US3201828A

US3201828A - High pressure apparatus

Info

Publication number: US3201828A
Application number: US245477A
Authority: US
Inventors: Fryklund Per Ake
Original assignee: ASEA AB
Current assignee: ABB Norden Holding AB
Priority date: 1961-12-27
Filing date: 1962-12-18
Publication date: 1965-08-24
Anticipated expiration: 1982-08-24
Also published as: CH408871A; GB1022973A

Description

Aug. 24, 1965 P. KE FRYKLUND HIGH PRESSURE APPARATUS Filed Dec. 18, 1962 3 Sheets-Sheet 1 Aug. 24, 1965 P. AKE: FRYKLUND HIGH PRESSURE APPARATUS 3 Sheets-Sheet 2 Filed DeC. 18, 1962 Allg- 24 1965 P. AKE FRYKLUND 3,201,828

HIGH PRESSURE APPARATUS Filed Dec. 18, 1962 3 Sheets-Sheet 3 United States Patent O 3,201,828 HIGH PRESSURE APPARATUS Per lre Frylrlund, Robertsfors, Su/eden, assigner to Allmanna Svenska Elektrisha Ahtiebolaget, Vasteras, Sweden, a Swedish corporation Filed Der. 18, 1%2, Ser. No. 245,477 Claims priority, application Sweden, Dec. 27, 1961, 12,962/61, 12,963/6l 12 Claims. (Cl. l8-l6.5)

With apparatus for generating very high pressures, for example apparatus which is used for conversion of graphite to diamond when the pressures are several tens of thousands of atmospheres, it is desirable that the pressure is generated in as large a volume as pos-sible and that the movement of `the punches movable for the pressure generation is .as small as possible. A large volume gives large yield of reaction products, and small movement in the punches decreases Vto a great extent friction losses and facilitates the possibilities of making good seals for the pressure.

According to the present invention high and uniform pressures can be produced in large volumes with small movements in the members which generate .or transfer t-he pressure to the pressure chamber.

The invention relates to a high pressure apparatus comprising 4a pressure chamber which includes two end surfaces and side surfaces, and which has an axis running through the end surfaces, in which a pressure is generated with a pressure-transmitting mechanical means, movable towards the interior of the pressure chamber. The high pressure apparatus according to the invention is characterized in that the pressure-transmitting means consists of several blocks, separated Iby intervening gaps, which have surfaces turned towards the pressure chamber and forming together the pressure chamber side surfaces and that substantially centrally in the pressure cham-ber an inner body with small compressibility is arranged protected from the inluence of .a material or mixture to be subjected to pressure in the pressure chamber, e.g. comprising a carbonaceous substance to be converted to diamond, and which between itself and the surfaces of the blocks turned towards the pressurechamber forms a tube-shaped space for the material to be subjected to pressure, and that the end surfaces of the pressure chamber comprise pressure-resisting means sealed to the blocks, lwhich during the movement of the `blocks towards the interior of the pressure chamber have a position ixed in axial direction in relation to the pressure chamber.

The seal between the pressure-transmitting means and the pressure-resisting means at the end surfaces may be effected with deformable sealing means.

The inner body may suitably have a cylindrical or conical outer surface and an axis coinciding with that of the pressure chamber.

According to a suitable embodiment the innerbody may consist of ya peg with an axis substantially coinciding with that of the pressure chamber, which peg is -axially movable and tapered, an-d of a case arranged around the peg and slotted in separate parts, the inner surfaces of which tit the external surfaces of the peg and the separate parts of which lare displaceable towards the side surfaces of the pressure chamber by displacing the peg in its axial direction. :If the inner body is shaped in this way the special advantage is attained that the material to ice be subjected to pressure can be precompressed before it is subjected to compression through the blocks.

The inner body with small compressibility can be protected against the inliuence of the material or material mixture by being formed of a material which in itself is resistant to the material or mixture under the conditions prevailing at the border surface between the material or mixture and the body. The interior body may also be protected against the influence of the material or mixture by being surrounded with a protective case which prevents the material or mixture from coming into direct contact with it.

The blocks of the pressure-transmitting -means may be so shaped that on the outside they form together a conical surface and be arranged in a surrounding mechanically strong pressure-absorbing casing with a coni-cal inner wall which llits the common outer surface of the blocks, so that through .axial displacement of the pressure-transmitting means in relation to the pressure-absorbing casing .the pressure-transmitting ,blocks may be displaced t-owards the interior of the pressure chamber.

