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Publication numberUS3742916 A
Publication typeGrant
Publication dateJul 3, 1973
Filing dateNov 12, 1971
Priority dateJan 7, 1971
Publication numberUS 3742916 A, US 3742916A, US-A-3742916, US3742916 A, US3742916A
InventorsAstrom K, Wessberg J
Original AssigneeGoetaverken Angteknik Ab, Gotaverken Heat Eng Co Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Arrangement for cleaning an air passage in the wall of a refuse burning furnace
US 3742916 A
Abstract
The passages in the wall of a refuse burning furnace for supplying combustion air thereto run an apparent risk of being clogged by particles of solid matter carried by the combustion gases. In order to remove such deposits a sleeve is fitted into the each passage, and is connected to a driving means designed to impart a reciprocatory forwards and backwards movement thereto. A scraper ring may be fitted inside the sleeve to support the pushing out action, and air for cooling purposes may be supplied to the clearance between the wall of the passage and the sleeve.
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United States Patent 11 1 Wessberg et al. July 3, 1973 [54] ARRANGEMENT FOR CLEANING AN AIR 2,480,394 8/1949 Cavel's et al. 266/41 PASSAGE IN THE WALL OF A REFUSE 2,161,110 6/1939 Tomlinson et al.... 122/7 2,696,979 12/1954 Berge 1l0/182.5 BURNING FURNACE 3,361,419 1/1968 Siemssen 266/42 [75 Inventors: Jacob Erland Magnus Wessberg, Torslanda; Kjell Edvard Ingmar Astmmv Stenungsund, both of Primary Examiner-l(enneth W. Sprague Sweden Attorney-Ralph E. Parker et a1. [73] Assignee: Gotaverkens Angtekniska AB (Gotaverken Heat Engineering Co. Ltd.), Goteborg, Sweden 221 Filed: Nov. 12, 1971 [57] ABSTRACT [21] Appl' l98382 The passages in the wall of a refuse burning furnace for supplying combustion air thereto run an apparent risk [30] Foreign Application Priority Data of being clogged by particles of solid matter carried by July 1, 1971 Sweden 92/71 the combustion gases In Order to remove Such depflsits a sleeve is fitted into the each passage, and is connected 52 us. 01. 122/390, 110/182.5 to a driving means designed to impart a reciprocawry [51] Int. Cl. F22b 37/48 forwards and backwards movement thereto- A Scraper 58 Field of Search 110/72, 182.5; ring y be fitted inside the Sleeve to Support the p 22 7; 2 41 42 ing out action, and air for cooling purposes may be supplied to the clearance between the wall of the passage [5 6] References Cited and the Sleeve- UNITED STATES PATENTS 2,244,079 6/1941 Phillips 266/42 4 Claims, 4 Drawing Figures mmmma ma SHEEF 1 [if d PATENTEDJULB 197a 3.742.916

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ARRANGEMENT FOR CLEANING AN AIR PASSAGE IN THE WALL OF A REFUSE BURNING FURNACE BACKGROUND or THE INVENTION Waste liquor from the processing of cellulose pulp is usually burnt in a recovery furnace to which the liquid is continuously supplied by means of one or more nozzles, which spray the liquor into the furnace in such a manner that part thereof will burn in suspension whereas the remainder adheres the walls of the furnace, where it is dehydrated and finally falls down into the hearth, where it forms a mound of dried matter where the final combustion occurs.

In order to burn the combustible particles in this mound which is continiously refilled by matter falling down from the jets and from the walls, combustion air is supplied at several levels in the furnace. An aim is to maintain the combustion as uniformly as possible over the cross sectional area of the furnace. This will result in a more complete combustion and a better heat recovery, and also minimizes the formation of H 8, will cause a nauseating smell in the surroundings, and with high concentration will accelerate the corrosion on the pressure parts of the furnace, especially in the lower portion thereof.

