Refrigerant loss from Hansen auto purger

[simplygold]

Hello all,

I am faced with a current dilemma that you can help me answer. I work for a plant that has ~50k lbs nh3 charge. Four operating pressure systems, 7"hg, 24psig, 30psig, and condensing of 124-135 (design).

We are currently purging from the condensing pressure, and the suction for our ap24 is at 24psig. The two highest of our four condensor receive 6 purge points each, at 15 min intervals. The two lowest receive 6 purge points ea at 5 min intervals. There is half inch purge line coming from each of the purge points into a common half in header. The total length of each purge line is about 250ft.

Problem: I think I am losing a lot of refrigerant through the purger. Upon observation the bubbler appears to function fine, but short of watching it all day I could not confirm this. It has been suggested that the check valve is faulty, which I will check today. Hansen said that the unit is designed to use a 30# check valve. Sometimes the discharge end of the purger can get up to 32-37 psig for about 20min (from the normal 24psig).

Thanks ahead of time.

[charlie n]

The purger would work much better if the suction was piped to your lower temperature suction (7"hg).

[Segei]

Hello all,

I am faced with a current dilemma that you can help me answer. I work for a plant that has ~50k lbs nh3 charge. Four operating pressure systems, 7"hg, 24psig, 30psig, and condensing of 124-135 (design).

We are currently purging from the condensing pressure, and the suction for our ap24 is at 24psig. The two highest of our four condensor receive 6 purge points each, at 15 min intervals. The two lowest receive 6 purge points ea at 5 min intervals. There is half inch purge line coming from each of the purge points into a common half in header. The total length of each purge line is about 250ft.

Problem: I think I am losing a lot of refrigerant through the purger. Upon observation the bubbler appears to function fine, but short of watching it all day I could not confirm this. It has been suggested that the check valve is faulty, which I will check today. Hansen said that the unit is designed to use a 30# check valve. Sometimes the discharge end of the purger can get up to 32-37 psig for about 20min (from the normal 24psig).

Thanks ahead of time.
Why do you think that you lose ammonia through the purger? Charlie N is right that purger will waste less ammonia at lower suction pressure.

[McFranklin]

There should be three check valves, 1 PSID, 30 PSID and 200/225 PSID.
The check valves are parts that Hansen included in the overhaul kit. So they a wear items. And I have sold a few over the years.
The 1 PSID valve is on the line to the bubbler. Check to make sure it is a 1 PSID and not a 30 PSID. That would explain the high pressure reading. Or it could just be a wore out check valve.

[piewie]

If it is an Auto purger then best to throw it away and fit a NEAP! I have recently done this and my purge problems have almost dissappeared.