single stage multihole restriction orifice plate.

[tushar13]

Can anyone guide me on single stage multihole restriction orifice plate??
As per my knowledge, it is used to reduce the noise level which will be created if we use single hole single stage orifice. Please correct me if wrong.
I want to know how to design a single stage multihole RO plate??
Can we apply the logic of calculating the hole dia for single stage & then distribute the area in number of small holes ??
Also I want to know, how will be the placement of the holes on the plate ?
Is there any standards evidence for the design ?

 

[dgallup]

How about some clues about what you are doing so this isn't another game of 20 questions?

Pressure, temperature, fluid, flow rate, etc?

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[georgeverghese]

Try the book " Flow measurement " by Miller to see if there is design guidance on this. Yes, these are used as low noise restriction orifices. Another way is to use several single hole RO connected in series. The thickness of the plate has to be good for the full diff pressure across it, and plate thickness has some effect on the discharge coeff.

 

[tushar13]

Sorry, I for the delay in reply.

Process parameters as under:
flow : 170. Nm3/hr, Inlet pressure : 40 bar(g), temperature: 40 deg C,
Service : Air.,.

Need. to drop pressure from 40 bar to 5 bar.

If we drop pressure in single stage, noise is getting generated. Hence we suggested to go for dropping the pressure in stages.
Connecting the multiple RO plates in series.

Client doesn't want this option.
He wants to drop the pressure in single stage only that too with less noise.
Hence the option is of Single stage Multihole orifice plate.

 

[roydm]

I would just calculate it as a single hole then drill the equivalent area in small holes perhaps erring on the lower side, it's a restriction Orifice, not some fancy measuring device, if you get too much pressure drop just whip out your handy electric drill.

Don't over-think it.

 

[tushar13]

I applied the same logic of dividing the single hole area into equivalent area in small holes.
But what about placement of holes ?? noise calculation across the plates ?
many claim that the noise across the multihole RO plate is much lesser than that of single stage RO. But what is the value ? How to arrive at the noise level ?? Can I have some reference to calculate the noise across this plate??

 

[georgeverghese]

No one in your company has the Miller book?

 

[tushar13]

Dear georgeverghese

I am in the process of purchasing the Handbook. I shall own it very soon.
But is is this type of plate referred in the book ??

 

[georgeverghese]

All I know is that this book was popular with instrumentation engineers in one of the companies I used to work in many years ago.