US3285039A

US3285039A - Apparatus for treating web material with a treating fluid

Info

Publication number: US3285039A
Application number: US351364A
Authority: US
Inventors: Macomson Wistar Wright
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-03-12
Filing date: 1964-03-12
Publication date: 1966-11-15
Anticipated expiration: 1983-11-15
Also published as: DE1635028A1; FR1492493A; CH464132A; NL6612918A; GB1151268A

Description

5 Sheets-Sheet 1 oogg o )6 0' W. W. MACOMSON WITH A TREATING FLUID APPARATUS FOR TREATING WEB MATERIAL mm @2355 op 54 0 0 Nov. 15, 1966 Filed March 12, 1964 ACOM$ON ,v/ML

ATTORNEYS /NVEN TOR \MsTAR NR\eHT M QQO N 5, 1966 w. w. MACOMSON 3,285,039

APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID Filed March 12, 1964 5 Sheets-Sheet 2 W IO m;

INVENTOR. \N\5TA'\P Wma HT MAcoMsoN ATTORNEYS Nov. 15, 1966 w w MACOMSON 3,285,039

APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID Filed March 12, 1964 5 Sheets-Sheet 2 INVENTORI W \STA WEJGHT MAcoMsoN ATTORNEYS Nov. 15, 19 w.w. MACOMSON APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID 5 Sheets-Sheet 4 Filed March 12, 1964 INVENTOR ATTORNEYS Nov. 15, 1966 w.w. MACOMSON APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID 5 Shee tsSheet 5 Filed March 12, 1964 ATTORNEYS United States Patent 3,285,039 APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID Wistar Wright Macomson, Charlotte, N.C., assignor of fifty percent to C. Dan Page, Jr., Gastonia, N-C. Filed Mar. 12, 1964, Ser. No. 351,364 Claims. (CI. 6862) The present invention relates to fluid treating apparatus and more particularly to apparatus for applying a treating fluid to a traveling web material.

Conventional fluid treating apparatus normally used today for applying a treating fluid, such as any liquid or gaseous matter used for washing, bleaching, dyeing, coating, impregnating, or the like, to traveling webs, usually direct the traveling web material into suitable tanks or vats where the same passes through a supply of the treating fluid therein. Such conventional fluid treating apparatus include squeeze rolls between treating tanks which exert considerable squeezing action upon the web material to insure complete penetration of the treating fluid therethrough and to remove any excess treating fluid therefrom.

Such conventional fluid treating apparatus suffer from many deficiencies, foremost of which is the deleterious effect which the squeezing rolls have upon the web material. Also, another deficiency in such conventional apparatus is uneven distribution of the treating fluid through out the web material.

In an attempt to obviate the deficiencies of the aforementioned conventional fluid treating apparatus, attempts have been made to provide fluid treating apparatus which would not have squeeze rolls and would thereby obviate the deleterious effects which such squeeze rolls have on the web material. These attempts have not been successful due to the complicated and expensive nature thereof and also because of the inability of such treating apparatus to effectively accommodate webs of various types of materials. Also, these attempts do not provide an even distribution of treating fluid throughout the web material.

It is therefore an object of the present invention to provide a novel fluid treating apparatus which provides a uniform and continuous distribution of treating fluid throughout the web material being treated without the use of squeeze rolls between treating stages and which therefore obviates the aforementioned deficiencies of conventional fluid treating apparatus.

A more specific object of the present invention is to provide a fluid treating apparatus of the character de- 3,285,639 Patented Nov. 15, 1966 'ice FIGURE 2 is an elevational view of the top end of the apparatus as shown in FIGURE 1;

FIGURE 3 is an elevational view of the other end of the apparatus shown in FIGURE 1;

FIGURE 4 is a longitudinal sectional view taken substantially along line 4-4 in FIGURE 1 with portions broken away;

FIGURE 5 is an enlarged fragmentary sectional view taken substantially along line 55 in FIGURE 4;

FIGURE 6 is a somewhat schematic transverse sectional view taken substantially along line 66 in FIG- URE 1;

FIGURE 7 is an enlarged fragmentary sectional view taken substantially along line 77 in FIGURE 5;

FIGURE 8 is a reduced fragmentary sectional view taken substantially along line 88 in FIGURE 7; and

scribed wherein treating fluid is directed against the web material uniformly and continuously across the full width of the web material and wherein the force at which the treating fluid impinges upon the web material may be controlled in accordance with the characteristics of the web material being treated.

