5 replies to this topic

[Mazfar]

We have a low pressure steam being wasted.

The pressure is about 350 KPA.The quantity is about 500 MTPD.

The steam is recovered if the pressure is about 400 KPA.

We cannot send to the header until we let down 500 MTPD and vent.

What are the typical ways of recovering it.

One option is to use thermocompressors.Do people use it for this purpose and these quantities.

[Art Montemayor]

Are you referring to gauge or absolute pressure units? It makes a big difference.

If you are talking about 350 kPag, then you have some attractive options - depending on your processing needs and operations. I can do a lot of things with 350 kPag. 350 kPaa might not be so attractive.

[Mazfar]

Are you referring to gauge or absolute pressure units? It makes a big difference.

If you are talking about 350 kPag, then you have some attractive options - depending on your processing needs and operations. I can do a lot of things with 350 kPag. 350 kPaa might not be so attractive.

Its 350 KPAG

[eilpar]

Since the difference is about 50 kpa is it possible to do optimise the upstream operation to get the steam at 400 kpag?

The 350 kpag steam has in fact application in deaeration, absorption refrigeration, evaporation, low temp heating etc.

In theory, a Thermocompressor and an Ejector are identical. The difference is in the application. Ejectors are used to produce a vacuum. Thermocompressors are used to entrain and compress a low-pressure fluid to an intermediate reusable pressure/temperature. So to boostup the pressure to 400 kpag perhaps HP steam (> 400 kpag) will be required.

Please check with a manufacturer to get the details.

Best wishes

PAR

[Satyajit]

I have seen people condensing 3,5 barg LP steam in condenser and recycling to Deaerator if there is no user. But here you loose the enthalpy to cooling water which is lost to the atmosphere with some additional power and cost.

Some plants send the steam to the neighbouring locality, offices ,restaurants for heating, cooking etc.

The best way to solve this excess steam in the plant is to review plant operation philosophy and switch turbine to motor or replace back pressure turbine to condensing turbine.

You are the best person to find out what are the best economically feasible and available options in your plant to stop the steam venting .

What type of plant you are talking here?

Good luck.
Satyajit

Little thoughts:

- Use the waste heat in a vapur absorption chiller and use for your plant chilling needs or HVAC. If you have any vapor compression system for chiller needs, you may replace them based on power cost advantages or supply chilled water to others.

- There are new power generators which can use this heat to generate power with some intermediate fluid. I have seen some literature, you may do internet search and find out.