Principle structure and process of pig farm deodorization equipment

In the past two years, domestic environmental protection requirements for breeding enterprises have become higher and higher, especially in terms of exhaust emissions. It is required to install odor collection and treatment facilities and equipment at key nodes such as pig houses and manure treatment, and to implement full-process monitoring and management of the air quality in the farm. , to reduce odor gas emissions. Therefore, major breeding enterprises have added exhaust emission purification and deodorization equipment in new projects and projects under construction this year.

It is foreseeable that in the next few years, with the gradual recovery of pig production capacity, various places will impose requirements on the exhaust gas emission of farms.

Although deodorizing equipment has been used abroad for many years, it is still relatively unfamiliar to most domestic breeding enterprises. According to the deodorizing equipment that has been put into use at present, this article makes a brief introduction for reference in the industry.

The principle of deodorization equipment for pig farms is relatively simple. It is the same as the principle of packing towers for industrial deodorization equipment. It is to let the odor pass through the filler, make the odor components fully contact with the spray liquid, and use the liquid phase to absorb the gas phase. Because the pig house The main components in the odor are ammonia and dust, and these substances are relatively soluble in water, so they can achieve the deodorizing effect.

At present, most domestic horizontal equipment adopts a single-layer filter wall, and the deodorizing wall stands at a distance of 5-6 meters from the air outlet of the fan. Spraying device and electrical control are composed of five main parts. In addition, water quality monitoring and regulation system can be added to increase the degree of automation of the equipment.

1. Filter material and filter material fixing frame (main core part)

The filter material is the core material of the deodorization equipment. At present, the main materials used are grid filter material and spherical filter material. These two materials are made of PP plastic injection molding. The grid filter material is stacked in pieces to make a module. , piled up on site to form a wall. The ball-packed filter material is made of a basket-shaped container, and the filter balls are scattered and piled up.
Mesh filter material is a filter material specially developed for ventilation and deodorization of farms. It is characterized by small wind resistance (less than 10Pa under no load), low requirements on the static pressure of the fan, easy installation and fixation, and no maintenance during use. The price of the spherical material is low, but the relative wind resistance is relatively large (35Pa), which requires high static pressure of the fan, and the spherical filter wall is easy to form dust accumulation, and it needs to be dismantled and cleaned regularly after long-term use.

2. Outer enclosure, pool and other civil infrastructure

Flat-floor pig houses are generally surrounded by steel structures, which are relatively cheap and fast in construction, but the sealing effect is not ideal, and some untreated odors are easy to leak. The buildings and pig houses are built with deodorizing rooms added to the civil structure, using brick-concrete or concrete structures. This structure has good airtightness, long service life, and higher cost than steel structures.

3. Circulating spray device (spray cleaning)

The main components of the circulating spray system are the centrifugal water pump, the spray pipeline and the spray nozzle.

The spray water pump needs to adopt anti-corrosion stainless steel pump head, which can be vertical or horizontal; the spray pipeline adopts UPVC water supply pipe, and the pressure requirement is 1.0Mpa; the spray nozzle adopts a spiral nozzle that is not easy to be blocked.

4. Electric control system

The electronic control system mainly controls the opening of the water pump. In order to control the spray pressure and adjust the flow of the water pump, frequency conversion control will be adopted.

5. Water quality monitoring and dosing device (control PH value and conductivity)

There is a limit to the absorption of odor by circulating spray water. When the concentration of pollutants in the water is too high, it will have a great impact on the deodorization effect. In order to increase the deodorization effect and improve the automation of the equipment, it is recommended to choose equipment When adding water quality monitoring devices and dosing adjustment devices, general equipment can be realized as long as the pH value and conductivity of the spray liquid are monitored.

This pig farm deodorization equipment can adopt water absorption, acid absorption and biodegradation processes. The water absorption process is the simplest process without adding any other substances, but the treatment effect of the water absorption process is average. In order to increase the deodorizing effect, acid can be added to the water, or biological bacteria can be added. These two processes will increase the deodorization effect on the basis of water absorption. For example, adding sulfuric acid can make the absorption rate of ammonia reach 80%, and the deodorization effect is very obvious. However, if the acid treatment is used, the daily consumption of acid is large, and there are The degree of corrosion to the equipment is increased, and the generated sewage cannot be discharged directly, and secondary treatment is required (in foreign countries, the lawn can be sprayed directly).

It is more reasonable to use the biological treatment process. The bacterial agent is added at one time, and the cost of use is relatively low. However, the living environment of biological bacteria is complex, and many factors such as temperature and pollutant concentration have a greater impact on biological treatment.

Based on the application experience of foreign deodorization equipment and domestic exploration experience in pig farm tail gas treatment for many years, the deodorization equipment introduced above is relatively economical in investment, relatively simple in use and management, and relatively low in operating costs. A solution with a relatively acceptable odor effect.