AU2748102A - Flueing system for a gas burner appliance - Google Patents

Description

I

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): RINNAI AUSTRALIA PTY. LTD.

A.C.N. 005 138 769 Invention Title: FLUEING SYSTEM FOR A GAS BURNER APPLIANCE The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 FLUEING SYSTEM FOR A GAS BURNER APPLIANCE This invention relates to a flueing system for a gas burner appliance.

The invention has particular application to gas burner appliances in the form of hot water heaters but gas burner appliances for other purposes could also be used in the present invention.

Water heating for large commercial or industrial applications generally includes a large reservoir of water S• which is heated by various different systems including gas burners, electricity heating and the like. Such water heaters find application in environments where hot water is required in large volumes such as in hotels or in other S"industrial sites. Such systems suffer from the draw back that if the system fails all of the hot water requirements .i Sare eliminated until the system is repaired.

Such systems do have the advantage of, in the case of gas burner appliances, requiring simple flueing in order to remove exhaustion products from the system.

The object of the present invention is to provide a system which produces some redundancy in the event that there is a failure in the system so complete shut off of hot water or other product produced by the gas burner appliance is not eliminated entirely, whilst at the same time addressing the need for flueing in such a system.

The present invention may be said to reside in a gas burner appliance including: a plurality of gas burner units, each unit having an exhaust flue for the exhaust of combustion products and an inlet flue for supplying air to the units to support combustion within the units; an exhaust manifold having an air inlet opening \\melb_files\home$\Luisa\Keep\Speci\Rinnai PR3857 Complete.doc 19/03/02 3 and an exhaust outlet; baffle means for dividing the manifold into an inlet compartment communicating with the air inlet opening and an outlet compartment communicating with the exhaust outlet; a communication opening for communicating the inlet compartment with the outlet compartment; each inlet flue being in communication with the air inlet compartment, and each exhaust flue being in communication with the outlet compartment; and wherein air is able to enter the inlet compartment and be drawn into the inlet flues from the ooooo S• inlet compartment to support combustion within the burner units and exhaust gas exits the exhaust flue into the 15 outlet compartment and wherein the communication opening oooo between the inlet compartment, and the outlet compartment S"enables air in the inlet compartment to flow into the outlet compartment to mix with the exhaust gas and then flow to the exhaust outlet.

Thus, according to this aspect of the invention should one of the gas burner units fail other of the gas burner units in the system can continue to operate to supply product which is intended to be supplied by the units, such as hot water. The exhaust manifold which is divided into the two compartments and therefore enables air to flow to the units to support combustion and extract exhaust gasses provides an efficient flueing system for the appliance notwithstanding the fact that the appliance includes a plurality of burner units each of which has its own exhaust flue and inlet flue.

In the preferred embodiment of the invention, when the appliance is in use, the air inlet is connected by duct work to the exterior of a building for the supply of fresh air into the inlet compartment and the exhaust outlet is coupled by ducting to the exterior of a building for the discharge of combustion products from the appliance. This \\melbfiles\homeS\Luisisa\Keep\Speci \Rimai PR3857 Complete.doc 19/03/02 4 enables the unit to be a fully sealed within a machine room (or the like) of a building and not remove air from the room or discharge exhaust gasses into the room. This has significant advantage when considering air conditioning requirements for the room because the requirements need not take into account the discharge of exhaust gasses into the room nor the use of air in the room for supporting combustion in the gas burner units.

In the preferred embodiment of the invention at least six gas burner units are included in the appliance. However, more or less than six burner units could be included oeooo depending on the environment or installation of the burner appliance.

Preferably the exhaust manifold is an elongate housing having the air inlet opening and exhaust outlet opening at one end, the baffle means comprising a plate extending within the housing in the longitudinal direction of the oo go ~20 housing, and the communication opening being formed by the plate terminating short of an end wall of the housing remote from the inlet opening and the exhaust opening.

o. Preferably the air inlet flues extend into the inlet compartment through openings in the manifold.

Preferably the exhaust flues are arranged within the inlet flue and are eccentric with the inlet flue and extend through the inlet compartment and through the plate so as to communicate with the outlet compartment.

Preferably the space between the plate and the end wall of the manifold includes vanes for directing air flow from the inlet compartment to the outlet compartment.

Preferably each exhaust flue has an outlet end and which is cut at an angle to the horizontal to provide an outlet opening which flues the exhaust outlet for directing \\mellb.files\home$\Luisa\Keep\Speci\Riuai PR3857 Complete.doc 19/03/02 5 exhaust gas emanating from the exhaust flue towards the exhaust outlet.

If desired, a plurality of banks of gas burner appliances can be provided in side by side relationship and exhaust manifolds of each of the appliances can be coupled to a common duct work for the supply of air and common duct work for the discharge of exhaust gas, to and from the manifolds respectively.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawing which shows a view of a gas burner appliance in the form of a gas water heater, according to the preferred embodiment of the invention.

