US2632089A - Smoke abatement apparatus - Google Patents

Description

March 17, 1953 J c c s E 2,632,089

SMOKE ABATEMENT APPARATUS Filed Feb. 15, 1951 3 Sheets-Sheet 2 INVENTOR. RHY JHGOB GLHY BUOKNHSTER 25 6'9 5'6 53 BY H/s T Q IIIMIIIIIIIIIIIIIIIIII'I R/J. c. BUCKMASTER SMOKE ABATEMENT APPARATUS March 17, 1953 3 Sheets-Sheet :5

Filed Feb. 15, 1951 INVENTOR.

HIS HTTOR/VEY Patented Mar. 17, 1953 UNITED STATES PTENT OFFICE SMOKE ABATEMENT APPARATUS Ray Jacob Clay Buckmaster, Detroit, Mich.

Application February 15, 1951, Serial No. 211,107

Claims. 1

The invention pertains to combustion control apparatus and more particularly to means for eliminating or reducing the smoke, odors and dirt which commonly emanate from the combustion of fuel. The claims to the jet projector, per se, and to the boiler and firebox combination are being prosecuted in a copending divisional patent application Serial No. 330,710 filed December 5, 1952.

It is an object of the invention to provide improved smoke abatement apparatus in a compact unit structure which is conveniently installable with various different boilers and combustion systems.

It is also an object of the invention to provide such a smoke abatement unit apparatus having auxiliary secondary heating means which provides additional heat for the air stream when the steam heating coils of the apparatus fail to amply heat the air stream to a suitable high temperature for effective operation.

A further object of the invention is to provide an improved system of installation for such a smoke abatement unit.

Further objects and advantages are within the scope of the invention, such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification in conjunction with the drawings disclosing specific embodiments of the invention, wherein similar reference characters are applied to corresponding elements throughout, and in which:

Fig. 1 is a side elevational view showing one of the smoke abatement units, with the internal steam heater coils represented in dotted lines;

Fig. 2 is a sectional view taken axially down through the unit; on line 2-2 in Fig. 1;

Figs. 3 and 4 are enlarged cross-sectional views taken on lines 3-3 and 4-4, respectively, on Fig. 1;

Fig. 5 is an enlarged fragmentary view taken on line 55 on Fig. 4, to show the support means at one end of the removable electrical heater elements;

Fig. 6 is a diagrammatic view, schematically showing the electrical energizing connections and the automatic temperature control for the electrical heater elements in the unit;

Figs. 7 and 8 are enlarged cross-sectional views on lines 'i'! and 88, respectively, in Fig. 2;

Fig. 9 is an elevational view showing. the jet projecting frame adapted to be installed in a firebox doorway;

Fig. 10 is a cross-sectional view on line lib-It in Fig. 9; Fig. 10A showing amodification thereof;

Fig. 11 is a sectional viewshowing a firebox, door and doorway having the jet projecting frame installed, and

Figs. 12 and 18 are sectioned and partially diagrammatic views illustrating the installation and operation of the improved smoke abatement apparatus for various kinds of boilers.

Referring more specifically to Figs. 1 and 2 of the drawings, I have illustratively disclosed an embodiment of my improved smoke eliminator apparatus comprising a tubular air flow conducting body 1 l which may be of substantially a cylindrical conformation. This air flow conducting body I I may be supported in a vertical position, for minimum floor space requirements, and it is preferably supported upon a plurality of legs I3 for convenience of installation in the various boiler rooms and plants wherein the. unit is to be utilized.

For this purpose the body II is supported by a clamp band I5 having. a plurality of internally threaded sockets ll secured in suitably spaced relation thereon, as by welding. As a further support, a ring. [8 may be welded to and around the unit body II. The legs l3 may be made of pieces of pipe having an elbow [9 at the upper end for supporting ashort piece of pipe or nipple 2| extending laterally and threaded to be screwed into the respective spaced sockets ll. The legs are of suitable lengths to support the lower end of the tubular body ll spaced above the level of the floor 23, so that air can freely enter the lower end of the body and pass upwardly therethrough.

