11 replies to this topic

[mbsahg]

Hello~

 

I am trying to design compressor for MVR.

This design condition is below;

 

1) Inlet pressure: 2.3kg/cm2g(at saturated)

2) Outlet pressure: 15kg/cm2g(without aftercooler)

3) Flowrate: 3ton/hr

 

I think that the compressor is needed two stage. And I am to want about optimum(or recommend) compression ratio.

If there is the value, I will be simulating according it.

 

Thank you for reading.

Edited by mbsahg, 27 April 2015 - 06:02 AM.

[Bobby Strain]

What is MVR? And what is the gas?

 

Bobby

[fallah]

mbsahg,

 

Yes, i think it needs to be designed in two stages. As far as i know, equal compression ratios across the first stage and second stage will result in optimum ones, as in your case is to be 2.2

[mbsahg]

What is MVR? And what is the gas?

 

Bobby

Hello, Bobby

 

It is 'Mechanical vapor recompression'.

Column overhead condenser(air cooler) will replace to steam generator in order to recovery waste heat.

And the steam is compressed to make M.P steam._M.P steam header pressure is 14kg/cm2g.

 

Have a good day.

[breizh]

hi ,

Consider reading the document attached .

Good luck.

Breizh

[mbsahg]

mbsahg,

 

Yes, i think it needs to be designed in two stages. As far as i know, equal compression ratios across the first stage and second stage will result in optimum ones, as in your case is to be 2.2

 

Thank, fallah

 

I am known to keep equal compression ratios for you.

There is a question for compression ratio.

What is the range of the compression ratio?

If the value know, Compressor stage is decided it.

 

Thank you for reading 

Have a good day.

[mbsahg]

hi ,

Consider reading the document attached .

Good luck.

Breizh

Thank, breizh

 

It seem to be good document. I am going to read it.

 

Have a good day.

[Bobby Strain]

You will likely find this to be a difficult application. And expensive. MVR is usually applied with a low pressure evaporator and a single stage compression with a rotary compressor. It's unlikely that your project will improve your cost. Let us know how it turns out.

 

Bobby

[PingPong]

There is a question for compression ratio.

What is the range of the compression ratio?

If the value know, Compressor stage is decided it.

Compression ratio as such is not an issue.

 

What normally sets the maximum compression ratio of each stage is the maximum allowable discharge temperature of each stage. So the first stage compresses to that allowable temperature, then there is intercooling, and then the second stage, et cetera.

 

If I understand you correct, you have saturated steam of 2.3 kg/cm²g and 136 ^oC, and you want to compress that up to 15 kg/cm²g ?

But with steam you can not have intercooling between multiple stages because that would condense it all.

 

So what you want to do is not feasible, in my opinion, because you would need a single stage compressor (without interstage cooling) and that would result in a very high discharge temperature that would be a problem for any compressor.

[mbsahg]

 

There is a question for compression ratio.

What is the range of the compression ratio?

If the value know, Compressor stage is decided it.

Compression ratio as such is not an issue.

 

What normally sets the maximum compression ratio of each stage is the maximum allowable discharge temperature of each stage. So the first stage compresses to that allowable temperature, then there is intercooling, and then the second stage, et cetera.

 

If I understand you correct, you have saturated steam of 2.3 kg/cm²g and 136 ^oC, and you want to compress that up to 15 kg/cm²g ?

But with steam you can not have intercooling between multiple stages because that would condense it all.

 

So what you want to do is not feasible, in my opinion, because you would need a single stage compressor (without interstage cooling) and that would result in a very high discharge temperature that would be a problem for any compressor.

 

Thank, PingPong

 

Target of the MVR system is to produce M.P steam(14kg/cm2g, 286.7℃) in order to supply header.

The steam flow rate is 30ton/hr.(3ton/hr is my mistake from typing.)

I think to get a centrifugal compressor.

Maybe it isn't possible to make required pressure(15kg/cm2g)with centrifugal compressor from one stage compressor.

And I am designing to install desuperheater between first stage and second stage in order to reduce temperature.(It is like intercooler.)

But there is a problem:  The flow rate of BFW of desuperheater is very small.(about 100~200kg/hr)  

Therefore, I think that isn't feasible.

 

Thank you for reading 

Have a good day~

Edited by mbsahg, 29 April 2015 - 12:10 AM.

[PingPong]

When the flow is 30 t/h (instead of only 3 t/h) allowing use of a centrifugal compressor it may be feasible to produce M.P. steam of 287 ^oC.

 

Atlas Copco states that discharge temperature can be up to 300 ^oC with their centrifugal machines:

http://www.dwa.nl/wp...Atlas-Copco.pdf

[Bobby Strain]

Well, you should proof read your queries before you post them! It's all in the details.

 

Bobby