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subhranshshekhar
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Reciprocating Compressor

02/23/2009 3:59 AM

Why the clearance between the piston and cylinder in the top dead centre side of a reciprocating air compressor is maintained more than the clearance in the bottom dead centre
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user-deleted-1104
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#1

Re: reciprocating compressor

02/23/2009 6:31 AM

Hello

You are right. But this gap is higher only before compressor start. Due the gas compresion the temperature of it is increasing, also the lenght of piston rod is modified and the both gaps become balanced. For this reason the clearance between the piston and cylinder in the top dead centre side of a reciprocating air compressor is maintained higher than the clearance in the bottom dead centre, but only before machine start.

Hope this help

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betomachine
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#2

Re: Reciprocating Compressor

02/24/2009 10:53 AM

I guess you are talking about the difference between the head-end clearance and the crank-end clearance of the compressor eh? It is a GA for the poster previous to this as I imagine it is for the piston rod growth once the compressor heats up during normal operation.

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U V
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#3

Re: Reciprocating Compressor

02/24/2009 11:38 AM

Or more simply put the efficiency is related to how close you can get the piston to the head. If you don't allow for thermal expansion they will strike each other.

The bottom dead center and side clearance are mostly improved by thermal expansion.

Brad

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