Study Of The Open Pig House Ventilation And Spray Evaporative Cooling System

The high temperature has greatly influenced the production of swine in the summer. The farmer can t product in normal with bad productivity and low feed s reward. Especially in open and semi-closed livestock houses over the whole 80 percent,there are no better cooling system can be used. We should study a new system in order to solve this problem. The new ventilation and evaporative cooling system is air-cooling fans. This cooling system is a positive ventilation system. The wind and the fog drop spurt out at the same time in the same apparatus. This air-cooling fan can be used both open houses and closed houses.A systematic study on this cooling system and the structure design has been made in this paper. Some cooling system have been installed in open and semi-closed houses,the original data show that this cooling system efficiently solved the problem of heat resistant. The drops movement has been analyzed,the details are as follows.1. According to the analysis of the movement and the evaporative process of fog drops. The horizontal and vertical movement of drops have been studied ,The time and the length of drops move on both horizontal and vertical movement were calculated ,while the fog s diameter is 50 u m and the preliminary velocity is 10 m/s,the length of drops move on horizontal is only 0.0379 m;while the fog s diameter is 50 u m and the temperature 30 and RH is about 90 percent ,the total time of drops movement is 18.8 second ,the length of drops movement is only 0.67 m .Those data can help how to install the cooling system correctly.2. A theory of jet about the air-cooling fan is made;the diameter of the jet and the cover range were studied. The key dimension of fan have been designed. Experimentally analyzed with water spray Analyzing the number distribution and mass distribution of drops when use different water volume ,The main diameter range is from 20 to 50 u m. The total drop quantity is 90 percent which diameter is less than 40 u m .Using proof analyzing,the water volume have litter effluence the evaporative rate ,and the whole drops can evaporate fully.3. The thennal balance has been founded after the ventilation rates and the heattransfer were analyzed.4. The air codling system have been installed in open and semi-closed livestock houses. The experimental result revealed that the range of average temperature is reduced about 4,and the RH is about 80 percent,this environment can reduce the swine heat resistant.5. The air-cooling fan can be used in open and semi-closed livestock houses without any houses reformation. It is easy to install and use. Compare with other cooling system,the air-cooling fan is pay less investment and can use in closed livestock house.