US2802546A - Method of treating smoke - Google Patents

Description

C. L. CLARK METHOD OF TREATING SMOKE Aug. 13,- 1957 2 Sheet's-Sfieet 1 Filed Doc. 24, 1953 INVENTOR. 0/1 esfer L Clark WW4 WM ATTORNEYS.

Aug. 13,1957 c, (#LARK 2,802,546

METHOD OF TREATING SMOKE Filed Dac. 24, 1953 2 Sheets-Sheet 2 M.- 90 INVENTOR.

CHESTER L. CLARK ATTORNEYS FIG. 6

United States Paten 2,802,546 METHOD OF TREATING SMOKE Chester L. Clark, Providence, R. I. Application December 24, 1953, Serial No. 400,237

. 7 Claims. (Cl. 183-120) This invention relates to an improved method for eliminating. smoke. More especially it has to do with an improved. method for removing smoke particles and noxious gases from those products of combustion which customarily are drawn from the place of combustion by a chimney, smoke stack. or flue.

In the burning of fuel and rubbish, and particularly in such burning with devices in which the combustion is not closely controlled, there is usually generated a considerable quantity of smoke particles and noxious gases. These particles and gases together with heated air must be continuously withdrawn from the place of combustion and disposed of, but their discharge into the atmosphere, as is customary, can be very offensive and in some instances dangerous to those in the immediate vicinity. The increasing number of so-called smoke abatement ordinances recently established by urban governments serves to further illustrate the desirability of preventing the discharge into the atmosphere of the particles and gases which offend. The problem has been to provide methods and apparatus which will satisfactorily eliminate smoke and not be prohibitively expenxsive.

I have discovered that when the smoke is treated in a particular manner which will be more fully described hereinafter a substantial portion of the smoke particles may actually be employed to assist in the removal of the noxious gases. Thus, the smoke particles are for the most part carbon and I have found that whensome of these particles are first cooled and later collected they are capableof adsorbing a portion of the noxious gases which accompany them and which pass over them at their place of collection.

Accordingly, one object of my invention is to effect removal of particles from smoke by first cooling and later collecting them and to effect removal of noxious gases from smoke by exposing them to these cooled, collected particles whereby those particles which are essentially carbon adsorb the gases.

Another object of my invention is to effect removal of particles and noxious gases from smoke in the described manner wherein the supply of particles capable of ad sorbing noxious gases is constantly beingreplenished.

Another object of my inventionis to effect removal of particles and noxious gases from smoke in the described manner wherein the particles collected are generally small enough in size to permit relatively free passage of the gases over them when they'are in their collected state.

Another object of this invention is to provide a large surface area of the collected carbonaceous particles so that this large surface area will be exposed to have passed over it additional gases which were the products of combustion thatsome of these gases may be absorbed by the exposed solid particles removed from the products of combustion.

With reference to the drawings:

Figure 1 is a sectional view showing diagrammatically the furnace, the smoke stack leading therefrom and the connections from the furnace to my apparatus and back to the furnace, illustrating in a general way the system employed in the invention;

Figure 2 is a perspective view broken away and diagrammatically showing by means of arrows the passage of the smoke and gases through the difierent areas of the apparatus;

Patented Aug. 13, 1957 ice Figure 3 is a top plan view of the eliminator plates shown in one of the areas through which the products of combustion pass;

Figure 4 is a central sectional view through the first two casings as shown in Figure 2 through which the products of combustion pass;

Figure 5 is a central sectional view through the last two areas of Figure 2 through which the products of combustion pass;

Figure 6 is a sectional view showing in greater detail the filters which are utilized and the collection of material in the filter.

The general layout of this invention is perhaps best understood by reference first to Figure 1. The furnace 15a is shown with the fire box 16a above the grate 17a which may be loaded through door 18a or be loaded by dropping fuel or refuse from the smoke stack 19 directly into the fire box. The apparatus Which is primarily the subject of this invention is designated generally 20 and receives the smoke from the fire box through conduit 21 to its inlet opening 22, after which it passes through the apparatus 20, which will be described in greater detail hereinafter, and is exhausted through outlet 23 by pump or blower 24 to be driven through conduit 26 to the stack 19. A by-pass tube 27 extends between conduits 21 and 26 while a fan 28 serves to force gases through the conduit 27 from the conduit 21 to the conduit 26.

