Industry new

Preventing fluid backflow leading to repeated metering and introducing errors

A chlor-alkali plant in Shanghai used a pump to pump the feed liquid from one department to another, and the delivery volume was measured by an intelligent electromagnetic flowmeter. When the batch of material is delivered, the pump stops running, so the liquid in the outer tube of the pump outlet is returned to the inlet of the pump. Since the outer tube has a large diameter and a long line, the amount of return is large each time. Only a period of time is found that the total amount of the flow meter is larger than the total volume calculated by the volume method in the storage tank.

A company has two fully automatic fuel-fired furnaces operating in parallel, one of which is normally steamed and the other is used for heat. The steam outlets of the two boilers are equipped with vortex flowmeters. Steam delivery dispenser. In the statistics of the total amount of steam generated and the total amount of steam consumed, it was found that the amount of hair sent was much less. After careful observation, it is found that the boiler in the hot standby state dissipates the heat dissipated from the steam boiler from the normal steam generator. Not only that, because the distributor pressure always fluctuates, when the distributor pressure decreases, the boiler B steam drum The steam is supplied to the distributor, and the flow meter counts the amount of steam supplied. When the pressure of the distributor rises, the distributor fills the steam of the boiler B. This part of the steam also changes frequently. Repeated metering often occurs, and finally the total amount of the total meter (the sum of the total amount of FIQ01 and FIQ02) ) significantly higher than the total amount of steam consumed. Moreover, the larger the pressure fluctuation amplitude, the more frequent, the higher the total amount of the total meter is.
A similar situation occurs at the gas station in the factory. When the pressure of the gas connection pipe rises, the system inflates the gas capacity of the deactivated furnace, and when the pressure of the gas communication pipe decreases, the gas capacity of the furnace is deactivated, and the system is supplied with gas. The meter counts the amount of “supply gas”.
Heat balance method The relevant data associated with the measured flow rate is substituted into the heat average equation to calculate the flow rate.

PREVIOUS：Description of the problem that the flow measNEXT：Flow meter quality and length of life