US2813578A

US2813578A - Burners

Info

Publication number: US2813578A
Application number: US408649A
Authority: US
Inventors: Ferguson William
Original assignee: NAT AIROIL BURNER Co Inc
Current assignee: NAT AIROIL BURNER Co Inc; NATIONAL AIROIL BURNER COMPANY Inc
Priority date: 1954-02-08
Filing date: 1954-02-08
Publication date: 1957-11-19
Anticipated expiration: 1974-11-19

Description

Nov. 19, 1957 w. FERGusoN 2,813,578v

BURNERS Filed Feb. a, 1954 Bgm@ TI'ORNE Y United States Patent @ffice 2,813,578 Patented Nov. 19, 1957 BURNERS William Ferguson, Philadelphia, Pa., assignor to National Airoil Burner Company, Incorporated, Philadelphia, Pa., a corporation of Delaware Application February 8, 1954, Serial No. 408,649 6 Claims. (Cl. 158-1) This invention relates to burners and more particularly to burners for heavy or residuum oils.

In modern oil refinery practice, upfired furnaces are frequently employed for furnaces, stills, heaters and similar separately tired devices. No substantial difliculties have been encountered in the use of gas or light oils as fuel. Upon attempting to burn heavy or residuum oils from the cracking processes, difficulties have been encountered because of coke deposition in the bore of refractory blocks used as part of the burner. The dripping of the heavy or residuum oils from the burner is objectionable both from the viewpoint of safety as well as cleanliness of operation and this also has tended to cause sticking of the air control mechanism.

In accordance with the present invention an improved burner is provided for heavy and residuum oils which is free from the objections heretofore encountered.

In accordance with the present invention, also, an irnproved burner is provided in which the temperature is maintained at levels such that the heavy or residuum oils are liquefied and vaporized so as to assist in the introduction and burning thereof.

In accordance with the present invention, also, an improved burner for heavy and residuum oils is provided in which a recirculation of hot furnace gases is employed for heating.

In accordance with the present invention, also, an improved burner for heavy and residuum oils is provided in which a recirculation of hot gases is employed for heating and in which the gases and the primary air for combustion are aspirated by the steam used for atomizing the oil and by the advance of the fuel.

Other objects and advantageous features of the invention will be apparent from the description and claims.

The nature and characteristic features of the invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part thereof, in which:

Figure 1 is a top plan view of a furnace oor having a burner in accordance with the invention mounted therebelow; and

Fig. 2 is a vertical sectional view taken approximately on the line 2-2 of Fig. 1.

It should, of course, be understood that the description and drawings herein are illustrative merely, and that various modifications and changes may be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

Referring now more particularly to the drawings, a fragmentary portion of a furnace floor is illustrated, of the character employed in stills, heaters and the like in refineries and other process industries, comprising a horizontal metal plate 11 with a horizontal refractory lining 12 thereon.

The oor 1,0 is provided with an opening 9 within which a mue block 14 of refractory material is mounted.

The upper face of the muffle block 14 extends a short distance above the upper surface of the floor 10 and the lower face of the mufe block 14 is approximately on the same level as the lower face of the floor plate 11. The muiile block 14 has a cylindrical opening 15 therethrough with a iiare 16 at the upper end thereof.

Axially disposed below the muffle block 14, a burner block housing 17 is provided, preferably ofI metal plate and having a vertical wall 18 and a horizontal wall 19. A burner housing 20 is provided below the housing 17 and in axial alinement therewith.

Within the block housing 17, a burner block 21 of refractory material, is provided, the burner block 21 terminating in spaced relation to the mufe block 14 to provide a chamber 22. The vertical length of the block 21 is preferably about two and one half times that of the mui-lie block 14. The wall 18, at a location above the upper face of the burner block 21, is provided with a plurality of pivotally mounted air inlet doors 23, which are adapted to be adjusted as desired with respect to quadrants 24 for determining the amount of air delivered through air inlet openings 23a to the chamber 22.

The burner block 21 has an interior bore shaped to provide a venturi action and for this purpose has an inlet section 25, a section of reduced diameter as at 26, and a frusto-conical section 27 of increasing diameter towards the chamber 22. The maximum diameter of the section 27 is slightly less than that of the opening 15 in the mufe block 14.

A steam supply pipe 30 having a valve 31 therein is provided for supplying steam for atomization and is connected by a coupling 32 having a burner control valve 33 therein to a burner supply pipe 34. A fuel pipe 35 is provided, for supplying heavy or residuum oil for combustion, is connected to the coupling 32, and. has a control valve 36 for controlling the flow therethrough.

The burner housing 20 has a vertical side wall 37 and a horizontal end wall 38 through which the supply pipe 34 extends.

At the inner end of the supply pipe 34 an atomizing burner head 39 is provided, in axial alinement with the bore in the burner block 21 and is located at the entrance to that bore.

The supply pipe 34 has mounted therearouud, on a tubular holder 4i), a frusto-conical llange 41 which may function as a collecting cup and the outer margin of which is in spaced relation to the inlet section 25 of the burner block 21 to provide a restricted passageway.