The invention will be more closely explained by describing .a number of embodiments referred to on the accompanying drawing. FGURE l shows a longitudinal section through a high pressure -apparatus with a cylindrical pressure chamber, in the middle of which an inner body with small compressibility is arranged, which consists of .two parts, yan inner peg and a slotted case surrounding this.

FIGURE 2 shows a cross-section of the apparatus shown in FIGURE l.

FIGURES 3, 4 and 5 show details of the high pressure apparatus shown in -FGURE l on a larger scale, FlG- URES 3 `and 4 particularly the pressure chamber in longitudinal section and cross section respectively.

FIGURE 6 shows a detail of a high pressure apparatus Wit-h .a cylindrical inner body formed as .a single part arranged therein.

In the high pressure apparatus shown in FlGURES 1 and 2 the pressure chamber, which is cylindrical, is limited along the envelope surface of the sector-shaped blocks ltltl, the parts lill of which situated nearest the pressure chamber are suitably made of harder material than the parts situated further away. The sector-shaped blocks 100, between which the gaps 102 are situated, form together a pressure-transmitting means in which the border surfaces M3, ldd and MD5 are conical and the border surface 10d is cylindrical. The gaps M2 are in planes running through the symmetry axis of the pressure chamber and their width is, in a preferred embodiment, sufilcient so that Contact between the walls of adjacent blocks facing each other does not occur even when they have aproached each other so much that the intended pressure has been reached in the pressure chamber. At the end surfaces, the pressure chamber is limited by the internally circular surfaces of the conical pistons 107 and M28 (in a higher position when pressure is applied) the parts 25.69 and 110 of which situated nearest the pressure chamber suitably are made of harder material than the parts situated further away. The pressure-transmitting means consisting of the sector-shaped blocks ltll is externally surrounded by a mechanically strong metal casing lll serving as pressure-absorbing means, said casing having internally conical form adapted to the exterior of the pressure-transmitting means. Between the said pressuretransmitting means and the casing 111, a layer 149 of a lubricating means is arranged, e.g. graphite, molybdenum disulphide, oil, etc. Above the casing a strong metal cylinder 112 is arranged, which is insulated from the casing by a layer 113 of asbestos, mica, paper, pressboard or similar material. Between the parts 100 (101) and 107 (109) a layer 114 of such insulating material is also inserted. Between the piston 107 and the cylindrical top plate 115 a compression chamber 116 is arranged, filled with a compression medium such as, for example, oil, water or other suitable medium. The pressure in the compression chamber may be regulated with an adjustable valve 117 arranged in a conduit 161 between the chamber 116 and a container not shown. Above the plate 115 and the metal cylinder 112 a stationary support 153 is arranged. The plate 115 is arranged with the peg 11S which corresponds to the recess 119 in the piston 107 so that it may be axially displaced. The chamber 116 is sealed at the recess by the seal 155, suitably of rubber. The compression chamber is sealed to the cylinder 112 by the sealing rings 120, suitably of rubber. Instead of the compression chamber 116 a mechanical spring means with adjustable spring pressure may be used.

In the lower piston 103 a conical peg 121 of a material with small compressibility is fastened. As more clearly shown by FIGURES 3 and 4 the conical body 121 has on the uppermost end surface a layer 122 of insulating material, for example asbestos, talcum, etc., for insulation against the upper piston, and is nearest the envelope surface surrounded by an internally conical and externally cylindrical slotted case, consisting of sector-shaped separate parts 123. The peg 121 and the parts 123 form together the previously mentioned inner body with small compressibility. This part is surrounded by tube-shaped insulation 124 consisting of, for example, pyrophyllite or talcum. Outside this insulation the reaction mixture 125 is arranged, for example consisting of a mixture of graphite and a metal such as nickel or iron. By subjecting this mixture to very high pressure, several tens of thousands of atmospheres, and high temperature, over 1000 C., the graphite can be converted to diamond. The reaction mixture is surrounded by an externally tube-shaped insulation 126 suitably of the same material as the insulation 124. The spaces between the blocks 123 are sealed against the material outside by the axially running sealing strips 127 having parallel-trapezium shaped cross-section, and which lie against axially running bevelledv surfaces 128 and 129 of neighbouring blocks. In a similar way the gaps 102 between the blocks 100 (101) are sealed to the pressure chamber with the axially running sealing strips 130, likewise with parallel-trapezium shaped crosssection. Each sealing strip 130 lies against axially running bevelled surfaces 131 and 132 of neighbouring blocks. The

pistons

107 and 108 are nearest to the pressure chamber provided with

circular discs

139 and 140 of steel or cemented carbide which towards the pressure chamber are bevelled as is seen more clearly from FIG- URE 5. Against the bevelled surface 141 of the discs 139 lies a sealing ring 142 with a surface 143 and with another surface 144 above the uppermost part of the insulation 126 against the blocks 100 (101). The ring 142 is plastically deformable. The

