Patent Application
20090023105
The invention concerns a system for controlling gas supply to a gas burner of a patio heater.
Patio heaters are used to provide heat and warmth to people in an outdoor environment such as a backyard, patio or courtyard. Patio heaters generally comprise a base to house a gas cylinder tank, an upright pole, a gas burner and a dome-shaped reflector mounted above the gas burner. A gas hose supplies gas from the tank to the gas burner through the upright pole. The reflector reflects heat downwards rather than allowing it to escape immediately upward.
To operate the patio heater, a control knob is rotated to the ignition position. The control knob is pushed down to ignite a pilot burner by an igniter. Then, the control knob is rotated to increase or decrease the amount of gas supplied to the gas burner to increase or decrease the temperature. When a patio heater is no longer required, the control knob must be rotated to the closed position, and the pilot burner is extinguished. In commercial use where multiple patio heaters are used for heating a large outdoor area, it may be time consuming to constantly monitor and remember to turn off each one. Also, if some have been forgotten to be turned off, gas is wasted as it is continually burned when heat is no longer required.
Accordingly, there is a desire to provide a simple, convenient and cost-effective system for minimising the wastage of gas burned by a patio heater when use of the patio heater is no longer required.
In a first preferred aspect, there is provided a patio heater gas control system, the system comprising:
The system may further comprise a thermometer and a temperature control module to maintain a predetermined temperature.
The system may further comprise a remote control to reset the predetermined amount of time for timing module.
The timing module may be a mechanical or an electronic timer.
The electromechanical valve may be a solenoid valve.
The patio heater may comprise:
In a second aspect, there is provided a method for controlling gas supply to a gas burner of a patio heater, the method comprising:
An example of the invention will now be described with reference to the accompanying drawings, in which:
Referring to
An oxygen depletion system (ODS) 80 is provided to automatically extinguish and shut off the gas burner if the oxygen level falls below a predetermined level. The ODS is a safety device which activates a fires flame supervision device in any situation resulting in the presence of excessive levels of co2 and carbon monoxide, which reduce the levels of oxygen causing the pilot flame to become unstable and lift off the thermocouple tip 70. The fire is then automatically turned off before the situation might become dangerous for people in the surrounding environment. The ODS 80 is a highly sensitive device to shut off a heating appliance if the oxygen level in an area falls below 18%. The standard oxygen level is 21%.
A tilt switch 40 is provided as another safety feature of the patio heater 20. If the patio heater 20 is accidentally knocked over and is non-vertical (more than 30° off the vertical axis), gas supply is automatically cut off to prevent a fire hazard.
A thermometer and thermostat 90 is provided to maintain a predetermined temperature. A user may set a predetermined temperature such as 25° C., and the thermometer monitors the temperature, and depending on the ambient environment will either maintain the current gas flow, increase the gas flow to increase the temperature or decrease gas flow to decrease the temperature accordingly.
An infrared remote control receiver 100 is provided to reset the predetermined amount of time for timing module. This allows a user to use a corresponding remote controller to control the temperature setting of the thermostat 90 and the timer 50 at a distance from the patio heater 20. The timing module 50 is a mechanical or an electronic timer. The electromechanical valve 60 is preferably a solenoid valve.
Generally, the patio heater 20 comprises: a base 21 to house the gas tank, an upright pole 22, the gas burner 23, a dome-shaped heat reflector 24 mounted above the gas burner 23 to reflect heat downwards, and a gas hose to supply gas from the gas tank to the gas burner through the upright pole 22.
The timer 50 functions as a circuit breaker. Electrical wiring 31 connecting the tilt switch 40 to the timer 50 to the solenoid valve 60 to the thermocouple tip 70 to the ODS 80 and back to the tilt switch 40 is able to form an electrical circuit. When the time remaining on the timer 50 has not expired, a closed and complete electrical circuit is formed which causes the solenoid valve 60 to be in an open state. When the solenoid valve 60 in the open state, the gas valve is opened and allows gas to flow from the gas tank to the gas burner. When the time on the timer has expired, the timer 50 causes the electrical circuit to become an open circuit which causes the solenoid valve 60 to change from the open state to the closed state. When the solenoid valve 60 is in the closed state, the gas valve to the gas tank is closed. Thus, when the time on the timer 50 has expired, gas is prevented from flowing to the gas burner which turns off the patio heater 20 safely and convenient without regular monitoring or user intervention.
Referring to
It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the scope or spirit of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects illustrative and not restrictive.
