NZ270154A

NZ270154A - Boiling water heater connection tube removably connected to heater tank and expansion tank

Info

Publication number: NZ270154A
Application number: NZ270154A
Authority: NZ
Inventors: Raymond Dennis Massey
Original assignee: Zip Heaters Aust Pty Ltd
Priority date: 1993-12-16
Filing date: 1994-12-16
Publication date: 1996-08-27
Also published as: HK1011073A1; GB2285854A; AUPM302193A0; SG45252A1; DE4444940A1; GB2285854B; DE4444940B4; ZA9410044B; GB9425372D0

Description

27 0134 r ri crity Date(s): I h: Complete Specification Filed: ./.fa: Class: {£) Publication Date: 2.8..JUIG..199S j P.O. Journal No: ...I.UOl.

Patents Form No. 5 Our Reft JT204163 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION CONNECTION TUBES We, ZIP HEATERS (AUSTRALIA) PTST LIMITED, an Australian Company of 67 Allinghaa Street, Condell Park, Hew South Wales 2200, Australia, hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: PT0594676 (followed by page la) - to- CONNECTION TUBES This invention relates to pipes and other fittings used within tanks and other vessels. This invention in particular relates to pipes and fittings used in hot water heaters which provide boiling or near boiling water in kitchens, tea rooms, cafeterias, 5 etc.

With reference to Figure 1, which is a schematic representation of a conventional hot water heater, the heater and its associated disadvantages will be described. The major component of the conventional hot water heater 1 is a water heater tank 2 and an expansion tank 3. Cold water is supplied to the water heater tank 10 2 via water supply pipe 4 which is attached to inlet fitting 5. A backflow preventing valve may also be incorporated with this fitting 5. The water within the heater tank 2 is heated to boiling or near boiling point by heating element 6.

A conventional connection tube 7 is located at the top of the heater tank 2, and passes through the expansion tank 3. The connection tube 7 has a threaded upper 15 portion 8 for attaching an outlet pipe 9 thereto. The connection tube 7 has a central bore 10 providing fluid communication between the heater tank 2 and the outlet pipe 9. A venturi hole 11 provides fluid communication between the central bore 10 and the expansion tank 3.

In use, the heater tank 2 is full of water. When the tap 35 is closed, and the 20 water within the heater tank 2 is heated, the water within the tank 2 expands. The expansion tank 3 is provided to contain the expanded water and prevent nuisance dripping from the free outlet. In the water heater 1 shown in Figure 1, the expanding water will pass up the central bore 10 of the connection tube 7, and out the venturi hole 11 and into the expansion tank 3. As the water expands the water level in the 25 expansion tank 3 rises to an upper level 12. The expansion tank 3 provides a large volume to contain the increase in the volume of water, and has a vent 36 to atmosphere.

When the tap 35 is opened, water under pressure within the heater tank 2 flows through the central bore 10 to the outlet pipe 9 and then to the free outlet. Also, water 30 within the expansion tank 3 will flow through the venturi hole 11 to the central bore 10 and then to the outlet pipe 9. The latter flow is due to the venturi effect of water flowing through the central bore 10 past the venturi hole 11. The water will flow out of the expansion tank 3 until the water level in the expansion tank 3 drops to the lower water level 13.

One embodiment of a conventional connection tube is shown in Figure 2. This connection tube 7 comprises a lower portion 14 and an upper portion 15, both having a central bore 10. The lower portion 14 is brazed at 26 or otherwise sealingly secured to an aperture in the upper wall 20 of the heater tank 2. Orifice 16 and venturi hole 11 (followed by page 2) 270154 C allow fluid communication between the central bore 10 and the insides 17,18 of the heater and expansion tanks 2,3, respectively.

The upper portion 15 is also brazed 26 or otherwise sealingly secured to an aperture until the upper wall 19 of the expansion tank 3. The top of the upper portion 15 5 is threaded 8 to allow the attachment of an outlet pipe. The diameter of the lower end 21 of the upper portion 15 is reduced to locate the upper portion 15 within the upper portion 14.

During construction of the water heater 1, each of the connection tube portions 14,15 are secured to the respective tank wall 20,19, prior to joining the expansion tank 3 10 to the heater tank 2.