metal discs

139 and 140 need not form separate arrangements but may be parts of the arrangements 107 and 10S. Between the

parts

139 and 123 an insulating layer 159, for example of asbestos, talcum or similar material, is arranged. Against the lower disc 140 another ring 160 of plastically deformable material is correspondingly situated. As seen from FGURE 3 this ring may lie directly against the blocks 100 (101) without intermediate insulation. Through the

pistons

107 and 108, the body 121 and the pegs 118 a cooling channel consisting of

parts

133, 134, 135 and 136 is arranged, through which a cooling medium, for example water, spirit, oil or the like may be conducted. Mainly at the end surfaces of the pressure chamber rings 137 and 13S of conducting material, for example steel, copper or the like are arranged for supplying electrical current to the reaction mixture. If this consists of graphite mixed with metal it has sufilcient conductivity to be directly subjected to resistance heat treatment. If the reactor mixture has not such good conductivity, the heating may be carried out by means of tubes, discs, threads, spirals or other bodies of electrical resistance material embedded in the reaction mixture. The current may be supplied via conduit 145 on the piston 103 and the piston 108, and led away via the piston 107 and the cable 146 arranged in a channel 147 in the casing 111.

The reaction mixture may be subjected to pressure by displacing the piston 103 upwards with a partly shown hydraulic press 154 of conventional type. A certain precompression of the contents of the pressure chamber then occurs merely because the body 121 is wholly carried into it. The consequence is namely that the slotted part consisting of the blocks 123 is displaced towards the envelope surface of the pressure chamber. When the ring 156 which is arranged around the lower part of the piston 108 or is a part of the piston 10S meets the plane surface 157 of the blocks 100, these begin to be displaced upwards in the stationary casing 111 along the common sliding surface. Since there is always a gap between the surfaces and 148 and gaps betweenthe blocks 100 (101) this causes a displacement of the blocks 100 (101) towards the middle of the pressure chamber, so that the reaction mixture is compressed between the body 121 and the blocks 100 (101). The sealing rings 142 and 160 at the

rings

139 and 140 are thus deformed. If the

rings

142 and 160 are arranged in direct contact with the reaction mixture the

rings

137 and 138 are unnecessary. The supporting pressure on the upper end surfaces of the pressure chamber may be maintained at the required level by adjustment of the pressure in the compression chamber 116. At the same time the position for the surface of the upper piston facing towards the pressure chamber may be displaced in axial direction and corrected according to the movements of the separate blocks. The supporting pressure on the lower end surface of the pressure chamber is exercised by the upper circular surface of the piston 103.

In FIGURE 6 another embodiment of the invention is shown, in which the pressure chamber is arranged differently from that shown in FIGURE 1, but the other details are the same. On the pistons 107 (109) and 108 (110)

circular metal discs

150 and 151 are arranged nearest the pressure chamber. On the disc 151 a cylindrical inner body 152 with small compressibility and consisting of one part is arranged, and immediately around this a material to be subjected to pressure, for example molybdenum disulphide. The body 152 may here be composed of for example stainless steel which is not inuenced by the material. During application of pressure on the movable "sector-shaped blocks the material is compressed according to the envelope surface of the body 152.

The lower piston 108, in the same way as the upper piston 107, may also be arranged to exercise an adjustable support pressure on the end surfaces of the pressure chamber. Outside the piston 108 (without the ring 156) a compression chamber with adjustable pressure may be arranged in an analogous way as outside the piston 107, which compression chamber is radially limited by a mechanically strong tube, the ends of which lie against the surface 157 and the piston 154, and axially limited by the lower surface of the piston 108 and a plate lying along the upper surface of the piston 154, corresponding to plate of the upper piston 107.

The inner body with small

compressibility including parts

121, 123 and 152 may, inter alia, be manufactured from a metal such as iron, nickel, cobalt, chromium, manganese, molybdenum, aluminium, tungsten, tantalum, zirconium, titanium, copper, and alloys of these such as, for

r example, a tool steel with a hardness of RC 65 (e.g. C 550,V

Fagersta Bruks AB, Sweden), a high speed steel with a hardness of RC 68 (eg. WKE 4, Fagersta Bruks AB, Sweden), a stainless steel with a hardness of RC 50 (e.g. RRNJ 44, Fagersta Bruks AB, Sweden), various types of brass and bronze, Monel (31% Cu, 67% Ni, 2% Fe, Mn, Si), ferro niobium (S0-60% Nb, 40-50% Fe), Nichrome (80-90% Ni, 10-20% Cr) and certain aluminium alloys. Further, sintered alloys, inter alia, of the cemented carbide type (c g. Coromant H05, H10, Sandvikens Jernverks AB, Sweden, Uddia H20, Uddeholms Jrnverks AB, Sweden, containing tungsten carbide and 4-10% cobalt). The material in the inner body is chosen in each particular case, inter alia, according to the conditions which the material to be treated in the pressure chamber is to be subjected to.