A still more specific object of the present invention is t to provide a fluid treating apparatus of the character described which may accommodate varying width webs of varying type materials.

A further more specific object of this invention is to provide a fluid treating apparatus of the character described wherein the angle at which the treating fluid is directed against the web material may be varied in accordance with the type of web material being treated.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which- FIGURE 1 is a top plan view of a fluid treating apparatus embodying the features of the present invention;

FIGURE 9 is a reduced fragmentary sectional view taken substantially along line 9-9 in FIGURE 7.

Referring now to the drawings, there is shown an apparatus 10 which includes the features of the present invention and comprises a base 11 preferably formed of suitable channel material. Base 11 supports a tank 12 comprising a bottom wall 13, side walls 14, 15 (FIG- URE 6) and end walls 16, 17 (FIGURE 4). Tank 12 has a partition 20 (FIGURE 6) extending laterally thereof between the

end walls

16 and 17 with its bottom edge spaced a predetermined distance above bottom wall 13 and serves to divide tank 12 into two treating chambers 12a and 12b.

Suitable inlet or supply pipes 21 (FIGURE 6) communicate with tank 12 and are connected to a suitable source of treating fluid (not shown) for supplying treating fluid to tank 12. Tank 12 is adapted to receive the treating fluid F therein up to a predetermined level which level is controlled by a drain pipe 22. Drain pipe 22 may be positioned at any desired height above bottom wall 13 of tank 12 to vary the level of treating fluid therein.

A first web guiding roll 23 (FIGURES 1 and 6) is disposed above treating chamber 12a and is rotatably mounted in bearings 24, which are in turn mounted on top of

end walls

16, 17. Roll 23 is adapted to have a web W to be treated directed thereover to guide the web into tank 12. A second web guiding roll 25 (FIGURE 6) is disposed within treating chamber 12a below first web guiding roll 23 and is journaled for rotation in suitable bearings, not shown. Roll 25 is adapted to have the web W pass around therebeneath and cooperates with roll 23 to define a substantially vertical path of travel of the web into treating chamber 12a.

A third web guiding roll 26 is disposed within treating chamber 121: on the opposite side of partition 20 from second web guiding roll 25 and is journaled for rotation in bearings 27 (FIGURE 4).

Rolls

25 and 26 are disposed within tank 12 relative to bottom wall 13 and partition 20 thereof so that the bottom surfaces there of are at substantially the same height between bottom wall 13 and the bottom edge of partition 20. The web W may therefore pass in a substantially horizontal path of travel between treating chambers 12a and 12b,

A fourth guiding roll 30 is disposed above treating chamber 12b and is journaled for rotation in bearings 31 (FIGURES 1 and 4) which are in turn mounted on top of

end walls

16 and 17. It is noted that

rolls

26 and 30 are positioned relative to each other to define a substantially vertical path of travel of the web out of treating chamber 12b.

A first pair of spraying means 32 and 33 are disposed in treating chamber 12a between

rolls

23 and 25 and on opposite sides of the path of travel of the web W between these rolls. A second pair of spraying means 34 and 35 are disposed in treating chamber 12b between

rolls

26 and 30 and on opposite sides of the path of travel of the web W between these rolls. Spraying means 32, 33 and 34, 35 direct streams of treating fluid against opposite sides or faces of the web W as the same passes into treating chamber 12a and as the same passes out of treating chamber 12b. Spraying means 32, 33, 34 and 35 are substantially identical in construction and therefore only one of these spraying means will be described in detail.

Each of the spraying means comprises a generally cylindrical casing 36 (FIGURES l and 7) extending substantially between the

end walls

16 and 17. Opposite ends of each casing 36 are closed by end plates 37 which have connected thereto one leg 38a of an inverted U- shaped bracket 38 (FIGURE 4). Brackets 38 have the bight portions 38b thereof mounted on

end walls

16 and 17 to mount casings 36 thereon in such a position that the lower portion thereof is within the treating fluid in tank 12.

This lower portion of each casing 36 has an opening 39 therein which extends for substantially the full length of casing 36. Each casing 36 also has a second elongate opening 40 in the side thereof adjacent the predetermined path of travel of the web W substantially the full width of casing 36.

