Page 253 - Boiler_Operators_Handbook,_Second_Edition

238 Boiler Operator’s Handbook

it. Today the cost of landfill space and the offset of better gallons of water consumed in a combined water and
flue gas cleaning systems has restored interest in trash sewer charge. It should be interesting to note that the
burning plants. It’s a unique boiler plant because you majority of that cost is for sewage treatment. I know
actually get paid for burning the fuel, a far cry from pay- a few localities where the rate is much higher, $15 per
ing for fuel. The cost of operating the plant, personnel, thousand and higher. A recent EPA estimate is $16.40.
and the continuous repairs required (like when you try Wise operators will address those costs and recognize
to burn an entire engine block) are covered by the value their contribution to the preservation of this invaluable
of the steam produced and the payments for processing natural resource.
the trash. I say processing it because there’s a consider- Major utility plants are doing something about
able amount of ash left over, around 10%, that’s usually it because water represents a significant cost to them.
returned to the county or city for placement in a landfill Where possible they’re using treated waste water (from
so what you’re doing is reducing the volume of trash sewage treatment plants) for make-up instead of fresh
they have to deal with. potable water. Despite the yuck factor there’s no reason
I’ve worked on boilers burning many other forms to question the quality of that water after proper pre-
of solid fuels including such unique materials as lami- treatment (see the section on water treatment) and the
nate trimmings and plastic bags. Almost any organic boilers don’t care what it may have been. PSEG’s power
material can be fired, the question is whether the source plant in New Jersey saves 10 million gallons of precious
of the fuel is consistent in generation of quantity and drinkable water each month by using waste water as
quality and how much it costs to prepare, handle, and makeup, saving more than thirty thousand dollars a
7
burn the fuel. If you have the opportunity to work in a month in the process. Sooner or later you will be work-
waste fuel plant you should realize that the cheap fuel ing in a plant that does it too.
has a lot of heating value and should be treated as if it It’s very important to understand what a gpm
was as expensive as any purchased fuel. If you don’t is worth. I’ve discovered that many operators have a
burn the waste fuel efficiently then any deficit has to be change in understanding once they do the math them-
made up with purchased fuels. selves. What is a gallon per minute worth? First, it’s a
Know your fuel, know what the fire looks like good idea to know that a minute doesn’t give us a fair
when it’s burning normally and get real concerned measure of the cost. There are 525,600 minutes in a year,
when it isn’t normal. Keep in mind that how the fuel is more than half a million. A two gallon per minute leak
stored and handled on its way to the burner can have an that we allow to continue represents more than one
effect on plant safety. million gallons wasted every year. At the low range of
water costs a one gallon per minute leak costs $1,500,
what some people consider minimal. I don’t consider
WATER such waste minimal. When you consider the fact that
half a million gallons of clear fresh water was converted
I consider a major problem with most Americans to sewage that leak is very expensive.
is their attitude about water. As a consumable water is I’m always objecting to something I see regularly, a
not an unlimited resource. Despite a recent three year boiler water sample cooler operating constantly. I know
drought in the Northeast I find my friends and neigh- that it takes a few minutes to clear lines and tune up a
bors still acting as if there was an unlimited supply of sample cooler each time you draw a water sample and
potable water. Continued growth of the human popula- a little more time to close the valves when you’re done.
tion will constantly expand the demand for fresh water It’s also easy to argue that the boiler water would be
and, like it or not, we’re dangerously close to conditions removed by blowdown anyway. However, the typical
of real water shortage; first a shortage of drinking qual- sample cooler uses about 12 gpm to cool a boiler water
ity water. sample and leaving it running constantly wastes over
A boiler plant has the potential to draw on, and six million gallons of water every year and costs at least
waste, millions of gallons of water each year and some $18,000 per year to convert good water to sewage. Don’t
plants consume and waste those millions in months or do it.
even weeks. I consider it regrettable that we place such Recycling the water in a boiler plant is becom-
a low value on water. I hope that’s beginning to change. ing increasingly important. Some utilities are actually
In the Baltimore metropolitan area we’re charged some- committed to zero discharge, where they don’t put one
thing in the range of three to four dollars per thousand gallon of waste water into the local municipal sewer