Design and experiment of the filtration and cleaning device for air emitted from poultry house

Abstract: Large-scale poultry houses can often emit the large amounts of dust and feathers via the exhaust fans, leading to the environmental pollution and potential biosafety. The air filter net can usually set outside the exhaust fans to intercept the feathers and filter dust, in order to reduce the impact of exhaust air on the environment and biosafety of the field. But, the accumulation of feathers and dust on the filter net can be reduced the ventilation efficiency of the poultry house after a period of use. The manual cleaning regularly is then time-consuming and harmful to the respiratory tract health of the cleaning personnel. In this study, a filtration and cleaning device was designed to realize the automatic and efficient purification of air that emitted from the large-scale poultry houses using validation tests, operation energy consumption, and cost calculation. The developed device mainly included four parts: filtering, cleaning, driving, and control mechanism. According to the characteristics of the exhaust pollutants in the poultry house and the industrial requirements of filtering/cleaning, the key parameters were optimized, such as the material and aperture of the filter net, the nozzle arrangement of the flush rod, the motor of the self-propelled trolley, and the diameter of the wheel. Besides, the operation control program of the device was written. The air in the poultry house was firstly discharged by the end fans, and then entered the dust removal room. The feathers and dust were intercepted by the filter net, and then adhered to the inner surface of the filter net, when the discharged air passing through the filtering mechanism. Part of the airflow was changed to the vertical direction after encountering the filtering mechanism. Specifically, the pollutants (such as feathers and dust) hit the top of the dust removal room and fell back again. Meanwhile, the self-propelled trolley was moved back and forth along the guide rail after the device running. The vertical flush rod and collecting trough were connected with the trolley, and then arranged on the outside and inside of the filter net. Once the device was cleaned the filter net, the flush rod was reversely sprayed the water to wash the filter net, while the collection trough was gathered the cleaning wastewater and dust at the same time. Wastewater was then discharged to the poultry farm wastewater collection system for the centralized treatment in the farm. A regular automatic cleaning of the filter net can be expected to ensure the filtering effect with the less manpower input. The validation test indicated that the device was reliable easy to control. Correspondingly, the improved device can realize to filter, intercept, and collect the feathers from the air that emitted from the poultry house. The removal rate of dust reached 55.0% in the air that emitted from the large-scale poultry houses. Operation energy consumption and cost accounting showed that the water consumption, the power consumption, and operation cost were 2.17 L/m2, 0.001 7 kW·h/m2, and 0.020 6 Yuan/m2 in a single operation, indicating a clear economic cost of the filtration and cleaning device. The finding can provide a significant reference to develop the air purification techniques for the air emitted from the poultry houses in engineering applications.