Over the years I have learned to run from the word "free" when connected to my wallet. This is one time when free steam may apply in your facility.

Flash steam occurs when high pressure condensate is discharged through a trap to a lower pressure and is liberated as the condensate drops temperature by creating lower pressure flash steam. Water at 100 psig boils at 338 F. If the pressure drop to 0 psig, 13.3% of the hot water will be transformed into steam at 212 F. The process occurs in a flash of time, hence the name flash steam. Flashing always occurs and can be a source of free steam.



Let's look at an example and see if in fact we have free steam. In our example, assume a plant is making 10,000 lb/hr of steam at 125 psig. Let's further assume that they have use for 10 psig for an area in the plant such has heating hot water or other suitable use for low pressure steam. Lets assume the cost of steam is $ 15.00 per 1,000 pounds.



The flash rate from 125 psig to 10 psig is 12.3%. A steam flow of 10,000 lb/hr will generate 1,230 lb/hr of steam at 10 psig. If we were heating water, we could heat 24.6 GPM on a temperature rise of 100 F (e.g. 60-160 F). At a steam cost of $ 15.00 per 1,000 lb/hr, our free steam would have a recovery savings of $ 18.45per hour or if we assume 5000 hours per year of operation $ 92,250. A ball park estimate on the equipment to allow recovery of this flash steam to occur would be $ 50,000 - $ 60,000. Payback time including installation would be well under one year.



To qualify for free steam your primary steam pressure should be at least 75 psig and you have a requirement for low pressure steam in your facility. This requirement could range from pre-heating boiler feed water, process hot water, domestic hot water, and other applications which can use steam in the 5 to 30/40 psig range. If you doubt the math, take a tour of your roof and check your condensate roof vents. If you see lots of vent steam, maybe we can convert it to free steam. Give us a call for a specific evaluation of your facility.