US2471724A - Gas washer - Google Patents

Description

May 3l, 1949.

N. C. CHRISTENSEN CTAS WASHER 2 Sheets-Sheet 1 Filed Deo. zo, *1944 N. C. CHRISTENSEN May 31, 1949.

GAS WASHER 2 Sheets-Sheet 2 Filed Deo. 50, 1944 Patented May 31, 1949 UNITED* STATES ATENT GAS WASHER Niels C. Christensen, Salt Lake City, Utah Application December 30, 1944, SerialNo. 510,619"

(Cl.` I8'3`--22)' 9' Claims. 1

This invention relates to improvements in air washers.

Washers' employing spray rotors to develop liquid sprays through which gas to be cleaned is passed, such as* disclosed in Christensen Patent- No; 1,462,363 or DaltonPatent No. 2,243,839, are well known, and this invention pertains to improvements in washers of this rotor spray type.

An object of this invention is to provide a rotor spray washer o-f extreme simplicity and cheap construction which will economically handle a large volumeof gas andwhi'oh possesses ahigh degree of efficiency.

It has been the conventional practice in rotor spray washers to direct all of the spray thrown' by the rotor into a washing chamber and to pass thev gas to be cleaned' through this entire mixture of spray. The air to be cleaned was passed through the spray counter the direction of travel of the spray or concurrently therewith or axially of the spray rotor as was desired.

An` object of this inventionis to provide a rotor spray gas washer wherein the entire spray thrown olf by the rotor is segregated into separate por'- tions of spray of diierent characteristics and the gas to be cleaned is so passed therethrough as to produce the most effective cleaning of thel gas.

While the characteristics ofthe spray thrown off by a spray rotor'vary with the dip of the rotor into the liquid and the speed' of rotation of the rotor aswell as with the character of the rotor itself, as set forth in the patent to Christensen supra, I have found that under normal operating conditions a liquid sprayrotor throws fromf 75% to 80% of the liquid spray on the rising side of the rotor and only to 25% on the descending' side ofthe rotor. I have also found that the portion of the spray which is thrown off on the rising side of the rotor is a coarse, heavy spray including large drops and globules of liquid` andthe spray thrown oi by the rotor onu its descending side is a relatively line spray and mist.

An object of this invention is to segregate the large Volume of coarse heavy spray from the smaller volumer of fine spray and to make the most advantageous use of each inthe washing of the gas passed through the spray.`

A further object oi this invention is the provi-` gas is passed throughtlie large volume of heavy' spray counter the direction of travel of the spray.

Another object is to provide an upright air washer casing superimposing 'a spray rotor which casing is dividedl interiorly by' a partition whichy superimposes the rotor in spaced relationship into a down-draft air passageway and an updraft air passageway. The partition-is disposed tangentially to the median line of the rising' side of the rotor so as to cause' theA largevolume of coarse heavy' spray which isthrown on' by the rotor on its rising side 'to enter the-downdraft passageway of tion consists in thev provision, within an upright air washer casing having a liquid? sumpin its bottom, of a plurality ci' sprayrotorsspaced apart in the same horizontall planeto dlp into the liquid inthe sump. The casingfis dividedf interiorly into a plurality of washing chambers by a plurality of spaced apart upright partitions spaced" above the rotors tangenti'ally respect tothe' risingsi'des l of the rotors. The partitions are so` arranged" that a selected portion ofthe spray thrown oil' by each rotor is thrown-intocrossing commingling relationship within onefportionof the casing with a similar portion of' the spray thrown off by another rotor. y

Other objects,advantages and meritorious features willf more fully appear from the `follbwin'g description, appended claims and Aaccompanying drawings, wherein:

Figure 1 is a vertical 'sectionall view through an air washer embodyingmy invention.`

Figure 2 is a vertical sectional viewtaken onA the line 2--2l of Figure I.

Figure 3 is a horizontal sectional ViewA taken on the line 3-3 of' Figure?.

Figure 4- is a vertical; sectional View of a washer similar to that of Figure ibut employing two spray rotors and two 'air inlet passages and one common air outlet passage.

Figure 5 is a fragmentaryverticai sectiona'l view' 3 taken on the line 5-5 of Figure 6 and showing a modied form of plural rotor construction.

Figure 6 is a horizontal sectional view taken on the line 6-6 of Figure 5.

Figure 7 is a vertical sectional view illustrating another modification of the invention.

Figure 8 is a fragmentary vertical sectional View illustrating a further adaptation of my invention.

