steam pressure reducing from 180psi to 80psi

[semfoss]

At our plant we use our boiler as a heat transfering energy. my problem is we max out our boiler when we have a full load and i have an idea of fixing it if it works. we used to go to 150psi on our boiler which heated our railcars fairly well over a 24 hour period but we decided to try new things to reduce the cost of natural gas its been out of the roof! so we went to 85 psi on our boiler our railcars dont heat as fast but our gas usage has been great! my idea is if we crank our boiler up to 180psi and use a steam pressure reducer to 80psi. our boiler will easily put out 80psi without using alot of fuel and keep its pressure at 180 saving gas and still having our temp in the steam correct? basicly creating a super heated steam. so will we save money and heat our railcars faster? or will this back fire? my thinking is take a air compressor if its at 150psi and open the valve wide open it drains the tank and the pump is trying to keep it at 150 but if you crack the valve it takes longer and the pump dosent work hard to keep the pressure. now putting that in prospective of a boiler would it be the same? and still have the heating properties.

 

[waross]

If you have problems with superheated steam for any reason, you can de-superheat by injecting water into the steam. It is fairly simple and cheap.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[stgrme]

Generating steam at higher pressures requires more heat input, not less. Therefore, higher pressures mean more gas consumption. Saturated steam enthalpies for the pressures you cited are:
80 psig - 1186.2 Btu/lb
85 psig - 1187.1 Btu/lb
150 psig - 1195.5 Btu/lb
180 psig - 1198.0 Btu/lb
Assuming that the feedwater enthalpy remains constant, you can see that the heat input increases as the pressure is increased.

 

[semfoss]

but here is the catch would 180psi make a big enough impact on heating these railcars faster that we could turn the boiler off sooner than keeping it on longer in order to get these railcars up to heat at 80psi?