What are the methods for selecting Roots blower model?

Roots blower is widely used in many industries, and there are many models of Roots blower. When using, it is necessary to select a suitable model. What are the methods for selecting the model of Roots blower?

Selection method of Roots blower model

1. Pick

When selecting Roots blower for sewage treatment station, the product sample of Roots blower manufacturer shows the technical parameters under the condition of standard air inlet. However, Roots blower is not in standard condition in actual use. When the natural conditions of Roots blower, such as ambient temperature, atmospheric pressure and average altitude, are different, the performance of the blower will also change. The technical parameters in the commodity samples cannot be directly used in the design and selection. Instead, the technical performance of the fan needs to be converted into fan parameters under the condition of normalized air inlet according to the actual use state.

2. Working pressure

The exhaust pressure of the positive displacement roots blower does not lie in the blower itself, but is determined by the condition of the device after the exhaust gas from the blower, which is determined by the so-called "back pressure type". The aeration blower has the characteristics of forced air supply. The exhaust pressure marked on the factory nameplate of Roots blower is the rated exhaust pressure of the blower. In fact, Roots blower can work under any pressure less than the rated exhaust pressure, only with the allowable strength and exhaust temperature, or under the exhaust pressure higher than the rated value.

For the sewage treatment station, the back pressure generated by the drainage system is the sum of the working pressure loss value of the pipeline system, the water level of the hydrolysis acidification tank and the ambient atmospheric pressure.

3. Exhaust air volume (oxygen consumption)

When measuring the oxygen consumption of wastewater treatment, the result is the gas flow qm (kg/min) requiring oxygen under the standard state, which is converted into the volume flow qv1 (m3/min) requiring air under the standard state. If the use state of Roots blower is not the standard state, for example, at high altitude, the density and water content of air will change, The total flow of exhaust air provided by Roots blower is the same as the standard condition, and the total flow of air quality will be reduced.

4. The difference between the four seasons

The selection of fans shall pay attention to the change trend of the exhaust air volume of centrifugal fans. For the same Roots blower, the volume flow is not easy to change in the four seasons of the year, but the gas flow will change due to different air density, that is, different oxygen supply concentrations. It is mainly because the temperature decreases in winter and the air density increases, so the flow of dry air supplied by the centrifugal fan is significantly higher than the standard condition, resulting in the increase of oxygen supply concentration.

The above is an introduction to the selection method of Roots blower model. If you select a Roots blower model, you can follow the above method.