral extrusion separation machinery: Spiral extrusion separator is a relatively new type of solid-liquid separation equipment, which is currently widely used in the solid-liquid separation of livestock and poultry manure. Its drawback is that before separation, the original fecal water needs to be stirred evenly with a stirrer, which causes a large amount of solid organic matter in the fecal water to dissolve in the water, making the post-treatment of wastewater extremely difficult and the treated effluent difficult to meet discharge standards.

In response to some of the existing shortcomings, a new type of solid-liquid separator can be researched and designed to improve the separation mechanism, prevent fecal liquid from directly entering the separation system, enhance the anti blocking ability of the screen mesh, greatly improve the working efficiency and separation effectiveness of the equipment, and reduce the solid moisture content.

The improvement of crushing equipment can start from optimizing the cutting angle of the fixed blade, optimizing the cutting speed of the cutterhead, blade parameters, and the arrangement of blades and hammers on the cutterhead, so that the crushing mechanism can quickly cut and knead diverse materials. At the same time, increase research on the feeding mechanism to solve the problem of difficult feeding and difficulty in entering the crushing chamber.

3.1 Stacked Fermentation Equipment

The strip stack fermentation equipment mainly refers to the strip stack flipping machine. The stack turning machine is a type of flipping equipment suitable for stack fermentation, which generally requires a large space. Stacking fermentation is the process of stacking materials into stacks of a certain height without the need for a fermentation tank. Through the flipping effect of a stacking machine, natural wind is fed into the stack from both sides, providing oxygen and achieving composting fermentation. The stack turning machine is mainly composed of a flipping device, a walking driven tractor, a transmission system, etc., and is mainly driven by an internal combustion engine. Stacking fermentation has poor heating effect due to low material stacking height. Due to outdoor fermentation, it is easily affected by seasons and rainy days. There are also environmental issues caused by exhaust pollution, odor, and water seepage. The stack turning machine is more suitable for pre-treatment of sticky materials, small-scale production, farm use fertilizer production, and no fixed production site or temporary production use. The stack flipping machine should increase research on the adaptability of the stacking height, so that the equipment has adaptive control function and enhances its ability to adapt to materials. Due to the manned equipment, a cockpit with air conditioning and air filtration purification system should be equipped to improve the working environment.