The air is distributed by means of wind boxes located at different levels outside the walls of the furnace, and from which the air is conveyed by means of a number of passages in the tube walls of the furnace. Alternatively the air from a common supply conduit is distributed by way of rows of separate pipes, with each ends at a wall passage. On both occasions these passages are distributed over the wall surface in principally the same manner. In order to make possible a basic adjustment of the volume of air to the different wind boxes, or to groups of wall passages each wind box is usually provided with throttling means in its supply conduits.

Such throttling means may also be provided at the supply conduit to a group of pipes leading to individual passages. Each passage may furthermore be provided with its own throttling means to make possible a selected distribution of the air within each wind box, or within each groups of pipes, respectively, and to maintain the desired air pressure ahead of the passages.

The complicated arrangement for the supply of combustion air above described is desirable because it is difficult to obtain an uniform distribution of the liquor over the cross sectional area of the furnace and because the operating conditions for the nozzles, and therefore also the requirement upon the distribution of the air, will vary depending upon the load on the furnace and also upon the moisture content of the liquor to be sprayed.

The type of fuel actual, viz. waste liquor, and the manner of supplying the same to the furnace results in the build up of heavy coatings on the walls of the furnace, which tend to clogg the openings of the air passages into the furnace.

In order to maintain the desired air distribution this clogging of the openings must be kept under control. The clogging will not appear uniformly over the wall surfaces and therefore the air distribution will be influenced, as well as the total volume of air and also the pressure thereof.

It is a tedious task for the operator, manually to keep the passages free by means of a lance, and it has been observed that the operator under continuous running of the plant is unable to maintain the same satisfactory combustion conditions as have been obtained during the delivery testing of the unit.

SUMMARY OF THE INVENTION The aim of the present invention is to eliminate, or largely to reduce the problems encountered by the clogging in and around the air passages, and it is characterized in a sleeve mounted in each passage, being shorter than the latter and shaped substantially to follow the internal cross section of the passage, as well as in means for imparting a forwards and backwards oscillating movement to the sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS According to a preferred form of the invention, sleeves in a number of passages within a series of passages are interconnected by means of a common actuating member. This latter is operatively associated with a driving means. The driving means is automatically actuated at pre-determined intervals by means of a governor, the activation at each occurrence being effected to perform a certain number of strokes.

FIG. 1 is a perspective view of part of the furnace wall surrounding an air passage having a sleeve mounting therein,

FIG. 2 shows a corresponding part of the wall as viewed in a vertical section,

FIG. 3 shows the arrangement on a larger scale and including more details, and

FIG. 4 illustrates the preferred form of the invention in which certain sleeves are interconnected by means of a common actuating member, a driving means and a governor for automatically activating said driving means.

DESCRIPTION OF THE PREFERRED EMBODIMENT The walls of the furnace consist of water cooled tubes 10, which form part of a steam boiler and the faces of which turned towards the furnace are covered with blocks of heat and corrosion resistant material and/or by a refractory compound. The desired air passages are obtained by bending apart two adjacent tubes. The passages will thus obtain an elongated form. The passage proper is formed as a housing 11, the outer shape of which corresponds to the opening obtained between the two tubes, and which will sealingly engage in the opening. The housing is open towards a wind box 12 mounted at the outside of the wall, and it is evident that a number of similar passages are connected to this box, which is supplied with heated air from a suitable source. In the back wall 13 of the box there is arranged opposite to each passage, an inspection opening 14 provided with a window of heat resistant material, as well as a further opening 15, provided with a lid 16, pivotably supported about its upper edge. Through this later opening a lance may be introduced into the air passage 11, ifit, as a result of a damage to the operating mechanism, will become necessary manually to break up deposits formed within air passage. At the inlet end of the air passage there is a throttling member 17 by means of which the volume of air can be adjusted individually for each passage.

