How can I make a refrigeration device with a slip stream off a 12" natural gas line @ 12lbs 200F?

Question

I need to cool the suction side of my 8M blower to keep it from cycleing on high temp 235F. Can I use a slip stream from the discharge side to run a refrigeration device to run the suction side gas through to keep my temps down if so how do I get the gas back to my discharge side

I was thinking about driving a turbin which turned an AC unit which ran refrigerated fluid through a radiator through which the hot gas passed

Answer 1

You really can't accomplish what you want with 12 psi gas. There isn't sufficient pressure differential. Also you will need a compressor to recompress the slip stream to return it to the system.

You haven't really provided sufficient detail to allow a good answer. It appears you are running a centrifugal compressor on recycle all of the time. Can you throttle the discharge (or suction)to help reduce the capacity

Even if you use a turbine, the pressure differencial is so small the turbine would have to be very large and you would still need to recompress the gas or waste it. As someone else has suggested, you might consider a new wheel design.

Answer 2

If I understand your question, you want to use the discharge gas to run a refrigeration system to cool the inlet gas of the blower?

If that is the question then yes you can, depending what the load demand will be, you can either use a natural gas engine connected to a highspeed gear that drives a refrigeration compressor such as a screw compressor. The inlet gas would now first pass through a chiller barrel cooling the gas down to what ever temp you desire prior to entering the blower. You can also use a Turbine to drive the compressor.

Depending on how much of a load (BTU's) you will have, you can also build a small refrigeration system that chills water, the water then can be circulated through a heater exchanger that is in the sution line of the blower.

Answer 3

A refrigeration device sounds very costly and would need to be properly engineered for safety reasons. Could look perhaps at a re-engineered impellor or new blower if design conditions have changed. What is the design max discharge temperature of the blower? (235F doesn't sound that bad) Recycling may be normal when pressure is high in the discharge system to protect the blower from surging. I would expect to see some kind of cooler (air or water) in recycle line. Sorry meaningful comments demand looking much more closely at system and doing sums.

Answer 4

You can use the natural gas as a heat source to drive a lithium bromide refrigeration system. These systems are very good at using low value heat sources to produce chilled water coolant. They are very common in building cooling systems.

Also, the same thing can be done using an ammonia refrigeration system. They used to make refrigerators that used natural gas as the primary energy source, but they were phased out as motor efficiencies improved.

Look into the lithium bromide system.

Answer 5

A vortex tube is a possibility, although the low pressure may be an issue. Reference below.