pressure reduction & desuperheating

[vrl3]

Dear Expert,

We are facing the problem of reducing the steam conditions of 6 ata 200°C to 0.5 ata 80°C. Do you have any soluion other than a PRDS valve.

Some people use the word dumping device, please advise.

Regards

vrl3

 

[UtilityLouie]

If the flow requirements are constant there are many options, but all with require some type of desuperheating. One option is an oriface plate or some other type of restriction size to reduce pressure at a constant flow. The problem with this is that you have absolutely no control over them.

Why is the PRDS the only option? A control valve with a separate desuperheater is cheaper than a PRDS and does the same job. Some people may argue that a PRDS does a better job of desuperheating and that they can handle high pressure turndowns, but I think that all valves have the same problems. If you are being pushed into a PRDS, push back a little and see why. The reason that manufacturers still make desuperheaters is that they work too.

I have never heard of a "dumping valve", but I would guess that some desuperheating would be required with this type of system.

If you could elaborate on why you are looking for something other than a PRDS that may help get some more detailed answers.

 

[rewatson]

If you need power, you can use a Back Pressure Steam Turbine and do some cogeneration. Pay back period would be from 9 to 24 months.