GB2345956A - Artificial coal log gas fire - Google Patents

Abstract

A gas fire which mimics the random way fossil fuels burn to give a pleasing appearance. The fire can be easily changed to use as a heat storage unit when the flame effect is not required, the fire may be equipped with a heat saving option and harmful gas detection mode of operation and the fires functions may be remotely controlled. In one embodiment gas is supplied through a medium 12 which is agitated by rotating arms 20 before being passed through grid 13 for ignition. The gas may flow through the arms 20.

Description

AN ARTIFICIAL COAL/LOG GAS FIRE This invention relates to an artificial coal/log gas fire.

There are known fires, which use gas as a fuel and heat up artificial coals or logs to give the effect of a real coal or log fire. However, they do not act as a real fire because the artificial coals/logs heat up in a uniform manner and therefore the flames tend to stay in one particular position and do not move around, as would a real coal/log fire.

According to the present invention there is provided an artificial fuel gas fire comprising a gas supply, an artificial medium to mimic real coal or wooden logs, a tray to hold a granular medium which acts to distribute the gas evenly throughout the medium, a grid to support the artificial coals/logs above the gas distributing medium, an ignition source, a means to agitate the distributing medium and a further means to control the agitating means.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in section through the center on the apparatus Figure 2 illustrates an alternative shaped agitator arm Figure 3 shows a side view with the flue arrangement attached to the tray 10 Figure 4 shows in perspective in part section the rotating plate assembly Figure 5 illustrates in perspective the sliding tube arrangement Referring to the drawing, the gas fire comprises a tray arrangement 10 in a form suitable to fit into a chimney hearth or opening, where the organic solid fuels is normally burned. The tray 10 is in the form of a boxed shape and preferably made of steel and provided with sides 11 all round the periphery to retain a non combustible gas distribution medium 12, in this example the gas distribution medium is a silica based material. The sides 11 around the periphery are approximately 50mm high and the gas distribution material should be ideally 5 to 10mm below the support grid 13 and the tray 10 being adapted to accept a connection for a gas supply 39. The front 14 of the tray being further adapted to house the control electronics (not shown) together with a gas supply regulator (not shown) which is controlled and operated by the electronic control, or may be manually operated in the case of a power failure. The tray 10 being further adapted with brackets 15 to support a grid 13 so there is a clearance between the underside of the grid 13 and the distribution medium 12, the grid provides a support for the artificial coals/logs 16 to rest on. The tray 10 has a further bracket 17 positioned centrally which is fitted with a micro switch 18, the switch being connected to the control electronics, the micro switch is activated when a notch, (not shown) which is provided in the agitator shaft, lines up with the micro switch. This indicates to the control electronics the reference point. If however on power-up the micro switch is not in line with the notch on the spindle then power is applied to the drive motor 19 until the reference point is reached, this allows the electronics to monitor the position of the agitator arms 20 for correct control and also so that user information may be input using the switches on the tray front or alternatively via a remote control (not shown). If the power supply is removed this does not affect the gas supply as this is left at the preset regulator setting which can be altered manually. With the addition of a backup battery, a power loss warning may be given. The micro switch 18 also provides the microcontroller with a reference point when power is applied to the electric motor 19 as an ongoing reference in operation.

The bracket 17 is fitted at the top end with a ceramic bearing 21 and the lower part of the bracket is adapted to accept an electric motor which also provides support for a rotating armed spindle arrangement 22 which is preferably T shaped in configuration when the agitator arms 20 are in position. As an alternative to flat arms, the arms may be tubular (not shown) in construction and provided with holes for the gas to flow through. The gas supply may be fed through the center of the spindle to the hollow arms, the holes must be smaller than the particles of distribution medium. The spindle arrangement is powered by a bi-directional geared electric motor 19, in this example, a 230V AC 5rpm motor is used. However, with the addition of a low voltage power supply and a voltage controller, different voltage/speed drive motors may be used.