In the drawings, an upright air washer casing is indicated as ID. The casing is shown in Figure I as provided with an air inlet I2 and an air outlet Ill. A fan I6 is shown mounted in the outlet in Figure 1 and is adapted to draw air or other gas to be cleaned through the casing. It is understood that in those figures of the drawings wherein the air inlet and outlet and fan are not shown that such would be provided in suitable form. The lower part of the casing serves as a liquid containing sump or reservoir I8 having a liquid inlet 2d and a liquid outlet 22 as shown in Figure 1. A weir 24 is provided separating that portion of the sumpsurrounding the outlet from the main portion of the sump and by its height determines the height of the water within the sump. A baille 26 extends across the sump spaced inwardly from the weir and a baffle 23 extends inwardly across the sump spaced inwardly of the inlet as shown in Figure 1. These two baffles serve to prevent surging of the liquid and maintain a quiet pool within the casing between the baffles.

Aspray rotor 3D is suitably supported to extend across the interior of the casing and dip into the liquid in the sump. In Figures 1 through 3 this rotor is shown as a hollow cylindrical rotor mounted upon a shaft 32 which shaft is suitably supported Vwithin end bearings and provided with packing glands as shown at 34 in Figure 2. The shaft is coupled with the shaft of an electric motor 36 whereby the spray rotor may be driven rotatably as desired.

Spray rotors of many different kinds have heretofore been provided. The smooth surfaced hollow cylindrical rotor shown in the Christensen patent supra has been used as has also a hollow cylindrical rotor provided with a roughened surface. Rotors formed of a plurality of discs mounted upon a horizontal shaft in axially spaced apart relationship as shown in the Dalton patent supra have also been used. As stated above, and as shown in the drawings, the spray rotors 36 extend across the interior of the shaft or casing from end to end-so that the entire cross-section of passages within the casingv is filled with spray thrown by the rotors so that no part of the gas passed through theapparatus can escape intimate mixture and contact with the sprayed liquid.

The interior of the casing superimposing the rotor shown inFigures 1 and 2, is divided by a partition 38to provide a downdraft passageway 40 which communicates with the air intake into the casing and an updraft passageway 42 which communicates with the air outlet from the casing. These two passagewaysr communicate with each other below the partition and-above the rotor. This partition depends from the ceiling of the casing and terminates spaced above the rotor as shown in Figure J.. It is disposed as shown in Figures 1 and 3 within an upright plane which is tangent to the median line of the rising side of the rotor. As will be clear from the drawings since the partition 38 is in a plane tangent to the rising side of the rotor 36 the spray projected upward in this plane is parallel to the partition and there is therefore no dead space, i. e. space not lled with spray, on .eitherv side of the parti- CEI tion 38 through which gases might pass without coming into contact with the sprayed liquid.

Conventional water eliminators 44 are provided in the upper end of the casing. They are here shown in Figures 1 and 2 as provided in the upper portion of both the updraft and downdraft passageways, though they might be provided only in the upper portion of the updraft passageway as shown in Figure 7.

It has been found that a rotating spray rotor when dipping into a liquid as here shown throws the larger portion of its spray upon the rising side of the rotor and that such larger portion of the spray is a coarse heavy spray including large drops and globules of water. vIt has also been found that the portion of the spray which is thrown off on the descending side of the rotor is a ne spray and is of much smaller quantity than that which is thrown off on the rising side of the rotor.

With a rotor made up of discs mounted upon a horizontal shaft on one and one-half inch centers and dipping approximately three inches into the liquid in the sump and with the rotor rotating at four to ve hundred revolutions per minute it was found that approximately '75% of the spray thrown off by the rotor was thrown olf on the rising side and approximately 25% of the spray thrown was thrown 01T on the descending side. The spray thrown orf on the rising side was much coarser and heavier than the spray thrown on" by the rotor on the descending side. With a cylindrical rotor as shown in the drawings the preferred dip is less than one-half inch and. speed of rotation is higher but the result of throwing the larger portion of the spray upon the rising side is similar and the spray thrown off on the rising side was much heavier and coarser than that thrown oir on the descending side.

The partition is here so disposed that it separates that portion of the spray thrown off on the rising side from that portion thrown oft on the descending side. The larger portion of the spray which is thrown off on the rising side is caused to enter the downdraft passageway 4B while the spray thrown oil on the descending side is thrown into the updraft passageway 42.

In Figure 4 a twin rotor arrangement is shown. In other words, the casing IIJ is provided with the liquid containing sump having a water inlet 20 and a water outlet 22 which sump is provided with baflies 26 and 28 and has mounted therein a pair of rotors 30. These rotors are disposed in the same horizontal plane and extend substantially in spaced apart parallelism. Two partitions 38 are provided, one for each rotor. This divides the casing into two downdraft passageways 40 and one updraft passageway 42 which updraft passageway superimposes the space between the rotors.

