Design of biogas digester in pig farm (diagram) how big biogas digester is needed for 500 pigs

Biogas digester is very common in rural areas. In addition to domestic biogas digesters, biogas digesters in pig farms are common in rural areas. Such a biogas digester can protect the environment, and there are many benefits. Now there are a lot of people who want to build biogas digesters, and before construction, many people must want to know what the specific design method is.

Design of biogas digester in pig farm (illustration)

1. Release the line. Laying off the line and digging the pit is the first step to ensure the quality of the pool, and it must be constructed according to the prescribed size. Draw the overall plane. Draw the warm room and the area of the pig house, which is on the east or west side. Draw the centerline of the width of the pattern. Take O as the starting point, find out the center point O of the pool on the inside of the pigsty, take O as the center, draw a circle with the radius of the pool plus 6 cm as the radius, and determine the location of the pool. Determine the position of feed inlet and outlet. To determine the center point of the feed inlet and the center point of the discharge port located in the solar greenhouse on the width centerline of the "mode", mark it with white ash.

2. Pool pit excavation. All the biogas digesters built in the "mode" are buried underground, and the earthwork of the biogas digester adopts the construction technology of large-scale excavation. First of all, the height of plus or minus zero should be determined. The depth of the pit is determined according to the design drawing, that is, the top of the biogas digester is kept on a horizontal surface with the outlet, and is 10 cm higher than the pig house floor. If the feed inlet is super high and the ground is 2 cm, if the biogas digester is dug too deep to make the biogas digester below the ground level, it will affect the matching use, dig too shallow to make the biogas digester protrude from the ground, and it is difficult to feed pigs and fertilize in the solar greenhouse.

3. Masonry outlet passage. The outlet passage is made of red brick and sand ash, cement: sand = 1 ∶ 2.5. In order to facilitate construction and discharge, the channel mouth is 50 cm wide and 70 cm high, and the top arch is arched, but the upper mouth is not less than 35 cm from the upper arch angle of the pool to prevent gas production from returning under the water surface and running away from gas.

4. The general masonry method for the pouring of the pool wall and the lower part of the water pressure room is to soak the bricks with water to prevent it from being difficult to remove. Each brick is laid horizontally, and the seams of each brick are staggered without mud or ash openings, so that one layer of brick is poured with concrete, and then the second layer is built after vibrating and compacting. The concrete mix weight ratio is cement: sand: gravel = 1 ∶ 3 ∶ 3. The pond wall is 1m high and 0.05m thick.

5. Construction of pool arch cover. At present, the biogas digester arch cover in the "mode" is made of brick, and the biogas digester in the "mode" generally uses straight pipe feeding, and the feed pipe should be installed before the masonry pool arch cover, and the ceramic pipe with a diameter of 200 mm and a length of about 600 mm is generally used. the pipe is tied to the wooden pile on the ground, and the trumpet of the feed pipe is facing up, vertical up and down, and fixed close to the pool wall. It is appropriate to insert the depth arch angle 250mm to 300mm in the pool. The masonry arch cover can be fixed by iron hook or rope method, starting from the feed pipe, which should be reinforced with cement around the feed pipe. For bricks of good quality, soak in water first, keep wet outside and dry inside, use 1 ∶ 2 cement mortar, sand and workability are better, ash mouth is full, bricks and bricks should be tight, each circle should be embedded with small stone, while building, pay attention to arch cover Radian, every 3-5 laps, the outer wall of arch cover is strictly smeared with 1 ∶ 3 cement sand, and when plastering the upper layer of brick in the first circle of arch corner. The thickness should reach 30mm to 50mm, which is used to replace the ring beam. As the masonry is plastered, the soil is filled evenly from the outside to the inside. Before backfilling, several layers of bricks should be laid on the upper part of the feed pipe to prevent the backfill from entering the pool from the feed pipe. The width of the feed port should be 240 mm and the length varies from household to household. Note that the first backfill of about 60% can prevent landslides, the rest of the soil can be backfilled before the pool is sealed the next day, and the whole pool can be completely backfilled 10 days after completion.

How many biogas digesters do 500 pigs need?

For 500 pigs, if the biogas slurry flushes back into the pig house and all pig manure goes into the biogas digester, it takes 100 cubic meters of real biogas slurry to automatically separate the biogas digester.

Design principle of biogas digester in pig farm

To build the biogas digester in the "mode", we must first do a good job in the design. Summing up the experience of scientific experiments and production practice over the years, the design of biogas digesters matched with the model must adhere to the following principles:

1. We must adhere to the principle of "four combinations" and "four combinations", which means that the biogas digester is connected with livestock pens, toilets and solar greenhouses, so that human and animal manure can continue to enter the biogas digester, which is conducive to the management of faeces and improve environmental hygiene. biogas slurry can be conveniently transported to the vegetable field in solar greenhouse for fertilizer use.

2. Adhere to the principle of "round, small and shallow". According to the principle of geometry, the surface area of a biogas digester with the same volume is smaller than that of a square or rectangle and is more economical. The tightness is good and firm. The internal structure of the circular pool is reasonable, and the pool wall has no right angle, so it is easy to solve the sealing problem, and the force is uniform around the pool, and the pool body is firm. The temperature in northern China is relatively low, and the circular pool is placed underground, which is conducive to winter heat preservation and safe overwintering.

What materials need to be prepared for the construction of biogas digester

Material preparation is the first step in biogas fermentation. Before the new biogas digester and biogas digester are recharged, sufficient fermentation raw materials must be prepared to maintain 6%-8% in summer and 10% in winter according to the fermentation concentration requirement of 6%-10%. As for the biogas built in Qingfeng County, the household biogas digester of 10m3 needs to prepare human and animal manure of 2.7m3 in spring and summer, and human and animal manure of 4.4m3 in autumn and winter.

Pig biogas digester in the construction must do a good job of site selection, and then line, pit excavation and so on need to be very accurate. The choice of cement and sand is also important. If it were 500 pigs, the biogas digester would be relatively larger.