Equipment for composting and screening organic fertilizers

Date: Nov. 02, 2022

The raw material for composting is solid manure. The sources of solid manure are dry clean manure and solids separated from “bubble manure” by solid-liquid separation method. To achieve solid-liquid separation, the most widely used and the best separation effect is mechanical separation. Mechanical separation equipment can be divided into 4 types: screening separation, centrifugal separation, filter press separation and screw extrusion separation.

1) Screening and separation machinery: The screening machinery used for the separation of livestock and poultry manure mainly includes inclined plate screen and vibrating screen. The cross-sectional shape of the screen bar is a wedge-shaped inclined plate screen, which is used for the separation of feces and has the characteristics of simple structure and no blockage. But 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 filter centrifuges and horizontal screw centrifuges. The advantages of centrifugal separators 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 moisture content of the filter cake, no vibration, no noise, and low energy consumption. Because the filter belt is used to separate the solid and the liquid, in order to prevent the filter belt from clogging, high-pressure water needs to be continuously washed, which increases the sewage treatment volume and costs high.

4) Screw extrusion separation machinery: The screw extrusion separator is a relatively new type of solid-liquid separation equipment, and is currently the most widely used equipment for solid-liquid separation of livestock and poultry manure. The disadvantage 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 the waste water extremely difficult, and the final treated effluent is difficult to meet the discharge standard. In view of some existing deficiencies, a new type of solid-liquid separator can be researched and designed, the separation mechanism can be improved, the fecal liquid can be prevented from directly rushing into the separation system, the anti-blocking property of the screen can be enhanced, the working efficiency and separation effect of the equipment can be greatly improved, and the reduction of Solid moisture content.