With a view of automatically controlling the operation of the apparatus 20 so that the same may be shut off when there is no fire in the furnace and to be placed in operation upon starting a fire in the furnace, the conduit 21 has opposite aligned openings 31 and 32 through the walls thereof at a location between the furnace and the by-pas's conduit 27 A photo tube 29, which is in the electric circuit (not shown) of motor blower 24 and motor fan 28, is positioned opposite one of said openings, as for example opening 31, to receive light rays projecting through said openings from an exciter lamp 30 which is positioned opposite the said opening 32. The photo tube may be shielded (not shown) in an obvious way to receive only light from lamp 30, which also may have a pro tecting shield (not shown). The photo tube is arranged to control the said electric circuit such that when smoke or gas flowing past the said openings 31, 32 is sufficiently dense as to block the light of lamp 30 from falling on the photo tube, the electric circuit will be closed at the blower 24 and open at the fan 28. Assuming that no fuel or refuse is being burned in the furnace, the light rays of lamp 30 will fall on the photo tube and actuate the same to close the circuit at the fan 28 to set the same in operation and draw through the by-pass 27 and conduit 21, the motor blower 24 being at rest. Upon the furnace being charged with refuse and set to burning, sufiicient of the smoke made will be drawn past openings 31, 32 to by pass 27. Upon such smoke becoming sufficiently dense as to block the light from lamp 30 from falling on the photo tube 29, the same will be actuated to open the circuit at the fan 28 and close the circuit at the blower 24 to set the same in action to draw smoke through the apparatus from conduit 21 through inlet Opening 22. When the refuse has been completely burned or the smoke flowing through conduit 21 becomes sufficiently clear so as to not require passing through the apparatus 20, the light of lamp 30 will fall on photo tube 29 to actuate the same in the other direction to open the circuit at the mo= tor blower 24 and close the circuit at the fan 28 to return the apparatus 20 to the idle condition thereof.

When the blower 24 is in operation, the pressure of the out flow of gases in conduit 26 will be somewhat in excess of the normal updraft of smoke in stack 19 so as to cause but a portion of the gases to be directed upwardly while another portion is directed downwardly at oneside of the pivoted bafiie 33 as shown by arrow 34 and thus cause a downward circulation and form a block to preventthe gases of combustion in the furnace from being normally pulled up the stack 19 but rather will cause. them to circulate through the apparatus 20; Thus, the

stack 19 is left open at all times for the dropping ofrefuse into the furnace such as down the chute of an apartment house, as shown by arrow'34, although the gases;

forms the function of removing about 75 percent? of the solid matter contained in the gases passing through the inlet 22, such as removing the heavy particles of combustion. The drying area serves to remove the moisture or water vapor which has been picked up by the gases during washing so as to condition the gases for eflicient filtration, it having been found that gases with considerable moisture in them serve to quickly clog a filter, making filter cleaning frequent. The drying therefore links the washing with the filtering so that the filtering may be performed in the etficient cleaning of the gases. The filtering serves to remove the carbonaceous material which still remains in the gases and to accumulate the carbonaceous material on the filter, and as this carbonaceous material is prepared for filtering, it is cooled so that the carbonaceous material, as it builds up on the filter, has a capacity for adsorbing other gases to be filtered and serves to increase the efiiciency of the apparatus in the removal of other undesirable solids from the gases.

The washing area of the apparatus 20 consists'of four units 40, 41, 42, and 43, each in the form of a generally rectangular casing with the casings 40 and 41 in superimposed relation one on the other and with the casings 42 and 43 in superimposed relation one resting on the other, these two sets of superimposed casings'being side by side with their walls contacting as shown in Figure 2 and secured together in any suitable manner. Connections between .the casings to provide a tortuous path for the gases are formed by openings in the contacting walls of the casing so as to secure the desired tortuous path. An'entrance opening 44 is provided in the end wall of the casing 40, while openings 45 are provided adjacent the opposite end of the casing 40. Thus, there will be an opening in the top wall of the casing 40 and in the bottom wall of the casing 41 so that gases entering at 44 and passing the length of the casing 40 will pass upwardly through the contacting walls of these two casings into the casing 41. An opening 46 is provided in the contacting walls of casings 41 and 42 so that the gases will thencepass from the casing 41 to the casing 42 through this opening 46. Thence the gases will again be directed longitudinally of the casing 42 and downwardly through opening 47 in the contacting walls of the casings 42 and 43 into the casing 43, thence again longitudinally of the casing 43.