The expansion tank 3 is then formed by attaching the expansion tank wall 19 to the heater tank 2, the uppei" wall 20 of which serves as the lower wall of the expansion tank 3. As the walls 19,20 are brought together the two connection tube portions 14,15 locate relative to one another by means of the lower end 21 of the upper portion 15 locating 15 within the lower portion 14. The expansion tank 3 is then sealed to the heater tank 2. holding the connection tube portions 14,15 together.

Problems arise during use of water heaters 1 constructed using conventional connection tubes of the type described above. During use, small openings may become blocked by, for example, calcium deposits. The venturi hole 11 is particularly vulnerable 20 to blocking due to its small size and the fact that it provides a horizontal or angle)! surface upon which deposits may settle. In as little as two to three years of use, and in some areas in only 2 to 3 months, deposit levels can build up to an extent which prevents: efficient and correct operation of the heater. Due to the nature of the construction of the water heater tanks 2,3, in which there is limited or no access to the internal fittings, it is 25 cheaper to replace both tanks 2,3 and the connection tube 7 with a pre-assembled substitute unit, rather than disassembling the tanks 2,3 to clean or replace the connection tube 7. Although cheaper than cleaning or replacing the connection tube 7, the cost of such replacement is still high. The practice of replacing the whole assembly is also wasteful of materials.

It is an object of this invention to provide a water heater, and a connection tube therefor, which allows easy cleaning or replacement of component parts, whilst reusing as many parts as possible.

This invention in one broad form provides a water heater, comprising: a water heater tank having a water heater tank aperture, a first member attached to the water heater tank aperture, the first member including a first member aperture extending therethrough, an expansion tank having an expansion tank aperture, a second member attached to the expansion tank aperture, the second member eluding a second member aperture extending therethrough, and (followed by page 2a) fN:MIBHH]005&4:SAK 270154 2a a tubular member having, a first end and a second end which are removably attached to the first and second members, respectively, a central bore which extends between the first and second ends, and which 5 provides fluid communication between the first member aperture and second member aperture, and a fluid communication means which extends from the central bore to an exterior of the tubular member, and which is located in proximity to the first end.

It is preferred that the fluid communication means comprises a venturi hole 10 extending laterally and at an angle from the central bore.

It is preferred that th ~ second member has an internal thread, that the tubular member has a mating external thread, and that the mating internal and external threads provide the removable attachment between the second member and the tubular member.

It is preferred that the first end has a diameter smaller than a diameter of the first 15 member aperture, and that the first end is removably attached within the first member aperture.

It is preferred that the second end includes means for attaching a second tubular member thereto.

It is preferred that the means for attaching a second tubular member comprises 20 threads.

It is preferred that any one or more of the first, second and tubular members comprise brass, metal or plastics.

It is preferred that the first member further comprises a flange to prevent the first member from passing through the water heater tank aperture.

It is preferred that the water heater further comprises: a first seal means disposed between the first member and the tubular member, and a second seal means disposed between the second member and the tubular member.

It is preferred that the first and second seal means comprise first and second 30 O-rings.

It is preferred that the first seal means is at least partially disposed in a first recess located in either the first or tubular members, and/or the second seal means is at least partially disposed in a second recess located in either the second or tubular members.

This invention in another broad form provides a connection tube for a water heater 35 which includes a first tank with a first tank aperture and a second tank with a second tank aperture, the connection tube comprising: a ^st member which is attached to the first tank aperture and which includes a , member aperture extending therethrough, | (followed by page 3) |N:\IIBHHI00554:SAK _ «.N Af ft E 1 270154 3 a second member which is attached to the second tank aperture, the second member including a second member aperture extending therethrough, a tubular member having, a first end and a second end which are removably attached to the first and 5 second members, respectively, a central bore which extends between the first and second ends, and which provides fluid communication between the first member aperture and second member aperture, a fluid communication means which extends from the central bore to an 10 exterior of the tubular member, and which is located in proximity to the first end.

It is preferred that the fluid communication means comprises a venturi hole extending laterally and at an angle from the central bore.

It is preferred that the second member has an internal thread, that the tubular member has a mating external thread, and that the mating internal and external threads 15 provide the removable attachment between the second member and the tubular member.

It is preferred that the first end has a diameter smaller than a diameter of the first member aperture, and that the first end is removably attached within the first member aperture.

