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[b]CONDENSATE RECOVERY USING PUMP-TRAPS[/b]

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gladkenn

Mechanical
Jul 25, 2004
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Can anybody enlighten me on the significance of using a pumptrap for our pasteurizer and bottle washer of beer paroduction? I am planning to install a pumptrap to be able to efficiently recover the condensate. Pasteurizer uses 1500 kg/hr steam while the bottle washer uses 3000 kg/hr steam on running load.
 
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In most bottle washing and pasturizing operations the steam has direct contact with the product and gets contaminated. Normally this condensate is not returned because of this and is just dumped.
If this is not the case, the pump (or pump/trap combination) will allow the process to work with zero back pressure and also provide additional pressure to push the condensate through the piping. This is especially usefull when you have low steam pressures or a modulating control valve on the steam inlet to the equipment.
 
In simple terms, when you fit a control valve on a process, as the valve throttles back due to low duty, the pressure after the valve naturally gets lower. In some instances, it can go sub-atmospheric.

When the steam has condensed, you obviously need to remove it. A steam trap would normally do this, but traps only work well if the condensate can fall back to the boiler feed tank by gravity (ie no back pressure)

Where gravity condensate recovery is not available, then a pumping trap can be used.

A pumping trap is a steam (or compressed air) operated pump. A set of interlocked valves allow the condensate to enter. Once the chest has filled with water, the inlet closes, the outlet opens and steam at high pressure (from your steam mains) forces out the condensate. This is pumped back to where you want it (i.e. to the boiler feed tank, or to waste or wherever you want it.

Pumping traps are mega bucks....2 to 3£K or more as opposed to a simple float trap at £200 say

Friar Tuck of Sherwood
 
I have seen this approach used in locations where water is expensive. Even the used condensate is cleaner than make-up water. So if filtration/RO is required before re-use it still saves money and water.
Watch the sizing. I know people tend to oversize equipment to be on the safe side, but this equipment will work poorly if it is not sized correctly.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
 
gladkenn, most all of these reponses are correct. the only other reason that has not benn mentioned is a condition called "stall". pumptraps are designed to overcome these problems. the problem usually rear their heads when a control valve is used on the process controlling pressures, and p1 is equal to or less than p2. in short, the pressure downstream is higher than the inlet pressure. goto "tlv" website to leasrn more about stall and pump/traps.

mogle
 
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