The drying area of the apparatus comprises an additional casing 48, while the filtering area of the apparatus comprises the additional casing 49. The casings 48 and 49 are in superimposed relation. These two casings 48 and 49 are in side by side contact with the casings 42, 43, and for a continued passage of the gases there is an opening 50 in the side walls of the casings 43 and 48 through which the gases pass from casing 43 to casing 48, the lower part of this opening being closed by an inclined wall 51 so that the gases pass into the chamber 48 and longitudinally of this chamber and thence upwardly through opening 52 by means of an opening in the top wall of the casing 48 and in the bottom wall of the casing 49 sothat thegases then pass longitudinally of the casing 49 and out through the'exit opening 53, which will be connected to the blower and exhaust pipe 26 to the casing having the doors 55thereon and generally parallel to the ends of the casing in which these doors.

are located. Nozzles 56 are positioned in the end walls of each of the casings including the casing 40 and in -the doors as at 57, all of which nozzles are directed longi tudinally of the casing with a flaring spray so that as the gases enter from conduit 21, they;will be washed in passing longitudinally of the casing. In the casing 40 where the gases initially enter, no*screen is provided, as this would soon become clogged because of the heavy particles which are first struck from the gases by the washing spray shown by the dot-dash lines 58. In the subsequent casings 41, 42, and 43 the streams of water 58 strike the screen 56 and provide substantially a film of water which is passing downwardly along the screen at all times so that the gases as they pass longitudinally through the chamber 42 and subsequent chambers 43, 44 will pass through this film of water and be washed thereby. Also gases will be washed from solid particles in the gases. The water as it collects upon the bottom wall of the upper casings will pass downwardly in a sheet 59 through the opening 45 and will provide additional meansof washing the gases by reason of the sheet of water moving downwardly through the openings between the casings. The water as it drops downwardly through the opening 61 in the bottom wall of casing 40 enters a trough 60, which extends beneath the casing 43 where it also picks up water through opening 62 (Fig. 2) and thence continues to discharge this water into a tank 63 (Fig. 5) located beneath the casing 48. This tank maintains the water at a level 64 by means of a float valve 65 and float 66 from a supply conduit 67 should water he needed in addition. A pump picks up the water from a portion of the tank which is screened from the dis charge into the tank 63 and supplies it to the nozzles for washing as shown in Figure 4.

The drying area comprising the casing 48 is of a size to provide an enlarged conduit to slow the passage of the gases that particles or moisture may more easily drop out. This casing contains a set of eliminator plates 70 which are shown in greater detail in Figure 3 as comprising a plurality of tortuous passages formed by plates 72 and 71 at angles to' each other, which areprovided with fins 73 and 74 so that as the washed gases are passed therethrough'in a zig zag path, drops of water which may have been picked up by these gases will be caught by these fins and taken out of the gases. Further, in order to assist in this drying, an opening 75 (Fig. 5) is provided in one end of the casing 48, and'in this opening there is pivoted a damper 76 having a weight 77 thereon to move the same to closed position ,but enabling fresh cooler air to be continuously drawn into the casing'48 as 'shown by arrow 78 (Fig. 5), whichwill cool these gases and cause moisture which may have been picked up by them to more rapidly condenseso that it may be more easily removed by the eliminator plates 70. These eliminator plates may also'be washed by water being directed upon theiriupper surfaces from time to'time. After the gases are dried by passing through the eliminator plates, they pass to the subsequent chamber 49 (Fig. 5) in which there are located a plurality of filtersdesign'ated generally '80 and consisting of a plurality 'of units, divided by walls 81.: A commonchannel 82 collects the gases which have just been dried in chamber 48 as they come from the chamber 48. This channel is on one side of these filters, while a common channel 83 is located on the other side of these filters and is connected to the outlet opening 53, which in turn connects to the gaseous discharge pipe 23, which in turn connects to the blower 24 and to the discharge conduit 26.

Each of the filters, a fragmental portion of which is shown in section in Figure 6, comprises a supporting wire screen 90 of one half inch mesh. On this screen 90 I place a layer or loose fiberglass in sheet form 91 about one inch thick. A second or dividing wire screen 92 of /2" mesh is placed on the layer of fiberglass, and on this screen I place a second layer 93 about one inch thick of loose fiberglass which has been mixed with hydrated lime and lamp black. A second supporting wire screen of k" mesh 94 is placed on the second layer of filtering material so as to support the layer between the screen with a dividing screen 92 therebetween to maintain the layers separated and for convenience in building the filter. The screens 90 and 94 are supported between open frames (not shown) which are secured to each other and form the filter units. The filter units thus formed are six square feet.

