Method and device for producing a flame, particulary for coloured flame lamps

Abstract

Method for producing a flame, particularly for coloured flame lamps using a small liquid flow at the upper end of a rising tube ( 4 ) of small transverse cross-section, the method consisting in allowing combustible gas in the form of a sequence of bubbles to pass into a bubble chamber ( 3 ) placed at the lower end of the rising tube, the gas bubbles ( 13, 17 ) having a cross-section at least equal to the transverse cross-section of the rising tube and in igniting and letting the mixture of combustible gas and liquid burn at said upper end of the rising tube. The liquid may contain a chemical compound chosen for the colour it can impart to the flames.

1 . A method for producing a flame by combustion of a combustible gas at the upper end of a rising tube of small internal transverse cross-section, characterised in that: 
 a) a supply of a liquid is set up with its level being maintained both below that of the upper end of said rising tube and above that of the lower end of this same tube,    b) the supply of liquid is brought into contact with a chamber, called a bubble chamber, that also communicates with the lower end of said rising tube, or is inserted into the latter in its lower part and also communicating with a combustible gas source by means of a gas inlet port,    c) while maintaining the liquid level in the supply as shown above, the combustible gas is allowed to pass into the bubble chamber through the gas inlet port at a sufficient rate of flow to produce at the base of the rising tube a sequence of combustible gas bubbles in the liquid, said rate of flow being however smaller than that which would lead to an accumulation of gas below the rising tube such that the liquid would no longer have access to the lower end of this tube, and said sequence of combustible gas bubbles separated by portions of entrained liquid is allowed to rise in the rising tube, and    d) the mixture of combustible gas bubbles and liquid is ignited and allowed to burn, at said upper end of the rising tube, so as to operate as a flame lamp.    
   
   
       2 . Method according to  claim 1 , characterised in that: 
 a) a supply of a liquid is set up with its level being maintained both below that of the upper end of said rising tube and above that of the lower end of this same tube,    b) the supply of liquid is brought into contact with a chamber, called a bubble chamber, that also communicates on the one hand, at its upper part, with the lower end of said rising tube and on the other hand with a combustible gas source by means of a gas inlet port which is located at a level of the bubble chamber below the level of the lower end of the rising tube, the cross-section of the gas inlet port in the bubble chamber being sufficient so as to produce in the bubble chamber liquid successive gas bubbles with a cross-section at least equal to the internal transverse cross-section of the rising tube, the liquid in the supply being brought into contact with the bubble chamber away from the path of said gas bubbles,    c) while maintaining the liquid level in the supply as shown above, the combustible gas is allowed to pass into the bubble chamber through the gas inlet port at a sufficient rate of flow to produce a sequence of combustible gas bubbles in the liquid, said rate of flow being smaller however than that which would lead to an accumulation of gas bubbles at the top of the bubble chamber, so as to allow said sequence of combustible gas bubbles separated by portions of entrained liquid to rise in the rising tube and to release said portions of liquid at the upper end of said rising tube, and    d) the mixture of combustible gas bubbles and liquid is ignited and allowed to burn, at said upper end of the rising tube, so as to operate as a flame lamp.    
   
   
       3 . Method according to  claim 1 , wherein the level of the lower end of the rising tube is lower than the top of the bubble chamber and wherein the combustible gas is allowed to pass under sufficient pressure so as to push back the liquid, present outside the rising tube, from its rest level, downwards, as far as the level of the lower end of the rising tube, thus allowing the gas in the form of successive bubbles, and the liquid to gain access by turns to this lower end of the rising tube.  
   
   
       4 . Method according to  claim 1 , wherein the gas is allowed to pass directly inside the rising tube, at its lower part, which acts as the bubble chamber.  
   
   
       5 . Method according to  claim 1 , characterised in that it is implemented in a rising tube of internal cross-section of less than 1 square centimetre and preferably less than 10 square millimetres.  
   
   
       6 . Method according to  claim 1 , characterised in that it is implemented with a bubble chamber with a transverse cross-section larger than both the maximum internal transverse cross-section of the rising tube and the transverse cross-section of the gas inlet port in the bubble chamber.  
   
   
       7 . Method according to  claim 2 , characterised in that it is implemented with a gas bubble outlet port whose cross-section represents 75 to 200% of the maximum internal cross-section of the rising tube.  
   
   
       8 . Method according to  claim 1 , characterised in that the rate of flow of gas is 5 to 20 times the rate of flow of liquid on a volumetric basis.  
   
