|Industrial dust treatment equipment series|
|Welding fume exhaust gas treatment series|
|Grinding polishing dust removal equipment|
|Stand-alone dust collector|
|Spiral duct and accessories series|
Sampling methods and methods in the industrial dust collector dust removal system:
(1) Predicted flow rate method
The predicted flow method is to measure the flow velocity of each sampling point of the flue with a pitot tube in advance, and then calculate the required sampling flow at each point under the condition of constant velocity according to the flow velocity of each point of the flue and the diameter of the sampling nozzle selected; or Calculate the sampling nozzle diameter required for each point according to the flow velocity of each point in the flue and a fixed sampling flowmeter. Regardless of which method is used, it is necessary to calculate the sampling flow or the diameter of the sampling nozzle to achieve the same speed. Due to the complexity of the calculation, this method is not suitable for high temperature and humidity flue sampling.
(2) Pitot tube parallel sampling method
The pitot tube parallel sampling method is generally suitable for situations where the flue gas working conditions are not stable, and the flue gas flow rate needs to be continuously detected in order to adjust the flow rate at any time to maintain constant velocity sampling. The S-shaped pitot tube and the sampling tube are fixed together so that the plane of the sampling nozzle and the opening plane of the S-shaped pitot tube are parallel, and the distance between them is 25-35mm.
In general, first, by measuring the relationship between the pressure difference of the S-shaped pitot tube and the flowmeter reading under the condition of constant velocity, draw it into a line solution diagram or a quick slide rule. In the subsequent measurement, when the pressure difference of the pitot tube, the temperature and pressure of the gas in the flue and the flow meter, and the diameter of the sampling nozzle are known, you can find out the Take the flowmeter reading.
(3) Instantaneous pressure zero point balance method
Industrial dust collectors can use this method when the flow velocity of the flue gas is unknown or when sampling at points where the flow velocity fluctuates greatly. It is to continuously adjust the flow rate during the sampling process so that the static pressure difference between the inside and outside of the constant velocity sampling tube is zero. At this time, it can be theoretically considered that the flow velocity in the sampling tube is equal to the flow velocity at the measurement point in the flue. However, it should be noted that, even if the internal and external static pressure difference is equal to zero, whether the flow velocity in the constant velocity sampling tube is equal to the flow velocity in the flue largely depends on the structural shape of the sampling tube.