The side wall 37 of the housing 20 has one or more air inlet openings 42, with air inlet doors 43 which are adapted to be adjusted with respect to quadrants 44 for determining the amount of air delivered to the interior of the housing 20.

The floor 1t) is provided with an opening 45 from which a duct 46 extends to and in communication with the interior of the housing 20. An adjustable damper 47 is preferably provided in the duct 46 for controlling the liow of gases therethrough. If it is desired to circulate more gases than would be aspirated or for circulation of hot gases without operating the burner to preheat the blocks 14 and 21 a steam jet 48 may be provided in the duct 46. A control valve 49 is provided in the steam supply line 50.

The mode of operation will now be pointed out.

Fuel under pressure delivered through the pipe 35 to the burner head 39 is atomized and delivered therefrom by the steam delivered through the pipe 30. The atomized fuel and steam delivered from the burner head 39, in its passage through the burner block 21, is subjected to heat therefrom so that the low hydrocarbon volatiles in the oil are gasied, the atomizing steam is superheated, and

the heavier fractions in the atomized fuel are heated to a high temperature approaching or exceeding vaporization, which combined with the air in the recirculated gases causes combustion to be rapidly initiated to insure combustion while the oil particles are in suspension.

As the combustible and burning gaseous material passes from the bore of the burner block 2l through the chamber 22. and into the opening 15 in the inutile block 14, sutilcient secondary air is drawn in through the openings 23a at the air doors 23 to continue and complete the combustion of the combustible constituents.

The aspirating eifect of the fuel and steam is effective, if desired, for drawing air through the openings 42 at the inlet doors 43.

Under normal operating conditions there is present at and above the floor 10 gaseous material having a preponderance of carbon dioxide with some free air containing oxygen. The average operating temperature at this point, depending on operating conditions and furnace design is from 100G F. to 2200 F., and the carbon dioxide content is from to 13%.

The aspirating effect of the fuel and steam from the burner head 39, or the steam from the steam jet 48, or both, is effective for drawing hot furnace gases through the opening 45 and the duct 45, as controlled by the damper 47, and into the interior of the housing 20 where they mix with and temper the air drawn in at the doors 43, contact and heat the flange 4l and then pass into the burner block opening where they aid in heating that block and the fuel and steam passing through the bore of the block 21.

Any fuel initially collected in the flange 4l, at starting, is quickly vaporized and drawn upwardly for combustion.

The arrangement and operation heretofore described has been found in practice to be very effective for preventing coke deposits on the blocks 2l and 14 and also to prevent any dripping of the oil.

I claim:

l. Apparatus for burning heavy oil cracking residuums comprising a furnace having a horizontal floor, a refractory heat transferring burner block spaced below said floor having a venturi opening therethrough, a muffle block in said floor in spaced relation to said burner block and having an opening therethrough alined with said burner block opening and in communication with the interior of the furnace, said venturi opening being of a greater length than said mule block opening, variable air inlet openings below said floor in communication with the space between said blocks, an atomizing fuel burner discharge head disposed at the inlet end of said burner block opening and discharging upwardly therethrough, fluid connections connected to said burner head for supplying atomizing fluid and oil cracking residuums to said burner head, a member at the inlet end of said burner block opening and extending in spaced relation to said burner block opening for restricting the inlet end of said burner block opening, a fluid connection from the interior of the floor of said furnace and in spaced relation to said mule block, said connection extending to the inlet end of `said burner block opening for the delivery of hot gases from the floor of the furnace to said burner block opening for admixture with and heating of said residuums and for heating said burner block, and a member carried by said fluid connection having a variable air inlet opening for controlling the delivery of air for admixture with said hot gases, said atomizing fluid aspirating the air through said inlet openings and the hot gases to said burner block opening.

2, A burner construction as defined in claim 1 in which a steam jet is provided in the fluid connection for additionally inducing the flow of hot gases therethrough.

n 3. Apparatus for burning heavy oil cracking residuums comprising a furnace having a horizontal floor, a refractory heat reflecting burner block spaced below said floor having a vertically disposed venturi openings therethrough, a muiile block in said floor in spaced relation to said burner block and having an opening therethrough alined with said venturi opening and in communication with the interior of the furnace, the length of said venturi opening being a plurality of times the length of said muffle block opening, variable air inlet openings below said iloor in communication with the space between said blocks, an atomizing fuel burner discharge head disposed at the lower end of said burner block opening and discharging upwardly therethrough, lluid connections connected to said burner head for supplying atomizing fluid and oil cracking residuums to said burner head, a member at the inlet end of said burner block opening and extending in spaced relation to said burner block opening for restricting the inlet end of said burner block opening, a iluid connection in spaced relation to the inutile block and extending from the interior of the iloor of the furnace to the inlet end of the restricted opening for the delivery of hot gases from the furnace to said burner block opening for admixture with and heating of said residuums and for heating said burner block, and a member carried by said fluid connection having a variable air inlet opening for controlling the delivery of air for admixture with said hot gases, said atomizing fluid aspirating the air to the space between said blocks and the hot gases to said burner block opening.

