3 replies to this topic

[go-fish]

Hi,

I have a few questions wrt to steam condensate recovery.

1) What is the difference between an automatic pumping trap and pressure powered pump or are they same?

2) When should one use an automatic pumping trap or pressure powered pump (if same) as compared to conventional condensate pot and centrifugal pump arrangement?

My exchanger does not have a stall point and the condensate return back pressure is always higher than the HE steam supply pressure. The condensate load is about 9000 kg/hr

Edited by go-fish, 16 February 2010 - 06:22 PM.

[Art Montemayor]

Fish:

There is nothing magical or arcane about steam traps. All that is involved is a phase change in the saturated state. If the saturated pressure of the formed liquid ("condensate") is higher than the target of the same liquid, then one should be able to simply apply a simple steam trap - which is nothing too different than a common comode float valve - it displaces the formed condensate to the target using the saturated pressure as the driving force.

However, as in your described case, when you don't have sufficient saturated pressure to force the formed liquid to the target, then YOU have to furnish the driving force. This is conventionally done by using a common centrifugal pump (when the required driving force is within approximately 150 ft of TDH) or a positive displacement pump when the required TDH is higher.

I don't know what you mean by an automatic pumping trap or a pressure powered pump. I think I have an idea of what you mean, but without specific explanations I don't know. However, the difference can only be on how the driving force is generated - and that is sufficient information. Therefore, which system (or pumping device) you select depends on your needs, preference, requirements, and other basic data and scope of work which we don't have.

[go-fish]

In an automatic pumping trap and a pressure powered pump, the motive force is provided by steam or compressed air instead of elctric power. My question was are both of these same thing and basically different names used by different manufacturers and under which parameters should one choose these pumps instead electric pumps?

[Dazzler]

The two names or descriptors that you mention are most likely referring to the same equipment design type. They operate batch wise and automaticaly.

From my experience with such pumps, the advantages and applications of pressure powered condensate pumps: 1) Lower purchase and installation cost, 2) Suitable for hazardous electrical area (no motors and power cabling), 3) Lower flow duty, 4) Variable condensate inflow (ie from a heat exchanger with steam condensing in it), 5) When steady discharge flow is not necessary for downstream equipment and instruments and process operations, and 6) Can be placed more readily on floor level above ground level (as opposed to rotating machinery such as electric pumps that need solid foundations to minimise vibration and noise etc.

Hope this helps.

Dazzler