Disposed within each casing 36 and extending for substantially the full length thereof is a centrifugal impeller 41 comprising a shaft 41a and a plurality of curved vanes 41b. Shaft 41:: extends outwardly through end plates 37 and

end walls

16 and 17 and is journaled for rotation in suitable bearings 42 mounted on legs 380 of U-shaped brackets 38 (FIGURE 4). Suitable sealing gaskets 43 are mounted on end walls 16 tion to shaft 41a to prevent the escape of treating fluid from tank 12. Vanes 41b are mounted at their inner side edges in shaft 411: and curve outwardly therefrom and terminate in outer edge portions adjacent the interior surface of casing 36.

One end of shaft 41a of spraying means 32 has a pulley 45 (FIGURE I) mounted thereon and around which are trained two V-belts 46, 47. Belts 46, 47 are supported at their other ends by a pulley 50 mounted on one end of shaft 41a of spraying means 34 (FIGURES 1 and 4). A suitable idler pulley 51 engages belts 46, 47 for insuring correct tension therein and is mounted on a bracket 52 Which is adjustably mounted on a bracket 53 which, in turn, is mounted on tank 12.

A pulley 54 (FIGURES l and 3) is mounted on shaft 41a of spraying means 33 and supports one end of V- belts 55, 56 (FIGURE 1). The other ends of

belts

55, 56 are supported by a pulley 57 mounted on one end of shaft 41a of spraying means 35. An idler pulley 58 engages

belts

55, 56 for tensioning the same and is mounted on a bracket 59 which is adjustably mounted on a bracket 60 mounted on tank 12.

Drive pulleys 61, 62 are drivingly mounted on the other ends of shafts 41a of spraying means 33 and 34, respectively, and have drive belts 63, 64 trained therearound. Drive belts 63, 64 are respectively supported at their other ends by pulleys 65, 66 mounted on output shafts 67, 70, respectively, of

motors

71, 72. It is noted that pulleys 65 and 66 are of conventional variable diameter sheave type for varying the speed at which the same drive pulleys 61 and 62. In this respect, the effective diameters of pulleys 65, 66 are inversely proportional to the tension in belts 63, 64. To vary the tension in belts 63, 64 and thereby vary the efiective diameters of pulleys 65, 66,

motors

71 and 72 are mounted on suitable bases 73, 74 (FIGURE 2) which, in turn, are slidably mounted on base 11 for movement toward and away from

pulleys

61 and 62, respectively. To effect this sliding movement, screw members 75, 76 (FIGURE 1) are threadably received at one end in motor bases 73 and 74, respectively,

and are mounted for rotation, but held against longitudinal movement, by

suitable brackets

77, 80. Hand wheels and 17 in surrounding relaand which also extends for 81, 82 are mounted on screw members 75, 76, respectively, for manual rotation thereof to move

motors

71 and 72 either toward or away from the

pulleys

61 and 62 for the reasons set forth above.

Each of the spray means 32, 33, 34 and 35 also includes nozzle means 83 which is provided at opening 40 in casing 36. Each nozzle means 83 comprises a lower plate 84 which extends for substantially the full length of casing 36 and is pivotally mounted thereon by two pairs of brackets 85 mounted on plate 84 adjacent opposite ends thereof and which straddle brackets 86 mounted on casing 36 adjacent the lower portion of opening 40 therein (only one of which is shown in FIGURES 7 and 8). A pivot pin 87

interconnects brackets

85 and 86 to pivotally mount the plate 84 on casing 36 for pivotal adjusted movement. A cover member 90 (FIGURE 7), preferably of spring steel material, is secured along one side edge to the portion of the casing 36 defining the lower side of opening 40 and member 90 extends outwardly therefrom into overlying, covering relation to the space between the inner side edge of lower plate 84 and casing 36 to prevent treating fluid from passing through this space.

Opposite end portions of elongate member 84 have depending brackets 91 (only one of which is shown in FIG- URE 7) secured thereto which have openings therein through which penetrate bolts 92. Bolts 92 also penetrate through elongate curved openings 93 formed in the upper portions of brackets 94 mounted on the interior portions of the

end walls

16 and 17, respectively, by bolts 95. Openings 93 have a radius of curvature the same as the distance between said openings and pivot pins 87 which pivotally mount lower plate 84 on casing 36. Brackets 91 have suitable pointers 96 secured thereto which cooperate with suitable graduations 97 on brackets 94 to visually indicate the angular position of lower plate 84 relative to opening 40 in casing 36.