Instead of providing merely two rotors as shown in Figure 4, a larger number may be provided as shown in vFigures 5 and 6. In these figures the casing is shown as being circular in cross section and contains six rotors 30. These rotors may be of the self-contained variety disclosed in my copending application Serial No. 563,257 (now Patent 2,448,297, dated Aug. 31, 1948) or they may be driven by power means located at a point external to the rotor. In this gure of the drawing the interior of the casing is divided by upright wall portions 46 relatively angularly disposed between successive rotors as shown in Figure 6 which wall portions denne a common downdraft passageway vIll commento each rotor and an updraft passageway 42 for each rotor. The downdraft 40 communicates with each of the updraft passageways. .The sump has a water inlet and an outlet 22 and a weir 24 is arranged within the outlet beyond the boundary of the casing I0. Baliles 4| are shown in Figure 4 to minimize surging of the water above the rotors. Baflles 4I beneath the spray rotors, such as shown in Figure 4, should preferably be used in all forms of the i apparatus to prevent lateral swinging movement `of the liquid in the basin or sump so as to. prevent surges in the spray above the rotor and secure a uniform spraying action.

In Figure '7 a modified form of the construction shown in Figures 1 and 2 is illustrated wherein the rotor and the partition 38 are so dis posed within the casing that the downdraft passageway has a cross sectional area which is only about half that of the updraft passageway 42. within the updraft passageway and a spray is directed thereupon from a header pipe 5|] which is provided with a linear arrangement of spray nozzles 52 and which may be fed from the same pump that supplies water to the sump. A bafe deflector 54 is shown as disposed beneath the rotor 30.

In Figure 8 an arrangement is illustrated which is designed for a small air-conditioning unit wherein it is desired to employ a minimum amount of water. In this construction the arrangement is similar to that shown in Figure 1 except that the Weir 24 defines an auxiliary tank portion wherein the water level is maintained by a float valve controlled inlet 56. dicated as 58. A pump 6D communicates with the auxiliary sump portion by an intake 62 and recirculates the water therefrom back into the sump through a pump outlet B4.

In the several constructions shown the upright partition is so disposed as hereinabove set forth to separate the coarse heavy spray thrown off from the rising side of the rotor from the fine spray thrown off upon the descending side of the rotor. Preferably the incoming air enters counter the heavy spray and iows downwardly toward the liquid in the sump and a substantial portion of the foul material is wetted and passes directly out of the air stream into the sump. The air born particles which are not wetted pass with the air into the updraft passageway and are there wetted bythe spray as it rises and falls and fallback therewith into the liquid in the sump.

In the construction shown in Figure 4, the spray thrown off upon the descending side of the two rotors commingles within the common updraft passageway to produce a more thorough wetting of the foreign particles in the air.

In the construction shown in Figures 5 and 6 the rotors are so driven that the coarse heavy spray from each rotor enters the central downdraft passageway 4l) and mingles therein with the corresponding spray from each of the other rotors and produces a particularly dense concentrated spray through which the air must pass downwardly for exit through the updraft passageways 42,

In Figure 7 the larger capacity of the updraft passageway as compared with the downdraft passageway permit the air to be taken into the downdraft passageway at a speed of approximately one thousand feet per minute and exhausted from the updraft passageway at a speed of not to exceed ve hundred feet per minute. This arrangement increases the capacity of the machine and fur- The water eliminators 44 are disposed only The float valve is ina rotatably driven spray rotor horizontally supported within the casing and extending from one side lof the casing to the other and disposed to dip into the liquid in the sump, an upright parti-l tion superimposing in spaced relationship the spray rotor and extending upward tangentially to the rising side of the rotor and extending from one side of the casing to the other dividing the space within the casing above the rotor into an upright downdraft portion and an upright updraft portion communicating below said partition.

2. In an air washer, an upright casing having a liquid containing sump in its bottom portion, a rotatably driven spray rotor horizontally sup-A ported within the casing and extending from one side of the casing to the other and disposed to dip into the liquid in the sump, an upright partition superimposing in spaced relationship the spray rotor and extending tangentially to the rising side of the rotor and extending from one side of the casing to the other dividing the space within the casing above the rotor into a vertical downdraft portion superimposing the rising side of the rotor and having an air inlet at the top and a vertical updraft portion superimposing the descending side of the rotor and having an air outlet at the top, said portions communicating through the space between the lower edge of the partition and the rotor, and means for introducing air into the casing through the upper end of the downdraft portion and exhausting air therefrom through the upper end of the updraft portion.

