Level Controll

[CHIEF DELPAC]

I have a gaugeomatic level controll on a low pressure receiver. The receiver is in low temp. NH3 service. The capacity is about 8000 lbs. of NH3. It is a pumped liquid system to four blast freezer evaporaters that are on a 3 to 1 overfeed ratio. The gaugeomatic uses mercoid switches which are no longer available. I hope within the next year to update or replace the column and the controll. I was wondering if anybody uses a Sporlan level controller? I would appreciate hearing from anyone if this idea would work or if there are problems that would rule out using a Sporlan Level Controll. Thanks C.D.

[Magoo]

Hi
I have used Hansen single point level controllers for years, very reliable and parts are available if required.

[RANGER1]

CHIEF DELPAC,
Are you refering to a levelmaster control or something else?

[mbc]

I use danfoss level control 38 E .
if you need information you well come.

[RANGER1]

CHIEF DELPAC,
Are you refering to a levelmaster control or something else?

I'll assume its a sporlan level master which are ok as is a modulating valve.
I could be wrong but doubt that you will get one big enough for what you want to do.

The valve also needs to be big enough to top up vessel when you turn a freezer on for example.

I think they are pretty basic & you will also have to instal high level/low level float switches
with it for plant protection.

There are a lot of more suitable controls to pick from with features to alter operating level if you like.

Most require a level probe & controller to operate it with control valve(ideally modulating as opposed to on/off operation).


Danfoss, Hansen, Parker

[CHIEF DELPAC]

Thanks for the info.fellow friggies. Ranger1 Your right the sporlan valve assembly would not have enough capacity. The reason I thought of using the sporlan valve is the way the sensor is positioned. The nh3 is contaminated with refrigeration oil. I am slowly recovering the oil. Meanwhile it is causing level control problems. That why I looking at an alternitive control system. Plus the fact that it is difficult to find Mercoid switches as they are no longer availible at the parts suppliers. C.D.

[sterl]

The capacitance probes tuned for R-717 are all fooled by an oil accumulation. At low temperatures and larger vessel movements, the probe will become filmed with oil over a considerable portion of its length and that really messes with the signal.

You need to pipe particularly the bottom connection carefully and support free draining of any oil from the liquid column to someplace else...an independent oil pot or even an extension to the liquid leg valved so that it acts like an oil pot. In some cases a 3" column is fed a trickle of refrigerant from the pumps to somewhere near the top; which will tend to keep the column itself from acting as an oil pot.

[JT4]

There is a new level sensor on the market that uses "TDR" technlogy not capacitance. It is unaffected by oil and is a simple cable style so you dont have to worrie about clearance above the vessel. This could be another option for you.

AKS 4100U