Design and experiment of manure separator for livestock manure and biogas slurry
With the rapid development of the livestock and poultry breeding industry, a large number of animal manure and related wastes come. As a practical engineering system, biogas engineering is an important way to deal with livestock manure, improve the environment, and use biomass energy.
However, there are still some problems in the biogas project with livestock manure as the main raw material, especially the pretreatment of livestock manure before fermentation and the separation of biogas slurry and residue after fermentation. In the biogas project, the delivery of materials mainly depends on the delivery pump, but in the process of delivery, raw materials caking and fibrous objects often cause blockage problems to the pump, valve, external and central control equipment.
The existing solid-liquid separators still can not meet the needs of solid-liquid separation of livestock manure and biogas slurry and residue in terms of separation efficiency, continuous operation, and separation quality. Most of the manure separators mainly deal with the fermentation liquid. The separated solid contains agglomerated raw materials and fibrous substances, and the liquid contains fewer organic components, which is not suitable for the pretreatment of fermentation raw materials.
Bluslot developed a kind of manure separator that can well adapt to the solid-liquid separation of livestock manure before fermentation and the solid-liquid separator of biogas slurry and residue after fermentation, so as to realize the biogas system nonblocking and efficient continuous operation.
Blu-series manure separator design:
1) Combined with the characteristics of the complex composition and high pH value of livestock manure and biogas slurry, a kind of machine and equipment for separation of livestock manure and biogas slurry was designed.
2) The manure separator can meet the requirements of joint operation and complete the feeding, conveying, solid-liquid separation, and discharging operations at one time.
3) The screen of the manure separator can fit closely with the auger, and the blades of the auger can clear away the impurities blocking the screen; it can automatically move outward when the pressure in the inner cavity is too high, so as to protect the equipment.
4) The feeding plate at the manure separator discharge end can be automatically rotated, the rotating speed meets the operation requirements, and can contact or separate with the end face of the discharge end of the separator according to the operation requirements.
5) On the basis of meeting the functional requirements, the structure of the whole machine is compact, reducing the volume of the whole machine; on the premise of meeting the strength requirements, reducing the quality of the whole machine, saving the use of materials.
6) The parts of the solid-liquid separator for livestock manure and biogas slurry should meet the requirements of interchangeability and assemblability.
Working principle of separator：
When the solid-liquid separator of poultry manure and biogas liquid biogas residue is operated, the motor drives the auger shaft to rotate through the belt wheel.
The material to be separated is fed from the feeding port, and the blades on the auger shaft continuously push the material to the right and push it to the wedge wire drum screen during the rotation movement.
The liquid phase material is separated through the screen hole under the action of extrusion and centrifugal force. In the process of moving to the right, the liquid phase material is continuously squeezed and separated to the end of the wedge wire drum screen to complete the solid-liquid separation.
With the increase of accumulated solid pressure, the solid material pushes the dial plate to compress the pressure spring through the universal ball bar and moves backward on the auger shaft at the same time. The dial plate breaks away from the contact fit with the shell, and there is a gap between the dial plate and the shell.
When the driven block on the dial plate and the driving block on the reduction gear are inserted and matched, when the solid material is reduced and the pressure of the solid material storage section is reduced, the dial plate returns under the action of the spring so that the driving block and the driven block are separated from each other, the solid material storage section is resealed, and the discharging process is completed temporarily.
Manure Separator performance test:
The performance test of solid-liquid separator for livestock manure and biogas slurry and biogas residue was carried out in the Energy Laboratory of a university. The main feed of cattle is silage and straw. The total solid content of cow manure is about 21%, fiber is more, and the content of coarse fiber and long fiber is close to 8.
The test results are as follows:
1) Working condition of auger and wedge wire drum screen. After the feed liquid enters from the feed port, it is pushed to the discharge end by the auger and goes to the screen. The fine feed liquid through the screen overflows through the screen hole, and the coarse and long fibers continue to move forward. When the coarse and long fibers block the screen hole, the auger blade can scrape away the blockage. If there are too many sundries or large objects, the floating screen will be squeezed and move to the outside. When the resistance is eliminated, the screen will return to its original position under the action of spring force, fit with the auger blade and continue to separate.
2) The working condition of the discharge end dial plate and the secondary deceleration. In the process of operation, the feed liquid is continuously separated in the process of advancing to the discharge end, and the separation is completed at the end. The remaining coarse fiber and long fiber gradually accumulate in the solid accumulation section under the force of the compression spring at the discharge end; When the solid material accumulates to a certain amount, it overcomes the spring pressure and ejects the dial plate, cooperating with the two-stage deceleration discharging mechanism to complete discharging.
Conclusion The experimental results show that the overall design scheme of the solid-liquid separator is feasible, which can realize the continuity and stability of solid-liquid separation. Its main features are as follows：
1) the designed two side wedge wire drum screen structure can effectively separate the solid and liquid phases and prevent the screen from blocking and damaging.
2) the unsettled solid material storage section not only plays the role of gathering solid material before discharging but also plays the role of sealing.
3) the machine can change the screen with different diameters according to the requirements of different working conditions. It is easy to operate, easy to master, and has high separation efficiency.
If the moisture content of feces exceeds 90%, the slope screen manure separator is recommended.