GB2512812A

GB2512812A - Method to reduce heat loss up a chimney or flue

Info

Publication number: GB2512812A
Application number: GB201302094A
Authority: GB
Inventors: Steven Thomas Barson
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-02-06
Filing date: 2013-02-06
Publication date: 2014-10-15
Also published as: GB201302094D0

Abstract

A gas fire (c, fig 2) having a system for opening and closing the passage to the flue (a, fig 2) to restrict air from being drawn up the flue from the room when the fire is not being used. The system involving a controller (r) for a gas supply and a controller (n) for a flue damper (f) where the operation of the controls is linked to the operation of a single control (o). The link is preferably provided by a single control (o) which slides along a slot (p). The movement of the control turns a lever mechanism (q) which operates the gas supply valve (j) and also moves a bar (n) which operates the damper. Preferably the damper is a baffle (f) pivotally mounted in the top portion of the fire chamber to close the passage (e, fig 2) from the fire chamber to the flue (a, fig 2).

Description

Method to reduce heat lost up a chimney or flue.

Currently, when a gas fire is installed in a fireplace, the flue or chimney is permanently open so the warm air in the room is constantly being drawn through the fire and up the flue, even when the appliance is not being used. There are available methods where a damper can be installed in the flue which is then interlocked to prevent the fire being used when the damper is closed. These methods however are expensive, difficult to install and tend to be unreliable due to the failsafe sensors necessary.

This invention describes how apparatus which opens and closes a passage to allow or restricts the movement of air from a room into a flue-way can be incorporated into the design of a gas fire, to ensure that when the fire is not in use the passage is closed and when the fire is in use the passage must be open.

Ai example shall now be described using the following diaams.

Figure I shows the cross section of a typical inset fireplace, (a) shows the flue up which smoke and / or combustion gasses are extracted, (b) shows the recess where the fire Figure 11 shows an example of a gas fire (c) with apparatus to prevent heat loss up the flue, positioned in the fireplace. in this example it is a decorative gas fire with a realistic flame effect. (dl) is the glass front through which the imitation coal and flames (h) can be viewed, U) is a control valve to regulate the flow of gas, (e) is the gap through which the combusted gasses exit the combustion chamber, arrows (k) show the route which the combusted gasses take, passing around baffle (O before exiting at point (g) and leaving via flue (a). Often there is also an amount of room air which is also drawn up the flue, this is shown by directional arrow (1) Figure lU shows closer detail of the baffle (fi. Near the rear end of the baffle is a hinge (v) which allows the baffle to pivot. Near the front end of the baffle is a bar (n) which is located in a slot (iii). The slot and the bar provide a means of limiting movement of the baffle, so in figure III the baffle is in its lower position allowing normal passage of gasses and room air up the flue.

Figure TV shows that the bar (n) has now been lifted to a higher position, effectively blocking off the passage of room air and combusted gasses up the flue.

Figure V shows a front view illustrating a preferred method of control. Slide controls for gas fires have been available for several years. A handle mechanism (o) is pushed down or pulled up along a slot (p). A lever mechanism (q) transfers the vertical movement to a horizontal movement, so when the handle is pushed down, the action pushes in plunger (r) on the gas valve which allows gas into the fire. A lighting mechanism can also be activated to light the gas (not shown).

I

When the lever is raised the plunger on the valve is released and the flow of gas is cut off therefore extinguishing the fire.

In figure VT it can be seen that when the valve is frilly raised, the handle lifts the bar (n) which closes the baffle (f'). Therefore, when the fire is to be used, the first action when thc handle is pushcd down is to open thc baffle, then thc handle is pushed further down which allows the flow of gas and lighting of the fire. When the fire is to be turned off, the first action when the handle is raised is to cut off the flow of gas, and the last action when the handTe is fully raised is to connect with bar (n) and close the baffle. By this means it is impossible for the gas fire to be on when the baffle is closed.

It is acknowledged that this is not the only method of achieving this, some other embodiments could be: By changing the linkage connected to the lever a rotary gas control could be used. A sliding plate could be used to block the flue exit from the fire.

Rather than a baffle as shown, the raising and lowering of the handTe could be changed to a rotary action which would open and close a butterfly valve.

Figures VII and VTTI show a possible alternative method which uses a more conventional design of gas fire and a flap and cable to close the flue-way. In this example when the handle (o) is pushed from right to left, the first action is for the wire (w) to pull open flap (0 to open the route to the flue, the next action would be to push plunger (r) on the gas valve to permit the flow of gas. When the handle is moved from left to right, the gas is cut off and then the slackening of the wire would allow a spring (not shown) to close flap (f).

Although for ease of use, safety and reliability a single handle action is preferred, it is acknowledged that two or more actions could be employed to achieve the same objective of closing passage to the flue-way when the fire is not in use. Just one such method is shown in figure IX, where (x) represents a D' shaped control knob on a rotary gas valve, a sliding lever (y) which runs along a slot (z. The flat of the D' shaped knob against the handle prevents the valve from being turned on. Before the fire can be turned on, the lever has to be slid along the slot. The lever is connected to a linkage which opens a flue-way baffle (not shown). Once the handle has been moved and the flue-way opened, the rotary knob is free to be turned. Figure X shows the fire in operation, it can be seen that the round of the D' prevents the handle from being slid back so the flue-way cannot be closed when the fire is in operation.

Most gas fires incorporate a pilot light with a thermocouple which generates an electrical current and keeps the valve open. An alternative method of achieving the desired effect would be to place an electrical contact or a micro-switch could be employed to interrupt the circuit between the thermocouple and the valve, should the baffle to the flue-way be closed.

Claims

Claims 1. A gas fire which incorporates a method of opening and closing the passage to the flue to restrict air from being drawn up the flue from the room when the fire is not being used.
2. A gas fire which incorporates within the design of the fire a method of opening and closing the passage to the flue to restrict air from being drawn up the flue when the fire is not in use.
3. A gas fire as described in claims 1 and 2 where the passage to the flue is opened and closed by a control which also operates flow of gas in the gas fire.
4. A gas fire where a control is used to first open a passage from the fire to the flue and then allows the flow of gas to the fire.
5. A gas fire where controls are used to first open a passage from the fire to the flue and then allows the flow of gas to the fire.
6. A gas fire where a sliding control is used to first open a passage from the fire to the flue and then allows the flow of gas to the fire.
7. A gas fire where a control cuts off the flow of gas to the fire and then closes the passage from the fire to the flue
8. A gas fire where a sliding control cuts off the flow of gas to the fire and then closes the passage from the fire to the flue
9. A gas fire in which a mechanical arrangement exists which prevents the flow of gas to the fire when the exit to the flue is closed.
10. A gas fire where a single control opens a passage to the flue and then turns on the flow of gas and also turns off the supply of gas then closes the passage to the flue.
11. A gas fire where a single sliding control opens a passage to the flue and then turns on the flow of gas and also turns off the supply of gas then closes the passage to the flue.