US2499203A - Agitating mixing device - Google Patents

Description

Feb. 28, 1950 c. F. WARREN 2,499,203

AGITATING MIXING DEVICE Filed June 6, 1947 2 Sheets-Sheet 1 INVEN TOR.

o a 5 5 614 434.55 E WHE/PEA/ BY MM, 4M AM eh. 2, 1950 G. F. WARREN 2,499y2m3 AGITATING MIXING DEVICE Filed June 6, 1947 2 Sheets-Sheet 2 IN V EN TOR.

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AT'TOENE Y5 Patented Feb. 28, 1950 UNITED STATES PATENT OFFICE 1'0 Claims.

This invention-relates to a mechanical mixer of the vibratory dasher type. The present application is a continuation in partof my application No. 532,748, filed April 26, 1944*, and now Patent 2,422,708 datBd-JuH 24y1947.

The objects of the'invention' include the provision of a vibratory dasher having a peculiar combination of oscillatory and reciprocatorymotion which hasbeen found particularly efiecti've in the mixing of certain materials. It is the further object of 'theinvention-to provide a tdiaphragm which not only seals the driving conneotions for the dasher but preferably constitutes the entire bottom, or substantially the entire bottom, of the container inwhich the dasher operates, thereby contributing to the vi"- bratory mixingmovement- It is a further objectof the invention to provide a construction in which the diaphragm not only performs thefunctions above mentioned; but also cooperates with an operating eccentric'to pro vide mechani cal support and guidance for the pitman whichcarries and operates the dasher.

Other objects of the invention will be more apparent from theiollowingv disclosure.

In the'drawings:

Fig. 1 is a detail view in-cross section through a device embodying the invention.

Fig. 2 is a diagrammatic View showing thepositions of the parts in various positions of operation.

Fig. 3 is a view in horizontal section taken'on the line 3--3 of- Fig. 1.

Fig. i is a view similar to Fig. 2 showing a modified embodiment of the invention and-diagrammatically illustrating the resulting movements. I

Fig. 5 is a fragmentary viewinaxial section similar to Fig. 1- andshowinga further modified embodiment of the invention.

The container l is provided at itsbottom-witha flange at- 2 which constitutes a seat to which a complementary flange 48 is clamped-by bolts tive positions of the parts, this would not necessarily be true. v

The flange 48 may be integral with a housing H in which the rotatable drive shaft All carries the eccentric M. The eccentricstrap i5, peripherally engaged with the eccentric, carries the pitma'n at. The pitman has a flange 53 centrally engaged with the diaphragm and is socketed' to receive the threaded end 55 of the pitman extension 54. This extension has a flange at 52' complementar'y to the flange 53,-the' central portion of the diaphragm being clamped between these flanges when the extension 54 is screwed through the diaphragm tightly to the pitman 66.

At the upper end of extension 54 is mounted the oscillatory and reciprocable agitator diskor dasher 56, this preferably being provided with holes of difierentsizes as indicated at 26 in Fig. 3.-

The shaft 49 may be rotated in either direction, but the circulatory movement of the contents of the container I will either be clockwise, or counterclockwise as viewed in Fig. 2, depending on the direction of shaft rotation.

Assuming the'shaft 48 to be-rotate'd clockwise, the movement of the pitmar'r and diaphragm and the contents of the container will bees diagrammatically illustrated in-Fig. 2.

'I-he assumed starting position-shown in Fig. l is designated, in Fig. 2, as position A, and the successive positions illustrated are designated positions B, C, D respectively. The reference characters applied to the various parts in their several positions will be followed by the appropriate letters.

The movement of the eccentric strap to the position shown at 45B will initiate the upward movement'of the pitman extension 55B and the dasher 583, but the main eiiect will be to oscillate the dasher to the position 56B. The flexingoi the diaphragm to position 5913 accommodates this lateral tilting movement of the dasher. The

diaphragm cooperates with the eccentric toguide In the continued clockwise rotation of the; eccentric, the eccentric strap, pitman and dasher will reach the position respectively shown at 45D, MD and 55D respectively.

While it is immaterial what thecontainer I is made of in practice, I have made up a container having a glass wall for the purpose of ascertaining how the liquid contents of such a container move during the operation of the device as disclosed. The diagrammatic lines in Fig. 2 show the movement of the container contents as observed.

At the side of the container toward which the dasher tilts in the initial movement of the eccentric (the right-hand side when the eccentric rotates clockwise as viewed in Fig. 2), there is a pronounced upward surge represented by the lines 60 which terminate in arrows.

