Liquid fuel burner having reduced thermal stress and rapid start-up time

Claim 2

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means directly interconnecting said burned gas removal port to said burned gas and fuel inlet, an air inlet to said mixing chamber for directing air under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, and a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 3

A liquid fuel burner as set forth in claim 1 in which there is insufficient air present in said interconnecting means to support combustion of said gasified fuel prior to its reaching said fuel mixture inlet port.

Claim 4

A liquid fuel burner as set forth in claim 1 including ignition means positioned proximate to, but before, said fuel mixture inlet port, for igniting said mixture of said fuel and air.

Claim 5

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, that improvement for reducing thermal stresses in hot gas feedback including means directly interconnecting said hot burned gas feedback port with said mixing chamber, means for introducing said gasifiable liquid fuel into said interconnectiNg means, so proximate to said refractory material that said fuel will be gasified by said hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses.

Claim 6

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, that improvement for reducing thermal stresses in hot gas feedback including means directly interconnecting said hot burned gas feedback port with said mixing chamber, means for introducing said gasifiable liquid fuel into said interconnectiNg means, so proximate to said refractory material that said fuel will be gasified by said hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses.

Claim 7

A liquid fuel burner improvement as set forth in claim 4 including a metering valve associated with said gasifiable liquid fuel inlet to control the rate of flow into said inlet.

Claim 8

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, means for connecting said hot burned gas feedback port to said fuel mixture inlet port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, and means for introducing liquid fuel into said connecting means so that it may be gasified prior to combustion, that improvement for start-up of said burner including: a liquid fuel nozzle disposed in said air source, ducts interconnecting said nozzle with said liquid fuel introducing means, and control valve means for controlling flow of said liquid fuel to said nozzle or to said connecting means, whereby said burner may be started by use of said nozzle to inject liquid fuel into said air for burning in said fire chamber prior to use of gasified fuel.

Claim 9

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, means for connecting said hot burned gas feedback port to said fuel mixture inlet port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, and means for introducing liquid fuel into said connecting means so that it may be gasified prior to combustion, that improvement for start-up of said burner including: a liquid fuel nozzle disposed in said air source, ducts interconnecting said nozzle with said liquid fuel introducing means, and control valve means for controlling flow of said liquid fuel to said nozzle or to said connecting means, whereby said burner may be started by use of said nozzle to inject liquid fuel into said air for burning in said fire chamber prior to use of gasified fuel.

Claim 10

A liquid fuel burner improvement as set forth in claim 6 including a sequence timing control for said control valve means.

Claim 11

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, said interconnecting means being a metallic pipe running between said burned gas feedback port and said burned gas and fuel inlet, an air inlet to said mixing chamber for directing air under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, and a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 12

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, said interconnecting means being a metallic pipe running between said burned gas feedback port and said burned gas and fuel inlet, an air inlet to said mixing chamber for directing air under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, and a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 13

A liquid fuel burner as set forth in claim 8 in which said gasifiable liquid fuel inlet is sufficiently proximate to said refractory material relative to the length of said interconnecting pipe and the temperature of said burned gas so as to gasify said fuel as it passes through said interconnecting means sufficiently to substantially avoid appearance of yellow in the flame in said fire chamber.

Claim 14

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, an air inlet to said mixing chamber for directing aiR under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, and a starter unit for creating a fire in said fire chamber when starting said burner so as to produce hot burned gas for feedback and gasification, said starter unit including a nozzle for inserting said fuel in its liquid form into said air inlet, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 15

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, an air inlet to said mixing chamber for directing aiR under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, and a starter unit for creating a fire in said fire chamber when starting said burner so as to produce hot burned gas for feedback and gasification, said starter unit including a nozzle for inserting said fuel in its liquid form into said air inlet, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 16

A liquid fuel burner as set forth in claim 10 including fuel supply for said fuel inlet and for said nozzle, and control valve means for controlling flow of said fuel to said nozzle or said fuel inlet sequentially.

