GB2199126A

GB2199126A - Combined flue and ventilator

Info

Publication number: GB2199126A
Application number: GB08629563A
Authority: GB
Inventors: Albert John Amor
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-10
Filing date: 1986-12-10
Publication date: 1988-06-29
Also published as: GB8629563D0

Abstract

Combined flue and ventilator apparatus comprises a flue (6) extending from the vicinity of a source (5) of unwanted gaseous products to an exterior location, the flue (6) being combined with a ventilator in the form of a duct (15) extending from an exterior location for the passage into the area of replacement air, fan means (18, 19, 22) being provided for extracting the unwanted gaseous products through the flue (6) for discharge exteriorly of said area, and fan means (18, 19, 21) for blowing air through the ventilator duct (15). The incoming air may be heated by the gaseous products. <IMAGE>

Description

COMBINED FLUE AND VENTILATOR This invention relates generally to flues through which pass unwanted gases such as the gaseous products of combustion and whilst the invention has been conceived primarily in connection with so-called gas log-effect or coal-effect fires, it has other applications.

Gas log-effect or coal-effect fires are fires in which a real gas flame plays on imitation logs or coals, whereby the latter are heated and glow to resemble an authentic log or coal fire. As with all fires, the combustion relies on there being a supply of oxygen to the fire and in the domestic situation, such a supply can sometimes not be as readily available as previously due to the increased use of sealed unit windows or secondary double glazing which prevents or restricts the ingress of replacement air. Accordingly, a room can soon become "stuffy", ie. deprived of oxygen with attendant discomfort to the occupants of the room.

According to the present invention, there is provided a flue extending from the vicinity of a source of unwanted gaseous products to a location exterior to the area containing the source of unwanted gaseous products, the flue being combined with a ventilator in the form of a duct extending from a location exterior to said area to a location within said area for the passage therethrough into the area of replacement air, means being provided for extracting the unwanted gaseous products through the flue for discharge exteriorly of said area, and means for blowing air through the ventilator duct.

Conveniently, the flue and the ventilator duct are located adjacent one another at least exteriorly of said area and may be provided with independent means for extracting the unwanted gaseous products through the flue and blowing replacement air through the ventilator duct.

However, it is preferable to employ common means in this respect, whereby a single motor may be provided which has an output shaft a portion of which extends into the flue and a further portion of which extends into the ventilator duct, the output shaft being provided with two sets of blades located in the flue and ventilator duct respectively, the flue blades being operable to extract the unwanted gaseous products and the ventilator duct blades being operable to blow air through the ventilator duct to said area.With this arrangement, it is a simple matter to arrange for the rate of extraction and the rate of inflow of replacement air through the ventilator duct to be set relative to each other by varying the size and/or pitch of the respective sets of blades so as to maintain a balance between outgoing a incoming gasses, which balance will be generally maintained irrespective of the speed of the motor which might be made variable.

Alternatively, the sets of blades could be made of variable pitch in order to adjust this balance. As a further alternative to affect a balance between the flow rates in the flue and ventilator duct, a restriction may be introduced into one or both thereof.

Preferably, an inlet for the ventilator duct is located remote from the outlet of the flue in order to prevent the unwanted gaseous products being discharged from the flue outlet being immediately reintroduced into said area via the ventilator duct.

The ventilator duct may incorporate a heat exchanger arranged to use the unwanted gaseous products in use flowing through the flue as its heat input, whereby the incoming replacement air flowing through the ventilator duct is first heated before being introduced into said area, whereby unpleasant cold drafts in said area are avoided. At the same time, the otherwise wasted heat is used to advantage thus effectively increasing the efficiency of the source of unwanted gaseous products which will typically be some form of log-effect or coal-effect fire. Instead of, or in addition to, the heat exchanger in the ventilator duct a heat exchanger may be incorporated in the flue and heated air directed into the room or another room or area.Air for the flue heat exchangers may come from within the room or outside thereof and a fan may be employed to distribute the heated air to the area of use.

The discharge end of the ventilator duct may be located closely adjacent the fire or other source of unwanted gaseous products in order to feed directly replacement air to that source in order to aid further combustion. Such an arrangement can be implemented irrespective of whether the fire or other source is of the so-called room sealed type.

Domestic fires having a combined flue and ventilator in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figures 1 to 4 illustrate diagrammatically four different embodiments of combined flue and ventilator in accordance with the present invention as fitted to a domestic fire, and Figure 5 is a view in the direction of arrow v of Figures 1 to 4.

