Why must the cooling water circuits for the filler cylinder be separated?

The diameter of the cooling circuits for the packing is very small; therefore, filters with higher precision are required to prevent blockages. If both the cylinder and the packing are cooled using softened water, it is possible to use a single supply line. To avoid liquid slugging, there may be restrictions on the temperature of the cooling water for both the cylinder and the packing, and separate circuits will be designed for this purpose

The water temperature in the cylinder is generally 46 degrees, while that for the packing is 35 degrees. It is mainly to prevent liquid shock. Also, the water used for the filler needs to be filtered.

Reply to 2# spoole: Why is the temperature of the cylinder cooling water higher than that of the packing cooling water? Is it to prevent liquid slugging? And why does liquid slugging occur?

In our factory as well, the water is separated based on the different requirements of the packing and cylinders for softened water. The softened water used for the packing needs to be at a lower temperature than that used for the cylinders; it also needs to be of higher purity, with less water consumption. So it’s better to supply water separately

What I saw is that the cooling water pipelines are indeed separated, but the packing cylinder isn’t filled with softened water. What will be the consequences of this? Will it lead to scaling and blockages? What to do, there is no water softening station

I think different units may have different requirements for cooling water; some units use circulating water for cooling the cylinders, while softened water is used for cooling the packing. We use circulating water for both the reciprocating machine cylinders and the packing. However, every time the unit is shut down for major maintenance, its cooling water pipelines must be cleaned using high-pressure jets. As for the question raised on the 4th floor, I have only heard from the technicians that for oil-free lubricated cylinders, the inlet temperature of the cooling water should be 5°C higher than the inlet air temperature. This is mainly to prevent sudden cooling of the cylinder, which could lead to condensation and damage to the lubricating film on the cylinder surface, thereby accelerating the wear of the piston rings. As for the cooling water temperature of the filler, there shouldn’t be any specific requirements, I guess.

In my opinion, due to the high precision of the packing design and the small heat exchange area, softened water with a filter is generally required. The cylinder has a large heat exchange area, so circulating water is sufficient; this water flows between the cylinder liner and the outer wall of the engine, and it does not require very high water quality. However, the amount of water needed for cylinder cooling is much less compared to that required for packing cooling. The temperature of the water used for cylinder cooling should be 5 to 10 degrees higher than the temperature of the gas entering the compressor, in order to prevent condensation of the incoming gas and resulting liquid slugging. If waste is not a concern, they can share one cooling water pipe. Generally, they are separate.

I’ve just started working with piston compressors, and I saw that only the cooling water for the packing was filtered; I didn’t realize there was so much to know about this.

On the one hand, there is the issue of filtration precision; on the other hand, the temperature requirement for the cylinder cooling water is relatively high, while that for the packing cooling water is lower. It is therefore reasonable to separate them.

The main requirement is cleanliness, and the temperature is adjustable!