Claim 17

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, an air inlet to said mixing chamber for directing air under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, and means for inserting additional liquid fuel into said mixing chamber at said air inlet to provide a second stage of liquid fuel gasification, said second stage utilizing heat energy remaining in said hot burned gas entering said mixing chamber, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 18

A liquid fuel burner for burning a gasifiable liquid fuel such as oil and having reduced thermal stresses, including a burner made of refractory material and having a fire chamber, said chamber having a fuel mixture inlet port, a burned gas removal port, and a hot burned gas feedback port, a mixing chamber for mixing said fuel and air, said mixing chamber being connected to said inlet port, a burned gas and fuel inlet to said mixing chamber, means interconnecting said burned gas removal port to said burned gas and fuel inlet, an air inlet to said mixing chamber for directing air under pressure into said mixing chamber, said air inlet including a Venturi for drawing burned gas and fuel into said chamber through said interconnecting means and said burned gas and fuel inlet, a gasifiable liquid fuel inlet connected to said interconnecting means proximate to said refractory material, and means for inserting additional liquid fuel into said mixing chamber at said air inlet to provide a second stage of liquid fuel gasification, said second stage utilizing heat energy remaining in said hot burned gas entering said mixing chamber, whereby said fuel will be gasified by hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses therein.

Claim 19

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, that improvement for reducing thermal stresses in hot gas feedback including means interconnecting said hot burned gas feedback port with said mixing chamber, means for introducing said gasifiable liquid fuel into said interconnecting means, so proximate to said refractory material that said fuel will be gasified by said hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses, and a starter unit to provide initial hot burned gas for feedback, said starter unit including means for inserting ungasified fuel into the air stream in said mixing chamber.

Claim 20

In a liquid fuel burner for burning a gasifiable liquid fuel such as oil which includes a burner made of refractory material and having a fire chamber therein, said fire chamber having a fuel mixture inlet port, a burned gas removal port and a hot burned gas feedback port, a source of air under pressure, a mixing chamber for mixing said fuel and air and being connected to said inlet port, that improvement for reducing thermal stresses in hot gas feedback including means interconnecting said hot burned gas feedback port with said mixing chamber, means for introducing said gasifiable liquid fuel into said interconnecting means, so proximate to said refractory material that said fuel will be gasified by said hot burned gas as it passes through said interconnecting means and the heat of vaporization of said fuel will cool said hot burned gases, thereby reducing the temperatures thereof and reducing thermal stresses, and a starter unit to provide initial hot burned gas for feedback, said starter unit including means for inserting ungasified fuel into the air stream in said mixing chamber.

Claim 21

In a liquid fuel burner for burning a gasifiable liquid fuel which includes a fire chamber and a mixing chamber for mixing air with said liquid fuel after gasification and for feeding same to said fire chamber, that improvement including duct means interconnecting said fire chamber and mixing chamber to carry hot combustion gases from said fire chamber to said mixing chamber, said duct means interconnectIng said burner and said mixing chamber by substantially the most direct path, said duct means having a fuel inlet area for receiving said liquid fuel prior to gasification, and said fuel inlet area being positioned sufficiently close to said firing chamber and sufficiently far from said mixing chamber as to permit substantial gasification of said fuel in said duct means before said fuel as carried by said hot combustion gases reaches said mixing chamber and as to permit the heat of vaporization of said oil to reduce the temperature of said duct means.

Claim 22

In a liquid fuel burner for burning a gasifiable liquid fuel which includes a fire chamber and a mixing chamber for mixing air with said liquid fuel after gasification and for feeding same to said fire chamber, that improvement including duct means interconnecting said fire chamber and mixing chamber to carry hot combustion gases from said fire chamber to said mixing chamber, said duct means interconnectIng said burner and said mixing chamber by substantially the most direct path, said duct means having a fuel inlet area for receiving said liquid fuel prior to gasification, and said fuel inlet area being positioned sufficiently close to said firing chamber and sufficiently far from said mixing chamber as to permit substantial gasification of said fuel in said duct means before said fuel as carried by said hot combustion gases reaches said mixing chamber and as to permit the heat of vaporization of said oil to reduce the temperature of said duct means.