To form the one-inch second layer 93, I take about forty pounds of loose fiberglass which is obtained in a loose, lumpy condition, two pounds of hydrated lime, and one pound of lampblack and machine mix these very thoroughly. The mixing of the loose fiberglass with the lime and lampblack reduces the fiberglass to a porous mass which serves to intercept the small particles of carbonaceous matter designated 95 which may have passed through the first layer 91. The lime tends to maintain the second layer in a rather dry condition to avoid matting. This filter collects the carbonaceous material 95 which has been cooled and thus has such gases as it originally contained driven therefrom. As the carbonaceous material collects, it provides a somewhat denser filter, and the carbonaceous material serves as an additional filter medium which is in 'a position to filter the gases as they pass therethrough. By reason of the gases being relatively dry by their passage through the eliminator, they do not clog the filter as otherwise would be the case if the collected particles were in a moist condition, which would enable them to pack more solidly upon a filter and block it up. The carbonaceous material collected, which particles may be globular in shape, provides an extended area which is sufficiently porous for the gases to pass therethrough. This porous 1structure also provides a large surface area so that the cooled particles from which the gases have been removed may serve to adsorb additional gases as they pass over their surfaces and thus provide an additional filter to pick up both solids and gases as the operation progresses. These deposited particles of carbon are continually adding to the filter and providing new surfaces for the adsorbing of additional gases as the process progresses.

I claim:

1. The method of treating smoke for removing unburned matter and obnoxious odors which comprises first passing the smoke between oppositely directed sprays of water to wet and knock down the heavier solid particles of unburned matter, then passing the smoke through a plurality of fine mesh screens While directing opposite sprays of water on the screens from locations spaced upstream and downstream from the plane of the screens, next inter-mixing the partially cleaned smoke with air at atmosphere to cool and cause condensation of moisture picked up -by the smoke in the washing steps, removing the water condensation from the smoke and passing the smoke from which moisture has been taken without further wetting through a filter to remove the finer unburned particles remaining in the smoke.

2. The method of treating smoke as set forth in claim 1 wherein air at atmosphere is continuously intermixed with the smoke. V

.3. The method of treating smoke as set forth in claim 2 wherein the sprays of water directed on the screens are of sufficient volume to form a continuous moving film of water on the screens.

4. The method of treating smoke for removing unburned matter and obnoxious odors which comprises first passing the smoke through a spray of water to wet and knock down the heavier solid particles of unburned matter, then passing the smoke through a plurality of fine mesh screens while directing a spray of water oneach screen, next cooling the partially cleaned smoke to cause condensation of the moisture picked up by the smoke in the washing steps, removing the water of condensation from the smoke and passing the smoke from which moisture has been taken and without further wetting through a filter to remove the finer unburned particles remaining in the smoke.

5. The method of treating smoke for removing unburned matter and obnoxious odors which comprises first passing the smoke through a spray of water to wet and knock down the heavier solid particles of unburned matter, then passing the smoke through a plurality of fine mesh screens while directing a spray of water on each screen, next intermixing the partially cleaned smoke with air at atmosphere to cool and cause condensation of moisture picked up by the smoke in the washing steps, removing the water condensation from the smoke and passing the smoke from which moisture'has been taken without further Wetting through a filter to remove the finer unburned particles remaining in the smoke.

6. The method of treating smoke for removing unburned matter and obnoxious odors which comprises first passing the smoke between oppositely directed sprays of water to wet and knock down the heavier solid particles of unburned matter, then passing the smoke through a plurality of fine mesh screens while directing opposite sprays of water on the screens from locations spaced up stream and downstream from the plane of the screens, next cooling the partially cleaned smoke to cause condensation or" the moisture picked up by the smoke in the washing steps, removing the water of condensation from the smoke and passing the smoke from which moisture has been taken without further wetting through a filter to remove the finer unburned particles remaining in the smoke.

7. The method of treating smoke and gases originating from combustion which comprises washing the larger solid particles from the smoke and at the same time cooling the gases and the smaller solid particles therein, passing the smoke through a fine mesh screen while directing a spray of water on the screen to wash solid particles therefrom, separately and additionally cooling the gases and smaller solid particles to condense the water picked up during washing, removing the condensed Water and then without further wetting collecting the smaller solid particles and passing additional gases over the collected smaller particles to absorb gases.

References Cited in the file of this patent UNITED STATES PATENTS 934,448 Lea Sept. 21, 1909 1,010,068 Pavella Nov. 28, 1911 1,063,320 Bayer June 3, 1913 1,382,975 Haslup June 28, 1921 1,577,703 Fedeler Mar. 23, 1926 1,651,636 Shaughnessy Dec. 6, 1927 2,207,774 Barthelemy July 16, 1940 2,307,292 Palmer Jan. 5, 1943 2,368,828 Hanson et a1. Feb. 6, 1945 2,513,174 Hess June 27, 1950 2,585,659 Kilpatrick Feb. 12, 1952 2,668,754 Lichtenfels Feb. 9, 1954 FOREIGN PATENTS 307,904 Great Britain Nov. 21, 1932

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