As examples of materials surrounding the pressure chambers in the shown high pressure apparatus may be mentioned: for the

parts

100, 101, 107, 108, 109, 110, 139, 140, 150, and 151 a cemented carbide (e.g. Carboloy 999, General Electric Co., U.S.A., or Coromant H05, Sandvikens Jernverks AB, Sweden) or a high speed steel with a hardness of RC 65-67 (e.g. WKE 4, Fagersta Bruks AB, Sweden), for the part 111 a toughened steel with a hardness of RC 45 (e.g. RO 7155, Bofors AB, Sweden), for the parts 127 and 130 a tempered steel with a hardness of RC 65 (e.g. ROB 21, Bofors AB, Sweden), and for the

parts

142 and 160 for example a toughened steel with a hardness of RC 50 (e.g. RO705, Bofors AB, Sweden), an austenitic stainless steel (e.g. Avesta 832, Avesta, Sweden), copper-beryllium alloys of various compositions (e.g. containing about 97.5% Cu, 2% Be and 0.25% CO), chromium-nickel-iron alloys of various compositions (e.g. containing 7% Fe, 78% Ni and 15% CO).

I claim:

1. High pressure apparatus comprising an outer pressure absorbing means, a pressure chamber including means forming two end surfaces and means forming side surfaces and having an axis running through the end surfaces, the means forming said side surfaces of the pressure chamber comprising a plurality of blocks arranged around the pressure chamber and having side surfaces facing each other, there being gaps between said side surfaces of the blocks, said blocks being movable in the axial direction in said outer pressure absorbing means, said blocks and said outer pressure absorbing means having cooperating means to produce movement of the blocks towards the interior of the pressure chamber in response to axial movement of the blocks in one direction for compressing a material arranged in the pressure chamber, said means forming end surfaces of the pressure chamber being pressure-resisting means sealed to the blocks and both mounted for axial movement in the same direction with respect to the outer pressure absorbing means to follow the axial movement of the blocks.

2. High pressure apparatus as claimed in claim 1, having deformable sealing means sealing said pressure chamber to said gaps between said blocks.

3. High pressure apparatus as claimed in claim 2, in which said deformable sealing means is slidably arranged between said pressure resisting means and said blocks.

4. High pressure apparatus comprising an outer pressure absorbing means, a pressure chamber including means for-ming one rst and one second end surface and means forming side surfaces and having an axis running through the end surfaces, said means forming side surfaces of the pressure chamber comprising a plurality of blocks arranged around the pressure chamber and having side surfaces facing each other, there being gaps between said side surfaces of the blocks, said blocks being arranged in an outer pressure absorbing means, said outer pressure absorbing means comprising a member having therein a hole with an axis common to that of the pressure chamber and with a constantly decreasing cross-section in one direction of the axis, said blocks having external surfaces fitting the surfaces of the hole of the pressure absorbing means and being displaceable in the direction of such axis with respect to the pressure absorbing means for effecting a movement of the blocks towards the interior of the pressure chamber for pressure generation in the pressure chamber, said means forming the first end surface of the pressure chamber being constituted of a rst axially movable pressure-resisting means, said means forming the second end surface being constituted of a second axially movable pressure-resisting means, and axially acting pressure means for producing movement of said blocks in the direction of decreasing cross-section of the hole, said iirst and said second pressure-resisting means being sealed to the blocks and both mounted for axial movement in the same direction with respect to the outer pressure absorbing means to follow the axial movement of the blocks.

5. High pressure apparatus as claimed in claim 4, in which a lubrication layer is arranged between the surfaces of the hole of the pressure absorbing means and the surfaces of the blocks adjacent thereto.

6. High pressure apparatus as claimed in claim 4, in which said axially acting pressure means causing the displacement of the blocks is arranged outside said rst end surface of the pressure chamber and constitutes a pressure support for said rst pressure-resisting means.

7. High pressure apparatus as claimed in claim 4, in which said pressure chamber has a cylindrical form, said hole of the pressure absorbing means having a conical form, said blocks forming together a body with an externally conical form litting the hole of the pressure absorbing means, said blocks being sector-shaped and said first and said second pressure-resisting means having a conical form and having circular surfaces turned towards the pressure chamber.