As above mentioned the nature of the fuel used brings about an apparent risk of a clogging of the opening of the air passage, said clogging having a marked influence upon the volume and the distribution of the air. In order to maintain each passage clean a sleeve 18 is mounted therein. This sleeve is shorter than the passage and the contour thereof substantially corresponds to the internal cross section of the passage. FIGS. 1 and 2 show the sleeve in its rest position, in which it is retracted as far back as to the throttling member 17. By means of a link mechanism 19, 20 a forwards and backwards oscillating movement is imparted to the sleeve from a motor 21, which might be a compressed air unit, the piston rod 22 of which is connected to link 20. The movement of the mechanism is selected in such a manner, that the sleeve will be brought forwards until the edge of, orjust outside the edge of the air passage. During this forward movement it will remove any matter deposited within the passage.

The sleeves at a number of passages located adjacent to each other preferably are connected to a common driving means 21, which may be governed by means well known in the art to be automatically activated at predetermined intervals, and which on each occasion will perform a certain number of strokes,

The design of the air passage and of the sleeve therein is shown more in detail in FIG. 3. The internal wall of the passage housing is provided with a number of axially directed ledges 23, which support the sleeve during its movements and reduce the contact face between the latter and the wall of the passage. This is furthermore provided with a number of openings 24, which by conduits not shown in the drawing are connected to the air wind box 12, so a limited amount of air will constantly flow to the clearance between the housing of the air passage and the sleeve in order to cool the latter.

The sleeve is provided with two sidewardly directed pegs 25, which pass through elongated slots in the housing of the passage, and which are connected to the links 19 in such a manner that a transfer of the movements to the sleeve may be arranged without changing the position of the throttling member 17. It is apparent that the sleeve actually will be the determining factor for the volume of air, but through the arrangement shown the volume of air to each passage will not be influenced by the occasional position of the sleeve within the passage. If the actuating mechanism should be put out of action as a result of some damage the arrangement due to the lancing openings will be fully equivalent to that of conventional air passages lacking the cleaning means according to the invention.

A scraper ring 26 is fitted within sleeve 18 is mounted on a number of pegs 27, which pass elongated slots 28 in the sleeve and are fixedly mounted in the housing.

The scraper ring, thus, will maintain a fixed position during the displacement of the sleeve, and it is mounted just inside the position held by the edge of the sleeve turned towards the furnace, when the sleeve is withdrawn to its rest position. Deposited matter, which during the outward movement of the sleeve is pushed into the latter will be removed by the scraper ring during each retracting movement, so it will again fall down into the air passage, and during the following outward movement of the sleeve be pushed out of the passage. In the preferred embodiment illustrated in FIG. 4 there is shown a repetition of the organization illustrated in FIG. 1, to which has been added a showing of a common rack 19, 19 operated by pressure fluid motor 21, the supply of motive fluid thereto is governed by a valve 30, which valve in turn is activated by an electric motor 31 which is supplied with electric current at selected intervals by means of a timing device 32.

What we claim is: 1. An arrangement for cleaning an air passage in the wall of a refuse burning furnace, comprising a sleeve mounted within the passage, being shorter than the latter and shaped substantially to follow the internal cross section of the passage, and

means for imparting a forwards and backwards reciprocatory movement to the sleeve within the passage,

the internal wall of the passage being provided with elongated ledges serving to govern the movements of the sleeve with a clearance with respect to the wall of the passage.

2. The arrangement according to claim 1, in which a scraper ring is fitted into the sleeve, near the end thereof turned towards the furnace, said ring being mounted at the wall of the passage by means of pegs passing elongated slots in the sleeve.

3. The arrangement according to claim 1, further including a number of openings in the wall of the passage, said openings communicating with the air supply side of the passage and being designed to supply a limited amount of air to the clearance between the sleeve and the wall of the passage.