Nozzle means 83 also includes an upper plate 100 (FIGURE 7) which is of substantially the same length as casing 36 and is pivotally mounted thereon by two pairs of spaced apart brackets 101 adjacent opposite ends thereof which straddle brackets 102 mounted on casing 36 adjacent the upper portion of opening 40 (FIGURE 1). A pin 103 pivotally connects

brackets

101 and 102 to pivotally mount upper plate 100 on casing 36.

Opposite end portions of plate l00 have upstanding brackets 104 (only one of which is shown in FIGURE 7) mounted thereon which have openings therein through which penetrate bolts 105. Bolts 105 also penetrate through elongate curved openings 106 formed in the lower portions of brackets 107 mounted on

end walls

16 and 17, respectively, by bolts 110. It is noted that openings 106 have a radius of curvature equal to the distance between openings 106 and pivot pins 103.

Brackets 104 have suitable pointers 111 carried thereby which cooperate with suitable graduations 112 on brackets 107 to indicate the angular relationship of upper plate 100 to opening 40 in casing 36.

The angular relationship of lower plate 84 and upper plate 100 relative to casing 36 and opening 40 therein and relative to each other may be adjusted through a wide range and

plates

84 and 100 may be locked in adjusted position. Therefore, the width of the discharge opening in each nozzle means 83 may be adjusted to vary the rate of flow of treating fluid being discharged therethrough for a given speed of rotation of impeller 41. Also, the angle of each nozzle means 83 relative to the path of travel of the web W may be adjusted to thereby vary the angle at which the streams of treating fluid impinge upon the Web.

Opposite end portions of upper plate 100 have two pairs of spaced apart upstanding brackets 113, 114 (FIGURES l and 5) mounted thereon and between each pair of which extends a shaft 115. Mounted on each of these shafts are preferably four generally L-shaped

bafiie members

120, 121, 122 and 123, respectively (FIGURES 5, 7 and 8). Baflie

members

120, 121, 122 and 123 are thereby mounted for pivotal movement between an operative position wherein one

leg

120a, 121a, 122a and 123a thereof rests upon the upper surface of upper plate 100 and the

other leg

120b, 121b, 122b and 123b thereof depends downwardly into closing relationship to the discharge opening of nozzle means 83, and an inoperative position wherein

legs

120b, 121b, 122b and 123b of

baflle members

120, 121, 122 and 123 are out of closing relation to the discharge opening.

It is noted that bafiie member 123 has a portion 123c thereof overlying the adjacent side portion of baffie member 122; that baflle member 122 has a portion 122c thereof overlying the adjacent side portion of bafile member 121; and baffle member 121 has a portion 121c thereof overlying the adjacent side portion of bafiie member 120. Therefore, when baffle member 120 is moved from the operative position to the inoperative position, the three remaining bafiie

members

121, 122 and 123 will also be moved therewith. Likewise, when baffle member 121 is moved from the operative to the inoperative position,

bafiie member

122 and 123 move therewith; and when baffle member 122 is moved from the operative to the inoperative position, baffle member 123 moves therewith. These baflie members may be moved singly to the inoperative position in reverse order to that described above. Also, the same may be moved singly or collectively from the inoperative position to the operative position.

By this arrangement of bafile members, the effective length of the discharge opening in each nozzle means 83 may be varied to accommodate varying width webs whereby the stream of treating fluid being delivered from each nozzle means 83 will correspond to the width of the web being treated. Therefore, undue turbulence on opposite sides of the web will be obviated.

While a tank 12 having two treating chambers has been shown and described, it should be understood that any desired number of treating chambers with the attendant web guiding rolls and spraying means may be provided without departing from the scope of the present invention. Also, the web W may be guided in any desired path of travel between the treating chambers.

In operation, the web to be treated is threaded around web guiding rolls 23, 25, 26 and 30 in the manner described above to pass the same through treating chambers 12a and 12b of tank 12 and between spraying means 32, 33 and 34, 35. Tank 12 is then filled to the predetermined level by delivering treating fluid thereinto through inlet or supply pipes 21 until the predetermined level desired is reached. This predetermined level may be controlled by raising or lowering drain pipe 22 and is such that the lower portions of casings 36 of spraying means 32, 33, 34 and 35 are disposed within the treating fluid.