A hood 25, substantially in the form of an inverted funnel, is secured upon the upper end of the tubular body, as by any suitable bolts 26 or other removable fastening means, for partially closing the upper end of thebody and providing a central discharge port or passage 2'1, opening upwardly therefrom through a reduced neck thereon. A steam blower nozzle 29 is disposed to project a jet of steam upwardly in said discharge passage 21 for inducing an air stream to enter the lower end of the body H and to flow upwardly therethrough and out of the discharge port. A steam heater 3|, which may be conveniently provided in the form of a coiled pipe of a good thermal conductive metal, is disposed in the body H for heating theair stream asit moves through the body.

The blast of hot air from the discharge port 21 is delivered into a flexible conduit 33 one end of which is disposed upon the reduced neck on the upper end of the hood. The flexible conduit 33 is preferably provided with heat insulation, and by this means it is conveniently conducted from the unit to a furnace or boiler to be most effectively projected into a combustion chamber to aid combustion, in a manner to be subsequent 1y disclosed in detail.

A steam pipe 35 is provided having a lead 37 extending through the side of the body I! and connecting to the upper end of the steam heater coils 3|. From the lower end of the heater coils a condensate pipe 39 passes through a bottom wall t! on the body It, which partially closes the lower end of the body II, and provides a central air intake port. The condensate pipe 35 returns condensate to the boiler water supply, sewer, or other disposal. From the steam pipe 35 a lead 43 extends to the blower nozzle 28 through a hand valve d5, whereby the intensity of the draft induced by the blower may be regulated. This steam supply pip-e 35 is preferably provided with a steam gage tl, whereby the operator will be advised of the pressure of steam being supplied to the smoke eliminator so that he may more readily regulate and set it for the most effective operation. As a safety precaution, a blow-off valve 49 may also be provided on this steam supply line, and this line extends from the unit through a hand valve for connection with a boiler, or any suitable source of steam. By means of the hand valve 5! in the main steam supply pipe the operator may regulate the admission of steam from the boiler and hence may set the operation of the smoke eliminator for the most efiective results, or may shut it off when desired.

In operation on low pressure systems, such as steam heating systems, the steam pressure is usually very low and it has been found under such conditions the heater coils 3! may not provide ample heat to heat the air stream flowing through the body H. In order to supply the air stream with additional heat under such conditions, I provide auxiliary heating means consisting of electrical heating elements 53 mounted in the hood 25 and exposed to the stream of air rising therein, as may be seen in Fig. 4. A great many of the available electrical heater elements may be used for this purpose. But for convenience of installation very satisfactory results are obtained with the types of electrical elements consisting of the electrical heater wires or coils imbedded in and supported by ceramic or other materials, and such types of heaters, as herein represented, are of a convenient elongated form to be supported at opposite ends on brackets 55 and 56 for extending across the hood in spaced apart relation for intimate contact with the flowing air stream.

To be conveniently removable for replacement, each one of these heater elements 53 is at one end clamped up to the under side of the bracket 55 by a screw 5! which is easily released for removing these elements, as shown in Fig. 4. As Fig. 5 shows, the other ends of the elements 53 merely rest upon bracket 58 in loops 59 thereon. As shown in Fig. 6, by positioning all the connection terminals toward one end an energizing wire 61 may be conveniently connected to one terminal 63 of each element while another wire 65 is connected to the other terminal 67 of each heater element, for energizing these in a parallel 4 relation, as shown in Fig. 4 and represented sche matically in Fig. 6.

