US2634111A - Spark arrester - Google Patents

Description

April 7, 1953 A. A; WICKLAND SPARK ARRESTER 2 SHEETS-SHEET l INVENTOR.

Filed Sept. 28, 1949 P 1953 A. A. WICKLAND 2,634,111

. SPARK ARRES'IER Filed Sept. 28, 1949 2 SHEETS-SHEET 2 IN V EN TOR.

. 400 degrees or more.

Patented Apr. 7, 1953 UNITED STATES PATENT OFFICE SPARK ARRESTER Algot A. Wickland, Chicago, n1. Application September 28, 1949, Serial No. 118,429

2 Claims. (01.261-17) candescent carbon particles of coke or coal which may be carried in suspension by the rising flue gases, thereby preventing danger of fire, which may occurwhen incandescent cinder particles fall on combustible materials adjacent to the stack and surrounding properties.

Another object .of my invention is to arrest the fly ash and minute carbon particles carried in suspension by the flue gases and collect same within an enclosure for final disposal, thereby preventing its. spread over the neighborhood.

A further object of my invention is to lower the temperature of the rising flue gases, also increase the specific gravity of volatile matter, minute carbon particles emitted from the furnace stack, by directing a moisture laden air stream to blanket the rising flue gases, thereby causing a turbulence or intermingling of water vapor and gases, resultingin thorough washing and cleaning process. 1

Another object of my invention is to provide means to cause and direct a cooling water vapor spray resembling ,fog or a mist discharged in all directions from nozzles suspended above the smoke flue or furnace stack. The moisture carried by the air blast will fiashinto steam when the rising furnace gases reach atemperature of I Owing to the large outlet area of the outercasing, the combined volume of air blast, water vapor, steam and flue gases will be emitted from'the spark arrester at low veloctural steel framing supports for the inner circular shell and outer casing.

Figure 2 is plan view showing the relative positions of the circular nozzles, air blast and water piping, including the structural supports for the piping and inner shell and outer casing.

Figure 3 is a sectional view taken on line 3-3, I

Figure 1.

Figure 4 is a fragmentary enlarged view in vertical cross section of the upper circular spray nozzle.

The same part is designated by the same reference character wherever it occurs in the several views.

The construction of my invention is as follows:

Figure 1 illustrates a typical furnace stack I, with interior firebrick lining. An inner shell 5 is mounted directly above stack l and is held in position by four or more vertical structural members 3 supported by angle iron rings 2 and also supported on brackets 22, the latter being attached to the furnace stack.

The function of partitions or gusset plates 4 secured at one end to the structural members 3, is primarily to support an outer casing 6, which is larger in diameter than and encompasses the stack 1 This casing may be made in several sections, as shown on Figure 3, to allow ease of erection. As noted, the outer casing 5 extends above and below the opening of the furnace stack. The main function of casing 5 is to shield the circular spray nozzles 18, and confine a water vapor spray within a predetermined area and. also prevent prevalent outdoor wind currents to deflect and distort directional air currents maintained within the outer casing 6, by the spray nozzles when same are in operation. I

Blast pipe I l and elbow [3 are supported on structural framing 9; inner shell 5 and outer casing 6 are held in position concentrically, relative to the furnace stack opening. Circular spray nozzles 18 are supported on blast pipe 23 and a companion nozzle is supported on pipe extension 2 I. The construction of the circular spray nozzle H3 in its simplest form consists of an inverted funnel shaped bell with a hub engagin pipe 23. The lower half of the assembly !9 comprises a cone shaped member held in a fixed position, leaving an annular peripheral aperture approximately one-half inch wide, for passage of air and water under pressure. The flow of air and water at high velocity is converted into vapor, which is directed as shown by arrows 20, to cover or blanket the entire area within the confines of casing 6. The necessity of providing one or more spray nozzles depends upon the volume and temperature of flue gases, also size and weight of cinders and percentage of fumes and dust particles carried by the rising flue gases.

The air blast required for one or more spray nozzles I8, is supplied by one power driven blower I 4, having a control gate 24. Each circular spray nozzle is provided with a perforated spray ring 25 connected to water supply through pipes i2 and l2 and independently controlled by three-way plug valves ll, connected to the water supply pipe Hi.

When water is shut off the exposed piping is drained to prevent freezing through waste pipes IS, the arrangement of blower and water piping shown on Figure 1 is schematic, since these appurtenances can be placed inside the building, at any convenient location.