It is preferred that the second end includes means for attaching a second tubular 20 member thereto.

It is preferred that the means for attaching a second tubular member comprises threads.

It is preferred that the connection tube further comprises: a first seal means disposed between the first member and tubular member, and a second seal means disposed between the second member and the tubular 30 member.

It is preferred that the first and second seal means comprise first and second O-rings.

It is preferred that the first seal means is at least partially disposed in a first recess located in either the first or tubular members, and/or the second seal means is at least 35 partially disposed in a second recess located in either the second or tubular members.

By way of example only, one preferred embodiment of a water heater including a :tion tube as well as a connection tube itself according to the invention will now be d^cAed with reference to the accompanying drawings, wherein: . v\\\ ^ I Fig. 1 is a schematic view of a conventional water heater; , „ . * .9/1 (followed by page 3a) /?E C (N:\LIBHH)OO5R4:0FD 2701 3a Fig. 2 is a partial side elevational view and partial sectional view of a prior art connection tube; Fig. 3 is a sectional view of a hot water heater incorporating a connection tube (followed by page 4) 2701 according to the present invention; and Fig. 4 is an enlarged partial view of part of Fig. 3.

Figures 3 and 4 show a preferred embodiment of the invention, indicated generally at 22. As with Figure 2, the connection tube 22 is symmetrical about the 5 centre line with the exception of the venturi hole 11, of which there is only one. Features similar to those of the prior art connection tube of Figure 2 are identified using the same reference numerals. In the embodiment shown in Fig. 3, the water heater is shown mounted in an outer case 39. The vent 36 from the expansion tank 3 passes through an aperture in the outer case 39, and preferably through a grommet 40. 1 o The water heater shown has a heating element 6, thermostat 42, and an over-temperature cut-out 43 to control the maximum temperature in the water heater.

The first member 23 comprises a squat cylinder 24 with a flange 25, and has a central bore 10. The first member 23 protrudes through an aperture in the upper wall 20 of the heater tank 2, and is brazed 26 thereto to both fix the first member 23 and 15 seal any gaps between the first member 23 and the heater tank wall 20.

A second member 27 having a hexagonal outer surface 28 and threaded internal surface 29 is likewise fixed sealingly 26 to the expansion tank upper wall 19. One end of the second member 27 has a rim 30 to which the wall 19 may be attached 26. The other end of the second member 27 h&s an annular recess 38 in which is 20 disposed an O-ring 97, to form a seal between the second member 27 and the tubular member 31.

The lower end 32 of the tubular member 31 has a reduced diameter which fits within the central bore 10 of the first member 23. The lower end 32 also has an annular groove 37 in which is located an O-ring 98, providing a seal between the first 25 member 23 and the tubular member 31. This lower end 32 has an orifice 33 which opens onto the central bore 10 of the tubular member 31. The venturi hole 11, which may be at any angle, is disposed adjacent to the lower end 32, to be located just above the flange 25 when the connection tube 22 is assembled.

The tubular member 31 has an external thread 29 adapted to mate with the 30 internal thread 29 of the second member, and a hexagonal outer surface 34. A lock nut 41 may be used to locate the tubular member 31 relative to the outer case 39. The tubular member 31 is sealingly secured to the second member 27 by screwing the tubular member 31 into the second member until O-ring 97 seals. Spanners or other tools may be used on the hexagonal surfaces 28,34 to ensure a tight seal. „35 A thread 8 is provided on the upper end of the tubular member 31 so that an /^outlet pipe may be attached thereto. The shape of the upper portion of the central bore be shaped as required for attaching an outlet pipe. t I The advantage of the present invention is that the tubular member 31 may be 270154 readily removed for cleaning or replacement, should the venturi hole 11 become blocked. After disconnecting the outlet pipe and lock nut 41, the outer case 39 can be removed from the water heater. It is then simply a matter of unscrewing the tubular member 31 from the second member 27, eg. using spanners on hexagonal surfaces 28 and 39, and withdrawing it from the expansion tank 3. The reverse procedure is used to reassemble the water heater. There is no need to disassemble the expansion tank 3 or destroy and then remake any welds or brazing 26.