   
       9 . Method according to  claim 1 , characterised in that ignition occurs on the surface of a piece of metal gauze, a compressed wire yarn sleeve or a porous body that is non-combustible or difficult to combust placed at the upper end of the rising tube.  
   
   
       10 . Method according to  claim 1 , characterised in that the liquid contains in solution or in suspension at least one chemical compound selected for the flame coloration it produces, so as to operate as a coloured flame lamp.  
   
   
       11 . Method according to  claim 1 , characterised in that the mixture of gas bubbles and liquid is burnt at the upper end of the rising tube in contact or mixed with an auxiliary flame.  
   
   
       12 . Device including a rising tube ( 4 ) communicating via its lower end with a chamber called a bubble chamber ( 3 ), said bubble chamber being furthermore in communication on the one hand with a tank ( 1 ) for liquid and on the other hand with a combustible gas source ( 9 ), said tank being able to contain said liquid at a level both above the level of the lower end of the rising tube and below the level of the upper end of said rising tube, the bubble chamber and the combustible gas source communicating by means of a gas inlet port ( 5 ), said device being characterised in that it additionally comprises a burner ( 10 ) at the upper end of the rising tube ( 4 ), intended for the combustion of the combustible gas and any liquid, as well as means for controlling the rate of flow of the combustible gas allowing the latter to pass into the liquid in the form of a string of successive gas bubbles with a cross-section at least equal to the internal cross-section of the rising tube, directed towards the base of the rising tube or introduced directly into it.  
   
   
       13 . Device according to according to  claim 12 , including a rising tube ( 4 ) communicating via its lower end with the upper end of a chamber called a bubble chamber ( 3 ), said bubble chamber being furthermore in communication on the one hand with a tank ( 1 ) for liquid and on the other hand with a combustible gas source ( 9 ), said tank being able to contain said liquid at a level both above the level of the lower end of the rising tube and below the level of the upper end of said rising tube, the bubble chamber and the combustible gas source communicating by means of a gas inlet port ( 5 ) located at a level of the bubble chamber below the level of communication of said chamber with the lower end of the rising tube and the bubble chamber and the tank of liquid communicating by means of at least one liquid inlet port ( 6 ) located away from the rising path followed by the bubbles of combustible gas which are able to form when the bubble chamber is filled with liquid and when the gas is allowed to pass into said chamber, said device being characterised in that it additionally comprises a burner ( 10 ) at the upper end of the rising tube ( 4 ), intended for the combustion of the combustible gas and any liquid, as well as means for controlling the rate of flow of the combustible gas allowing the latter to pass into the bubble chamber in the form of a string of successive gas bubbles with a cross-section at least equal to the internal cross-section of the rising tube.  
   
   
       14 . Device according to  claim 12 , wherein the upper part of the bubble chamber ( 3 ) is in the form of a downward-widening funnel, intended to receive the gas bubbles and to direct them towards the lower end of the rising tube ( 4 ), the transverse cross-section of the bubble chamber being greater than both the maximum internal transverse cross-section section of the rising tube and the transverse cross-section of the gas inlet port ( 5 ) in the bubble chamber.  
   
   
       15 . Device according to  claim 12 , wherein the bubble chamber ( 3 ) is located at least partly inside the tank of liquid ( 1 ).  
   
   
       16 . Device according to  claim 12 , wherein the tank of liquid comprises a well at its base, and wherein the bubble chamber is placed at least partly in said well.  
   
   
       17 . Device according to  claim 12 , wherein the rising tube ( 4 ) has at all points an internal cross-section of less than 1 square centimetre and preferably less than 10 square millimetres.  
   
   
       18 . Device according to  claim 13 , wherein the cross-section of the gas bubble outlet port represents 75 to 200% of the maximum internal cross-section of the rising tube.  
   
   
       19 . Device according to  claim 12 , wherein the burner consists of a piece of metal gauze, a compressed wire yarn sleeve or a porous body that is non-combustible or difficult to combust.  
   
   
       20 . Device according to  claim 12 , additionally comprising an auxiliary gas burner placed in contact with the burner at the upper end of the rising tube.  
   
   
       21 . Use of the method according to  claim 12 , in order to produce a coloured flame, the liquid containing in solution or in suspension at least one chemical compound selected for the flame coloration it produces when the combustible gas and possibly said liquid is ignited in the burner ( 10 ).