Ignition system for flame emitting apparatus

Abstract

A flame-emitting apparatus is provided, whereby a burner has an inlet connected to a fuel source. Fuel burned by the burner provides a flame extending from an outlet of the burner. A flame ignition system detects the presence of the flame during operation of the apparatus and controls supply of fuel to the burner in response to flame detection.

What is claimed is: 
     
         1 . An ignition system for flame emitting devices, the system comprising:
 a. a burner;   b. a temperature sensor positioned proximate to said burner; and   c. a controller in communication with said temperature sensor, the controller configured to analyze output from the sensor, including a current temperature and changes in the temperature, to determine if a flame is present.   
     
     
         2 . The system as recited in  claim 1 , wherein the controller is further configured for analyzing an instant temperature detected by the temperature sensor to determine whether the flame is present. 
     
     
         3 . The system as recited in  claim 1 , wherein the controller is configured to determine that the flame is present if the change in temperature determined by the controller is greater than a threshold temperature change. 
     
     
         4 . The system as recited in  claim 3 , wherein the controller is configured to determine that the flame is present if the change in temperature detected by the temperature sensor is greater than the threshold temperature change over a predetermined time period. 
     
     
         5 . The system as recited in  claim 1 , wherein the controller is further configured to transmit a signal to shut down the burner if:
 the controller determines that the flame is present prior to commencement of an ignition attempt; or   the controller determines that the flame is not present subsequent to a specified number of ignition attempts.   
     
     
         6 . The system as recited in  claim 1 , further comprising an igniter configured for igniting the burner to emit the flame, wherein the igniter is in communication with the controller and the controller is configured to transmit signals to cause activation of the igniter. 
     
     
         7 . The system as recited in  claim 1 , wherein the controller is further configured to transmit a signal to shut down the burner if:
 the temperature detected by the temperature sensor is higher than a maximum temperature; or   the temperature detected by the temperature sensor is lower than a minimum temperature; or   the temperature detected by the temperature sensor decreases by a first threshold amount over a time period; or   the temperature detected by the temperature sensor increases by a second threshold amount over the time period.   
     
     
         8 . The system as recited in  claim 1 , wherein the temperature sensor comprises a thermocouple. 
     
     
         9 . A flame emitting apparatus comprising:
 a. a burner having an aperture, the burner configured to burn a fuel to emit a flame from the aperture when the burner is ignited;   b. a temperature sensor having a portion positioned proximate the aperture to detect a temperature of the flame, wherein the portion of the temperature sensor is configured to be positioned within the flame when the burner is ignited; and   c. a control system in communication with the temperature sensor, the control system configured for analyzing output from the temperature sensor to determine if the flame is present.   
     
     
         10 . The apparatus as recited in  claim 9 , wherein the controller is further configured for determining if the flame is present based on at least one of a change in temperature detected by the temperature sensor and an instant temperature detected by the temperature sensor. 
     
     
         11 . The apparatus as recited in  claim 10 , wherein the controller is configured to determine that the flame is present if:
 the change in temperature detected by the temperature sensor is greater than a threshold temperature change over a predetermined time period; or   the instant temperature detected by the temperature sensor is greater than a minimum threshold.   
     
     
         12 . The apparatus as recited in  claim 9 , wherein the controller is further configured to transmit a signal to shut down the burner if:
 the controller determines that the flame is present prior to commencement of an ignition attempt; or   the controller determines that the flame is not present subsequent to a specified number of ignition attempts.   
     
     
         13 . The apparatus as recited in  claim 9 , further comprising:
 an igniter configured for igniting the burner to emit the flame, wherein the igniter is in communication with the controller and the controller is configured to transmit signals to cause activation of the igniter.   
     
     
         14 . The apparatus as recited in  claim 9 , wherein the controller is further configured to transmit a signal to shut down the burner if:
 the temperature detected by the temperature sensor is higher than a maximum temperature; or   the temperature detected by the temperature sensor is lower than a minimum temperature; or   the temperature detected by the temperature sensor decreases by a first threshold amount over a time period; or   the temperature detected by the temperature sensor increases by a second threshold amount over the time period.   
     
     
         15 . The apparatus as recited in  claim 9 , wherein the temperature sensor comprises a thermocouple having an end configured to be positioned within the flame. 
     
     
         16 . The apparatus as recited in  claim 9 , wherein the temperature sensor comprises two thermocouples, and the controller is further configured to transmit a signal to shut down the burner if a difference between temperatures detected by the two thermocouples is greater than a threshold amount. 
     
     
         17 . The apparatus as recited in  claim 9 , wherein the burner comprises a plurality of apertures, the burner configured to emit flames from each of the apertures, and wherein the portion of the temperature sensor is configured to be positioned within at least one of the flames when the burner is ignited. 
     
     
         18 . A method for detecting a flame, said method comprising the steps of:
 a. receiving a first reading from a temperature sensor;   b. waiting a predetermined amount of time;   c. receiving a second reading from a temperature sensor; and   d. determining whether a difference between the second reading and the first reading is within an acceptable range for passage of the predetermined time.   
     
     
         19 . The method of  claim 18 , further comprising the step of returning a “flame detected” condition if the difference between the first reading and second reading is within an acceptable range for the passage of the predetermined time or returning a “flame not detected” condition if the difference between the first reading and second reading is not within an acceptable range for the passage of the predetermined time. 
     
     
         20 . A control unit configured to practice the method of  claim 18 .