8. High pressure apparatus comprising an outer pressure absorbing means, a pressure chamber including means forming one first and one second end surface and means forming side surfaces and having an axis running through the end surfaces, said means forming the side surfaces of the pressure chamber comprising a plurality of blocks arranged around the pressure chamber and having side surfaces facing each other, there being gaps between said side surfaces of the blocks, said outer pressure-absorbing means comprising a member having therein a hole with an axis common to that of the pressure chamber and with a successively decreasing crosssection in one direction of the axis, said blocks having external surfaces fitting the surfaces of the hole of the pressure-absorbing means and being displaceable in relation to the pressure-absorbing means in the duration of such axis for effecting a movement of the blocks towards the interior of the pressure chamber for pressure generation in the pressure chamber, said means forming the first end surfaces of the pressure chamber comprising a first axially movable pressure-resisting means including first means to exert an adjustable pressure at the rst end surface to equal the pressure blocks towards the interior of the pressure chamber, said means forming the second end surface of the pressure chamber comprising a second axially movable pressure-resisting means including second means to exert an adjustable pressure towards the pressure chamber for adjusting the pressure at the second end surface to equal the pressure generated in the pressure chamber upon the displacement of the blocks towards the interior of the pressure chamber, said rst and said second pressure-resisting means being sealed to the blocks and both mounted for axial movement in the same direction with respect to the outer pressure absorbing means to follow the axial movement of the blocks, and axially acting pressure means for producing movement of said blocks in the direction of decreasing cross-section of said hole, said pressure means supporting said first pressureresisting means.

9. High pressure apparatus as claimed in claim 8, in which said iirst pressure-resisting means and said blocks have opposed surfaces thereon transverse to such axis.

10. In high pressure apparatus as claimed in claim 1, an inner body of small compressibility substantially centrally positioned in the pressure chamber, said inner body forming between itself and the surfaces of the blocks turned towards the pressure chamber a tube shaped space for the reaction mixture to be subjected to pressure.

11. High pressure apparatus as claimed in claim 10 in which the inner body is surrounded by a casing preventing the material being compressed from coming into direct contact with the inner body.

12. High pressure apparatus as claimed in claim 1), said inner body comprising a peg with an axis substantially coinciding with that of the pressure chamber and being movable in the direction of the axis and tapered,

References Cited by the Examiner UNITED STATES PATENTS 2,737,998 3/56 Meanor et al. 2,947,034 8/ 60 Wentorf. 3,096,544 7/63 Lundblad. 3,105,994 l0/ 63 Gerard et a1. 3,123,862 3/ 64 Levey.

and a case around the peg comprising several separate 15 WILLIAM J. STEPHENSON, Primary Examiner.

Claims

1. HIGH PRESSURE APPARATUS COMPRISING AN OUTER PRESSURE ABSORBING MEANS, A PRESSURE CHAMBER INCLUDING MEANS FORMING TWO END SURFACES AND MEANS FORMING SIDE SURFACES AND HAVING AN AXIS RUNNING THROUGH THE END SURFACES, THE MEANS FORMING SAID SIDE SURFACES OF THE PRESSURE CHAMBER COMPRISING A PLURALITY OF BLOCKS ARRANGED AROUND THE PRESSURE CHAMBER AND HAVING SIDE SURFACES FACING EACH OTHER, THERE BEING GAPS BETWEEN SAID SIDE SURFACES OF THE BLOCKS, SAID BLOCKS BEING MOVABLE IN THE AXIAL DIRECTION IN SAID OUTER PRESSURE ABSORBING MEANS, SAID BLOCKS AND SAID OUTER PRESSURE ABSORBING MEANS HAVING COOPERATING MEANS TO PRODUCE MOVEMENT OF THE BLOCKS TOWARDS THE INTERIOR OF THE PRESSURE CHAMBER IN RESPONSE TO AXIAL MOVEMENT OF THE BLOCKS IN ONE DIRECTION FOR COMPRESSING A MATERIAL ARRANGED IN THE PRESSURE CHAMBER, SAID MEANS FORMING END SURFACES OF THE PRESSURE CHAMBER BEING PRESSURE-RESISTING MEANS SEALED TO THE BLOCKS AND BOTHE MOUNTED FOR AXIAL MOVEMENT IN THE SAME DIRECTION WITH RESPECT TO THE OUTER PRESSURE ABSORBING MEANS TO FOLLOW THE AXIAL MOVEMENT OF THE BLOCKS.