Tube axial fan's function difference

The role of tube axial fan and centrifugal fan in mechanical ventilation

1. Due to the large difference between temperature and grain temperature, the first ventilation time should be selected in the daytime to reduce the difference between grain temperature and temperature and reduce the occurrence of dew condensation. The ventilation in the future should be carried out at night as much as possible, because this ventilation is mainly for cooling, and the atmospheric humidity is relatively high and the temperature is low at night, which not only reduces the water loss, but also makes full use of the low temperature at night and improves the cooling effect.

2. At the initial stage of ventilation with centrifugal fan, there may be dew condensation on doors and windows, walls, and even slight dew condensation on the surface grain surface. As long as the fan is stopped, the window is opened, the tube axial fan is turned on, and the grain surface is turned over when necessary to remove the hot and humid air from the warehouse. The slow ventilation with tube axial fan will not cause condensation, but the grain temperature in the middle and upper layers will rise slowly, and the grain temperature will decline steadily as the ventilation continues.

3 when the axial fan is used for slow ventilation, because the air volume of the axial fan is small, and the grain is a poor conductor of heat, it is easy to have slow ventilation in individual parts at the initial stage of ventilation. As the ventilation continues, the grain temperature in the whole warehouse will gradually balance.

4 the grain with slow ventilation must be cleaned by vibrating screen, and the impurity area caused by automatic classification must be cleaned in time for the grain entering the warehouse, otherwise it is easy to cause local uneven ventilation.

5. Calculation of energy consumption: the tube axial fan used in warehouse 14 has been ventilated for 50 days, with an average of 15 hours per day and a total of 750 hours. The average moisture content has decreased by 0.4%, the average grain temperature has decreased by 23.1 degrees, and the unit energy consumption is 0.027kw.h/t. ℃. Warehouse 28 has been ventilated for 6 days for 126 hours. The average water content has decreased by 1.0%, the average temperature has decreased by 20.3 degrees, and the unit energy consumption is 0.038kw.h/t. ℃.

6. Advantages of slow ventilation with tube axial fan: good cooling effect; Low energy consumption per unit is particularly important today when energy conservation is advocated; Ventilation time is easy to grasp, and condensation is not easy to occur; It is convenient and flexible without separate fan. Disadvantages: long ventilation time due to small air volume; The precipitation effect is not obvious, and the tube axial fan should not be used for ventilation of high moisture grain.

7 advantages of centrifugal fan: obvious cooling and precipitation effects, short ventilation time; Disadvantages: high energy consumption per unit; If the ventilation time is not well controlled, condensation is easy to occur.

Conclusion: in the ventilation for the purpose of cooling down, the axial fan should be used for safe, efficient and energy-saving slow ventilation; Centrifugal fans are used in ventilation for the purpose of precipitation.