Claims

270154 6 WHAT VE CLAIM IS:

1. A water heater, comprising: a water heater tank having a water heater tank aperture, a first member attached to the water heater tank aperture, the first member 5 including a first member aperture extending therethrough, an expansion tank having an expansion tank apeiaire, a second member attached to the expansion tank aperture, the second member including a second member aperture extending therethrough, and a tubular member having, 10 a first end and a second end which are removably attached to the first and second members, respectively, a central bore which extends between the first and second ends, and which provides fluid communication between the first member aperture and second member aperture, and 15 a fluid communication means winch extends from the central bore to an exterior of the tubular member, and which is located in proximity to the first end.

2. The water heater of claim 1, wherein the fluid communication means comprises a venturi hole extending laterally and at an angle from the central bore.

3. The water heater of claim 1 or claim 2, wherein the second member has an 20 internal thread, the tubular member has a mating external thread, and the mating internal and external threads provide the removable attachment between the second member and the connection tube.

4. The water heater of any one of claims 1 to 3, wherein the first end has a diameter smaller than a diameter of the first member aperture, and the first end is 25 removably attached within the first member aperture.

5. The water heater of any one of claims 1 to 4, wherein the second end includes means for attaching a second tubular member thereto.

6. The water heater of claim 5, wherein the means for attaching a second tubular member comprises threads. 30

7. The water heater of any one of claims 1 to 6, wherein any one or more of the first, second and tubular members comprise brass, metal or plastics.

8. The water heater of any one of claims 1 to 7, wherein the first member further comprises a flange to prevent the first member from passing through the water heater tank aperture. 35

9. The water heater of any one of claims 1 to 8, further comprising: a first seal means disposed between the first member and the tubular member, and ' a second seal means disposed between the second member and the tubular iber. it. . & |N:\UBHH)005S4:SAK 270154 7

10. The water heater of claim 9, wherein the first and second seal means comprise first and second O-rings.

11. The water heater of claim 9 or claim 10, wherein the first seal means is at least partially disposed in a first recess located in either the first or tubular members, 5 and/or the second seal means is at least partially disposed in a second recess located in either the second or tubular member.

12. A water heater having a tubular member as substantially as hereinbefore described with reference to figures 3 and 4 of the accompanying figures.

13. A connection tube for a water heater which includes a first tank with a first i o tank aperture, a second tank with a second tank aperture, the connection tube comprising: a first member which is attached to the first tank aperture and which includes a first member aperture extending therethrough, a second member which is attached to the second tank aperture, the second member including a second member aperture extending therethrough, 15 a tubular member having, a first end and a second end which are removably attached to the first and second members, respectively, a central bore which extends between the first and second ends, and which provides fluid communication between the first member aperture and second member 20 aperture, ! a fluid communication means which extends from the central bore to an exterior of the tubular member, and which is located in proximity to the first end.

14. The connection tube of claim 13, wherein the fluid communication means comprises a venturi hole extending laterally and at an angle from the central bore. 25

15. The connection tube of claim 13 or claim 14, wherein the second member has an internal thread, the tubular member has a mating external thread, and the mating internal and external threads provide the removable attachment between the second member and the connection tube.

16. The connection tube of any one of claims 13 to 15, wherein the first end 30 has a diameter smaller than a diameter of the first member aperture, and the first end is removably attached within the first member aperture.

17. The connection tube of any one of claims 13 to 16, wherein the second end includes means for attaching a second tubular member thereto.

18. The connection tube of claim 17, wherein the means for attaching a second 35 tubular member comprises threads.

19. The connection tube of any one of claims 13 to 18, wherein any one or 270154 8

20. The connection tube of any one of claims 13 to 19, wherein the first member further comprises a flange to prevent the first member from passing through the water heater tank aperture. 13 2D

21. The connection tube of any one of claims X to %, further comprising: A A a first seal means disposed between the first member and the tubular member, and a second seal means disposed between the second member and the tubular member.

22. The connection tube of claim 21, wherein the first and second seal means comprise first and second O-rings.

23. The connection tube of claim 21 or claim 22, wherein the first seal means is at least partially disposed in a first recess located in either the first or tubular members, and/or the second seal means is at least partially disposed in a second recess located in either the second or tubular member.

24. A connection tube as substantially as hereinbefore described with reference to figures 3 and 4 of the accompanying figures. (AUSTRALIA) PTY LIMITED itsr attorneys DWJN, SON & CAEEY (N:\LI0HH)OO554:SAK