The arms 20 are preferably made from metal, in this example, they are made from 1. 5mm zinc plated mild steel and are welded to a collar 23 so that it maybe removably attached to the spindle 22 which is provided with a flat which matches a flat in the collar to locate the arms in the desired position. As an alternative the distributing medium 12 and arms 20 may be replaced by a rotating round plate assembly which is positioned below the fixed plate 32 which has numerous holes running out from the center at an angle to the periphery as shown in fig 4. The lower movable plate 31 is provided with several ribs 33 preferably made from a ceramic material which slide on the surface of the fixed plate 32. As the plate 31 rotates, the holes in plate 32 are covered and uncovered, this gives a flickering flame effect as illustrated in fig 4. The gas in this example is fed through two inlets juxtapose on the periphery of plate 32.

The rotating plate assembly 31 and plate 32 may be replaced with a sliding tube arrangement wherein the gas is fed through a suitable adapter (not shown) into the center if the inner tube 35 the opposite end being blocked off. The tube (s) 37 are fixed to the tray 10 via brackets (not shown) at about 10mm below the grid 13, several tubes may be fitted to give the desired flickering flame effect. Tube 35 is provided with ribs 36 around the periphery which acts as a seal at the ends of the tubes and also covers and uncovers the holes 34 when the outer tube is osalated as shown in the direction of the arrows fig 5. Tube 35 is provided with holes 38 located in-between the ribs 36 for the gas to pass through. The outer tube 37 is oscillated via a motor driven cam arrangement (not shown) in the direction of the arrows fig 5. The arm assembly 20 rotates within the confines of the tray 10, the arms may be straight or curved dependent on the type of flame effect required, an alternative shaped agitator arm is shown in Fig 2. The arms are submerged in the distribution medium 12, so that the arms 20 are under the surface of the gas distribution medium, the depth of the arms may be set by sliding the collar to which the arms are fixed. The arm assembly may slide up or down on the spindle 22 by the action of a cam 24 which is fixed to the tray's 10 base, a cover is placed over the cam arrangement to stop the ingress of the distribution medium, if the cam is not used the arms assembly may be simply fixed in the desired position with grub screws. When power is applied to the spindle 22 the arms 20 rotate, this moves and agitates the gas distribution medium allowing the gas an easier route through to the surface of the distributing medium where combustion takes place. As the arms are rotated, this may be in either direction, this alters the flow of gas through the distribution medium so the gas flames change their height and position thus providing a moving flame effect which mimics the character of the combustion effects of real solid fuel fires. In this example, the electronic control (not shown) has several stored programs that may be initiated to move, stop and start the arms to create several different types of flickering flame effects, and also allows the user to automatically switch on or off the fire. A temperature sensor 25 is provided for monitoring the heat given off by the artificial fuel and also for safety should the fire fail to light, or be accidentally extinguished. The temperature sensor is monitored by the control electronics continuously, should the gas fail to ignite or sensor fail then a warning may be given so the fault may be rectified. Further diagnostic monitoring or connection to other control devices may be incorporated as required, for example, the fire may be connected to a central remote control (not shown) within the home thereby the user may switch on appliances by telephone. It may be advantageous for the electronic control to have a timer mode for the user to set up timing cycles, this may be by switches provided in a convenient position or alternatively via the remote control. The different program's can be activated by the user via switches (not shown) provided on the front of the tray 10, or as an alternative they may be activated remotely via a hand held unit preferably via infra-red (not shown). The stored electronic programs are preferably stored in the memory of a microcontroller and the ability for the user to store their own preferences may be advantageous, these may be stored in EEPROM. In this example a 16C84 microcontroller is used to store programs and control the gas regulator valve (not shown) and also the speed and direction of the agitator. The fire may be fitted with a means to control the flow of air/combustion gasses up the flue or chimney, in this example, this is via a flap 26 preferably made from sheet steel which is opened and closed by a solenoid 27, this would be the fires economy mode and preferably would be suitably fixed to the tray 10 to form one unit. When the fire is required to provide heat without the need for the fires visual aesthetics, the artificial coals/logs are heated up to an optimum predetermined temperature. Once the correct temperature is reached then the control electronics shuts off the gas supply and after a short time the electronics activate the solenoid to close the flue flap 26 which is spring 28 biased, so if the power fails the flap 26 remains open. When the temperature falls below a predetermined level the power is removed from the solenoid and the flap 26 opens and the gas supply is turned on and the heating cycle starts again. When the gas supply is off the heat stored in the artificial fuel is convected into the room via a vent 29 fitted just below the flue flap 26 instead of being vented to atmosphere. It may be advantageous to provide a heat storage block (not shown) in the form of a honeycomb that would provide a means of improving the efficiency of the fires heat output. When the visual effect is not required the artificial fuel may be removed and replaced with the higher efficiency heat storage block. The fire may be provided with a suitable door if required. The fire may be fitted with a safety means to detect the combustion gases which may not be exhausted correctly due to a partially or blocked flue or chimney. In this example, a carbon monoxide sensor 30 is provided, this may be fitted in any convenient position, in this example, the sensor 30 is located in the tray front 14, should the sensor be triggered the gas supply is cut off and a warning is given via an audible sounder (not shown) giving off 103dB at one metre and also a visual indication for those people who's hearing is impaire, in this example, an ultra bright red led is used.