For automatic control of the electrical heater, I provide a thermostatic switch unit 69 mounted upon a bracket H on the hood 25 having its heat responsive element 73 inserted into the hood to be responsive to the temperature of the air stream flowing therein. Such temperature control switches are available on the market in a wide variety, one type of which is herein shown. The heat responsive element 13 may be enclosed in a narrow housing i5 which passes through the side of the hood into the air stream and which is made of metal so that by conduction it transmits the air temperature to the sensitive element. From the switch, a cable it extends into the hood, through a suitable bushing, and from the cable the wires EH and 65 connect with the terminals 63 and El of the heater elements, which may be energized in a parallel relation as previously described.

As represented diagrammatically in Fig. 6, the temperature responsive element 13, which may be adjusted by a screw M, closes the temperature control contacts ll and 19, responsive to a drop in the air stream temperature, and this completes the energizing circuit from the service line L! by way of a conductor 36, the winding of a relay R, through contacts l7 and T9, and then returning by way of conductor 8.2 to the other line L2. The relay energizes the heater circuit from line L! by conductor 8%, relay contacts 88, wire 6i, heater elements 53, and conductor 65 to line Li...

A manual switch 92 is connected in shunt with the relay contacts 88 by conductors 94. Switch 9-2 may be closed manually to take over manual control and eliminate the automatic control when desired. The smoke eliminator may of course be made in various sizes, but in one installation the three electrical heating elements 53 were each of four hundred watts capacity operating on one hundred and ten volts for producing 390 F. at a wind velocity of eight to ten miles per hour of the air flowing through the hood. This data is given merely by way of example so that anyone skilled in the art will have no difiicul-ty in selecting suitable heating elemen-ts and in providing and adjusting a suitable thermal control switch in cooperation therewith, and it may be varied to suit different installations and operating conditions.

To silence the roaring noise caused by the air entering the bottom of the tubular body I I, I provide a perforated air intake tube 8! surrounded by a larger air flow tube 83. The air intake tube 8! is substantially smaller in diameter than the air intake port in the center of the bottom wall i! of the body 6 l, and it is secured and supported by means of a collar of a suitable diameter to fit up into a clamp band 81 which projects downwardly from the bottom wall All of the body H. This collar 85 may be secured to the perforated air intake tube 3! in any suitable manner, as by welding. The larger air flow tube 83 is of such a size that its lower end fits down snugly into the collar 85 whereon it is assembled. This air bafile and muliler assembly is then inserted up into the body H, and drawing up the bolt 39 in the clamp band 87 secures the collar 85 and the air intake tube and assembly in the body to receive the air, as indicated by the arrows. The collar 35 is also provided with air receiving apertures 85.

A baille tongue Si is provided at an intermediate position inside of the perforated air intake tube 8| where it partially obstructs the cross-sectional passage in this tube. This causes most of the entering air to flow laterally through the orifices in the Sides of thi tube. It has been found that this is very effective in silencing the noises caused by the blast of air entering the device. At the upper ends, the air intake tube 3! and the larger air flow tube 83 are held ri idly in a proper spaced and concentric position by a spacing flange Q3 which is secured upon the upper end of this larger tube, and which is centrally apertured to pass the upper end of the smaller air intake tube 8i therethrough. This spacing flange 93 also closes the upper end of this larger tube 83 so that all the entering air which has passed into the space between these two tubes must now pass back into this smaller tube through the perforated sidewalls thereof. The air then flows up out of the upper end of this smaller air intake tube where it encounters th upper closed end walls as of a still larger reverse flow tube 91, and the air now turns and flows downwardly in the space 9% between the air flow tubes 83 and 9?, as represented by the arrows. This space is maintained uniform and these tubes are held in rigid spaced concentric relation by means of a plurality of spacers 95 extending vertically therebetween. These spacers are readily provided by applying suitable pieces of light weight angle iron on the outside of the air fiow tube 83, welded thereto. Clips toil may be provided on the outer edges of these spacers :"19 to aid in holding the steam heater coils BI which are in the space 96 for heating the air as it flows downwardly in this space.

