Does your pig house have an emergency ventilation system?

11 months ago

Due to the uncontrollable and unpredictable effects of natural ventilation systems, modern large-scale livestock and poultry farming generally uses closed mechanical ventilation.

Does your pig house have an emergency ventilation system?

Due to the uncontrollable and unpredictable effects of natural ventilation systems, modern large-scale livestock and poultry farming generally uses closed mechanical ventilation.

The heat, moisture and gas generated during the production of livestock and poultry are excluded from the wind turbines and introduced fresh air outside the house. Provide animals with the oxygen necessary for survival and a suitable temperature and humidity environment.

Many animals, especially broilers, have a very high metabolic rate and require a large amount of heat to be continuously excluded. In addition, broilers simultaneously produce larger amounts of carbon dioxide.

A large number of broilers are kept in a closed house. If the carbon dioxide produced cannot be eliminated in time, because carbon dioxide is heavier than air, it will quickly form a gas layer near the floor, causing the broiler to breathe enough oxygen to produce suffocation.

Based on this, the ventilation system failure or power failure should be monitored and equipped with the standby ventilation system.

In addition to installing the alarm system and the backup generator, it is widely used to open the vents, using the natural ventilation principle to provide timely ventilation and ventilation for the animals, delaying the time of animal suffocation, and obtaining time for manual intervention or directly solving the problem.

1.Natural ventilation

Natural ventilation refers to the way of ventilating and conveying indoor areas by utilizing natural wind pressure, air temperature difference, and poor air density.

Natural ventilation relies on the wind pressure caused by outdoor wind and the hot pressure caused by the difference between indoor and outdoor air temperature, which promotes air flow and exchanges air inside and outside the building.

2.Wind pressure driven natural ventilation

When the outdoor airflow encounters the building, due to the impact of the airflow, a stagnant zone will be formed on the windward side of the building, where the static pressure is higher than the atmospheric pressure and is in a positive pressure state.

In general, when the angle between the wind direction and the plane is greater than 30°, a positive pressure zone is formed.

When the outdoor airflow is around, a curved circulating airflow will form on the top and rear sides of the building. The vortex area in the upper part of the roof is called the return air cavity, and the vortex area of the leeward side of the building is called the swirling air flow area.

The static pressure in these two regions is lower than atmospheric pressure, forming a negative pressure zone called aerodynamic shadow zone. The aerodynamic shadow area covers the windward facing surfaces of the building (such as the roof, the outer walls on both sides, and the leeward outer wall) and extends a certain distance until the wake of the airflow.

When the outdoor airflow blows through the building, the static pressure of air formed on the surface of the building changes to wind pressure.

Wind-driven natural ventilation relies mainly on wind speed and wind direction.

If the wind speed is small or the wind direction is parallel to the long axis of the building, the ventilation in the house is small and there are many dead zones. At the same time, the position and spacing of livestock houses are relatively high, and not all livestock houses can fully utilize the wind pressure.

3.Hot-pressure driven natural ventilation

When the power is off, the internal battery of the actuator will open the air inlet and the air outlet - use the hot pressure to form the chimney effect ventilation

When designing an emergency ventilation system, the natural ventilation formed by hot pressing is generally considered. The wind pressure should be utilized as much as possible to increase the effect of natural ventilation, and the adverse effect of wind pressure on natural ventilation should be avoided.

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