Drycleaning machine fridge problems
Let me begin by saying that I have no idea about refrigeration and am posting here only to see if I could further help the refrigeration guy who is going to pay a visit to sort out the issue I have in a day or two.
I dont know if you guys knows how a cycle runs in the drycleaning machine but let me explain. First the garment is washed, then drying happens, followed by cooling and then deodorization.
Sometime in the last week of April we called the refrigeration technician and asked him to check if the fridge was okay and do leak testing. He said he charged the gas and did a nitrogen leak test. Ever since the machine is tripping when it runs the cooling phase. Immediately after drying, cooling proceeds and within the first 20 secs the machine triggers an alarm saying lack of fridge water. There is no problem with the fridge water because water pressure is correct(2 bar) and the temp of the water is also correct(50F). Fridge water is supplied through an external chiller connected to the machine. It also aids in distillation of the solvent.
I asked an industry associate of mine in the US and he said he suspects that the fridge has been overcharged. He said it leaves no room for the gas to expand and hence is tripping and triggering the alarm. The last 6 weeks is my location are traditionally the hottest weeks of the year. Average temp during the period was about 115F in the plant.
What I want to know if how much gas there should be present in the fridge for optimum functioning? I know the technician should know all this but my hunch is that he may be inexperienced because he got it wrong on the first attempt.
Please look at the attachments to see if they can aid you in giving me a suggestion.
Thanks a ton!
P.S> I'm located in India.
I forgot to add some important data :
The refrigerant is R22.
Your machine's refrigeration system consists of the compressor, an evaporator coil and two condensers. It operates during two modes of the cleaning process.
Originally Posted by slicksilver79
The first mode is during the drying cycle. In the dry cycle, the evaporator is used to condense the cleaning solvent vapors back to a liquid. The heat created from this function is rejected to both condensers...first to the condenser coil located downstream of the evaporator (where the rejected heat augments the steam coil's heat for drying) and then in series to the water-cooled condenser, which also serves as a refrigerant receiver where excess refrigerant is stored.
The second mode is the cool-down cycle where all heating is stopped and the evaporator is used to further recover vapors (deodorizing) and subsequently cool the load to just above room temperature. During this mode, only the water-cooled condenser is used.
It is during the cool-down mode when less refrigerant is used, so this is when the water-cooled condenser will store the excess refrigerant. If the system is indeed overcharged, too much refrigerant will decrease the condenser's capacity to reject heat. This will cause the compressor's discharge pressure to rise high enough to trip the high pressure safety control...and give you that cooling water alarm.
If the system is not overcharged, the cause may lie with the cooling water regulating valve...either in its setting or its functionality.
I too suspect it's simply overcharged.
If you look at the manufacturer's data sticker on the machine, I believe it states the refrigerant required charge is 2.5 Kg of R22.
now did he pull all the gas out and then pressurize with nitrogen or did he add gas and then pressurize with nitrogen? in your post you state he added gas and then nitrogen tested. he should have pulled gas pressure tested evacuated to500 microns or less and then recharged with correct r22 charge
Thank you for the replies. The guy hasn't come yet. He will probably come today and I will do what you have recommended and report back.