0 With reference to Figure 1 a gas burner appliance 10 is S. shown which includes a plurality of gas burner units 12 in the form of water heaters. The water heaters 12 are known per se and most preferably comprise Rinnai Infinity (registered trade mark) gas water heaters for delivering hot water on demand. Each of the units 12 has a cold water inlet 16, a gas inlet 18 for the supply of gas for combustion in the unit, and a hot water outlet 20. The inlets 16 are each connected to a common supply of cold water, the gas inlet 18 is connected to a common gas conduit and the hot water outlets 20 are connected to a common hot water supply pipe for supplying hot water to the installation in which the appliance is installed.

Since the units 12 are well known as is the method of supplying gas, cold water and extracting hot water from the units well known the units 12 will not be described in further detail.

The units 12 can be supported on a support structure which can provide a frame work and which is only schematically shown in the drawings. The frame work will also support the remaining components of the appliance.

\\melb..files\home$\Luisa\Keep\Speci\Rimai PR3857 Complete.doc 19/03/02 -6- Each of the units 12 has an air inlet flue 30 and a combustion exhaust flue 32. The exhaust flue 32 is cocentric with and arranged within the inlet flue 30. The inlet flue 30 provides air into the units 12 for combustion purposes and the flue 32 discharges combustion products from the units 12 in a manner which is also known per se and will therefore not be described in any further detail herein.

A flue manifold 40 is arranged above the units 12 and comprises an elongate generally rectangular housing having .ooooi S" an upper wall 42, bottom wall 44, end wall 46, end wall 48 and side walls 50 only of which is shown in Figure 1.

15 Although a generally rectangular or square cross-section oooo is preferred for the flue manifold 40 other crosssectional shapes could be used if desired. An air inlet is provided in the wall 48 and an exhaust outlet 62 is also provided in the wall 48. The inlet 60 includes a fan 64. The manifold 40 is divided into two compartments by a baffle plate 70. The baffle plate 70 extends in the longitudinal direction of the manifold 40 and is provided between the inlet 60 and the exhaust outlet 62. The plate 70 divides the manifold 40 into an air inlet compartment 72 and an air outlet compartment 74. The inlet compartment 72 is in communication with the air inlet and the compartment 74 is in communication with the exhaust outlet 62. The baffle 70 terminates short of the end wall 46 so that a space or opening 78 is provided between the end of the baffle plate 70 and the wall 46 to allow communication between the compartments 72 and 74.

The inlet 60 may be connected to duct work shown schematically by reference 79 which extends to the exterior of a building for supplying air to the inlet The exhaust outlet 62 may also be connected to the duct work schematically shown by reference 81 which also extends to the exterior of a building. Air which is drawn \\melbtfi es\homeS\Luisa\Keep\Speci\Rinnai PR3857 Complete.doc 19/03/02 7 into the appliance for supporting combustion within the units 12 is drawn from the exterior of a building and combustion gasses are also discharged to the exterior of the building. Thus, the appliance can be contained in a machine room and combustion air can be supplied from the exterior thereby not using air within the room and exhaust gasses are discharged to the exterior of the room as well.

This has a significant advantage when considering air conditioning requirement for a room which includes such appliances.

The air inlet flues 30 extend up from the appliances 12 *through bottom wall 44 of the manifold 40 so that the flues 30 communicate with the air inlet compartment 72.

15 The internal and co-centric exhaust flues 32 extend up through the inlet compartment 72 and have outlet ends which extend into the outlet compartment 74. In the embodiment shown the outlet ends 85 are cut at an angle of about 450 and have openings 86 which face the exhaust outlet 62. The outlet ends 85 are sealed to the plate to prevent air from travelling from the compartment 72 to the compartment 74 (or vice-versa), through the plate in the vicinity of the exhaust flues 32. Similarly, the air inlet flues 30 are also sealed to the bottom wall 44 so as to prevent escape of air from the compartments 72 to the exterior in the vicinity of the flues In order to operate the appliance, the units 12 are operated in the normal manner and the fan 64 is actuated so as to draw air into the inlet compartment 72 in the direction of arrows A in Figure 1. Some of that air will be drawn into the inlet flues 30 in the direction of arrows B so as to supply combustion air to the units 12 to support combustion within the units 12 and the heating of water within the units 12. Combustion product is exhausted from the units 12 via the flues 32 and enters the outlet compartment 74 through outlet ends 85 of the flues 32.

\\melbfies\home\Luisa\Keep\Speci\Rirai PR3857 Complete.doc 19/03/02 8 Air which is forced into the inlet compartment 72 by the fan 64 and which does not enter the inlet flues 30 travels in the direction of arrow A and is directed by curved vanes 96 arranged in the space 78 between the end of the baffle plate 70 and the wall 46 so as to travel in the direction of arrows C into the outlet compartment 74. The air flows through the outlet compartment 74 in the direction of arrow C towards the exhaust outlet 62 and mixes with the exhaust combustion gasses emanating from the flues 32 so as to dilute the exhaust gasses for supply through the outlet 62 to the duct work 81 and into the eoooo exterior of a building.

