When high volumes of hot water are needed, Thermal Engineering’s “SUPERHEATER” Direct Contact Water Heater should be your first choice. The near 100% energy efficiency can provide the most economical water heating costs. Traditionally, water heating has involved transferring all the heat thru one or two metal walls. Water quality, fouling, rust, etc, all combine to reduce the efficiency of the heat transfer process. The result is an exhaust stack gas temperature many hundreds of degrees above that of the incoming water to be heated. Direct contact water heaters have ended these problems! Since their commercial introduction during the energy crisis years of the seventies, thousands of these heaters have been installed and have resulted in unmatched levels of performance.
THIS IS HOW THE “SUPERHEATER” WORKS
When heated water is needed, the natural gas burner is started which generates large volumes of hot gases. These gases enter the lower heat transfer chamber and start moving upward thru the “packed mass” heat exchanger. At the same time, cold fresh water starts flowing thru the distributor, onto and downward thru the torturous path of the packed mass heat exchanger. The large surface area of the packings causes the water to spread out into a very thin film. The hot gases traveling upward through the packings readily releases its heat to the water film which rapidly raises its temperature. Just as quickly, the hot gases cool. The efficiency of the heat transfer is dramatic - the hot gases are normally cooled to within 10 or 15 degrees of the incoming cold-water temperature before discharge into the exhaust stack.
The heated water trickles downward through the packed mass keeping it cool and protecting it from the high temperatures of the combustion gases. The water falls thru the lower heat transfer chamber where it picks up additional heat before going into the reservoir. A temperature sensor in the reservoir controls the burner to insure the proper amount of hot gases is generated to maintain the desired hot water discharge temperature.
THE ENERGY BONUS
How can the “SUPERHEATER” claim near 100% thermal efficiency? It’s done by “over-cooling” the exhaust gases. The normal combustion process of natural gas combines hydrogen and oxygen chemically to form water, which is instantly vaporized by the heat of combustion. This process absorbs heat and it is normally lost to the atmosphere with the exhaust gases.
The “SUPERHEATER” ends this loss!
As the hot combustion gases pass thru the packed mass heat exchanger, the gases cool so much that the water vapor in the combustion gases re-condense releasing the heat it took to vaporize it initially. It is a fact that about 12% of the total heat contained in natural gas is absorbed in vaporizing the water generated - and the“SUPERHEATER” RECAPTURES THIS HEAT.
STRUCTURAL COOLING: “The key to long heater life”
With the burner being able to generate hot gases of over 3500 degrees F, uncooled metal walls exposed to this heat can rapidly fail. Only TEA offers high velocity cooling jackets in the combustion zone on its Direct Contact Water Heaters. By precisely controlling the velocity of water thru special cooling channels, the temperature of the inner structural walls can be maintained near cooling water temperatures. This controlled wall temperature is the key to long heater life. Thermal stresses are controlled eliminating the resulting cracking and distortion so common in other heaters.
Actually, the cooling water also picks up a significant quantity of transmitted heat. And this cooling water is added to the water passing thru the combustion zone, further reducing the quantity of heat necessary to produce the desired final water discharge temperature. This SUPERHEATING further increases the efficiency of the TEA heater.R