Roots FansIn the process of using the ventilation fan pipe network resistance calculation is inaccurate, then what is the reason for this situation? Roots fan editorial take you to understand.
The actual ventilation and dust pipe pressure loss, for some reasons will be different from the calculation results, which is unavoidable, and thus the design specification of the calculation of the maximum permissible error of 10%-15%. any neglect of this necessary program calculations, will have a significant impact on the operating efficiency of the ventilator to play a major role in the must be given great attention.
1, ventilator pipe network resistance calculation rated value inaccurate reasons: pipe network resistance calculation of sloppy and the use of resistance coefficient is not accurate enough; unreasonable configuration system effective radius; determine the fan intake conditions are not true; selection arbitrary lack of due guidelines; construction supervision nurses construction process on-site design changes in the impact, etc.. All will make the calculation results and the actual loss error more than 30% or even more, resulting in the selection of the rated performance and the actual operating performance does not match, as a result of the actual operating performance changes. If the calculated resistance than the actual need is too large, centrifugal ventilator operation caused by increased flow, it will implement a significant increase in power consumption, the result is a reduction in the efficiency of the full pressure within the efficiency, but also to make the motor rated power easy to overload, there is a risk of burning electric maneuvering, but the straight inclined to the full-pressure curve of the flow rate of the change of the impact of the change to become smaller, and vice versa, inevitably lead to the operation of the flow rate is reduced due to the reduction in flow rate, caused by the dust removal system in the duct flow rate is reduced, and Promote dust settling.
2, the consequences of inaccurate full-pressure rating of the ventilation fan selection. Handling of high-temperature furnaces and kilns discharged exhaust gas, such as the selection of induced draft fan negative pressure is too large, will destroy the normal thermal balance of the furnace, due to increase the amount of induced draft air, so that the temperature inside the furnace to reduce the impact of combustion or heating, resulting in an increase in the loss of energy of the heat source, when the induced draft fan discharged dusty exhaust gas, the source of pollution at the maintenance of sufficiently confined to form a state of negative pressure can effectively prevent the proliferation of hazardous pollutants.