At the opposite side (the left-hand side as viewed in Fig. 2 when-the shaft rotates clockwise), there is a secondary upward surge as indicated at 6|. These waves or surges rise to material heights above the initial level of liquid within the container l which may be assumed to be as indicated by the line 62.

The liquid thus displaced bodily returns in a downwardly circulating current represented by the lines 63 which, in the example under discussion, are at the left as viewed in Fig. 2. This current continues beneath the dasher across the container from left to right as shown by the lines 64.

In the meantime, there are well-defined and clearly visible pulsation waves distributed with considerable uniformity throughout the entire body of liquid, such waves being shown by wavy lines 65 both above and below the dasher in Fig. 2.

Extending through the pulsating liquid in fairly well-defined spurts and jets shown by lines 66 are columns of liquid escaping both upwardly and downwardly through the reciprocating dasher through the holes therein. The size and volume of these jets may be pre-determined by varying the dimensions of the holes in the dasher, while the violence of agitation generally is controllable by regulating the speed of rotation of the shaft. This, in turn, may depend also upon the material under treatment and the purpose of the treatment, which has wide utility as indicated in the parent application above identified.

It is broadly immaterial to the present invention whether or not the container I is provided with a closure or whether it is used in the position shown. Reference to the diaphragm 50 as constituting a bottom for the container is intended to be relative. In other container positions, the diaphragm may constitute some other container wall, such as the side end or top. For the particular vibratory and current movements illustrated, it is preferred that the container be upright as shown, and, whether or not the container is upright, it is preferred that the diaphragm be submerged in order that its movement may contribute to the action on the liquid treated.

It is to be noted that there are particular advantages in having the material treated confined in part between the diaphragm or flexible wall, which has primarily an axial movement, and a dasher which also partakes of the same axial movement but further has an oscillatory movement causing circulatory exchange of the confined material with other material above or outwardly from the dasher.

As suggested in Fig. 6 of my parent application, it is not essential for all purposes that the diaphragm be as large in relation to the container size as in the construction here illustrated by way of exemplification of a preferred embodiment.

Fig. 4 shows a container I 0 in which the diaphragm 4 comprises only a portion of the bottom wall of the container, being clamped thereto by bolts 5 which pass through the flange 8 of gear housing 9 and also through a spacing collar ll connected with a cylinder or bearing I2 in which the plunger [3 is reciprocable. The pitman I4 engages the lower surface of diaphragm 4, and the pitman extension (5 extends through the central aperture of the diaphragm into threaded connection with plunger 13 to clamp the diaphragm against pitman M in the manner already described. The plunger I3 serves as a cross head to constrain the dasher 16 to axial reciprocatory movement, producing an effect upon the contents of container I0 which is quite different from that shown in Fig. 2. The plunger or crosshead I3 may be reciprocated in cylinder l2 by a connecting rod l1 driven from shaft in either by an eccentric as previously described, or by an equivalent crank arrangement As in the dasher previously shown, the dasher I6 is preferably provided with large and small holes of varying sizes as indicated at I8, 19. Since only a small portion of the container wall is flexible, every movement of the dasher toward the fixed portion of the bottom of the container will result in displacing quite a large volume of liquid which must flow either through the apertures of the dasher or between the dasher and the side wall of the container. As in the construction previously described, the dasher preferably occupies quite a large portion of the cross sectional area of the container. In actual practice, there will be well-defined upward and downward circulatory movement. Due to the provision of relatively large ports at I8 in the dasher, major upward currents will be established at 68, and minor upward currents along the container at 69, the major downward flow occurring just inside of the tubular upward stream 69 as indicated by arrows at 10. Currents 69 and 10, due to the axial movement of the dasher, and the symmetrical disposition of the apertures and the dasher as a whole, will be quite generally symmetrical annular currents. During all of this circulatory movement, however, the entire body of liquid will be subjected to vibratory pulsating waves 65 as already described.

Fig. 5 shows a container lUl having a fixed bottom 12 having a flange 13 which is socketed to receive a spherical bearing member 14 held therein by a complementary socketed nut 15. The pitman I6, driven from shaft I00 by orbitally movable portions thereof, as above described, is reciprocable as well as oscillatory in the bearing member 74 so that the dasher H has a movement comparable to that indicated in Fig. 2. However, the effect on the material mixed is somewhat different due to the fact that all of the material between the dasher 11 and the container wall 12 must be bodily displaced as the dasher moves to and from the fixed wall, whereas in the construction shown in Fig. 2, the diaphragm is so large as to have a major component of movement in unison with the dasher, requiring relatively little circulation into and from this space.

I have shown both an eccentric and a crank, it being understood that these are interchangeable in the various embodiments shown. In fact, the invention is not particularly concerned with the manner in which reciprocatory motion such as that shown in Fig. 4 is communicated to the dasher. It is only where the dasher is to have the preferred combination of orbital and reciprocatory motion as in Figs. 1, 2 and 5 that some form of orbital movement of the exposed end of the pitman is desired. In these devices, the dasher and its pitman. are dependent for position on the orbitally movable rotor portion and on the portion of the container Wall in which the pitman is supported and guided for pivotal and reciprocable movement.

While the rates of dasher vibration will be varied within wide limits according to the nature and viscosity of the material treated and the nature of the results desired by the treatment, I have found that in general the rate of vibration should be in excess of one thousand vibrations per minute. There is no known top limit. I have used vibrations to the rate of three thousand vibrations per minute and over. The vibrations are of relatively low amplitude as compared with the surges which are produced.

I claim:

1. In a container having'a laterally tensioned flexible wall, a dasher, a pitman connected with the dasher within the container and having a relatively fixed connection with said wall, and a rotor outside the container having an orbitally movable portion with which said pitman is connected for oscillatory and reciprocatory movement, the pitman being rigid from the rotor to the dasher and dependent on the rotor and said wall for position.

2. The combination set forth in claim 1 in which the flexible wall comprises at least a portion of the bottom of the container, the pitman having an intermediate, substantially upright position.

3. The combination set forth in claim 1 in which the flexible wall comprises substantially the entire bottom of the container.

4. In a container having a laterally tensioned flexible wall in a position to be submerged during use of the container for mixing purposes, the combination therewith of a dasher within the container, a pitman connected with the dasher and having a relatively fixed connection with the flexible wall and extending beyond the wall outside of the container, and a shaft outside the container having an eccentric, said pitman having a bearing strap engaged with the eccentric, the pitman being dependent for movement and position upon the eccentric and upon said Wall, whereby said dasher has a combination of reciprocatory and oscillating movement upon the rotation of said shaft.

5. A mixing device for producing the combination of vibratory wave motion and circulatory surge motion in a liquid to be mixed, said mixer comprising a container, a dasher having a cross section extent equal to a major part of the cross section of the container, and means mounting said dasher for combined reciprocating and oscillatory movement, said means comprising a normally submerged wall for said container, a pitman extending through the wall and connected to the dasher within the container and having a sealing connection with the wall, said wall providing support for oscillatory and reciprocating movement of the pitman, and a transverse shaft outside of the container provided with an orbitally movable portion with which said pitman has bearing connection, the pitman and dasher being substantially wholly dependent for position and movement upon said shaft and Wall.

6. The combination set forth in claim 5 in which said wall is flexible and comprises substantially the entire bottom wall of said container.

7. The combination set forth in claim 5 in which said wall is flexible and comprises substantially the entire bottom wall of said container, together with a housing for the orbitally movable portion of said shaft, said housing comprising a clamping flange, and said container having a cornplementary flange, the said flexible wall having its perimeter clamped between said flanges.

8. In an agitating device, a container having a flexible bottom, a rotary eccentric journaled below the container on a transverse axis, a pitman connecting said eccentric with the flexible bottom and extending through said bottom in sealed relation thereto, and a dasher in the container attached to the pitman in spaced relation to the flexible bottom for vibration in response to the rotation of the eccentric.

9. A mixer comprising the combination with a container having a transversely tensioned flexible wall, of a dasher transversely disposed therein in spaced relation to the wall and occupying a major portion of the cross sectional extent of the container, a .pitman connected with said dasher and having a relatively fixed connection with said flexible wall and for which such wall constitutes a seal, and an actuator outside the container and having an orbitally movable part operatively connected with the pitman for the reciprocation and oscillation thereof.

10. The device of claim 9 in which the pitman is free of any support other than said Wall and part and depends upon said flexible wall in part for its position.

CHARLES F. WARREN.

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

UNITED STATES PATENTS Number Name Date 44,732 Lanham Oct. 18, 1864 541,658 Crooke June 25, 1895 1,211,426 Farrington Jan. 9, 1917 1,373,674 Rodger Apr. 5, 1921 1,597,271 Fleck Aug. 24, 1926 2,093,898 Taplin Sept. 21, 1937 2,124,983 Martin July 26, 1938 2,215,288 Hays Sept. 17, 1940 FOREIGN PATENTS Number Country Date 182,446 Switzerland Apr. 16, 1936

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