Tuning your steam system for best results will lower energy costs, reduce water consumption, and lower your stack emissions.

Let's profile an average medium sized steam system and work with some formulas to see what is possible. Our sample steam system is as follows:

(2) 300 hp boilers operating at a 50% firing rate
Fuel to steam efficiency of the boilers is 77%
Primary fuel is natural gas at $ 10.00 per mcf
Back up fuel is number 2 oil at $ 3.00 per gallon
An electric boiler is being considered to cut oil use
The plant contains 100 steam traps
Condensate return is 30%

Using this basic information, a profile of the system is as follows (conversions bold face):

1 boiler hp = 34.5 lb/hr
2 x 300 hp x 50% firing rate = 300 hp on line
Steam produced is 34.5 x 300 = 10,350 lb/hr
1,000,000 BTU (mmbtu) = 1,000 lb/hr = 1 mcf (gas)
(10.35 mmbtu output) /.77 = 13.44 mcf input gas
Operating cost for gas = 10.00 x 13.44 = 134.40/hr
1 mmbtu = 7.29 gallons number 2 oil
(10.35 mmbtu output)/.77 = 13.44 mmbtu oil input
13.44 mmbtu # 2 oil = 98 gallons # 2 oil
Oil operating cost = 98 x $ 3.00 = 294.00/hr

If this plant operates 24 hours per day and 30 days per month, the cost of steam using gas would be $ 96,768 per month and $ 211,680 for oil. Small efficiency gains can save substantial dollars in a year.

Notice that operating costs for the energy source can vary by a significant amount for small changes in energy costs. Gas and oil prices can vary by quite a bit over the year so it is wise to pay attention to costs. With increasing pressure to lower emissions, you can expect energy prices to rise.

Steam traps last 3-10 years depending on brand, type, operating pressure and application. Expect 10-30% of your trap population to fail per year. A failed trap will waste 50 - 100 lb/hr of steam. Using our gas costs as an example, a single failed trap will waste $ 800 per month. A few failed traps can add up to significant losses very quickly.

An analysis of water use is as follows:

500 lb/hr (steam) = 1 gpm (water)
(10,350 lb/hr) / 500 = 20.7 gpm = 894,240 gal/month

With a condensate return of 30%, 625,968 gallons of water is being lost in the system per month. Failed steam traps and condensate return pumps are the primary contributors to low condensate return rates. Preheating the make up water to 200 F will cost $ 18,880 per month in extra fuel used.

A plant steam system can yield substantial savings in fuel dollars, water consumption, chemical savings, lowered emissions, and labor savings. In our sample plant example, a 10% improvement in steam system efficiency could save $ 116,121 per year and 60,000 gallons of water per month.

We can provide complete assistance in maximizing your steam system.