There is air in the multi-cylinder plunger metering pump
Thread Content
It is a multi-cylinder metering piston pump, one of which uses lye as the medium. Increasing the speed of the motor driving this piston pump has no effect on the other pumps; however, gas is generated within the piston pump that uses lye, which affects the flow rate (the flow rate appears high, but in reality the flow is insufficient due to the presence of gas). When the piston area is dried with steam, the flow rate can be controlled, while without steam application the flow rate fluctuates greatly. By opening the exhaust valve located below the buffer tank (dampener) at the pump’s outlet, gas is continuously discharged. I would be extremely grateful if experts from all walks of life could offer some guidance!
What is the concentration of the liquid caustic? Is it possible to have crystals? If there is no air in the inlet pipe, then the only place where air might be present is at the packing area. I also want to ask: since it’s a metering pump, why is it the speed that is increased instead of adjusting the stroke to change the flow rate? Finally, I saw a female colleague. Come and take a look! ! !
For 48% liquid caustic, crystallization is not possible; the temperature in the caustic tank is around 45 degrees, and the outlet pipeline of the tank is equipped with heating. The packing maintenance team says there is no leakage, but I personally think it’s a packing issue. For our multi-cylinder plunger pumps, we adjust the flow rate of the alkali according to production requirements; the flow rates of other materials don’t need to be changed
In such cases, it is possible to start by examining the source of the gas, beginning with the inlet tank; checking the liquid level, as well as any leaks in the pipeline flanges and valves, and finally looking at the packing. There is always a place where air can enter. Using steam instead will do, which is quite suspicious.
Hello, the inlet tank, liquid level, and pipeline flange valves have all been checked, and there are no issues. It was accidentally discovered that the filler does not allow permeation; without steam drying, the flow rate experiences significant fluctuations, while with steam drying the flow rate remains more stable. In my opinion, heating reduces the viscosity of the liquid alkali. But the temperature of the alkali tank is around 45 degrees, and the pipelines from the tank outlet to the pump inlet are insulated with copper tubes; so, by using steam to heat the area around the pump plunger, I’m really puzzled as to why any component might experience thermal expansion and contraction. Our sump is located at a height of approximately 4.5 meters from the pump inlet, and the spring pressure of the pump inlet valve is 0.7 bar. During today’s maintenance, it was set to 1 bar, and immediately there was no flow at all.
What material are your alkali liquid pipelines made of? Alkali embrittlement can easily occur with external heating.