What are the reasons for the decrease in fan inlet pressure?
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It was discovered when restarting after a short period of shutdown for insulation. . The negative pressure at the inlet of the Roots blower decreases. What are the main reasons? How should it be handled?
There are a few points: 1, the load isn’t increased enough. 2. The purification and drying load in the negative pressure section is not necessarily the same when it first starts up as it is when it stops operating. 3. Generally, the electrostatic fog is flushed during shutdown. In short, it’s not strange for the negative pressure to be a bit lower. If you’re really worried, use glass tubes to test the negative pressure on those five or six devices. See what the difference is from normal!
It is very likely that there are air leaks in the processes prior to the fan inlet, including equipment such as the purification system and drying towers. Let’s check it out; there should be a result
First, it is necessary to determine what issues exist in the system ahead of the fan, then examine the impact of the reduced negative pressure on the system, and finally analyze the causes.
It is possible to measure the air leakage rate of the purification process; this can be determined by checking the SO2 concentration at the inlet of the purification system and at the outlet of the drying tower.
If the system load is different before and after, there is no basis for analysis in this case. Next, check whether there are any leaks in the negative pressure system, whether the equipment in front of the fan has been cleaned after shutdown, and whether the volume of air in the purification cycle and the drying cycle has decreased…… ； Let’s take a look at the pressure at the fan outlet; if the outlet pressure is high, then the negative pressure at the inlet is naturally lower.
The system is leaking air; if this happens right after starting the machine, the pressure will definitely be low, as the concentration of gas isn’t high enough at that moment, and the density of the furnace gas is low, resulting in a low negative pressure