Referring first to Figure 1, this illustrates a portion of a room bounded in part by a cavity wall 1 on one side, a ceiling 2 and a floor 3. Adjacent the wall 1 there is provided in the room a fireplace 4 comprising a fire basket or grate 5 and which may be of the gas log-effect or coal-effect type.

A flue 6 is provided for the fireplace, the flue having a first portion 7 extending substantially vertically within a canopy 8 comprising a gatherer 9 connected to the bottom end of the flue portion 7. The upper end of the flue portion 7 is connected to a generally horizontal second flue portion 11 which extends through the wall 1 to a housing 12 secured to the exterior of the wall 1 through a flange 13. A louvred outlet 14 in the lower portion of the housing 12 provides a discharge outlet for the unwanted gaseous products of combustion flowing through the flue 6.

The flue arrangement so far described may be similar to that disclosed in British Specification No. 2152650 to which reference is made. Thus, the first flue portion 7 may be of a double skin construction which is sealed in a gas tight manner to the second portion 11 which may be telescopic in order to accommmodate varying distances between the wall 1 and the fireplace 4.

A ventilator duct 15 is combined with the flue 6, the ventilator duct extending from the housing 12 along a portion of the second flue portion 11 and having a discharge end 16 located within the room, the discharge aperture being louvred as indicated at 17 but this is not essential. The flue 6 and the ventilator duct 15 are separated within the housing 12 and a motor is mounted within the ventilator duct portion of the housing 12 and has an output shaft 19 extending from opposed sides of the motor, one end of the shaft being fitted with a first set of blades 21 and the opposite end being fitted with a second set of blades 22. The first set of blades 21 is located in the ventilator duct portion of the housing 2, whereas the second set of blades 22 is located within the flue portion. Thus, on operation of the motor 18, both sets of blades 21, 22 are rotated, the first set serving to draw air in from the exterior of the room and to force it through the ventilator duct so as to be discharged into the room via the discharge outlet 17. The second set of blades 22 serves to extract the unwanted gaseous products through the flue 6 and discharge them exteriorly of the room. In order to prevent the discharged unwanted gaseous products from being immediately drawn into the ventilator duct and reintroduced into the room, an inlet 23 for the ventilator duct 15 is provided which extends from the housing 12 to a location remote from the discharge outlet of the flue. For example, the distance between the remote inlet end 24 of the inlet and the discharge outlet 14 of the flue 6 may be of the order of 2 metres.

In as much as a single motor 18 is employed to drive both sets of blades 21, 22, then the basic balance between the rate of extraction of unwanted gaseous products and the rate of introduction of replacement air through the ventilator duct 15 will be maintained irrespective of the speed of the motor which may be arranged to be variable so as to adjust the relative rates referred to.

Figure 2 of the drawings illustrates a basically similar arrangement to that of Figure 1, the exception being that the ventilator duct 15 terminates within the room in a heat exchanger 25 which is associated with the flue 6 and which receives heat input from the unwanted gaseous products being extracted through the flue. Thus, the replacement air flowing through the ventilator duct 15 is first heated before being discharged into the room.

Accordingly, there are no cold draughts created by the incoming replacement air and advantage is taken of the otherwise lost heat, thus increasing the overall efficiency of the fire 4.

In Figure 3 of the drawings, there is again illustrated an arrangement basically similar to that of Figure 1 but with the ventilator duct 15 extended so as to pass down the interior of the wall 1 and be turned through 900 so as to terminate closely adjacent the fire grate 5. With this arrangement, the incoming replacement air is discharged in the immediate vicinity of the fire grate 5 so that combustion is considerably aided. A somewhat similar arrangement is also disclosed in Figure 4 although the fireplace in this embodiment is of the room sealed type which means that it is sealed in a basically gas-tight manner from the room by being enclosed in a chamber which would normally have glass doors 26 forming its front wall so that the fire can be viewed therethrough.The ventilator duct passes through a side wall of this chamber and is sealed with respect thereto so as to discharge replacement air again directly in the vicinity of the fire grate 5. This arrangement can provide interesting flame effects, particularly with log-effect and coal-effect fires as the replacement air plays on the "fuel" and flames.

