US2870913A

US2870913A - Centrifugal device for dehydrating a fine-granular material

Info

Publication number: US2870913A
Application number: US465046A
Authority: US
Inventors: Heckmann Wolfgang Gertr Joseph
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1953-10-30
Filing date: 1954-10-27
Publication date: 1959-01-27
Anticipated expiration: 1976-01-27

Description

J 27, 1959 w. G. J. HECKMANN 2,870,913

CENTRIFUGAL DEVICE FOR DEHYDRATING A FINE-GRANULAR MATERIAL Filed Oct. 27. 1954 5 Sheets-Sheet 1 Jan. 27,1959 w. G. J. HECKMANN 2,870,913 FOR DEHYDRATING A FINE-GRANULAR MATERIAL CENTRIFUGAL DEVICE 3 Sheets-Sheet 2 Filed Oct. 27. 1954 Jan. 27, 1959 wics. J. HECKMANN 2,

CENTRIFUGAL DEVICE FOR DEHYDRATING A FINE-GRANULAR MATERIAL 5 Sheets-Sheet 6 Filed Oct. 27. 1954 Fig.3

' INVENTO; I B/ W CENTRIFUGAL DEVICE FOR DEHYDRATING A FINE-GRANULAR MATERIAL Wolfgang Gertrud Joseph Heckmann, Koln-Deutz, Germany, assignor to Klt'ickner-Humboldt-Deutz Aktiengesellschaft, Koln, Germany, a corporation of Germany The present invention relates toa centrifugal device for dehydrating a material, and more particularly to a centrifuge for dehydrating a sludge or slurry, such as a slurry consisting of coal particles.

It is an object of the present inventionto render simple the construction of a centrifugal device of the kind described.

It is another object of the present invention to provide a centrifugal device having driving members which are easily accessible.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof when read in connection with the ac companying drawings showing, by way of example, an embodiment of the present invention. In the drawings Fig. 1 is an elevation, partly in section, of a first embodiment of the present invention,

Fig. 2 s a plan view of the device shown in Fig. 1,

Fig. 3 is a cross-section taken along the line E-F of Fig. 1,

Fig. 4 shows a detail of Fig. 1 on an enlarged scale.

Referring now to the drawings, the centrifugal device is provided with a sieve drum 1 open at the upper end thereof and having a bottom plate 2. The sieve drum 1 includes a conical sieve portion 3 provided with perforations having a diameter of approximately 0.15 mm. The conical sieve portion 3 is inclined relative to the axis CD of the drum by an angle of 10 to 15. Preferably the sieve drum 1 is provided .at the upper rim thereof with a flangef37 projecting towards the outside. The mean diameter of the sieve drum 1, i. e. the diameter at half the height thereof amounts, for example, to 400 mm. To the bottom plate 2 is attached by means of a fiange 65 a central shaft projectingv upwards beyond the sieve drum 1 and comprising the two preferably

hollow shaft portions

4 and 4a screwed to one another by means of flanges 30 and 30b between which an inner projection 32a of a pulley 32 isarranged. The

parts

30, 31 and 32 are connected by screws 30a. The upper shaft portion 4a is supported rotatably about the axis thereof by roller bearings 5 and 6 which abut against a casing or housing 7 so that the shaft portion 4a cannot move axially with respect to the casing or housing 7. The bearings 5 and 6 are adjustable by means of a look hot 8 arranged on the upper end of the shaft 4a and fastened by means of a screw 9. The housing or casing 7 is provided at the lower edge thereof with a flange 10 (Fig. 3) preferably having three aims and is secured against the penetration of dirt and moisture by means of a disc 38 carrying a packing 39. The flange 10 is clamped at three points uniformly spaced about said shaft between

rubber springs

11 and 12. The rubber springs 11 abut with the lower face thereof against a plate 13 secured by means of screws to the cylindrical outer wall 14 of the frame of the centrifuge generally denoted by 80. The plate 13 is provided with an aperture 66 through which the shaft 4 may be introduced from. above; The upper end faces of United States Patent 1 O the rubber springs 12 abut against a cover 16 of a box- Y shaped member 17 open at the lower side thereof and enclosing the

springs

11, 12. The box 17 is, asshown in Fig. 3, preferably formed with three

arms

18, 19 and 20 providing ample space for receiving the

rubber springs

11, 12 and the flange 10. Whereas the

arms

18 and 19 are relatively short, the arm 20, reinforced by a transversal rib 51, is lengthened toward the outside so as to extend beyond the outer wall 14 of the frame 80. The enclosing wall 17a of the box 17 is provided at the lower edge thereof with

lugs

21 and 22 directed. to the outside and forming members connecting the box 17 with the plate 13. The height of the enclosing wall 17a is chosen so that the

rubber springs

11, 12 are slightly compressed when the box 17 is screwed to the plate 13 so as to prestress the

rubber springs

11, 12. The prestressing may be increased or regulated by inserting plates, such as 12a, for instance, between the flange 10 and the

springs

11, 12. Preferably the

springs

11, 12 are provided with an axial boring 25, the cover 16, the flange 11], and the plate 13 being provided with

plugs

26 and 27 protruding some what into the bore 25. By this arrangement it is achieved that the

springs

11, 12 retain the correct positions thereof during the assembling of the device. Furthermore, as will be seen from Figs. 2 and 3, the plate 13 is provided inside the gaps separating the

arms

18, 19 and 20 with sector-shaped recesses 23 so that the sieve drum 1 is accessible through the same and may be easily. watched in operation.

The pulley 32 is connected by means of three V-belts 33 with a motor 34 attached to the wall 14. The V- belts 33 are arranged within the arm 20 of the box 17, the arm 20 having a widthsufl icient for accommodating the V-belts 33. Preferably, the outer end of the arm 20,

is provided with a cap 35 embracing the drive pulley 36 connected to the motor 34. The cap 35 forms the closure member of the arm 20 toward the outside so that the V- belt drive 36, 33, 32 is protected against dust and dirt.

Within the arm 20, and more particularly in the middle with the flange 10. The torsion spring 31 has a diame ter suificient to take up the belt pull of the

drive

36, 33, 32. In this manner, the

shaft

4, 4a cannot be displaced toward the left under the action of the pull of the V-belts.

The casing 7 is rigidly connected to a frame 42 which forms the upper cover of the casing 7 so that the inner I part of the same is protected also against the penetration of dirt and moisture from above. A shaft 44 arranged in parallel to the plane of symmetry H] is arranged for rotation in the frame 42 by means of roller bearings 43. The shaft 44 projects at both ends beyond the frame 42 and carries two

discs

45, 46 being provided, respectively with eccentrically arranged

weights

47, 47. The shaft 44 is connected with a second motor 50 arranged on and above the arm 20 by means of two

resilient coupling members

70, 71 shown on an enlarged scale in Fig. 4, and an intermediate shaft 76. The

coupling members

70, 71 each include a resilient member or rim 74 being arc-shaped in cross-section and consisting,

for instance, of rubber, the rim 74 by means of rings. 75, 75a and

screw bolts

76, 77 connecting the clutch; halves 72 and 73 arranged at a distance from each other.,, Thus the

coupling members

70, 71 are resilient in the,

axial direction thereof owing to the resilient rim 74, and are movable transversely in all directions in the manner of a universal joint.

A centrally arranged tube or pipe 51 is connected to the lower side of the plate 13 symmetrically to the aperture 6,6, the tube or pipe 51 terminating at a small distance above the bottom plate 2 of the sieve drum 1. Aninclmed tube or pipe 52 opens laterally into the tube or pipe 51, the tube or pipe 52 being connected at its upper end with a feed pipe (not shown) for the material to be centrifuged. The sieve drum 1 is surrounded by an annular wall 53 preferably shaped in the upper part thereof as a cone. Ribs 54 secure the lower part of the annular wall 53 to the outer wall 14. The annular wall 53 is closed at the lower end thereof by a bottom 55 so as to form a container 56 collecting the water separated from the material to be centrifuged. Immediately above the bottom 55 two pipes 57 and 5.8 open into the contamer at opposite places, the

pipes

57 and 58 withdrawng the separated water from the container 56. The wall 53 extends upwards so that its upper edge is separated from the lower side of the flange 37 so as to define a gap therebetween. Preferably the wall 53 is provided at the inner side thereof with a hollow cylindrical ring 59 directed downwards, Furthermore, it is advisable to arrange on the flange 37 a hollow conical ring 60 extendmg parallel to the conical part of the wall 53 and having a lower edge arranged below the ring 59. Preferably a hollow conical ring 62 is provided within the container 56 formed by the wall 53. The conical ring 62 is attached by means of ribs 63 to the wall 53 and extends parallel to the ring 60 so as to project with the upper edge portion thereof into the gap between the conical sieve portion 3 and the ring 60. The lower edge of the ring 62 is arranged at a distance from and above the bottom 55. The annular space 61 between the

walls

53 and 14 opens towards the lower side thereof into a collecting bunker 65 on which the centrifuge is mounted, preferably on rubber springs 66. Preferably a hollow cylinder 64 consisting of rubber or similar resilient material is arranged on the inside of the upper end of the Wall 14 and at a distance therefrom, the cylinder 64 extending downward so far that its lower rim is arranged below the level of flange 37.

The operation of this device is as follows:

The

shaft

4, 4a and the sieve drum 1 rigidly connected thereto are rotated by the motor 34 by means of the

belt drive

36, 33 and 32 at, for instance, 1400 revolutions per minute. At this speed of revolutions a centrifugal acceleration raw of approximately 400 times the acceleration of gravity prevails at half the height of the drum 1, that is where the same has a diameter of 400 mm. At the same time, the

discs

45 and 46, with the eccentrically arranged weights 47, 47' are rotated by the motor 50 connected with the

discs

45, 46 by the

coupling members

70, 71 and the intermediate shaft 76. On an average about 30v cubic meters per hour of concentrated coarse coal slurry containing about 600 grams of coal per liter, having a particle size below and including 1 mm. diameter, are supplied to the sieve drum 1 by the tubes or

pipes

52 and 51. The slurry, after its exit from the tube 51 hits the bottom 2 of the sieve drum 1 from where it is transported by the action of the centrifugal force to the conical sieve portion 3, a large portion of the water contained in the slurry being discharged through the openings in sieve portion 3.

The torsion spring 31 is flexible in all directions and furthermore, permits a twisting of the casing 7 about the longitudinal axis thereof. In consequence thereof, the casing 7 may rotate within certain limits about the point G, being the intersection of the axis of the torsion spring 31, with the axis C-D, the rotation being effected as it were in the manner of a universal joint. By this, the

shaft

4, 4a is enabled to carry out precession move ments about the fixed point G if an unbalance is produced 4 within the sieve drum 1, for instance, owing to nonuniform distribution of the material.

The center of gravity S of the system suspended from the

springs

11, 12 is very low owing to the large mass of the sieve drum 1--3 and of the contents thereof. In consequence thereof, the

shaft

4, 4a which is influenced by substantially horizontal centrifugal components caused by the rotating weights 47, carries out a pendulum movement about the point S. The casing 7 may follow these movements since the torsion spring 31 is flexible in all directions. The pendulum movement carried out by the sieve drum 1-3 is so small owing to the short distance of the center of gravity S from the bottom 2 of the sieve drum 1 that it is practically negligible. The vertical 5 components of the centrifugal forces exerted by the weights 47 impart vertical vibrations having an amplitude of about 1.5 to 3 mm. to the

shaft

4, 4a and'to the sieve drum 1'.-.3 carried by the same. The drive for the vibrational movements is preferably operated at hypercritical speeds, that is far above the natural frequency of vibration, for instance, at a frequency of 50 cycles per second. Under the action of the vibrating movement, the coal travels as a layer of about 10 mm. thickness on the sieve drum 3 towards the upper rim 37 thereof, the coal being further dehydrated thereby. The dehydrated coal finally leaves the sieve drum 3 over the flange 37 from whence it is thrown against the rubber ring 64 preventing the coal from hitting the wall 14. Thus further disintegration by a bounding effect, particularly of the coarser coal particles is prevented by the rubber wall 64. The coal dropping from the wall 64 passes through the annular space 61 into the collecting bunker 65. The water passing through the conical sieve portion 3 hits the conical rings 62 and 60 and is deflected by the same toward the bottom 55. Sprayed water particles which might be deflected toward the top are caught by the cylindrical ring 59. Thus, the

rings

62, 60 and 59 practically prevent the water from passing from the container 56 into the annular space 61. The water collecting in the container 56 is discharged through the

pipes

57 and 58.

I have described a preferred embodiment of my invention, but it should be understood that this disclosure is only for the purpose of illustration and that various omissions or changes in shape, proportion and arrangement of parts, as well as the substitution of equivalent elements for those herein shown and described, may be made without departing from the spirit and scope of the invention set forth in the appended claims.

I claim:

1. A centrifugal device for dehydrating a fine-granular material comprising, in combination: a frame, a casing .resiliently mounted on said frame for performance of vibrating movements substantially in the direction of its longitudinal axis, a first shaft, a first portion of said shaft being rotatably and axially immovably arranged in said; casing, a second portion of said shaft projecting from said casing, a sieve drum surrounding at least a part of said second portion of said shaft and being rigidly connected therewith, driving means for rotating said shaft, and vibrating means for imparting vibrations to said casing whereby said sieve drum is subjected to vibrating movements in addition to its rotating movements.

2. In a centrifugal device as claimed in claim 1, said sieve drum having an open end, and one end of said shaft extending beyond said open end of said sieve drum.

3. In a centrifugal device as claimed in claim 1 said driving means including a motor and means operatively connecting same with said shaft, said motor being mounted on said frame.

4. A centrifugal device as claimed in claim 1, said casing and said first shaft being coaxial with one another.

5. A centrifugal device as claimed inclaim 4, including a flange fixedly attached to said casing, and resilient means for clamping said flange to. said frame.

6. A centrifugal device as claimed in claim 5, said resilient means including rubber springs.

7. A centrifugal device as claimed in claim 6, said rubber springs being arranged in pairs, said flange being clamped between said pairs of springs.

8. A centrifugal device as claimed in claim 7, said rubber springs being arranged in a plurality of positions uniformly spaced on said flange about said first shaft.

9. A centrifugal device as claimed in claim 8, including a second shaft rotatably arranged on said casing at an angle to said first shaft, drive means for rotating said second shaft, and vibrating means responsive to rotation of said second shaft to impart axial vibrations to said casing.

10. A centrifugal device as claimed in claim 9, including at least one weight arranged eccentrically on said second shaft for imparting to the same vibrations in the transversal direction thereof, and means for transmitting said axial vibrations to said casing.

11. A centrifugal device as claimed in claim 9, includinga belt drive for rotating said shaft about the axis thereof, said belt drive having a plane of symmetry, and said axis being arranged in said plane of symmetry of said belt drive.

12. A centrifugal device as claimed in claim 11, including a resilient member connecting said casing with said frame, said resilient member being arranged in said line of symmetry of said belt drive.

13. A centrifugal device as claimed in claim 12, said resilient member being a resilient bar the respective ends thereof being fastened to said flange and to said frame.

14. A centrifugal device for dehydrating a fine-granular material comprising, in combination: a frame, a casing resiliently mounted on said frame for performance of vibrating movements substantially in the direction of its longitudinal axis, a shaft, a first portion of said shaft being rotatably and axially immovably arranged in said casing, a second portion of said shaft projecting from said casing, a sieve drum surrounding at least a part of said second portion of said shaft and being rigidly connected therewith, means for rotating said shaft, a second shaft arranged on said casing at an angle to said shaft, means for rotating said second shaft, coupling means including resilient parts for coupling said second shaft with said means for rotating the same, and at least one weight arranged eccentrically on said second shaft and imparting to the same vibrations in the transversal direction thereof, said transversal vibrations imparting axial vibrations to said casing whereby said sieve drum is subjected to vibrating movements in addition to its rotating movements.

References Cited in the file of this patent UNITED STATES PATENTS 275,874 Weston Apr. 17, 1883 2,254,455 Sorenson Sept. 2, 1941 2,361,767 Hays Oct. 31, 1944 2,494,584 Rouse Jan. 17, 1950