US2279546A - Igniting means for fuel-air burners - Google Patents

Description

' Patented Apr. 14,1942

UNITED `STATES PATENT oFFice IGNITING MEANS FOR FUEL-AIR BURNERS Serge Ziegler, Berlin, Germany Application April 11, 1939, Serial No. 267,357

' In Germany July 14, 1934 4 Claims. (Cl. 158-28) The present invention relates to' a device for igniting a mixture 'of air and fuel when it leaves a burner. in which a measured quantity of burner oil is automatically atomized when the burner is switched on, and is then fed to an electrical igniting device whereupon the igniting flame which is thus obtained ignites the air-fuel mixture issuing from the burner. Such ignition devices do not, however, always provide immediate ignition, especially if the associated burner consumes heavy oil having a high ignition point. If ignition does not occur immediately an unburned air-fuel mixture will escape for some time vfrom the burner into, for instance, the associated boiler so that an explosive mixture is likely to be produced therein, the subsequent ignition of which might cause fatal accidents.

The new igniting device is adapted to avoid the disadvantagev mentioned by the provision of a pump-like mechanism which is actuated by the pressure either of the oil or of the atomizing medium for the oil or of the combustion air, said mechanism forcing a measured amount of readily inflammable igniting oil, which is contained in 'a reservoir, into a jet of air. The easily inflammable gas mixturecreated thereby isV now ignited electrically and the flame which is thus obtained serves for lighting the mixture composed of heavy oil and air which is leaving the burner.

Y Thesaid pump-like mechanism 'preferably conssts of a single-acting diaphragm pump, the diaphragmof which is compressed when the burner is set into operation, so that a portion of the igniting o il contained inside the pump is forced through the igniting oil pipe `to the ignition device. When the burner ceases to operate the pressure decreases whereupon the suctionv chamber of the pump expands under the action of a spring and is filled afresh with igniting oil which is drawn in through a valve from a reservoir.

It is essential for a satisfactory operation of the device that the diaphragm pump be always completely filled with igniting oil when the burner comes into operation. Since the pump must be located quite near to the boiler which is to be heated, because otherwise the-resistance in the piping would be too great, a complete filling of the suction chamber of the pump may often not be obtained due to a partial vaporisation of the igniting oil within the pump under the iniiuence of the heat-radiated from the boiler. In such u 'a case a part of the suction chamber of the pump is lled with oil vapours instead of`igniting oil Igniting devices are already known lll so that at the moment of operation of the heating plant nov igniting oil at all or only an insucient amount thereof is forced into the ignition device. According to the invention this disadvantage is met by arranging the reservoir immediately vertically above the pump and by connecting it to the latter through a non-return valve which closes only when the pump is performing its working stroke, whilst it is open when the diaphragm pump is deated. The vapours created in the pump through the radiation of heat from the boiler and also air` bubbles, particles of dirt, etc., are now free to rise through the open non-return valve 'into the reservoir for the igniting oil whilst a corresponding quantity of the latter ows down into the suction chamber of the pump. Thus the pump is always completely lled with ig'nitng oil. Other drawbacks are avoided by dispensing with suction pipes and long syphoning feed chanels connecting the igniting oil reservoir with the pump, or the pump with the electric ignition apparatus.

Further variations and developments of the invention will be apparent from the following dey scription of an example illustrated in the drawing.

The igniting oil is housing of the pump is connected with the oil piping or with the atomizing air pipe or with the combustion air pipe by a tube which is attached at I0. Inside the body of the diaphragm and 'the valve housing igniting oil is contained which flows down from the igniting oil reservoir I, arranged vertically above the pump, through the non-return valve Il into the suction chamber of the pump.

When the burner is put into operation, the dia- 5 'phragm 9 is compressed against the action of the spring I2 dueto the pressure which' is exerted fed from the reservoir ,I

through the pump-likejmechanism, vmore fully described hereinafter, into the igniting oil pipe 2 and from thence into the tube 3. From this tube it is blown into a hollowl i'gnition'plug .by

ing out its working stroke.

through the pipe I by the oil or by the atomizing air or by the combustion air. The non-return valve Il isvthus closed and a portion of the igniting oil which is available in the diaphragm body and the valve housing 1 is forced through the igniting oil pipe 2 to the ignition device.

When the burner ceases to operate the pressure exerted through the pipe I0 decreases. The diaphragm expands under the action of the spring l2 and opens the non-return valve Il so that fresh igniting oil may ow into the diaphragm body-and the valve housing through valve Il. The igniting, oil is prevented from being drawn back from the oil pipe 2 by the provision of a valve that is arranged within said pipe. Instead of inserting a valve specifically for this purpose, the diameter of the said igniting oil pipe may be made so small that a flow-back of the igniting oil contained in the said oil` pipe cannottake place because of the great resistance thereto. An unhindered escape in the upward direction of the vapours created within the pump and a replacement thereof by fresh igniting oil flowing down from the res-ervoir is assured by the fact that the igniting oil reservoir is arranged vertically above the pump and that the said two devices are connected with each other byga nonreturn valve or by some other closing means which closes only while the diaphragm 9 is carry- Also, air bubbles which may enter the interior of the pump, and particles -of dirt, find their way in an upward direction passing the valve Il into the reservoir of the igniting oil. On the other hand by the arrangement of the reservoir on a level lower than that of the ignition device the flowing away and waste of igniting oil is prevented which otherwise might occur in case of a breakdown or disorder of the associated plant.