Returning to Figure 3 of the drawings, this shows in broken lines three possible locations for a heat exchanger 27, 28 or 29 in the flue 6, the first two being in the flue portion 7. Air for the heat exchangers 27, 28 and 29 may come from within the room or from outside, the source of air not being illustrated. Air heated by these heat exchangers 27, 28 and 29 may be directed into the room or into another room or area as desired, no ducting in the latter respect being illustrated. For the heat exchangers 27 and 28, the heated air could be directed into the room through air ducts illustrated at 30 and provided in the canopy 8. If required, a motor and fan 31 could be provided to distribute the heated air into the room or elsewhere.

The embodiments of Figures 1 and 3 can be used to provide air conditioning during warm weather when the fireplace is not in use and the embodiments of Figures 2 and 4 could be modified in order to provide a similar facility. Another advantage of the present invention when a single motor 18 is utilised to extract the unwanted gaseous products and to introduce the replacement air through the ventilator duct 15 is that the flow of ventilating air over the motor serves to cool the latter which can be very important because the heat from the unwanted gasses being extracted can, in certain circumstances, overheat the motor.

It will be understood that a heat exchanger may be incorporated into the flue, as indicated in Figure 3, as well as a heat exchanger in the ventilator duct as illustrated in Figure 2. Furthermore, all of the illustrated embodiments may have a heater exchanger in the ventilator duct and/or the flue.

It will be appreciated that the present invention provides a simple but effective arrangement of combined flue and ventilator which solves the problem of oxygen starvation for fires be they of the natural fuel type or the log-effect or gas-effect type.

Claims

1. Combined flue and ventilator apparatus comprising a flue in use extending from the vicinity of a source of gaseous products to a location exterior to the area containing the source of unwanted gaseous products, the flue being combined with a ventilator in the form of a duct extending from a location exterior to said area to a location within said area for the passage therethrough into the area of replacement air, means being provided for extracting the unwanted gaseous products through the flue for discharge exteriorly of said area, and means for blowing air through the ventilator duct.

2. Apparatus according to claim 1, wherein the flue and ventilator duct are provided with respective means for extracting the unwanted gaseous products through the flue and blowing replacement air through the ventilator duct.

3. Apparatus according to claim 1, wherein the flue and ventilator duct are located adjacent one another at least exteriorly of said area and are provided with common means for extracting unwanted gaseous products through the flue and blowing replacement air through the ventilator.

4. Apparatus according to claim 3, wherein the common means comprise a motor having an output shaft a portion of which extends into the flue and a further portion of which extends into the ventilator duct, the output shaft being provided with two sets of blades located in the flue and ventilator duct, respectively, the flue blades being operable to extract the unwanted gaseous products and the ventilator duct blades being operable to blow air through the ventilator duct to said area.

5. Apparatus according to claim 4, wherein the two sets of blades on the output shaft of the motor are of variable pitch to vary the rate of extraction of the unwanted gaseous products and the rate of introduction of replacement air.

6. Apparatus according to any of the preceding claims, wherein the ventilator duct is provided with an inlet and the flue is provided with an outlet, the ventilator inlet being located remote from.the flue outlet in order to prevent the unwanted gaseous products being discharged from the flue outlet being immediately reintroduced into the said area via the ventilator duct.

7. Apparatus according to any of the preceding claims and further comprising a heat exchanger arranged to use the unwanted gaseous products in use flowing through the flue as its heat input, whereby the incoming replacement air.flowing through the ventilator duct is first heated before being introduced into said area, and whereby the otherwise wasted heat is used to advantage thus effectively increasing the efficiency of the source of unwanted gaseous products.

8. Apparatus according to any of the preceding claims and further including a heat exchanger disposed in the flue and operable to direct heated air into said area or another area.

9. Apparatus according to claim 8, wherein the heat exchanger in the flue is fed with air either from said area or exteriorly thereof, the heated air being distributed by fan means associated with the flue heat exchanger.

10. Apparatus according to any of the preceding claims, wherein an outlet for the ventilator duct is disposed closely adjacent the source of unwanted gases, whereby replacement air is fed directly to that source to aid combustion.

11. Apparatus according to any of the preceding claims, wherein the source of unwanted gaseous products is a coal-effect or log-effect gas fire.

12. Apparatus according to any of the preceding claims, wherein the source of unwanted gaseous products is-a a --fire of the room sealed type.

13. Combined flue and ventilator apparatus substantially as herein particularly described with reference to Figure 1 or Figure 2 or Figures 4 and 5 of the accompanying drawings.