Claims (15)

1. CLAIMS 1 An artificial coal/log fire comprising a gas supply with a means to alter the direction and volume flow of the gas that is delivered to the ignition point (s) which mimics the characteristics of a real coal or log fire.
2. 2 An artificial coal/log fire as claimed in claim 1 wherein the means to alter the direction and volume flow of the gas supplied to the ignition piont (s) is a moving mechanical means.
3. 3 An artificial coal/log fire as claimed in claim I and claim 2 wherein the means to alter the direction and volume flow of the gas supplied to the ignition point (s) is by moving/agitating a gas distributing medium.
4. 4 An artificial coal/log fire as claimed in any preceding claim wherein the gas distributing medium is moved/agitated by rotating arms.
5. 5 An artificial coal/log fire as claimed in any preceding claim wherein the means to alter the direction and volume flow of the gas supplied to the ignition point (s) is via a moving plate.
6. 6 An artificial coal/log fire as claimed in any preceding claim wherein the means to alter the direction and volume flow of the gas supplied to the ignition point (s) is via a reciprocating tube arrangement.
7. 7 An artificial coal/log fire as claimed in any preceding claim wherein the means to power the means to alter the direction and volume flow of the gas is by an electric motor which is capable of speed and directional changes.
8. 8 An artificial coal/log fire as claimed in any preceding claim wherein the artificial coals/logs are supported on a grid above the moving mechanical means.
9. 9 An artificial coal/log fire as claimed in any preceding claim wherein the artificial coal/logs may be replaced with a high efficiency heat storage means.
10. 10 An artificial coal/log fire as claimed in any preceding claim wherein the gas fire incorporates a means to detect carbon monoxide gas.
11. 11 An artificial coaL/log fire as claimed in any preceding claim wherein the detection of harmful levels of carbon monoxide gas will cause an alarm to be initiated and the supply of gas to be cut off.
12. 12 An artificial coal/log fire as claimed in any preceding claim wherein the heat and flame effect may be controlled remotely.
13. 13 An artificial coal/log fire as claimed in any preceding claim wherein the remote control of the fires functions is via a light source.
14. 14 An artificial coal/log fire as claimed in any preceding claim wherein the fire has a means to control the flow of residual hot air given off by the fires artificial coals/logs from escaping to atmosphere and subsequently to being directed back into the room.
15. 15 An artificial coal/log fire substantially as described herein with reference to figures 1-5 of the accompanying drawings.