The preferred embodiment of the invention has the advantage that if any of the units 12 should fail, other of the units can continue operating to supply hot water (or other product which the units are intended to supply) so that the products supplied by the appliance are not completely eliminated upon a failure. Workmen can attend to the appropriate to repair the unit or replace it as is necessary without shutting down the entire appliance. The preferred embodiment also provides an efficient and unique flueing system to accommodate the separate units 12 and allow supply of air to the units and discharge of exhaust gasses from the units.

In various applications of the invention a number of banks of appliances of the type shown in Figure 1 can be used in side by side relationship to increase the hot water capacity of the system. Each bank will be identical to that shown in Figure 1 except that each bank need not have its own duct work 79 and 81 to supply air or discharge exhaust products. Rather, each of the outlets 62 can be connected to common duct work for the discharge of exhaust gasses and each of the inlets 60 can be connected to a common duct work for the supply of combustion air.

\\melbfiles\homeS\Luisa\Keep\Speci\Rimai PR3857 Complete.doc 19/03/02 9 The baffle plate 70 shown in Figure 1 may be generally horizontally arranged or, alternatively, the baffle plate can be inclined slightly and an outlet pipe 90 can extend up to the baffle adjacent wall 48 so that any condensation which exits the exhaust flues 32 and condenses down onto the baffle 70 will flow towards the pipe 90 and be drained from the appliance. For example, the baffle plate 70 may be spaced from bottom wall 44 adjacent wall 48 by a distance of 250mm and be spaced from bottom wall 44 at its end adjacent wall 46 by a distance of 300mm.

S* The bottom wall 44 is preferably spaced from the units 12 by a distance of at least 100mm. In one embodiment in which six units 12 are included the length of the manifold 40 is about 2400mm and the width into and out of the plane of the paper in Figure 1 is about 300mm. The height of the top wall 42 above bottom wall 44 is approximately 550mm.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

\\melb~fies\home\Luisa\Keep\Speci\Rinnai PR3857 Complete.doc 19/03/02

Claims (9)

1. A gas burner appliance including: a plurality of gas burner units, each unit having an exhaust flue for the exhaust of combustion products and an inlet flue for supplying air to the units to support combustion within the units; an exhaust manifold having an air inlet opening and an exhaust outlet; baffle means for dividing the manifold into an inlet compartment communicating with the air inlet opening and an outlet compartment communicating with the exhaust outlet; *o .o *a communication opening for communicating the inlet compartment with the outlet compartment; each inlet flue being in communication with the air inlet compartment, and each exhaust flue being in communication with the outlet compartment; and wherein air is able to enter the inlet 0 *compartment and be drawn into the inlet flues from the inlet compartment to support combustion within the burner units and exhaust gas exits the exhaust flue into the outlet compartment and wherein the communication opening between the inlet compartment, and the outlet compartment enables air in the inlet compartment to flow into the outlet compartment to mix with the exhaust gas and then flow to the exhaust outlet.

2. The appliance of claim 1 wherein, when the appliance is in use, the air inlet is connected by duct work to the exterior of a building for the supply of fresh air into the inlet compartment and the exhaust outlet is coupled by ducting to the exterior of a building for the discharge of combustion products from the appliance.

3. The appliance of claim 1 wherein at least six gas burner units are included in the appliance.

4. The appliance of claims 1, 2 or 3 wherein the \melb.files\homeS\Lisa\Keep\Speci\Rnnai PR3857 Complete.doc 19/03/02 11 exhaust manifold is an elongate housing having the air inlet opening and exhaust outlet opening at one end, the baffle means comprising a plate extending within the housing in the longitudinal direction of the housing, and the communication opening being formed by the plate terminating short of an end wall of the housing remote from the inlet opening and the exhaust opening.

The appliance of any one of claims 1 to 4 wherein the air inlet flues extend into the inlet compartment through openings in the manifold.

6. The appliance of any one of claims 1 to 5 wherein the exhaust flues are arranged within the inlet flue and 15 are eccentric with the inlet flue and extend through the inlet compartment and through the plate so as to communicate with the outlet compartment.

7. The appliance of claim 4 wherein the space between the plate and the end wall of the manifold includes vanes for directing air flow from the inlet compartment to the outlet compartment.

8. The appliance of any one of claims 1 to 7 wherein each exhaust flue has an outlet end and which is cut at an angle to the horizontal to provide an outlet opening which flues the exhaust outlet for directing exhaust gas emanating from the exhaust flue towards the exhaust outlet.

9. A gas burner appliance substantially as hereinbefore described with reference to the accompanying drawings. Dated this 19th day of March 2002 RINNAI AUSTRALIA PTY LTD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melbfies\homeS\Luisa\Keep\Speci\Ri ai PR3857 Completedoc 19/03/02