how to Avoid liquid flodback in wet evaporator

[Pushkar]

i am working in cold stoppages, ice plant, dairy industries they use ammonia as a refrigerant but the common problem with all is liquid back in compressor. we use wet evaporators.
in an article i have also read that we cannot set a superheat for wet evaporator we maintain liquid level in accumulator or LP receiver..
can u explain how to prevent liquid flood back

[mbc]

liquid backing to compressor might be from
your level system is not working well
your separator is a small
the pipe slope is not right. or....

to give you right suggestion I need to see your drawing , and when it happen ? during running time or after defrosting time or after starting time
also To prevent that if liquid backing is a small amount might it solve by putting suction accumulator
any way send me your drawing

[Pushkar]

as i m working in compressor company yes we use Accumulator in the system. many time we also use Liquid level switch but some time we dont use LLS in the accumulator.
please tell me the roll of seprator????
n how to adjust the Expansion valve correctly ?????

[Magoo]

Generally liquid carryover from surge drum to compressor relates to the surge level in surge drum, which in turn relates to sudden pressure change in surge drum, so slow down the loading rate of compressor/ s. Slow and easy response to pressure increase in suction. Alternative is to operate a lower control level in surge drum if pump circulation, or instal a bigger surge drum with a higher safety /surge volume.
Most of my lower temp system [ -40'C SST ] have a suction loss/super heat of 1.0 'C so any rapid loading, suction pressure changes are not allowed to happen.

[mbc]

in large system with one or more stage we have separator in suction line ( or surge drum) and separator could mounted in vertical or horizontal ( horizontal better than vertical) and in large system we use pumping system from separator to Evaporator .

in wet evaporator have you Expansion valve? are you sure

[mbc]

please mail your drawing it would be better to help you.

[Josip]

Just notice this thread....


Seems OP solve his problem, not coming back, good for him, for us will be nice to find out what happen i.e. what he did to stop liquid flood back ....

Best regards, Josip :)

[aham]

Maybe the plant was oversized and heat load was not large enough to effectively evaporate enough liquid. If it is pump recirc, then maybe decrease recirc rate.