Problems and improvement schemes that often occur in summer chicken house (part 3)
1. Insufficient local ventilation
Common phenomenon: It is difficult to cool the local area, and the chickens leave the area automatically. This phenomenon occurs in flat-housed chicken houses, especially those on the ground, and also appears in the middle of the house and the waist rib area on both sides.
Cause: This phenomenon is mostly caused by improper operation. The cooling damp curtain is installed on both sides of the head end, the negative pressure of the damp curtain air inlet is too low or too high, and the airflow coverage is uneven. The air flow direction is shown in the following figure:
Improvement method: Open the size of the wet curtain according to the width of the chicken house and the number of fans. If you don’t know how to operate, hang a recording tape every 1.5m between the left and right wet curtain inlets and both sides of the chicken house. Adjust the size of the air inlet by observing the movement of the tape. It is best to install a 24-plate stirring fan every 15 meters on both sides of the chicken coop to force air to circulate evenly.
2. Large temperature difference between head and tail
Common phenomenon: the temperature difference between the tail and the head is more than 3 ℃, and some high-density cages can even exceed 5 ℃.
(1) Reason 1: The chicken coop is too long. The chicken houses in large-scale chicken farms are getting longer and longer. There are many 120-meter broiler houses, even 150 meters, and 80--100 meters in cage houses. During the flow of low-temperature air from the head end to the tail end, the heat generated by the chicken continuously increases the temperature of the flowing air, which causes the temperature at the tail end to be higher than the temperature at the head end. The longer the chicken house, the greater the temperature difference.
Improvement method 1: Move 15~20% of the wet curtain from the head to the middle of the chicken house, so that the wind speed of the back of the chicken in the first half is 2m/s, and the wind speed of the back of the chicken is 2.5m/s, which can reduce the temperature difference. The chicken's somatosensory temperature can also be kept basically the same. This method must be calculated accurately. If the area of the wet curtain in the middle is too large, the effect will be counterproductive.
Improvement method 2: For a house more than 120 meters long, you can try to install a wet curtain on the side wall in the middle of the house, and install fans at both ends of the house, but the investment of such fans and wet curtains will be doubled. I have only seen such pictures of foreign chicken coops, no data has been collected, and the actual effect is not very clear.
(2) Reason 2: The chicken house is not closed tightly. The main reason is that the air inlet windows, lighting windows, eaves and walls, the head and tail doors and the outlet are too tight, resulting in the house wind speed is lower than the design wind speed or the difference between the front and rear wind speed is too large.
Improvement method: improve the airtightness of the chicken coop, especially the tail outlet can be sealed with a 3mm thick rubber soft plate, nailed to the top, and can be automatically opened and closed as the manure cleaner enters and exits.
(3) Reason 3: The ventilation time is too long. In summer, if the wind speed is too low, it will make the chicken house ventilation time too long, thereby increasing the heat accumulation of the flowing air, resulting in an excessive temperature difference. Generally speaking, the ventilation time of the flat house is not more than 60 seconds, and the cage house is not more than 45 seconds.
Improvement method: increase the wind speed in the house, level house 2~2.5m/s, ladder cage house 2.3~2.7m/s, cascade cage house 3~4m/s.
3. Poor cooling effect of wet curtain
Common phenomenon: The wet curtain water pump is turned on, but the cooling effect is not obvious. Only the head of the chicken house feels cool within 10~15 meters, and it is difficult to lower the temperature later.
Reason: High temperature and high humidity weather, such as the sun exposure after thunderstorm, outdoor relative humidity exceeds 80%, evaporation is difficult, and the cooling effect is not obvious.
Improvement method: change the water source of the spray line from normal temperature water to low temperature well water, while maintaining normal ventilation, and adopt water cooling to force the temperature to be lowered. When the outdoor relative humidity exceeds 80%, the relative humidity in the chicken house is also very high. At this time, the spray has little effect on the relative humidity in the house.
Some typical poultry chicken broiler animal feed pellet making plant projects Richi has done: