US 3669351 A
A feed line leads from a water heater to a radiator and to a heat exchanger for domestic water. A return line has branches from both the radiator and the heat exchanger to a valve which communicates with the return trunk to the water heater.
Description (OCR text may contain errors)
United States Patent Meier et al. 51 June 13, 1972  CIRCULATION WATER HEATER WITH DOMESTIC HOT WATER SUPPLY [5 References Cited  inventors: Hans Meier, Remscheid; Fritlriof Carouge, UNITED STATES PATENTS Solingen, both of Germany 3,426,971 2/1969 Meier ..237/i9  Assignee: Joh. Vmllant KG, Remscheld, Germany 22 Filed; 7, 1970 Primary Examiner-Charles Sukalo [2 pp No: 62,054 A!t0rneyDarbo, Roberston & Vandenburgh  ABSTRACT  Foreign Apphcauon Priority A feed line leads from a water heater to a radiator and to a Sept. 9, 1969 Austria "8891/69 heat exchanger for domestic water. A return line has branches from both the radiator and the heat exchanger to a valve U.S. communicates the return trunk to the water [5 1 Int. Cl ..F24d 3/08 beaten  Field ofSearch ..237/19; 165/22, 50, 101, 35, 165/36, 37
1 Claim, 1 Drawing Figure CIRCULATION WATER HEATER WITH DOMESTIC HOT WATER SUPPLY BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a circulation water heating system having provision for domestic hot water supply. Through the use of a change-over valve, the water circulation is changed from a heating circuit to a shunt connection between the feed line and a return line by-passing the heating system and containing the heat exchanger of the domestic hot water supply.
In prior art systems of this type, the change-over valve is arranged in the feed line, i.e. the pipe directing the heated water from the water heater to the radiators of the heating system. See, for example, the apparatus of U. S. Pat. No. 3,426,971. It has been found that annoying water hammer occurs with this type of system during the changing over, i.e. when the flow of the radiator is closed at the start of the draw of domestic hot water. It has been found out that this water hammer is due to the closing of the water passage by a closing movement of the valve in the direction of the water flow. This has the result that the pump pressure and the kinetic energy of the flowing water supports the closing process. The valve closure abuts the valve seat suddenly, which results in a water shock in the heating system.
To avoid this undesirable phenomenon and based on the aforementioned discovery, the present invention positions the change-over valve in the return pipe in such a manner that the radiator portion of the system and the shunt connection are always cut off by a closing movement of the valve oppositely to the direction of the water flow.
DESCRIPTION OF THE DRAWING The drawing schematically illustrates an embodiment of the The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and said understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intented as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.
The heating system comprises a water heater 1 including a gas burner 4. A pump 2 forces the water through a trunk return line 3 to heater 1 and thence to the trunk feed line 5. The feed line has a branch 6 going to a heat exchanger for domestic water and then to return branch 6. Similarly, flow through feed branch 8 goes to radiator 9 and return branch 8'. The return branches 6' and 8', respectively, open into the change-over valve 10. Valve 10 has movable valve closure means which in one position opens a passage so the return branch 6' communicates with return trunk 3 (and branch 8 is closed off) and in the other position an alternative passage is opened so that branch 8' communicates with trunk 3' (and branch 6 is closed off). When closing, these valve closure means move oppositely to the direction of water flow. Thereby the disadvantage described hereinbefore can be eliminated.
1. In an apparatus for heating a radiator and a domestic water heat exchanger from a water heater including first means defining a feed line from the water heater with branches to the radiator and the heat exchanger, second means having branches from the radiator and heat exchanger respectively which join a return line to the water heater, and a change-over valve, the improvement wherein said valve is located at the point in said second means where the branches thereof join the return line, said valve always performing a closing movement oppositely to the direction of waterflow. =1: