EP0040037A1

EP0040037A1 - A heat exchange unit

Info

Publication number: EP0040037A1
Application number: EP81301975A
Authority: EP
Inventors: Ronald James Brown
Original assignee: Franicevic Edward John; Harmon Rodney Alan
Current assignee: FRANICEVIC, EDWARD JOHN; HARMON, RODNEY ALAN
Priority date: 1980-05-05
Filing date: 1981-05-05
Publication date: 1981-11-18
Also published as: AU546897B2; AU7015981A; DE3165740D1; ZA812963B; JPS5737695A; ATE9180T1; EP0040037B1; NZ193612A

Abstract

A heat exchange unit incorporating an electrically heated boiler (1) mounted within a housing (2), the boiler having extending therethrough at least one air tube (11) arranged so that air can be drawn or blown therethrough to be heated by the boiler before it is passed from the housing through an outlet, the electrically heated boiler having a supply tank (7) connected thereto to maintain a desired water level within the boiler, the boiler having a steam outlet (19) in the upper end thereof through which steam can flowto one or more condensor tubes or coils (21) in which the steam condenses before flowing under gravity back through an inlet (20) to the boiler, the latent heat of evaporation given up by the condensing steam can be collected surrounding the condensor with air or water to be heated. The housing within which the boiler is mounted can have a series of baffles or scoops (14) which direct the flow of drawn or blown air so that it passes through successive levels of air tubes through the boiler before being passed over the boiler and out the outlet in the housing.

Description

This invention relates to a heat exchange unit and more particularly relates to a heat exchange unit which can-be used in both industrial and home situations to provide heated air and/or heated water.
An object-of the present invention is to provide a heat exchange unit which may be used in a home or industrial situation, which heat exchange unit provides from a single source of heat a supply of heated air and/or a supply of heated water.
A further object of the present invention is to provide a heat exchange unit which offers to the public a useful alternative choice.
Further objects and advantages of the present invention will become apparent from the following descriptions which are given by way of example only.
According to a first aspect of the present invention there is provided a heat exchange unit incorporating an electrically heated boiler mounted within a housing, the boiler having extending therethrough at least one air tube arranged so that air can be drawn or blown therethrough to be heated by the boiler before it is passed from the housing through an outlet, the electrically heated boiler having a supply tank connected thereto to maintain a desired water level within the boiler, the boiler having a steam outlet in the upper end thereof through which steam can flow to one or more condensor tubes or coils in which the steam condenses before flowing under gravity back through an inlet to the boiler, the latent heat of evaporation given up by the condensing steam can be collected by surrounding the _condensor with air or water to be heated.
The housing within which the boiler is mounted can be provided with a series of baffles or scoops which direct the flow of drawn or blown air so that it passes through successive levels of air tubes through the boiler before being passed over the boiler and out the outlet in the housing.
The supply tank can be connected to the electrically heated boiler by a pipe through which water can pass to maintain the water level within the boiler and supply tank at a predetermined level. The end of the pipe can be arranged to allow a back flow of heated water from the boiler to the supply tank to heat the water therein.
The steam outlet in the upper end of the boiler can be connected to a coil or to a series of tubes so that steam can flow therethrough to condense before being returned to the boiler. The _condensor coil or tubes can be fitted within a hot water storage reservoir which is heated by the latent heat or evaporation given up by the condensing steam.
The steam outlet to the coil or tubes can alternatively be mounted within a suitable casing provided with air inlets so that air can surround the coil or tubes to be heated, the heated air being allowed to flow via convection through outlets in the casing to heat the area in which the casing is situated.
According to a second aspect of the present invention there is provided a heat exchange unit incorporating an electrically heated boiler mounted within a housing, the boiler having extending therethrough at least one air tube arranged so that air can be drawn or blow therethrough to be heated by the heated water within the boiler before it is passed from the housing through an outlet, the electrically heated boiler having a supply tank connected thereto to maintain a desired water level within the boiler and supply tank, the boiler having at least one pair of outlets and inlets therein, the outlets and inlets being connected to a hot water cylinder so that water therein can flow under a thermosyphon effect to heat the water within the hot water cylinder.
The outlet from which heated air is blown or drawn can be connected to ducting to transfer the heated air to wherever it is required within a building.
Further aspects of the present invention which should be considered in all its novel aspects will become apparent from the following descriptions which are given by way of example only.
Embodiments of the present invention will be described with reference to the accompanying drawings in which:

Figure 1: shows a section thrbugh a heat exchange unit according to the present invention;
Figure 2: shows a section taken on the line II - II through the heat exchange unit shown in Figure 1; and
Figure 3: shows a plan view of an example of housing in which the boiler of the heat exchange unit can be mounted.

The heat exchange unit according to the present invention can be used in a number of situations, for example, in the home or in an industrial situation. The present invention can, for example, be used as a substitute for an open or closed type fire.
The example of heat exchange unit shown includes an electrically operated boiler generally indicated by arrow 1. The boiler is mounted within a box shaped housing 2. The boiler 1 and the outer housing 2 are preferably constructed from sheet metal materials. The boiler 1 has at least one electrically operated heating element 3 therein and has on an end wall thereof a thermostat (not shown). In the example shown the housing 2 has in an end wall 4 thereof an inspection cover 5 which allows access to the heating elements 3 and thermostat for repair and/or maintenance purposes. The end wall of the housing can also have mounted thereon an on/off switch and/or an appropriate fuse or fuses as required by the Electrical Wiring Regulations.
It is also envisaged that the floor, walls and top of the housing 2 can be formed as a cavity wall (not shown) within which is positioned insulation so as to reduce loss of heat therefrom.
The water level A within the boiler 1 is maintained by a flow of water from a supply tank 7. The water level A within the boiler 1 and supply tank 7 are the same and are governed by a ball cock valve 8 (Figure 3). The flow of water between the supply tank 7, and the boiler 1 is by way of the connecting pipe 9. The supply tank 7 can include an overflow pipe 10.
The boiler 1 has extending therethrough a number of air tubes 11 (shown dotted in Figure 1) through which air can pass to be heated by the hot water within the boiler 1. In the example of boiler 1 shown there are three levels of air tubes 11 with six tubes 11 in each level. The open ends 12 of the tubes 11 can be seen in Figure 3. The boiler 1 can include a drain pipe 13.
The boiler 1 when operating is a main source of heat and the flow of hot air can be controlled by a double bladed tangential fan 14 which draws or pushes air into inlet pipes 15. The inlet pipes 15 direct air in the direction of the arrows (Figure 1) through the first level of air tubes 11 against a baffle 17 at the other end of the housing 2 which baffle directs the flow to the middle level of air tubes back to the first end of the housing 2 above the inlet pipes 15 to a second baffle 17 which directs the flow to the upper level of air tubes 11 at the other end of which is a baffle 17 which directs the air over the top 18 of the boiler 1 to the outlet 16. The outlet 16 from the housing 2 can be connected to ducting (not shown) to transfer the heated air to wherever it is required within a building. Alternatively the outlet 16 can be a series of apertures or louvres near to the upper edge of the housing 2 to allow air to be blown into the space or room in which the housing 2 is situated.
The flow of air around the boiler 1 can be in the direction of the arrows shown in Figure 1, that is, the cold air is initially blown through the inlet pipes 15 and through successive levels of the air tubes 11 before the air passes up and over the top 18 of the boiler and through the outlet 16.
The boiler 1 has in the top 18 thereof a steam outlet 19 through which steam flows to condensor tubes or coils 21 in which the steam may condense giving up its latent heat of evaporation to the material surrounding the condensor tubes or coils 21. The condensed water returning to the boiler through the return pipe 20. The return pipe 20 can have therein a pressure relief tube 22 draining back to the supply tank 7.
The condensor tubes or coils 21 can be surrounded for example as shown in Figure 1 by water in a hot water storage tank 23. The tank 23 can be provided with additional heating elements (not shown) as required for use during the summer when the boiler 1 is not in use or when an extra supply of hot water is required. The storage tank 23 is provided with a supply outlet and inlet and insulation in known manner.
As an alternative to the example shown the steam outlet 19 from the boiler 1 can be connected to a radiator or to a series of coils (not shown) within a casing which acts as a radiator heater. The casing has air flowing therethrough or therearound so that the area in which it is sited is heated by convection.
In use the boiler 1 according to the present invention can be fitted to supply at least heated air/and or hot water in the manner described.
Thus by this invention there is provided a heat exchange unit for use in a home or industrial situation which provides from a single source a supply of heated air and/or a supply of heated water.
A particular example of the present invention has been described herein by way of example and it is envisaged that improvements and modifications to the invention may take place without departing from the scope of the appended claims.

Claims

1. A heat exchange unit incorporating an electrically heated boiler mounted within a housing, the boiler having extending therethrough at least one air tube arranged so that air can be drawn or blown-therethrough to be heated by the boiler before it is passed from-the housing through an outlet, the electrically heated boiler having a supply tank connected thereto to maintain a desired water level within the boiler, the boiler having a steam outlet in the top thereof through which steam can flow to one or more condensor tubes or coils in which the steam condenses before flowing under gravity back through an inlet or inlets to the boiler, the-latent heat of evaporation given up by the condensing steam can be collected by surrounding the condensor with air or water to be heated.

2. A heat exchange unit as claimed in claim 1 wherein the housing within which the boiler is mounted has a series of baffles or scoops which direct the flow of drawn or blown air so that it passes through successive levels of air tubes through the boiler before it is passed over the top of the boiler and from the outlet in the housing.

3. A heat exchange unit as claimed in claim 1 or claim 2 wherein the connection between the supply tank and the electrically heated boiler is a pipe arranged to allow a back flow of heated water from the boiler to the supply tank to heat the water therein.

4. A heat exchange unit as claimed in claim 3 wherein the end of the pipe within the supply tank extends to a point near to the base of the supply tank.

5. A heat exchange unit as claimed in any one of the preceding claims wherein the steam outlet in the top of the boiler is connected to a coil or to a series of tubes through which the steam flows and in which the steam condenses before it is returned to the boiler.

6. A heat exchange unit as claimed in any one of the preceding claims wherein the condensor tubes or coils are placed within a hot water reservoir which is heated by the latent heat of evaporation given up by the condensing steam.

7. A heat exchange unit as claimed in claim 5 wherein the coils or tubes are mounted within a casing through which air can circulate so that air can surround the coils or tubes and be heated, the heated air being allowed to flow from air outlets, louvres or the like in the casing to allow the warm air to heat the area in which the casing is situated.

8. A heat exchange unit incorporating an electrically heated boiler mounted within a housing, the housing having extending therethrough at least one air tube arranged so that air can be drawn or blown therethrough to be heated by the heated water within the boiler before the heated air is passed from the housing through an outlet, the electrically heated boiler having a supply tank connected thereto to maintain a desired water level within the 0040037 boiler and supply tank, the boiler having at least one pair of outlets and inlets therein, the outlets and inlets being connected to a hot water cylinder so that water therein can flow under a thermosyphon effect to heat the water within the hot water cylinder.

9. A heat exchange unit as claimed in any one of the preceding claims wherein the outlet from which heated air is blown or drawn is connected to ducting to transfer the heated air to where it is required within a building.

10. A heat exchange unit as claimed in any one of the preceding claims when the boiler is constructed from a heavy gauge metal material and the housing within which it is mounted is constructed from a lighter gauge sheet metal material.

ll. A heat exchange unit as claimed in claim 10 wherein the housing has in a wall thereof an inspection cover which allows access to the heating elements, fan and thermostats therein.

12. A heat exchange unit as claimed in any one of the preceding claims wherein the housing is formed as a cavity wall within which a layer of insulation material is fitted.

13. A heat exchange unit as claimed in any one of the preceding claims wherein the heat exchange unit is sited in a commercial or home situation 13