The effective length of the discharge openings of nozzle means 83 of spraying means 32, 33, 34 and 35 is then adjusted to correspond to the width of the web to be treated by positioning the requisite

bafile members

120, 121, 122 and 123 in closing relation to the opposite end portions of the discharge openings. Also, the upper and lower plates of each nozzle means 83 are angularly adjusted relative to casing 36 and to each other to set the width of the discharge openings of nozzle means 83 to control the rate of flow of the treating fluid being discharged by the spraying means 32, 33, 34 and 35 against the web W. By this means, the rate of flow of the treating fluid can be controlled in accordance with the type of web being treated such that optimum penetration can be achieved without any adverse effects on the web. Also, the angle at which

plates

84 and 100 of each nozzle means 83 are disposed relative to opening 40 in casing 36 may be adjusted to control the direction of the stream of treating fluid or the angle at which the same impinges upon the web W.

Further, the rate of flow and volume of treating fluid being discharged by spraying

means

32, 33, 34 and 35 may be varied by adjusting the position of

motors

71 and 72 relative to

pulleys

61 and 62, respectively, on the shafts 41a of spraying means 33 and 34.

The web 'W is drawn through treatment chambers 12a and 12b by any suitable means, such as squeeze rolls (not shown).

Motors

71 and 72 drive impellers 41 of spraying means 33 and 34, which, in turn, drive the impellers 41 of spraying means 32 and 35. These spraying means discharge streams of treating fluid against and completely and uniformly across opposite faces of the web, both before the same enters the treating fluid and as the same leaves the treating fluid, to insure even distribution and penetration of the treating fluid in the web.

It will therefore be apparent that a novel fluid treating apparatus is provided wherein uniform and continuous streams of treating fluid are directed against and across the full width of web material being treated, wherein the rate of flow and volume of treating fluid in the streams may be controlled in accordance with the characteristics of the web being treated, wherein the angle at which the streams of treating fluid impinge on the web material may be varied, and wherein varying width webs may be accommodated.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. Apparatus for treating web material with a treating fluid comprising (a) a tank adapted to contain a supply of treating fluid therein up to a predetermined level,

(b) means operatively associated with said tank for directing the web material in a predetermined path of travel into, through, and out of said tank and any treating fluid therein, and

(c) spraying means disposed within said tank for spraying said treating fluid upon the web material, said spraying means comprising (1) a housing mounted within said tank at a predetermined height above the bottom thereof and having inlet and outlet openings therein, said housing being adapted to be partially disposed within the treating fluid in the tank with the inlet opening thereof below said predetermined level and with the outlet opening disposed above said predetermined level,

(2) impeller means disposed within said housing for directing fluid from said housing through said outlet opening,

(3) nozzle means carried by said housing at said outlet opening and comprising upper and lower elongate wall portions disposed on opposite sides of said outlet opening and defining therebetween an elongate, uninterrupted, constricted, discharge opening directed toward said predetermined path of travel of the web material through said tank and of a length corresponding to the width of the web material to be treated to provide a continuous and uniform flow of treating fluid across the web material, and

(4) means mounting said nozzle wall portions for relative adjustment to vary the width of said discharge opening to thereby vary the velocity of the fluid being discharged through said discharge opening.

2. Apparatus according to claim 1 wherein means are provided to mount said nozzle wall portions on said housing for angular adjustment relative to the outlet opening to vary the direction of flow of the treating fluid being discharged through said discharge opening.

3. Apparatus according to claim 1 including means carried by said housing for varying the effective length of the discharge opening of said nozzle means to accommodate web material of varying widths.

4. Apparatus according to claim 1 wherin said spraying means includes adjustable means operatively connected to said impeller means for rotating said impeller means at variable speeds to vary the rate of flow and volume of treating fluid discharged from said nozzle means.