4. The arrangement according to claim 1, which further comprises a common actuating member which interconnects sleeves in a number of passages within a series of said passages and wherein a driving means is in operative association with said common actuating member, the arrangement further including a governor automatically activating said driving means at predetermined intervals on each occasion to perform a certain number of strokes.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2161110 *May 16, 1935Jun 6, 1939Babcock & Wilcox CoMethod of and apparatus for burning waste liquor
US2244079 *Nov 4, 1940Jun 3, 1941Phillip C HallPunching device
US2480394 *Feb 7, 1947Aug 30, 1949Falconbridge Nickel Mines LtdPunching pipe for converter tuyeres
US2696979 *Apr 16, 1951Dec 14, 1954Kennecott Copper CorpAutomatic tuyere punching apparatus
US3361419 *May 10, 1966Jan 2, 1968Selas Corp Of AmericaAir preheating burner with furnace preheating passage cleaner means
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3875904 *Feb 20, 1974Apr 8, 1975Goetaverken Angteknik AbDevice for cleaning air passage openings in the walls of a refuse burning furnace
US3900011 *May 2, 1974Aug 19, 1975Goetaverken Angteknik AbAir supply means for a furnace
US3920377 *Jun 28, 1974Nov 18, 1975Ishikawajima Harima Heavy IndCombustion apparatus
US3943861 *Dec 30, 1974Mar 16, 1976Gotaverken Angteknik AbDevice for operating air governing means at a refuse burning furnace
US4027604 *Sep 29, 1975Jun 7, 1977Gotaverken Angteknik AbMeans for governing the air supply to a furnace
US4099471 *Nov 19, 1976Jul 11, 1978Combustion Engineering, Inc.Apparatus for cleaning the air nozzles and regulating air flow thereto in chemical recovery boilers
US4554320 *Feb 13, 1985Nov 19, 1985Basf AktiengesellschaftBlend with ethylene-alkyl acrylate copolymer having acid groups
US4653409 *Jan 31, 1986Mar 31, 1987Lt-Produkter Skutskar AbApparatus for regulating and cleaning an air passage in the wall of a furnace
US4837264 *Jan 5, 1988Jun 6, 1989Basf AktiengesellschaftPolyamide compositions containing alkyl orthotitanate or dialkyltin dilaurate
US4940004 *Jul 7, 1989Jul 10, 1990J. H. Jansen Company, Inc.High energy combustion air nozzle and method for improving combustion in chemical recovery boilers
US5034450 *Feb 24, 1989Jul 23, 1991Basf AktiengesellschaftBlends of polymers for impact and tensile strength
US5528999 *Feb 1, 1995Jun 25, 1996Tampella Power OyAir nozzle for a recovery boiler
US6055943 *Sep 21, 1998May 2, 2000Anthony-Ross CompanyAir port casting
US6431125Mar 3, 1999Aug 13, 2002LT-Produkter Skutskär ABDevice for regulating and cleaning an air intake
US6672227 *Feb 15, 2001Jan 6, 2004Kvaerner Pulping AbArrangement for cleaning, airflow control and pushing away melt in air ports of incineration boilers
US8707911 *Oct 26, 2005Apr 29, 2014Andritz OyCooling system for ports in a boiler
US20090272339 *Oct 26, 2005Nov 5, 2009Andritz OyCooling system for ports in a boiler
EP0192382A2 *Feb 6, 1986Aug 27, 1986Lt-Produkter Skutskar ABApparatus for regulating and cleaning an air passage in the wall of a furnace
EP0461747A2 *Apr 10, 1991Dec 18, 1991THE BABCOCK & WILCOX COMPANYAuxiliary port cleaner for boiler wall sensing port
EP1646827A2 *Jun 14, 2004Apr 19, 2006Clyde Bergemman, Inc.Automatic combustion air port cleaner with air/oil indexing mechanism
WO1999045323A1 *Mar 3, 1999Sep 10, 1999Eriksson ToreA device for regulating and cleaning an air intake
WO2001061248A1 *Feb 15, 2001Aug 23, 2001Kvaerner Pulping TechArrangement for cleaning, airflow control and pushing away melt in air ports of incineration boilers
Classifications
U.S. Classification122/390, 110/182.5
International ClassificationF23J3/00, B08B9/043, B08B9/02
Cooperative ClassificationF23J3/00
European ClassificationF23J3/00