Walk-in freezer problem.

[romaurie]

A -18 cake freezer has started to get a "snow-like" build-up front and back of evaporator.All defrost heaters are working. The bakery has started placing plastic covers over all the product.These are open at the base and are full of condense as a result of the hot cakes being placed while still warm into the holding freezer.The "snow' can be cleared in minutes with a water spray, but within 3 hours is starting to clog again.
No air curtain on the entrance.
Could this be due to a restriction on the T.E.V.? No obvious signs of "starving" or temperature drop over the the drier.

[tony--1]

nothing wrong with tev . placing warm cakes in to it is the problem.is it getting down to temp ?.there using it as a blast frezzer now

[smpsmp45]

I suspect the Drain problems The air must be coming in through the drain pipes. Is there a U loop with water head provided?

[Kp3]

same point as tony 1 its called heat depression on the coil. warm air touching something cold like steam touching a cold window causing water instead freezing it on the coil

[tony--1]

yeah dont look at the drain .the problem is there using it as a blast freezer . not designed too freeze product just to keep it at -18. theres a big difference

[romaurie]

Appologies for replying to my own query. I found the "Eliwell 974" microprocessor was sometimes not cancelling the liquid line solenoid valve.So it was cooling and defrosting at the same time.Having now replaced the m.p. with a 984 Eliwell all is well.Apparently the plastic bags over the trolleys with food are a health ministry directive.
Also the drain passes from the freezer thru a vegetable cold room.A carrot was stuck in the outlet restricting both drains.
Never a dull moment!
Many thanks for your help.