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Kevin Yeo
29-12-2005, 08:26 AM
Dear all,

From my limited knowledge, I understand that for supermarket cabinets (multi evaporators), it is recommended to tap liquid refrigerant from bottom of main liquid line, making a 'U' before going up to evaporators to ensure 100% liquid feed. (Assuming liquid receiver is lower than cabinets).

My question is what will be the impact if liquid feed to cabinets is a direct Tee from top of main liquid line? Is the impact the same for R22 and R404a refrigerant?
Again, assuming liquid line sizing is proper, no flash gas is developed.
Have a nice day....

Rgds,
Kevin

Dan
29-12-2005, 03:29 PM
If there is no flashing then you're fine. However, at low load, even when there is no flashing occurance, liquid line flow tends to take the form of sewer flow. Then you're left feeding paths of least resistance.

I picture sewer flow as what some of my technicians call a "lazy sightglass." Where you can see both liquid and vapor almost as a view of a river from above it, but contained within the atmosphere of the pipe. That easily applies to a liquid line sightglass in a horizontal liquid line, but I see it in vertical liquid lines too, which has always puzzled me.

A store manager called in today with a wonderful metaphor: "My canary case is running warm." What do you think he was talking about?