What Steam Pressure Do I require

[iyerm2]

Hi
How do i calculate how much of Steam Pressure I need at a heat exchanger to heat water at a flowrate of 12000l/h from room temp to about 95 degrees celcius?

Thanks in advance

 

[fegenbush]

The steam pressure required is directly related to the temperature of the steam required. The steam and the condensate will (ideally) both be at the same temperature and the energy transferred will be in the form of latent heat of vaporization (condensation).

The tricky part is that the higher the pressure, the lower latent heat of vaporization (condensation) per pound (or kg) of steam so the law of diminishing returns applies.

 

[SNORGY]

You also need to know your heat exchanger size and steam side pressure drop, or at least balance it against the required water (and steam) duty. You can do this with 14# steam if your exchanger is big enough. Usually, I suspect, you know the steam pressure available, so the required flow is derived from that.

Regards,

SNORGY.

 

[Latexman]

Do you know the quantity of steam (kg/hr) needed?

You may want to look at websites for steam traps, like Spirex Sarco. They have a lot of technical help documentation and on-line calculators.

Good luck,
Latexman

 

[willard3]

You're not giving enough information to help you.

Find someone where you work to help at least get the parameters of the problem.

 

[zdas04]

It is more common to treat steam pressure as a given and ask "what mass flow rate of steam is required?"

Your demand is Q=mc[Δ]T

Your steam mass flow rate is m=Q/(c[Δ]T) Pick a [Δ]T for the steam (which is different from your water flow rate) and you get mass flow rate (at 100% effeciency, you might want to add some steam for inefficiencies)

David

 

[ione]

The manufacturer of the heat exchanger should know this value. The heat exchanger has been designed to give a certain performance when fed with steam at a given temperature. For saturated steam a given temperature implies a given pressure (and vice versa). Usually and as already noted above the latent heat (enthalpy of evaporation) is exploited in the heat transfer process (unless superheated steam or live steam is involved in the process), and this is why a heat exchanger, fed with steam is fitted with a steam trap on its outlet. Who designed the heat exchanger must also have taken into account the pressure drop on the steam side. This is indeed a vital parameter as each steam trap is able to discharge condensate upon condition there's enough deltaP across it.