US3787156A

US3787156A - Press for treating products under high isostatic pressure

Info

Publication number: US3787156A
Application number: US00249149A
Authority: US
Inventors: K Engedal; T Landa; P Johannsson
Original assignee: ASEA AB
Current assignee: ABB Norden Holding AB
Priority date: 1971-05-06
Filing date: 1972-05-01
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22
Also published as: DE2221487A1; FR2135255A1; FR2135255B1; JPS5746959B1; GB1379058A; SE346714B; DE2221487B2

Abstract

A process for treating products with high pressure includes a high pressure cylinder with end closures projecting thereinto and a press stand. The supply of pressure medium is made through one end closure which includes a cylindrical unit with an axial and a radial channel, applied in an axially arranged recess in the end closure and sealed to the recess at its inner part and a second cylindrical unit with an axial chamber which is applied in a recess perpendicular to the axial recess and connected to the first unit. This permits the units to be readily interchanged if any part of the unit cracks under the high pressure.

Description

United States Patent Landa et a1.

PRESS FOR TREATING PRODUCTS UNDER HIGH ISOSTATIC PRESSURE Inventors: Torstein Landa; Paul Johannsson;

Knud Engedal, all of Vasteras, Sweden Allmanna Svenska Elektriska Aktiebolaget, Vasteras, Sweden Filed: May 1, 1972 Appl. No: 249,149

Assignee:

Foreign Application Priority Data May 6, 1971 Sweden 5877/71 U.S. Cl 425/77, 425/405 H, 425/406, 100/269 R Int. Cl B291) 11/32 Field of Search 425/77, 151, 406, 405 H; 100/269 R References Cited UNITED STATES PATENTS 11/1962 Custers et al. 425/77 3,091,804 6/1963 Gerard et a1 425/405 H X 3,103,699 9/1963 Gerard et a1 425/77 3,123,862 3/1964 Levey, Jr. 425/77 3,550,199 12/1970 Landa 425/405 H X 3,664,801 5/1972 Martrier 425/405 H Primary ExaminerRobert L. Spicer, Jr.

[5 7] ABSTRACT A process for treating products with high pressure includes a high pressure cylinder with end closures projecting thereinto and a press stand. The supply of pressure medium is made through one end closure which includes a cylindrical unit with an axial and a radial channel, applied in an axially arranged recess in the end closure and sealed to the recess at its inner part and a second cylindrical unit with an axial chamber which is applied in a recess perpendicular to the axial recess and connected to the first unit. This permits the units to be readily interchanged if any part of the unit cracks under the high pressure.

' 4 Claims, 5 Drawing Figures PRESS FOR TREATING PRODUCTS UNDER HIGH ISOSTATIC PRESSURE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press for treating products under high pressure, for example for isostatic compacting of powder bodies. The press comprises a high pressure chamber consisting of a high pressure cylinder and end closures projecting into the cylinder and a press stand which surrounds the high pressure chamber during the pressing operation and takes up the axial forces exerted on the end closured by a pressure medium. The press may be of the type described the invention are clear from the accompanying claims.

2. The Prior Art In presses of this type medium has hitherto been supplied to the pressure chamber through a channel directly in the end closure and consisting of an axial part and a radial part. However, it has been found that at the extremely high pressures used in equipment of this type, up to 6000 bars, such high stresses occur in the connection between the channel parts that cracks are formed. When the liquid under high pressure penetrates into a crack, this is expanded and the end closure is destroyed.

SUMMARY OF THE INVENTION According to the invention, at least the part of the supply channel where the axial and radial parts of the supply channel meet is arranged inside a replaceable separate unit. If there is a rupture, therefore, it is limited to the replaceable unit and replacement of the whole end closure, which is very heavy and expensive, is avoided. The advantage is also gained that the liquid sprayed out upon a rupture is only sprayed into a recess in the end closure. The liquid is thus prevented from shooting out with considerable force into working premises and causing damage to both people and material. Another advantage with the replaceable units is that these can be manufactured in a higher quality than a large end closure and more easily be heat-treated to give them great ductility and strength.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described more fully with reference to the accompanying drawings.

