Water Heaters

TEA’S " Superheater"

The Ultimate in Direct Contact Water Heating

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 through 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.

How the SUPERHEATER Works

When heated water is needed, the gas fired burner is started which generates large volumes of hot gases. These gases enter the lower heat transfer chamber and start moving upward through the "packed mass" heat exchanger. At the same time cold fresh water starts flowing through the distributor onto and downward through the torturous path of the packed mass heat exchanger. The large surface area of the packing causes the water to spread out into a very thin film. The hot gases traveling upward through the packing readily releases its heat to the water film, rapidly rising 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 to 15 degrees, or less, of the incoming cold water temperature before discharge into the exhaust stack.

The heated water flows downward through the packed mass keeping it cool and protecting it from the high temperatures of the combustion gases. The water falls through 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 are 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 through 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 waste 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, un-cooled 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 through special cooling channels, the temperature of the inner structural walls are maintained near the actual water temperature. 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. This cooling water is added to the water passing through 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.

Exclusive "Flow Distributor"

The key to superior performance is to distribute the incoming water uniformly across the entire packed mass heat exchanger, regardless of flow rate or incoming water pressure. Only TEA uses a flow distributor to insure this happens. Our heaters can operate at any desired flow rate from 25% to 125% of rated output as required by process needs. 

Dozens of gravity orifices spread incoming water over entire heat exchanger. Flow can change from 25 to 100% of design for a true 4:1 turndown. Water pressure can be 0 or 100-PSI with perfect distribution. Booster pumps for limited spray nozzle range are never needed.

Key "SUPERHEATER" Features

1. Fully removable top. Full diameter access for internal servicing. Other heaters on allow access through stack ports, 18" diameter on heaters up to 200 hp.

2. Burner nozzle cooling. High velocity water cooling channels maintain inner liner at cooling water temperature. No expensive heat shields or burner shrouds are required. Competitive heaters with poor cooling use a failure prone heat shield, which requires periodic maintenance.

3. Combustion zone cooling. Computer designed high velocity combustion zone cooling. Metal temperatures never exceed 200° F with flame at 2600° F plus.

4. Inlet water distributor. Eliminates pressure sensitive spray nozzles – the major cause of heater shut down. Larger water droplets all but eliminate mist discharge from the stack. Excellent water distribution over packed bed through entire burner range. No flow rate changes due to nozzle restrictions or pressure fluctuations. Changing hot water demands – 100% down to 25% are easily handled automatically.

5. Fresh water manifold. Shipped fully assembled, tested and mounted. The control valve allow full range ability from high demand conditions (100%) to low hot water needs (25%) for a true 4:1 turndown ratio of plants flow-rate with full burner temperature control. Competitive heaters can only operate at rated water flows of the spray nozzle. A change of flow results in thermal cycling, a major cause of metal failure.

6. RECORDING FRESH WATER FLOW METER. Show GPM and total water used. Also insures minimum water flow for safe operation. Water pressure switches, a major cause of heater burnout, are never used.

7. Pre-Assembled transfer pump. For rapid heater installation.

8. SMART TOUCH CONTROL PANEL. The touch screen has the ability to completely operate and monitor the entire heater operation. Water temperatures, tank levels, heater output in BTU's, trouble shooting and alarm logging are shown. This system is standard a no extra cost.

"SUPERHEATER" Benefits

SMART-THERM Total Temperature and Flow Control

Water heaters, like steam boilers benefit greatly from modulating water and burner controls. Frequent on/off cycling of heaters causes thermal stresses that distorts metal, cracks welds, reduces efficiency and in general will shorten the heater life. "Smart Therm" eliminates this problem. Plant demands for hot water are matched with automatic flow controls valves. This smoothes out water make-up flow rates down to even 25% of full rated flows at the maximum temperature rise. No competitive heater can make this statement.

Smart Touch Control Panel

TEA’S Touch Screen Control Panel has the ability to completely operate and monitor the entire heater operation. Water temperatures, tank levels, heater output in BTU's, trouble shooting and alarm logging are shown. This system is standard a no extra cost. 

"SUPERHEATER" Sizing and Performance Data

     *Normal high fire output – turndown ratios of 4:1 are standard without modification

For more information E-mail: sales@teatucson.com  

or call us at: (520) 888-4000
Copyright by Thermal Engineering of Arizona, Inc. All rights reserved.