The upper end of the large reverse air flow tube 53? is also provided with brackets Ill! which project laterally so as to be attached to the inner wall I E of the body H to support this tube with its lower end preferably slightly above the bottom wall 31 of the main body. The lower end of this reverse flow tube may also be provided with apertures :53, so that the down flowing air may turn and pass outwardly. The air then flows up around the outside of this tube 91, and as the heated air rises into the hood its temperature may be sumcient to hold the switch open and the electrical heater elements may remain deenergized. A baffle I54 is preferably secured on the inner end of the thermostat casing I5 and projects over the heater elements to protect these from any drops of water. If at any time the heat is inadequate, the electrical heater elements will be energized automatically, in the manner previously described, and additional heat will be supplied to raise the temperature of the flowing air stream to the required effective temperature.

By means of the flexible conduit 33 leading from the discharge port 27 of the device, the blast of heated air can be delivered to the combustion chamber or firebox where more perfect combustion is to be provided. This stream of preheated air, mingled with steam from the blower nozzle 29, is preferably delivered as a plurality of jets passing over the fire and back into the combustion chamber in a manner to provide intimate contact with the combustion gases and the byproducts of combustion.

Figs. 9 and 10 show a jet projecting frame I55 which I have provided for delivering such jets into the firebox from the firebox door in the most effective manner. The jet frame I05 consists of an apertured conduit bent to a rectangular form to fit around the doorway opening, and arranged for connection to the hot air source. To make'a more rigid frame and provide for connection, the ends of the conduit may be bent to a spaced apart relation and then a T-pipe fitting I0? is inserted and welded between the ends of this bent conduit. Connection can then be conveniently made with the flexible conduit 33, or with any other conduit or a rigid pipe, for receiving the blast of hot air and steam from the smoke eliminator unit. The jet frame It? is mounted around the inside of the doorway opening I I3 and it is secured thereto, as by adjusting spaced screws I08 to engage in the doorway. The screws it may threadably turn in the projecting ends of brackets Hi9 welded to the conduit and projecting into the doorway. Or the screws may pas threadably through the conduit 8% to turn outwardly into engagement with the doorway H3, as shown in Fig. 10A. The jet frame conduit I05 is drilled to provide a plurality of jet orifices or apparatus i I I opening toward the combustion chamber side. Care is taken to position each such orifice so as to project each jet in the proper direction to suit the combustion conditions to be corrected or improved.

Fig. 11 represents such a jet projecting frame 565 installed in the doorway I I3 opening through a firebox wall H5 into any conventional firebox or combustion chamber M1, for supplying heat for any usual boiler H9, only one end being represented. As shown, the jet projecting frame E so installed, is connected to a pipe I 2! extending out snugly along the upper side of the doorway and turning snugly up along the outer side of the firebox wall IE5. The door I23 of this doorway, shown in its open position, is provided in its upper edge with a slot I25 to fit around the pipe liZi, as the door closes. This slot I25 is preferably made slightly larger than the pipe I2 I. For this reason, and also because the pipe I2I turns up snugly around the upper outer edge of the doorway at a mid-position, there is no interferenoe with the swinging action of the door I23 as it opens and shuts. The pipe I2I is extended for connection with the eliminator unit body if, to receive the stream of hot air therefrom. This may be readily accomplished, either by extending the flexible conduit 33 from the unit to the pipe I2I, or by extending the pipe I2| for direct connection to the discharge port 2? of the unit. Also a jet projector may be installed in the stack space if desired.

The orifices I i l of the jet projecting frame I05 are adapted for projecting the jets of hot air and steam into the combustion chamber, as indicated by the straight line arrows, at suitable positions above the grates I28 and over the bed of coals to mingle intimately with the combustion products, represented by the rough free hand arrows, to aid combustion and burn the gaseous and solid portions of the fuel which so commonly escape up the stack unburned. It is my opinion that the smoke difliculty is caused by the fact that the portions of the fuel passing up the stack unburned have a higher combustion temperature than that present in the combustion chamber. At the lower temperature present therein, the fractions of the fuel which are ignited and burned are only those which have low temperatures of combustion and these in burning do not create a temperature which is quite high enough to burn those other fractions of the fuel which commonly pass up the stack. It is therefore my theory that, in order to have complete combustion, it is necessary to bring the combustion chamber temperature up to this higher combustion temperature. And this is what such an installation of my unit accomplishes to provide more perfect combustion.