FIG. I shows a press stand with one end of a pressure chamber having an end closure with a conduit for the supply of pressure medium to the pressure chamber,

FIG. 2 shows on a larger scale a section through an end closure,

FIG. 3 a detail of the connection between two components,

FIG. 4 a view of an end closure and FIG. 5 a section through an end closure with an alternative embodiment of the lead-in for the pressure medium.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings 1 designates a high pressure cylinder having an end closure 2 which projects slightly into the cylinder 1 and is sealed to the cylinder by means of a sealing ring 3 and a lower end closure 31. The end closures at both ends of the cylinder 1 are kept in place by a press stand, having an upper yoke 36 and a lower yoke 37, which takes up the outwardly directed force generated by the pressure medium. In the end closure 2 is an axial recess 4 and a radial recess 5 perpendicular to said axial recess. In the axial'recess is a first cylindrical unit 6 which on the inside is sealed against the recess 4 by a compressible seal 7 on a level with the seal 3. The unit 6 is provided with a central hole 8 extending from its inner end to the level of a hole 9 drilled from the side. A second unit 10 which is provided with a central hole 11 is arranged in the recess 5 and connected to the unit 6 by means of a bushing 12 so that a tubular connection is obtained between the space 13 inside the cylinder 1 and a pressure medium source, not shown, through the

holes

8, 9 and II drilled in the units 6 and I0 and a conduit connected to the unit 10. The bushing 12 is arranged in

recesses

14 and 15 of appropriate size in the

units

6 and 10 and bridges the gap 16 between these. The bushing is relatively thin-walled and provided with sealing

rings

17 and 18 which at low pressure seal between the bushing 12 and surrounding walls in the

recesses

14 and 15. At high pressure the bushings are expanded to make contact with the walls of the recesses l4 and 15 so that the direct contact prevents the seals from being pressed out into the gap between the elements and gives a reliable seal at high pressure. It is suitable to make the recess 5 and the unit 10 of such dimension that a substantial clearance 19 is obtained between the recess and the unit in it. This means that deformation of the unit 6 or movement between the unit 6 and the main part of the end closure 2 itself can be permitted without risk that the deformation or movement will give rise to damaging stresses or cause leakage at the connection between the

units

6 and 10. In the alternative embodiment shown in FIG. 5 of the device according to the invention there is a relatively shallow recess 21 in the end closure 2 for the first unit 22 which is provided with an axially drilled hole 23 and a radially drilled hole 24. The second unit 25 is connected to the first unit 22 in the manner indicated in FIG. 3. The unit 22 is connected at the bottom of the shallow recess 21 to a channel 26 drilled in the closure 2 with the help of a bushing 27 of the same type as the bushing 12.

We claim:

1. Press for treating products with high pressure, comprising a high pressure chamber comprising a high pressure cylinder with end closures projecting into the cylinder, and a press stand which surrounds the high pressure chamber during the pressing operation and takes up the axial forces exerted by a pressure medium in the pressure chamber on the end closures, in which, for the supply of pressure medium, one end closure contains a first cylindrical unit with an axial and a radial channel, which unit is applied in an axially arranged recess in the end closure and a compressible seal between the inner part of the first unit and the axial recess, and said one end closure further contains a second cylindrical unit having an axial channel, which unit is applied in a recess perpendicular to the axial recess and connected to the radial channel in the first unit.

2. Press according to claim I, in which a gap is provided between the second unit and its recess.

3. Press according to claim I, having a thin-walled sleeve connecting said first and second units for the supply of pressure medium to each other, said sleeve being provided with two sealing rings which project into recesses in the two units and that is expanded by the pressure medium to make contact with the walls of the recesses.

4. Press according to claim 1, the first unit having a sealing sleeve connecting it to an axial channel drilled in the end closure.

Claims

2. Press according to claim 1, in which a gap is provided between the second unit and its recess.

3. Press according to claim 1, having a thin-walled sleeve connecting said first and second units for the supply of pressure medium to each other, said sleeve being provided with two sealing rings which project into recesses in the two units and that is expanded by the pressure medium to make contact with the walls of the recesses.