The inner shell 5, Figure 1, directs the flow of the rising flue gases into closer union with the water spray and air blast discharged from the spaced nozzles 18, i3, thereby minimizing interference with the downward flow of particles or matter collected within the outer shell ii.

With reference to Figures 1 and 4, elbow i3 is a part of air blast system including piping connected with a blower [4. Water pipes 12 and [2 engage pressure-tight joints in passing through elbow l3 with each pipe extending downward and connected to a perforated spray ring 25 with the air blast and water spray being directed through the annular opening in each spray nozzle above the conical member 59.

It should be noted that the construction and general arrangement of the spray nozzle assemblies are identical except for size, water pipe connections, and outside diameter.

With particular-reference to a cupola furnace, my invention operates as follows: In starting such furnace a fairly large quantity of wood and coke is ignited and permitted to burn for two or three hours before the melting process begins. During this period smoke from the burning wood passes through the cupola stack to the atmosphere, and while this is not necessarily objectionable it is considered advisable to reduce the velocity and minimize the visible smoke by admixture of natural air current rising within the outer casing 6.

In addition, a small amount of water vapor and air blast discharged through the nozzles will deflect sparks and increase the mixture of fresh air to the escaping smoke.

During the melting operation large volumes of incandescent ilue gas pass to the atmosphere, and during this period the air blast and water spray should be adjusted to suit. At the end of the melting period the contents of the cupcla, consisting of unburnt fuel and slag, are dropped to the floor. which release large volumes of incandescent gases, including sparks and cinders, which must be quenched and collected in passing through the spark arrester. This is accomplished by operating the blower and water supply at full capacity for a short interval of time. The blower may then be shut down and the water permitted to flow into the furnace stack, to cool the refractory lining, but principally to quench the incandescent fuel emptied from the cupola.

The details of construction of the nozzle form no part of the present invention.

Having fully described my invention which I claim as new, and desire to secure by Letters Patent, is:

1. A spark arrester for a vertical stack, comprising an outer casing encompassing and spaced from the stack and extending above and below the opening from the stack, means for supporting the casing upon the stack in concentric relation therewith, a blast pipe arranged above the stack and having a downwardly projecting pipe section and a reduced extension depending therefrom with the pipe section and the extension arranged centrally of the casing and the stack and with the lower end of the projection disposed adjacent the outlet of the stack, a spray nozzle at the lower end of the pipe section, and another spray nozzle at the lower end of the extension to provide spaced spray nozzles each disposed centrally above and of a size substantially less than that of the outlet of the stack, said Spray nozzles each comprising an upper inverted funnel-shaped bell and a lower cone-shaped member held in spaced relation to provide an annular, downwardly and outwardly opening aperture therebetween for directing a mixture of water spray and air under pressure diagonally and counter-current to the rising fiue gases and particles carried thereby issuing from the stack, means for supplying air under pressure to the blast pipe and extension and. to each of said nozzles, and means projecting into the blast pipe for supplying each nozzle with water under pressure.

2. A spark arrester for a vertical stack, comprising an outer casing encompassing and spaced from the stack and extending above and below the opening from the stack, a blast pipe disposed above the stack and provided with a depending end projecting downwardly toward the stack and centrally of the casing, a reduced extension depending from the end of the blast pipe, a blower for supplying air under pressure to the blast pipe and extension vertically spaced downwardly and outwardly flaring spray nozzles one depending from the end of the blast pipe and the other from the lower end of the extension for discharging the air under pressure delivered by the blast pipe, and means for supplying water to each of the spaced spray nozzles through the depending end of the blast pipe, said nozzles each being arranged and located directly above and centrally and inwardly of the wall of the stack and having spaced conical surfaces providing an annular, outwardly and downwardly opening aperture of substantially less diameter than the outlet opening of the stack for the simultaneous spraying of water and air under pressure from therebetween outwardly and downwardly across the outlet opening of the stack and counter-current to the rising high temperature fiue gases and contained particles issuing from the stack to thereby introduce water vapor into the issuing fuel gases causing a substantial drop in temperature and a reduction in the volume and high velocity of these gases and contained particles, and the air under pressure directing these contained particles outwardly against the outer casing.

ALGOT A. VVICKLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,0173% Dvorak Feb. 13, 1912 1,291,840 Gran Jan. 21, 1919 1,604,769 Fox Oct. 26, 1926 2,495,281 Fisher Feb. '7, 1950 2,529,045 Ortgies Nov. '7, 1950

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