The present invention may. be varied and altered in many ways still'within the scope of the invention as set forth in the appended claims. For instance the new igniting device may obviously beused also for lighting other kinds of burners, e. g., burners for pulverised coal, instead of using it for heavy oil burners.

What I claim and esire to secure by Letters Patent of the United tates is:

1.' In an igniting means of the character described, an .ignition device, means for supplyingigniting fuel to said device, said means comprising a spring loaded diaphragm pump, a valve housing in communication with and located directly above said pump, an igniting oil pipe from said valve housing below the top thereof to said ignition device and constantly in communication at its entrant end with said valve housing, a nonreturn valve located in said valve housing above the place where said pipe is connected to the housing, an ignition fuel reservoir located directly above said valve housing and communicating with the same via said non-return valve, means to apply force to said diaphragm pump in opposition to that of its spring to force ignition fluid from said valve chamber into and through said igniting oil pipe, said igniting oil pipe having means to prevent return flow of igniting oil into said valve housing, by virtue of all of which any vapors in the diaphragm pump and in the valve housing will, upon the opening of said valve, pass into said reservoir thereby preventing such vapors being forced into said.

igniting fuel to said device, said means comprising a spring loaded diaphragm pump, a valve housing in communication with and located directly above said pump, an igniting oil pipe from said Valve housing below the top thereof to said ignition device and constantly in communication at its entrant end with said valve housing, a nonreturn valve located in said valve housing above the place where said pipe is connected to the housing, an ignition fuel reservoir located directly above said valve housing and communicating with the same via said non-return valve, means to apply force to said diaphragm pump in opposition to that of its spring to force ignition fluid from said valve chamber into and through said igniting oil pipe, said igniting oil pipe having means to prevent return flow of igniting oilinto said valve housing, by virtue of all of which any vapors in the diaphragm pump and in the valve housing will, upon the opening of said valve, pass into said reservoir thereby preventing such vapors -being forced into said igniting oil pipe, the arrangement of the pump, the valve housing and the reservoir being such that the escape of vapor from the pump and valve housing into the reservoir Aand the flow of oil from the reservoir into the valve housing and the pump take place in a vertical direction.

3. In an igniting means of the character described, an ignition device, means for supplying igniting fuel tolsaid device, said means comprising a spring loaded diaphragm pump, a.valve housing in communication with and located directly above said pump, an igniting oil pipe from said valve housing below the top thereof to said ignition device and constantly in communication at its entrant end with said valve housing, a nonreturn valve locatedin said valve housing above the place where said pipe is connected to the housing, an ignition fuel reservoir located directly above said valve housing and communicating with the lsame via said non-return valve, means to apply force to said diaphragm pump in opposition to that of its spring to force ignition fluid from said valve chamber into and through said igniting oil pipe, said igniting oil pipe having means to prevent return flow of igniting oil into said valve housing, by virtue of all of which any vapors in the diaphragm pump and in the valve housing will, upon the opening of said val-ve, pass into said res-ervoir thereby preventing such vapors being forced into said igniting oil pipe', said igniting oil pipe communicating with the substantially highest part of the valve housing'below the non-return valve and communicating with the ignition device at substantially its highest place, and said ignition device being located at a higher level than said pump and reservoir.

4. In an igniting means of the character described, an ignition device, means for supplying igniting fuel to said device, said means comprising a spring loaded diaphragm pump, a valve housing in communication with and located directly above said pump, an igniting oil pipe from said valve housing below the top thereof to'said ignition device and constantly in communication at its entrant end with said valve housing, a nonreturn valve located in said valve housing .above the place where said pipe is connected` to the housing, an ignition fuel reservoir located directly-above vsaid valve housing and communicating with the same via said non-return valve, means to apply force to said diaphragm pump in opposition to that of its spring to force ignition fluid from said valve chamber into and through said igniting oil pipe, said igniting oil pipe having means to prevent return fiow of igniting oil into said valve housing, by virtue of al1 of which any vapors in the diaphragm pump and in the valve housing will, upon the opening of said valve, pass into said reservoir thereby preventing such vapors being forced into said igniting oil pipe, the arrangement of the pump, the valve housing reservoir being such-that the escape of and the vapor from the pump and valve housing into the 'l0 reservoir and the ow of oil from the reservoirinto thevalve housing and-the pump take place in a vertical direction, said igniting oil pipe communicating with the substantially highest part of the valve housing below thenon-return valve and communicating with the ignition devceat substantially its highest place, and said ignition device being located at a higher level than said pump and reservoir.

SERGE ZIEGLER.

Images