8 replies to this topic

[omara2000]

hi every one ,

                   really i am surprised  and interesting in this site as  i have  great useful information and experience we have large problem in propane refrigeration plant , we have lost the oil continuously in the oil separator as indicated bt  level transmitter and level glass  which ensure this actually  . we make up  oil to the separator to compensate  the this loss and start the compressor the problem repeated again ,this  is due to the large carry over for the oil from the oil separator  or what .please  how can you see this problem     

[omara2000]

are not there any replay 

[Art Montemayor]

 

You say you have “great useful information” and that is exactly what we need in order to help you out with our members' experience on this Forum.  We need such information as:

1. A P&ID of your propane process; if this is not available, then at least a detailed flow diagram that you can sketch;
2. A description of your compressor.  Is it a screw, reciprocating, or centrifugal?
3. If a screw, is it flooded with oil?
4. What type of propane vaporizer are you using?
5. Who designed and built your unit?
6. What is the size or capacity of the unit, tons of refrigeration or Btu/hr?

Await reply.

[omara2000]

Mr Art 
this unit used oil flood screw compressor
the propane vaporizer is kettle
 the capacity is 1500 KW
the problem appear recently by loss of oil and activated LSLL in oil separator which confirmed with level glass

[omara2000]

 pfd.docx   93.49KB   28 downloads

[Art Montemayor]

The answer to why the oil is "disappearing" is very simple.  It isn't disappearing; it is probably in the kettle type of evaporator that you are using.  If I am not mistaken, you are putting the liquid propane refrigerant in the shell side of the kettle unit.

 

Your problem is one that many operators of oil-flooded screw compressor are facing every day when they are using a screw compressor package designed and assembled by a very inexperienced or poorly operated compressor packager.  I don't know where you are located or where you bought your package, but I suspect that it is not from a leading, experienced and recognized packager.  The use of small oil separators, badly designed instruments and cheap oil level detectors and instruments is very prevalent among some packagers in order to be more "competitive" in pricing.   This leaves the end user with a poor design that operates very badly in the field.

 

As I state, I believe your lost oil is going to be found accumulated in the kettle evaporator.

[Geordie87]

I echo Art's reply. I have hit this problem a number of times. Get a better separator.

[omara2000]

dears you mean that not better separator, not better sizing  for separator or not better performance 

[Art Montemayor]

What I mean is that the loss of sealing and lubricating oil in an oil-flooded screw compressor is not to be taken lightly.  It is a very serious probem and can cause great harm to your system.  That is why I recommend you identify the source of your obvious problem.

 

To find the source of your problem, find where your oil has disappeared off to.  If, in fact, you find that the oil has accumulated in your kettle evaporator, then you definitely know that your oil separation system is not working correctly.  It that is the case, immediately contact your supplier of the refrigeration system and demand a solution to this very critical problem.

 

You cannot simply contiue to add "make-up" lubricating oil to the system.   If I am correct, this will agravate your heat transfer in your evaporator to the point that you will not be able to refrigerate due to the oil fouling there.