4. Apparatus for burning heavy oil cracking residuums comprising a furnace having a horizontal floor, a refractory fuel heating burner block spaced below said floor having a vertically disposed venturi opening therethrough, a mulfle block in said floor in spaced relation to said burner block and having a Vertical opening therethrough alined with said venturi opening and in direct communication with the interior of the furnace, said burner block and its opening being of greater length than said mufile block and its opening, variable air inlet openings below said oor in communication with the space between said blocks, an atomizing fuel burner discharge head disposed at the inlet end of said burner block opening and discharging inwardly therethrough, fluid connections connected to said burner head for supplying atomizing fluid and oil cracking residuums to said burner head, a member at the inlet end of said burner block opening and extending in spaced relation to said burner block opening for restricting the inlet end of said burner block opening, said last member being alined with said openings, a fluid connection in spaced relation to said muffle block and extending from the interior of the floor of the furnace to the inlet end of the restricted opening for the delivery of hot gases from the furnace to said burner block opening for admixture with and heating of said residuums and for heating said burner block, and a member carried by said fluid connection having a variable air inlet opening for controlling the delivery of air for admixture with said hot gases said atomizing fluid aspirating the air vthrough said air inlet openings and the hot gases to said burner block opening and through said burner block.

5. Apparatus for burning heavy oil cracking residuums comprising a furnace having a longitudinal floor, a burner construction for said furnace below the floor of the furnace comprising a muflle block disposed in the furnace floor and having a vertical opening therethrough, a housing extending downwardly from the floor, a refractory heat transferring burner block mounted in and supported by said housing and spaced downwardly from said muifle block, said burner block having a vertically extending venturi opening therethrough axially alined with said Inutile block opening, the length of said burner block opening being a plurality of times the length of s'aid muflle block opening, the space between said blocks providing a chamber, variable air inlet openings in the housing in communication with said chamber, a burner housing disposed below said first mentioned housing and having a chamber therein in communication with the inlet end of said burner block opening, a burner supply pipe extending vertically through said burner housing chamber, an atomizing burner head on the inner end of said pipe and at the inlet end of said burner block opening and discharging upwardly therethrough, a member surrounding said pipe and extending in spaced relation to said burner block opening and providing a restriction at the inlet end of the burner block opening and a receptacle for vaporization of fuel fallout, a variable air inlet opening in communication with the chamber in said burner housing, uid connections connected to said burner supply pipe for supplying atomizing uid and oil cracking residuums to said burner supply pipe, the atomizing fluid from said burner atomizing said residuums, aspirating air through said air inlet openings and aspirating the hot gases to said burner housing and into said burner block, a uid connection in spaced relation to said mufe block and in communication with the interior of the furnace chamber at its inlet end and with the chamber in said burner housing for the delivery thereto of hot gases from the furnace chamber for admixture with and heating of said residuums and heating of said burner block, and a steam jet in said uid connection for additionally delivering said gases from said furnace chamber to said burner housing chamber.

6. Apparatus for burning heavy oil cracking residuums comprising a furnace having a horizontal Hoor, a burner construction for said furnace disposed below the floor of the furnace comprising a muflle block disposed in the furnace floor and having a vertical opening therethrough, a housing extending vertically downwardly from the floor, a refractory heat transferring burner block mounted in said housing and spaced downwardly from said mufle block, said burner block having a vertically extending venturi opening therethrough axially alined with said muiie block opening, the space between said blocks providing a chamber, the length of said burner block opening being a plurality of times the length of said mue block opening, variable air inlet openings in the housing in communication with said chamber, a burner housing disposed below said rst mentioned housing and having a chamber therein in communication with the inlet end of said burner block opening, a burner supply pipe extending vertically through said burner housing chamber, an atomizing burner head on the inner end of said pipe and! at the inlet and of said burner block opening in axial alinement with said burner block opening and discharging upwardly therethrough, a member surrounding said pipe and providing a restriction at theY inlet end of the burner block opening and a receptacle for yaporization of fuel fallout, a variable air inlet opening in communication with the chamber in said burner housing, uid connections connected to said burner supply pipe for supplying atomizing fluid and oil cracking residuums to said burner supply pipe, a fluid connection in communication with the furnace chamber through the furnace oor and'with the chamber in said burner housing for the delivery thereto of hot gases from the furnace chamber, and a member in said uid connection for controlling the ow through said uid connection, said atomizing fluid aspirating the air through said inlet openings and the hot gases to and through said burner block opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,145,504 ONeil July 6, 1915 1,609,150 Breese Nov. 30, 1926 1,684,991 Inglis Sept. 18, 1928 1,790,870 Mantle et al. Feb. 3, 1931 1,891,877 Falkenwalde Dec. 20, 1932 2,050,577 Littleton Aug. 11, 1936 2,086,812 Luty July 13, 1937 2,333,531 Ferguson Nov. 2, 1942 2,512,319 Ferguson .Tune 20, 1950 2,688,360 Haynes et al Sept. 7, 1954 2,701,608 Johnson Feb. 8, 1955 FOREIGN PATENTS 523,871 Great Britain July 24, 1940