Water heater for Domestic Hot Water Z-BIS type for oil or gas boilers

Aplication:

Z-bis
full protection against legionella

1. European Patent Office – PCT/PL02/00068
2. International number – WO 03/09/681681A1
3. Polish Patent Office RP-W-113164
4. Owner A.Sadowski

The water heater Z-BIS type has been designed for producing Domestic Hot Water (DHW) in gas or oil boilers. Z-BIS removes problems with economic supply of water from boilers. Thanks to the Z-BIS we have stability of temperature, simple service and effective avoid the risk of legionella.

• Demanded temperature of supply water – 70°C.
• Constant outlet temperature 60°C and 55°C for DHW without increase temperature of heating water up to 90°C in rush hours.
• Small dimensions and big efficiency.
• Effective avoid the risk of legionella.
• Adequate cooling of returned water below 57°C, it ensures good cooperation with condensed boilers.
• Lower cost at high demand for DHW than application several other water heater.

In oil or gas boilers are used old type capacity water heaters with a coil of pipe. This solution demands higher temperatures (up to +90°C) for ensuring required temperature DHW at rush hours. Improving efficiency by adding capacity water heaters is not economic solution. The solution of this problem is the water heater Z-BIS. In this water heater Z-BIS has been used modern plate heat exchangers witch cooperating stabilizer SWC-BIS. At this device thermal power maybe from 70 to 780 kW and it is required for produce DHW at temperature +60°C from 1200 to 13800 l/h. Demanded temperature of heating water is +70°C, so increasing the temperature up to +90°C is not necessary, on the contrary like in capacity water heaters. Thanks to constant temperature of outlet water +60°C is ensured full protection against bacteries of legionella. The bacteria can cause a broad spectrum of disease from mild cough and fever to serious pneumonia. The bacteria may be traced in water supply, central heating and air conditioning systems. Any water system with operating temperatures between 20.5°C and 50°C is a potential legionella source. The legionella bacteria cannot survive water temperatures above 55°C for more than five or six hours. General protection against the bacteria can be achieved by designing an operating water temperature of at least 60°C. At application the Z-BIS regularly cleaning, heat and chemical treatment are not necessary to avoid potential development of the bacteria.

Principle of operation:

Cold water flows trough magnetic strainer (16) and here has been cleaned. After this water is mixed with water from a circulation pump (3) and flows to heat exchanger (2). In the stabilizer SCW-BIS (1) is mixed heated water with returned water from DHW. The flow factor is steering by the procesor with the sensor mounted in the stabilizer DHW. Circulation pumps (3,4) keeping constant temperature in vessel (1).

Construction of water heater Z-"BIS"

Z-BIS                             MP module
1. Stabilizer ZCWS (286l)         11. Automatic air vent
2. Heat exchangers                12. Supply pump
3. Internal circulation pump      13. Supply from boiler
4. DHW circulation pump           14. Return to boiler
5. Pressure gauge                 15. Cold water supply
6. Temperature sensor             16. Magnetic strainer
7. Hot water cicrulation          17. Expansion vessel:
8. Circulation pipe               18. Filter
9. Safety valve
10. Supply of DHW installation
11. Automatic air vent

Technical data: