US3813084A

US3813084A - Vibrating device with a heat insulated treatment chamber, particularly a vibrating mill

Info

Publication number: US3813084A
Application number: US00208291A
Authority: US
Inventors: J Langmaack; H Haas
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1970-12-24
Filing date: 1971-12-15
Publication date: 1974-05-28
Anticipated expiration: 1991-05-28
Also published as: FR2119615A5; GB1350228A; ZA718137B; DE2063688A1; CA961462A; SU383247A3; AU3736271A

Abstract

In a vibrating device provided with a treatment chamber surrounded by a heat insulating jacket, the heat insulating material of this jacket is surrounded by a solid outer jacket, for instance made of plastic, and this outer jacket is rigidly connected by solid connecting members with the outer circumference of a tube the interior of which forms said treatment chamber. The connecting members may comprise radial tongues bent inwardly from said outer jacket or straps wrapped around said tube and attached with their ends to said solid outer jacket or thin discs arranged in the space between the inner wall of said solid outer jacket and the outer wall of said tube. The discs are provided with a plurality of circular series of apertures to reduce the heat conductivity of the discs.

Description

United States Patent 1 Langmaack et al.

[ 1 May 28, 1974 VIBRATING DEVICE WITH A HEAT INSULATED TREATMENT CHAMBER, PARTICULARLY A VIBRATING MILL Inventors: Jiirgen Langmaack, Niederkassel;

Helmut Haas, Cologne, both of Germany Klockner-Humboldt-Deutz Aktiengesellschaft, Cologne, Germany Filed: Dec. 15, 1971 Appl. No.: 208,291

Assignee:

Foreign Application Priority Data Dec. 24, 1970 Germany ..,2063688 US. Cl. 259/72, 220/9 R Int. Cl B0lf 11/00 Field of Search 220/9 R, 9 A, 15; 259/72,

259/1 R, DIG. 42, DIG. 43, DIG. 44, DIG. 41

References Cited UNITED STATES PATENTS 7/1917 Frank 220/15 Pheteplace...., 220/9 A UX 1,973,880 9/1934 Moody 220/) D 2,416,017 2/1947 Nol'zinger 2,763,321 9/1956 Schuster 220/15 X Primary Examiner-Robert W. Jenkins Attorney, Agent, or FirmHill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT In a vibrating device provided with a treatment chamber surrounded by a heat insulating jacket, the heat insulating material of this jacket is surrounded by a solid outer jacket, for instance made of plastic, and this outer jacket is rigidly connected by solid connecting members with the outer circumference of a tube the interior of which forms said treatment chamber.

The connecting members may comprise radial tongues bent inwardly from said outer jacket or straps wrapped around said tube and attached with their ends to said solid outer jacket or thin discs arranged in the space between the inner 'wall of said solid outer jacket and the outer wall of said tube. The discs are provided with a plurality of circular series of apertures to reduce the heat conductivity of the discs.

10 Claims, 6 Drawing Figures PATENTED MAY 2 8 1334 saw 1 BF VIBRATING DEVICE WITH A I-IEAT INSULATED TREATMENT CHAMBER, PARTICULARLY A VIBRATING MILL The invention relates to a vibrating device which is equipped with a treatment chamber surrounded by an insulating jacket and particularly relates to a vibrating mill.

In such devices, particularly vibrating mills or oscillating conveyors, in which the material is subjected simultaneously to a temperature treatment, particularly a cooling treatment or low-temperature treatment, respectively, the problem is to construct the insulating jacket in such manner that the same is capable of withstanding the high acceleration forces which, for instance, may amount to a value which is times the value of the acceleration due to gravity. On the other hand, the attachment of the insulating jacket to the treatment chamber of the vibrating device has to be effected in such manner that the securing means transmit only very small amounts of heat from the exterior toward the interior or from the interior toward the exterior. This is the more important, the higher the difference in temperature is between the interior of the treatment chamber and the surrounding atmosphere, because these securing means may cause substantial losses in temperature which endanger the economy of the method practiced with the device.

It is an object of the invention to provide the vibrating device with an insulating jacket which is able to withstand the mechanical stresses and complies with the necessary insulating requirements to which such vibrating devices are subjected.

In accordance with the invention, a solid outer jacket on the insulating jacket is rigidly connected with the walls of the treatment chamber by connecting elements having the smallest possible cross-sectional area. When this is done, the insulating material arranged between the walls of the treatment chamber and the solid outer jacket is subjected in respect of its strength solely to inertia forces which by means of their own mass may act upon the insulating material. From the inner side and from the outer side, the insulating material is held against the wall of the treatment chamber by means of the outer jacket which is rigidly connected to the treatment chamber, so that relative movements of the insulating material under the influence of the vibrating movement cannot develop. Since furthermore the cross-sectional area of the connecting elements between the outer jacket and the treatment chamber have the smallest possible cross-section, it is assured that in spite of the direct connection between the treatment chamber and the outer jacket, the conduction of heat from the exterior toward the interior or from the interior toward the exterior, respectively, is reduced to a minimum.

Another object of the invention is that the connecting elements between the outer jacket and the treatment chamber in each of the respective attachment ranges are constructed as strap means which preferably are arranged in the end range of the outer jacket or a section of the outer jacket. In such an arrangement a verysimple attachment of the outer jacket to the treatment chamber is possible since in the range of the ends of the outer jacket or the sections of the outer jacket the strap means are easily accessible, so that the same in a simple manner produce a rigid connection between the outer jacket and the treatment chamber by suitable meansfor instance, by means of welding, gluing or screws.

In an advantageous embodiment of the invention, the connecting elements between the treatment chamber and the outer jacket comprise a material of low-heat conductivity. In this manner, the insulating effect of the connecting elements when having a very small crosssectional area can be increased, or if in view of the stresses during the operation larger cross-sections have to be selected, the enlargement of such cross-section compensates for a suitable heat transmission by heat conductivity. Depending upon the type of the connecting elements, it may be sufficient when the same are made only partially of a material having a low heat conductivity.

In another embodiment of the invention, the solid outer jacket is made of a plastic, preferably of a plastic reinforced by fibers. This has the advantage that on the one hand, a solid outer skin is provided for the protection of the insulating material, which skin is also resistant to mechanical stresses from the exterior which, however, on the other hand, in view of the customary small specific weight of the plastic, which comes into consideration for the material of the outer jacket reduces the mass of the same. In this manner, the advantage is obtained that the stresses acting on the connecting elements under the influence of the mass forces created by the vibrating movement are noticeably reduced by a suitable decrease of the mass of the outer jacket.

For improving the insulating effect, the invention provides also that the outer jacket on its outer surface is provided with a coating which reflects heat rays. When in this manner the difference in temperature between the interior of the treatment chamber and the environment is very high, particularly when practicing a low-temperature process in the treatment chamber, the insulating effect of the insulating material is improved.

The invention will now be described in greater detail with reference to the accompanying drawings which disclose a few embodiments of the invention and additional features of the same.

In the drawings:

FIG. 1 illustrates diagrammatically a tubular vibrating mill with insulated grinding tubes.

FIG. 2 illustrates in an enlarged longitudinal sectional view, a portion of a grinding tube of a vibrating mill.

FIG. 3 is an enlarged cross-sectional view along the line III-III of FIG. 1.

FIG. 4 illustrates a development of the outer jacket in the range of the cross-sectional view IIIIII of FIG. 1.

FIG. 5 illustrates another embodiment of the connecting elements which may be used; and

FIG. 6 illustrates still another embodiment of the connecting elements which may be used.

Referring to FIG. 1, the illustrated tubular vibrating mill is provided with two heat insulated

grinding tubes

1 and 2 arranged in spaced relation one above the other and extending with their axes in a horizontal direction. This tubular vibrating mill with its heat-insulated grinding tubes is suitable for performing grinding operations at low and very low temperatures, respectively. For this purpose, the two horizontally disposed

grinding tubes

1 and 2 are each provided with an insulating jacket 10 and are arranged in a supporting frame 3 mounted for vibratory movement. The supporting frame 3 is provided with a not-illustrated vibration-producing device. The

grinding tubes

1 and 2 are connected with the mentioned supporting frame 3 by means of clamping straps 4. The upper left-hand end of the grinding tube 1 is connected with a vertically disposed insulated feed pipe 5. The material which has been ground leaves the left-hand end of the lower grinding tube 2 through downwardly divided discharge pipe 6 which also is insulated. The two right-hand ends of the vertically spaced parallel and

horizontal grinding tubes

1 and 2 are connected with each other by a vertically disposed insulated pipe 7. The insulating jacket of each grinding tube owing to the attachment of the grinding tubes to the supporting frame and owing to the particular arrangement of the feed pipe and the discharge pipe is subdivided into individual sections. One section extends from each end to a separating joint on the feed head or discharge head, respectively; a further section extends from the joint to the fastening means of the grinding tube to the supporting frame. Furthermore, one section is arranged between the two fastening points. Such a subdivision of the insulating jacket isnot required, however, in other devices in which the construction permits the arrangement of an undivided insulating jacket.

FIG. 2 illustrates in a longitudinal section the upper portion of the feed end of the tubular vibrating mill on an enlarged scale. The grinding tube 1 is provided at its left-hand end with an outwardly extending flange 8 to which is attached by means of bolts and nuts the outwardly extending flange of a feed head 9 which closes the left-hand end of the tube 1. This feed head 9 has attached thereto the upwardly-extending feed pipe 5. The outer surface of the grinding tube 1 is completely surrounded by an insulating jacket 10 comprising a thick layer of insulating material on the outside of which is placed a solid outer shell or jacket 11. The insulating jacket 10 in accordance with the construction of the tubular vibrating mill is subdivided into a number of sections. In order to obtain a rigid connection between the grinding tube 1 and the outer solid jacket 11, the outer jacket of which in accordance with the invention gives the insulating material a sufficient hold even at very high accelerating values, it is necessary to provide at least in the end ranges of each section of insulating jacket, a number of connecting elements between the outer jacket and the grinding tube.

In the range of the flange, the connecting elements could consist in accordance with one embodiment of the invention, of a tongue-shaped radial extension 12 of the solid outer jacket 11, as this is illustrated in FIG. 4, which shows a development of the outer jacket 11. As shown in the sectional view of FIG. 2, these tongueshaped extensions are bent as shown in FIG. 4 along the dotted lines, namely inwardly and then again with their extreme outer ends in axial direction of the grinding tubes in such a manner that the outermost ends of these tongues can be fixedly secured to the outer circumference ofthe flange 8, preferably by a welding operation.

FIG. 3 illustrates an end view of the grinding tube 1 with the feed head 9 removed therefrom in order to show clearly the position and arrangement of the radial tongues 12. The advantage of this embodiment is that the entire construction of the connecting elements is very simple. The outwardly extending and abutting

flanges

8 and 9 of the grinding tube 1 and of the feed head 9, respectively, are connected with each other by bolts and nuts, as shown in FIG. 2.

In place of tongues 12 having a rectangular crosssection, as shown in the FIGS. 2, 3 and 4, another embodiment of the invention has certain advantages when the outer jacket 11 is connected by means of tubular members with the grinding tube 1. This is particularly then of advantage when owing to great accelerations of the grinding tube caused by the vibrating movement, the outer jacket also is subjected to substantial inertia forces, so that the tubular form of the connecting members insures a greater strength of the connecting elements, while on the other hand the cross-sectional tubular members insure a very small heat conduction.

In the vibrating mill selected as an example of the invention, each grinding tube is force-lockingly connected with the supporting frame 3 by clamping straps 4. When using insulated grinding tubes, then in each fastening range a supporting ring 13 is placed around the grinding tube, and this supporting ring 13 is connected rigidly by radial members 14 consisting of solid insulating material with the grinding tube 1. The solid insulating material may, for instance, comprise polytetrafluorethylene. This supporting ring 13 may at the same time advantageously be used as a fastening element for the adjacent ends of the sections of the solid outer jacket 11. For this purpose, the adjacent ends of the outer jacket 11 are caused each to engage slidably an annular groove 15 in the supporting ring 13 and are then welded thereto.

FIG. 5 illustrates, by way of example, another connecting element which may be arranged between the solid outer jacket 11 and the grinding

tube

1 or 2 of a vibrating mill. FIG. 5 illustrates in an end view similar to the section III-III in FIG. 1, a connecting element which comprises a relatively thin circular disc 16 which is provided over its entire surface with apertures. In this embodiment, the apertures comprise slots 17 extending concentrically with respect to the center of this disc 16. According tothe invention, the apertures or slots are arranged in a number of rows concentrically placed about the axis of the center of this disc, whereby the apertures or slots in adjacent circular rows are offset with respect to one another. The advantage of this particular arrangement of the aperture and slots is that there remains between the apertures or slots solid portions which first of all may transmit heat from the outer jacket to the inner chamber or vice versa, and this heat conduction is substantially increased with respect to the radial distance between the outer jacket and the treatment chamber. In this manner, it is possible to reduce the temperature loss within the range of the securing elements substantially even though the disc may consist of material which is a good heat conductor.

FIG. 6 illustrates another embodiment of a connecting element for the vibrating mill of the present invention. In this embodiment, the treatment chamber-for instance the grinding tube l-is provided at opposite sides with at least two

flexible straps

18 and 19 or wires which are wrapped around the grinding tube 1 and which at their ends are attached to the solid outer jacket 11. This type of connecting element is particularly suitable for all fastening ranges which do not lie any more at the end range of the outer jacket and, therefore, need not be slidably moved over extensions of the treatmentchamber, such as outwardly projecting flanges, or which for other reasons are no longer accessible from the outside. In this arrangement, the straps or wires are first fixedly attached with one of their ends to the outer jacket, while the other end has a suitable length and is loosely pushed through an opening in the outer jacket. Only then when the correct position of the outer jacket with respect to the treatment chamber has been obtained, the loose end of the straps or wires is tensioned and is fixedly attached to the outer jacket.

In the event that the thickness of the outer jacket or the strength of the material is not sufficient, it is necessary to provide in the fastening range of the straps on the outer jacket a suitable clamping ring. The arrangement of such a clamping ring permits the attachment of clamping elements which make a re-tensioning of the straps possible.

The invention is not limited to the examples of the connecting elements which have been described in connection with a tubular cross-section of the treatment chamber and is also not limited to vibrating mills. In fact, the mentioned connecting elements are suitable for any vibrating device which is provided with a treatment chamber surrounded by an insulating jacket. According to the basic principle of the invention, it is solely of importance that a solid connection is made between the outer jacket and the wall of the treatment chamber and that the connecting elements between the same have cross-sectional areas which are so small that a heat conduction is kept as small as possible.

What we claim is:

1. In a vibrating device having a treatment chamber with the wall surrounded by an insulator sleeve having an outer jacket, said chamber being supported in a frame which is provided with a vibration producing device, the improvements comprising a fixed clamping strap connected to the frame, and connecting elements disposed between the wall of the treatment chamber and the clamping strap to rigidly interconnect the chamber to the clamping strap, said connecting elements having a cross-sectional area which is small as possible to prevent transfer of heat between the strap and the wall of the chamber.

2. In a vibrating device according to claim 1, wherein the connecting elements are constructed of a plurality of members disposed between the clamping strap and the wall of the treatment chamber.

3. In a vibrating device according to claim 2, wherein the member of the connecting elements include a tubular member spaced from the wall of the treatment chamber by a plurality of rigid radial members.

41-. In a vibrating device according to claim 3, wherein the edges of the tubular member are contoured to receive edges of the adjacent jackets of the insulative sleeve.

5. In a vibrating device according to claim 1, which further includes at least two flexible bands surrounding opposite sides of the wall of the treatment chamber and affixed to the jacket of the insulative sleeve for rigidly connecting the sleeve to the chamber.

6. In a vibrating device according to claim 1, wherein the outer jacket of the sleeve is connected to the wall of the treatment chamber by an annular disc having a plurality of apertures therein.

7. In a vibrating device according to claim 6, wherein said apertures are elongated slots disposed along circles of different radii in said disc with the slots of one circle overlapping the slots of adjacent circles.

8. In a vibrating device according to claim 6, wherein the apertures are arranged in several rows with the apertures of one row being offset to the apertures of the other rows.

9. In a vibrating device according to claim 8, wherein the apertures are elongated slots which overlap the slots of adjacent rows.

10. In a vibrating device according to claim 1, wherein the connecting elements consist at least partially of a material with a low heat conductivity.

Claims

4. In a vibrating device according to claim 3, wherein the edges of the tubular member are contoured to receive edges of the adjacent jackets of the insulative sleeve.