Reducing Energy Cost Through Boiler Efficiency – Crown Jakarta Management

Boiler Efficiency – Why is it important?
·          Cost of boiler fuel is 2.5–3 times higher than 4 years ago and continues to rise.
·          May be the highest single feed manufacturing cost??
·          Competition knows it is important!!
·          Company feed mill managers
·          Agri-stats
·          BOSS wants lower costs!!!
Boiler Efficiency
·          Input Energy
·          Fuel oil
·          Natural gas
·          Propane
·          Output Energy
·          Process Steam
General Boiler Information
·          1 boiler horse power = 42,000 BTUs of INPUT
·          1 pound of steam =1,200 BTUs of INPUT fuel
·          Typical boiler efficiency = 75-85%
·          New high efficiency near 90%
·          Fuel sources:
·          Natural Gas = 1,031 BTU/ft3
·          Propane = 91,000 BTU/gal
·          Fuel Oil = 139,000 BTU/gal

A Fable
A feed mill manager once went to a wise man for help in improving his inefficient, unprofitable feed milling operation. The wise man wrote a charm on a piece of paper and sealed it in a box that he gave to the manager.
“Carry this box into every part of your mill three times each day for a year,” he told him. The mill manager did so.
In the morning he carried the box and its charm into the warehouse and found a laborer fast asleep on a pile of sacks instead of working. At noon, he carried it up to the milling floor, he noticed a leak in a spout that was contaminating a bin of grain. He also spotted a hot bearing and called a mechanic to grease it. At night, he carried the box to the packing room and found his employee overfilling the bags.
Everyday, as he took the box and its charm from place to place in the mill he found things to correct. At the end of the year, he returned the box to the wise man.
“Let me keep the charm for one more year,” he begged. “My mill is more efficient and more profitable than it has every been before”
The wise man smiled and took the box. “I’ll give you the charm itself,” he said. He broke the seal, lifted out the piece of paper and handed it to the mill manager.



Boiler project at treatment plant paying dividends



APPLETON — A new boiler system installed in 2011 at Appleton’s wastewater treatment plant is paying dividends for taxpayers, yielding $300,000 in energy savings annually.


The $1.2 million methane system captures the byproduct of the bacterial breakdown of sludge to operate the boiler and heat the rest of the plant.


The plant’s natural gas bill — which previously averaged $453,511 a year — dropped to $140,938 in 2012 and the savings are expected to continue annually.


“Overall our billings for natural gas have been reduced by two-thirds,” said Chris Shaw, Appleton’s utilities director. “It was a good project and the payback is less than four years. It’s a very good deal for Appleton residents.”


The methane boiler system heats the 38-acre facility’s 19 buildings and tunnel system. On very cold winter nights, the plant relies on the old natural gas system to supplement the methane boilers. While natural gas has an energy value of 1,000 Btu per cubic foot, methane produces about 650 Btu, Shaw said.


The wastewater treatment plant has two giant egg-shaped digesters. The tan Teflon and fiberglass tanks — which are easily recognizable along the Fox River — each hold 2.2 million gallons of sludge that go through an anaerobic bacterial breakdown.


“They both have to be heated up to 95 degrees so regardless of time of year, we’re constantly heating those vessels and the material,” Shaw said. “In the winter we’re fortunate to have some residual gas to heat the facilities as well.”


The “waste solids” start as a thick cottage cheese consistency before they are broken down over 40 days to the gas and tomato juice-like liquid.


The methane gets piped into a boiler room, where it’s burned. That heats water that is circulated throughout the facility. Excess methane is flared off in two stacks that can be seen from the river.


After the full process is complete, the plant returns more than 5.8 billion gallons of treated water per year to the Fox River — enough to fill a 20-foot deep lake covering 900 acres, or just about fill Little Lake Butte des Morts.


“Most people flush the toilet and think it ends there but there’s a big process down the line,” said Parks, Recreation and Facilities Director Dean Gazza.


Storing 500,000 gallons of methane yields energy savings, but creates some safety concerns.


Strict no smoking policies went into effect at the plant after the boiler system was installed to prevent a fire.


If a fire breaks out at the plant, firefighters would be kept out until the methane could be vented below a certain “explosive limit.”


“We’re obviously very careful and have a lot of monitoring sites that would alert us to any elevated levels or leaks,” Shaw said.