This reduces and eliminates smoke and odors and is also obtains more heat from the fuel.

Another advantage of my properly installed permanently positioned jet projecting means is that it remains effective when the firebox door is opened for stoking.

When the firebox door is opened for checking the fire, the hand valve I22 may be turned off to stop the hot air jets which would interfere with the admission of cold air through the doorway,

Fig. 12 illustrates the installation for the well known Scotch marine type of boiler, the front doorway construction being omitted for clearness. As may be seen, the flexible conduit 33 from the smoke eliminator unit l connects with a. conduit !25 which extends across the end of the boiler I24 resting upon the stack floor I26 and connecting down therethrough into two of the jet projecting frames 5535 which are mounted before the combustion chambers at positions corresponding to the doorways (not shown) A hand valve 52! is provided in the pipe 525 for cutting of the hot air blast when desired. In such an installation it is also important to provide connections i28 for hot air delivery through two of the fire tubes or fiues lid of this boiler. This delivers such heated air and steam, represented by the straight arrows, into the smoke space l3il, represented by dotted lines, at the other end of the boiler, and there maintains good combustion to consume portions of the fuel which commonly remain unburned at this point.

Fig. 13 shows an arrangement for installation or" my smoke eliminator in combination with a conventional vertical, fire-tube, type of boiler i3 I, having fire tubes or fiues 33. In such an installation, a central one of the dues 533 is utilized for passage of a blast of hot air down therethrough to project it efiectively into the combustion chamber above the fire, at the lower end of the boiler. The hot air supply pipe E35, which connects into the upper end of this flue, leads off laterally through the stack housing I31 on the upper end of the boiler and it is connectcd with my smoke eliminator unit in any manner convenient for the particular installation. In this installation the hot air blast is directed in the most effective position. and direction over the grates 339 to aid cmnoustion under such c. boiler while avoiding interference with the cold air entering the doorway it, at such times as it is open for checking the fire.

To conserve heat in the moving air stream, my unit is constructed with a suitable heat insulation material Hi5 filled in the space between the outer and the inner walls H and H of the body. For similar reasons the hot air delivery flexible conduit 33 is preferably provided with heat insulation material and such flexible insulated conduits are available. In installation heat can be further conserved by making the distance for delivery of the hot air blast as short and direct as possible. Electrical conductors and cables for use with my unit are selected of heat resisting types for durability under the high temperature conditions of operation encountered.

It will be seen that I have provided improved smoke abatement apparatus in a compact unit structure for convenience in manufacture. in stallation and maintenance as Well as providing improved jet projectors, per se, and systems of delivery for the combustion aiding jets.

It is apparent that within the scope of the in-' vention modifications and different arrangements may be made other than herein disclosed, and the present disclosure is illustrative merely, the invention comprehending variations thereof.

What is claimed as the invention is:

1. In an air heater and humidifier unit for use with a steam boiler the combination of, a tubular air flow conducting body of substantially a cylindrical conformation, support means for mounting the cylindrical body vertically with the lower end spaced above the floor level for receiving air flowing freely from all directions and conducting it upwardly through said body, a hood in the form of an inverted funnel secured around its lower edges upon the upper end of said body and having a reduced neck providing a central discharge port opening upwardly therefrom, a blower nozzle disposed for projecting a jet of steam upwardly in said discharge port to induce a flow of air upwardly through said body and said discharge port and for imparting humidity to the air stream, steam heater coils in said body for heating air flowing therethrough, steam supply conduit means for supplying steam under pressure into said nozzle and said heater coils from a steam boiler, and a flexible conduit disposed upon said reduced neck and conveniently extendable to connect into a combustion chamber of a steam boiler.