5. Apparatus for treating web material with a treating fluid comprising (a) a tank adapted to contain a predetermined supply of treating fluid therein up to a predetermined level (b) means operative-1y associated with said tank for directing the web material in a predetermined path of travel into, through and out of said tank and any treating fluid therein, and

(c) spraying means disposed within said tank for spraying treating fluid upon the web material, said spraying means comprising (1) at least one housing mounted within said tank at a predetermined height above the bottom thereof and adapted to be disposed partially within the treating fluid in said tank, said housing having an inlet opening in the bottom portion thereof through which treating fluid is adapted to enter into said housing and an elongate, uninterrupted outlet opening in a side portion thereof disposed above said predetermined 1 level in said tank,

(2) impeller means disposed within said at least one housing and rotatable at varying speeds for directing fluid at a variable rate and volume through said outlet opening therein, and

(3) nozzle means carried by said at least one housing at said outlet opening therein and comprising upper and lower plate members mounted on said housing on opposite sides of said outlet opening and extending outwardly from said housing toward said predetermined path of travel of the web material through said tank and above said predetermined level, said plate members defining an elongate, uninterrupted, constricted discharge opening therebetween of a length corresponding to the width of the web material to be treated to provide a continuous and uniform flow of treating fluid across the web material, and

'8 means mounting said plate members on said housa ing for relative adjustment to vary the width of said discharge opening and for angular adjustment relative to said outlet opening for varying the direction of flow of the treating fluid being discharged from said discharge opening.

- 6. Apparatus according to claim 5 wherein at least one spraying means is disposed adjacent said predetermined path of travel of the web material at its entrance into and exit from the tank for spraying the web material with treating fluid as it enters and leaves the tank.

7. Apparatus according to claim 6 wherein a pair of spraying means is disposed on opposite sides of each of the inlet and outlet portions of the predetermined path of travel of the web material and wherein said spraying means are substantially oppositely disposed for spraying treating fluid against opposite sides of the fabric at each location. A

8. Apparatus according to claim 5 wherein said plate members are each mounted for pivotal movement ,on said housing, and including releasable locking means connected to said plate members for releasably maintaining the same in adjusted positions.

9. Apparatus according to claim 5 including a plurality of b-aflle members pivotally mounted on said nozzle means and each being adapted to be selectively moved between an operative position wherein the same are disposed in covering relation to portions of the discharge openings defined between said nozzle plate members and an inoperative position wherein the same are out of covering relation to said discharge opening.

10. Apparatus according to claim 9 wherein said baffle members are disposed at opposite end portions of said plate members and have overlapping edge portions to permit the baffle members at each end portion to be moved collectively between the operative and inoperative positions.

References Cited by the Examiner UNITED STATES PATENTS 473,266 4/1892 Rusden 69-62 485,695 11/1892 Haworth 6862 FOREIGN PATENTS 691,496 7/ 1930 France. 429,592 5/ 1935 Great Britain. 3 81,044 2/1963 Japan.

IRVING BUNEVICH, Primary Examiner.

Claims

1. APPARATUS FOR TREATING WEB MATERIAL WITH A TREATING FLUID COMPRISING (A) A TANK ADAPTED TO CONTAIN A SUPPLY OF TREATING FLUID THEREIN UP TO A PREDETERMINED LEVEL, (B) MEANS OPERATIVELY ASSOCIATED WITH SAID TANK FOR DIRECTING THE WEB MATERIAL IN A PREDETERMINED PATH OF TRAVEL INTO, THROUGH, AND OUT OF SAID TANK AND ANY TREATING FLUID THEREIN, AND (C) SPRAYING MEANS DISPOSED WITHIN SAID TANK FOR SPRAYING SAID TREATING FLUID UPON THE WEB MATERIAL, SAID SPRAYING MEANS COMPRISING (1) A HOUSING MOUNTED WITHIN SAID TANK AT A PREDETERMINED HEIGHT ABOVE THE BOTTOM THEREOF AND HAVING INLET AND OUTLET OPENINGS THEREIN, SAID HOUSING BEING ADAPTED TO BE PARTIALLY DISPOSED WITHIN THE TREATING FLUID IN THE TANK WITH THE INLET OPENING THEREOF BELOW SAID PREDETERMINED LEVEL AND WITH THE OUTLET OPENING DISPOSED ABOVE SAID PREDETERMINED LEVEL, (2) IMPELLER MEANS DISPOSED WITHIN SAID HOUSING FOR DIRECTING FLUID FROM SAID HOUSING THROUGH SAID OUTLET OPENING,