3. In an air washer, an upright casing having a liquid containing sump in its bottom portion, a pair of rotatably driven spray rotors supported in horizontally spaced apart relationship within the casing dipping into the liquid in the sump, a pair of upright spaced apart substantially parallel partitions dividing that portion of the casing spaced above the spray rotors into a plurality of upright passageways communicating directly above the spray rotors, one partition occupying a plane tangent to the rising side of one rotor,

the other partition occupying a plane tangent to the rising side of the other rotor whereby a portion of the spray thrown by one rotor commingles with a portion of the spray thrown by the other rotor within the upright passageway which superimposes the space between the rotors and the remaining portion of the spray thrown by each rotor is directed into a dierent passageway, and means for introducing air into the upper end of one of said upright passageways to pass downwardly therethrough and upwardly through another of saidupright passageways for exhaust from the casing.

4. In an air washer, an upright casing having a liquid containing sump in its bottom portion, a pair of rotatably driven spray rotors supported in horizontally spaced apart relationship within the casing dipping into the liquid in the sump, a pair of upright spaced apart substantially parallel partitions dividing that portion of the casing spaced above the spray rotors into a plurality of upright passageways communicating directly above the spray rotors, one partition occupying a plane tangent to the rising: side of lone rotor, theV other partition occupying a plane tangent to the; rising side of the otherv rotor whereby a portionoi thespray thrownlby one rotor com'mingles withv a portion of the spray thrown by the other rotor within the upright passageway which superimposes the space between the rotors and the remaining portion of thespray thrown by each rotor is directed into a different passageway, and means forl introducing air into the upper ends of the` two upright passageways which superimpose the spaces over the rising sides of said rotors to flow downwardly through the passageway which superimposes the spacer between the rotors.

5. 1n an air washer, an upright casing having a liquid containingv sum-p in its bottom portion, a rotatably driven spray rotor horizontally supported within the casing to dip into the liquid inthe sump, an upright partition superimposing in spaced relationship the spray rotor and extending tangentially to the rising side of the rotor and' dividing. the space within the casing above the rotor into a downdraft portion superimposing the'ri-sing side of the rotor and having an air inlet at thel top and, an updraft portion superimposing the descending side of the rotor and having an air outlet at the top, said portions communicating through the space between thelower edge of the partition and the rotor, and, means for introducing air into the casing through the upper end of the downdraft portionI and exhausting air therefrom through the upper end of the updraft portion, said updraft passageway having a cross sectional area substantially greater than the cross sectional area of the downdraft passageway whereby the air flows through the updraft passageway at a substantially slower rate than it flows through the downdraft passageway.

6. The invention described?. in claim 5 characterized in that the updraft passageway is prcvided within its upper end with water eliminator plates and means is provided for directing a water spray on to said eliminator plates to ow thereover and' on to the partition to flow down over the partition and on to the rotor.

7. Theair washer described in claim 5 wherein the partition is tangent tothe rising side of the rotor.

8. An air washer comprising, in combination,`

an upright casing having a liquid containing sump inits-lower portion, a weir dividing the sump into an auxiliary portion and a main portion, means for delivering: water into the auxiliary portion to maintain a determined water leveltherein belowthe height ofthe weir, varotor extending across the main portion and dipping into the Water therein, and' apumphaving an inlet communicating with the auxiliary portion ofthe sump to draw water therefrom and deliver water into the: mainl portion of the sump to flow therethrough. and over the weir.

9. Apparatus for washing air comprising, im combination', an upright casing surmounting a liquid containing sump, a spray rotor supported within the casing for rotation about a horizontal' axis and dipping into the liquid of the sump, means for rotating said rotor at such a speed' as to cause a diverging fan of spray to be thrown` upwardly from ythe rising side of the rotor charac;- tex-ized by being relatively coarse and heavy in;- the area generally over the rising side of the rotor and being relatively fine in the area` generally over the descending side of the rotor, a substantially vertical partition within the casing extendingk downwardly ta-ngentially to one side of thcv rotor and into said fan of spray and having thee llower edge thereof terminating at a height above-r theJtop level-'of the rotor, the lower portion ofA the. partition entering the fan of spray and acting tof separate the coarser lheavier section thereof from the ner section thereof and to subdividethe space?` within the casing above the rotor into two verticalai-r passageways communica-ting with one another through` the opening provided between the lower" edge of the partition and the rotor, and means` for causing air to bedrawn down one of said passageways into one of said sections of said spray and thence through the communicating opening' and up the other passageway throughy the other" section of the spray.

N [ELS C. CHRISTENSEN.

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

Urrrrnny STATES. PATENTS Number Name Date 816,371 Platzl Mar, 27, 1906 1,462,364 Christensen July 17, 1923 1,803,792 Christensen May 5, 1931l 1,978,938 Y Grob oet. 80, 1934 2,171,617 Wintermute sept. 5, 1939 2,243,839 Dau-,on June 3, 1941

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