2. An air heater and humidifier unit for use with a steam boiler in accordance with claim 1 and having electrical heater means, means removably mounting said electrical heater means to be exposed to the flowing air in the body at a point after the air has passed from the steam heating coils, temperature responsive electrical switch means mounted to be responsive to the temperature of the flowing air at a point after the air has passed from said steam heater coils, and adapted to close an energizing circuit to said electrical heater means when the air is at a temperature below a desired temperature.

3. A smoke abatement unit for use with a steam boiler comprising, a tubular air flow conducting body of substantially a cylindrical conformation, support means for mounting said body vertically with the lower end spaced above the floor level for receiving air and conducting it upwardly through said body, a hood in the form of an inverted funnel secured upon the upper end of said body and providing a central discharge port opening upwardly therefrom through a reduced neck, a blower nozzle disposed for projecting a jet of steam upwardly in said discharge port to induce a flow of air upwardly through said body and said discharge port and to impart humidity to the air stream, steam heater coils in said body for heating air flowing therethrough, steam supply conduit means connected into said nozzle and said heater coil and extendable for connection to the steam boiler for supplying steam under pressure, Wall means partially closing the air intake end of said body and providing an air intake port therein, and a plurality of tubular members of different diameters disposed in a nested concentric relation in said body and positioned for receiving air entering the air intake port into the body and diffusing the entering air to spread outwardly and pass in a reverse flow relation for intimate circulation about the coils of the heater.

A smoke abatement unit for use with a steam boiler in accordance with claim 3 and further characterized by having electrical heating means exposed for imparting heat to the air flowing through said body, heat responsive switch means disposed to be responsive to the flowing air after it has passed the steam heater coils for closing an energizing circuit for the electrical heating means to impart additional heat to the air at such times as the steam heater coils fail to heat the air to a suitable high temperature, and electrical conductors connecting said switch in a controlling relation in the energizing circuit for said electrical heating means.

5. A smoke eliminator unit for use with a steam boiler comprising, a tubular air flow conducting body of substantially a cylindrical conformation, support means for mounting said body vertically with the lower end spaced above the floor level for receiving air and conducting it upwardly through said body, a hood in the form of an inverted funnel secured upon the upper end of said body and having an upturned neck providing a central discharge port opening upwardly therefrom, a blower nozzle disposed for projecting a jet of steam upwardly in said discharge port to induce a flow of air upwardly through said body and said discharge port, steam heater coils in said body for heating air flowing therethrough, steam supply conduit means connected into said nozzle and said steam heater coils for supplying steam under pressure from a steam boiler, baflle means in said body to divert the air flowing therein to pass in intimate thermal exchange relation to said steam heater, a plurality of electrical heaters, means removably 10 mounting said electrical heaters to be exposed to the flowing air in the body at a point after the air has passed from the steam heating coils, temperature operative means mounted in said hood to be responsive to the temperature of the flowing air after the air has passed from said steam heater coils, an electrical switch connected with said temperature responsive means to be closed thereby when the air is at a temperature below a desired temperature, electrical conductor means connecting said switch in an energizing circuit for said electrical heaters, and a flexible conduit extending in fluid flow relation from said upturned neck for convenient connection with the combustion chamber of said steam boiler.

RAY JACOB CLAY BUCKMASTER.

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

UNITED STATES PATENTS Number Name Date 717,566 Gibson Jan. 6, 1903 1,131,107 Beam Mar. 9, 1915 2,003,496 Roe June 4, 1935 2,015,982 Witzel Oct. 1, 1935 2,152,251 Gay Mar. 28, 1939 2,231,090 Ross Feb. 11, 1941 2,238,688 Guler Apr. 15, 1941 2,501,795 Stephens Mar. 28, 1950

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