Here are highlights of the technical details about our Sidel Condensing Economizers. We’ll also explain how our products can help meet your energy-efficiency goals and provide your organization with the greatest ROI possible. If you would like more details or have any questions, we invite you to contact us. There’s never any charge or obligation when you call. We would love to hear from you, so be sure to contact us today with any questions or comments.
The SRU FLUE GAS CONDENSING ECONOMIZER heat recovery unit is designed to recover almost all of the waste energy from the forced draft heating unit, and turn it into usable heat. The waste flue gases are redirected through the SRU Flue Gas Condenser unit, which is placed beside the boiler or heating unit, or alongside the chimney. This placement ensures that no condensation can get back inside the appliance to cause corrosion. The SRU recovery unit is designed to cool the flue gases to the point where the sensible as well as the latent heat is recovered.
The SRU FLUE GAS CONDENSER is a double-walled, finned-tube heat exchanger. The hot waste flue gas is diverted into the bottom receiver of this unit which then flows upward through a series of specially designed stainless steel and aluminum finned tubes. The water that is being heated flows on the inside of these stainless steel tubes. The SRU series is designed so that the waste flue gas temperatures can be lowered well below the water dewpoint (58°C/ 136°F) temperature. There are times when the exiting flue gas temperature can be below the outside air temperature.
NATURAL GAS FACTS
Each pound of natural gas has a heat value of approximately 22,000 BTUs. When natural gas is combusted, each pound of gas produces about 2 pounds of moisture (steam) with a heat value of 2,400 BTU. Therefore, the BTU’s lost during combustion of a pound of natural gas is about 11%.
POTENTIAL SAVINGS WITH SRU WASTE HEAT RECOVERY
For a typical 100 HP natural gas fired boiler, operating with an exhaust gas temperature of 410°F and 15% excess combustion air the efficiency is approximately 80%. The fuel input is 4.2 million BTU/hr, and 20% of the fuel’s total energy is available for recovery. By incorporating a SRU waste heat recovery system to produce 104°F water, about 15% of the fuel’s original energy can be recovered. If the boiler operates for an equivalent of 6,000 full load hours per year, and natural gas costs $1/therm, the annual savings realized from our waste heat recovery system would be: 4.2 M BTU/HR x 15% x 6,000 hrs/yr x $ 10.00/M BTU* = $37,629. We are confident your organization can find something to do with that extra money every year.
*1 M BTU = 10 therm
The key to the successful application of heat recovery is the ability to put the recovered heat to use. Two primary uses for recovered heat are domestic water heating and space comfort heating. Other uses include laundry wash water, industrial process water and district heating systems. This technology can benefit Hospitals and Health Centers – Food Processing Plants – Schools and Universities – Laundries – Breweries – Hotels – Wineries – Government Buildings – Swimming Pools – Textile Plants – Pulp and Paper Facilities, Greenhouses and other large buildings.
Condensation is created from the flue gases when the temperature falls below the dewpoint. The lower the flue gases can be cooled, the higher the performance efficiency of the Sidel SRU Waste Heat Recovery Unit. When the temperature of the waste flue gas is reduced below 133F, condensation occurs. The SRU condensing economizer is designed for natural gas or propane fired equipment only. When the heating appliance is required to operate on oil or other fuels, the flue gases must be bypassed from the Sidel Waste Heat Recovery Unit. The vertical construction of the SRU waste heat recovery unit makes for the best possible use of available space. This design also allows the condensate to flow down from the top rows of tubes in the recovery unit, providing a complete self-cleaning action of the aluminum fin tubes. Our units require minimal maintenance.
The SRU waste heat recovery unit has a large gas-side heat transfer surface of aluminum fin tubes. Pure aluminum is an excellent heat conductor; it is also exceedingly resistant to the mildly acidic flue-gas condensate. The aluminum fin tubes are fitted around a stainless steel tube. Stainless steel is used to prevent corrosion on the waterside surface. Compared to other materials, stainless steel will not allow the build-up of iron particles on the inner tube surface, which would act as an insulator.
FLUE GAS RESISTANCE
Because of the high conducting properties of aluminum, the fins on the heating tubes are very thin. This allows more room for the flue gases to pass through. The result is an optimal ratio of the flue gas flow with respect to the fin surface area, which keeps the resistance low on the flue gas side. Because there is only a small increase in the flue gas back pressure, in most cases the heating appliance is still capable of moving the exhaust gasses through the Sidel SRU unit using its existing combustion air fan, without requiring any additional fan capacity.
The Sidel SRU standard sizes are for equipment with inputs from 2 million to 42 million BTU per hour, with larger custom-designed units so far up to 1,680,000,000 Mmbtu/hr. All units are constructed in accordance with ASME codes.
Sidel benefits include increased system efficiency (typically 90-95%) – energy savings (typically 10-15%) – relatively short payback – easy installation, low maintenance – reduced particulate, water vapor and noxious gas emissions – reduced stack noise emission – operates over a broad range of equipment conditions – computer-aided design (to ensure optimum sizing) – computer-aided investment analysis – 7-year limited guarantee.
Want to find out how much money we could save you?
Contact us today for your FREE, No-Obligation Savings Analysis. With a little technical information about your heat source and potential energy application, we can show you just what a SRU waste heat recovery unit can do to reduce your company’s operating costs. There’s nothing to lose and so much to gain, so please call, email or fax us right away!