Method of processing organic or inorganic products

Abstract

Method for processing organic material is disclosed which breaks down the inedible components of fruit and vegetables (core, skin, pips, pithy material) into an edible substance with a cream-like consistency. The method includes pressurizing the material and forcing it through a passage having a number of end-to-end sections which are at right angles to one another. The material as it emerges from each section impacts on the impact surface at the end of each section and changes direction and flows into the next section of the series.

Claims

1. A method of processing material which comprises: providing a reciprocating piston in a cylindrical bore and a pressure chamber which forms a continuation of the cylindrical bore; reciprocating the piston in the cylindrical bore in alternating forward pressurizing strokes and return strokes; feeding the material to the pressure chamber and cylindrical bore, while the piston is retracted; pressurizing the material in the cylindrical bore with the forward pressurizing strokes of the piston and forcing the material under pressure from the cylindrical bore, directly through the pressure chamber into a passageway under a pressure of between 200 and 2000 bar so that it emerges from the passageway at a speed of between 500 and 6000 kph: causing the material to flow from the passageway through a passage comprising a plurality of sections including at least a first section and a second section, each of said sections having an inlet end and an outlet end and each of said sections being at an angle with respect to the section which precedes it, said method being performed on apparatus comprising a first part that defines surfaces and a second part that defines surfaces corresponding to the surfaces of the first part, said passage being formed between said corresponding surfaces of the first and second parts; and urging the second part towards the first part with a bias mechanism, so that the material changes direction as it flows from of said sections to the next, and providing an impact wall at the outlet end of each section so that the material, as it emerges from each section, impacts on the impact wall at the end of that section, changes direction and flows into the next section of the passage.

2. The method according to claim 1, wherein the pressure is between 300 and 1600 bar.

3. The method according to claim 2, wherein the pressure is between 350 and 1200 bar.

4. The method according to claim 1 wherein the speed is between 2000 and 4000 kph.

5. The method according to claim 1, which includes the prior steps of forming a slurry of the material by reducing the material to particulate form and dispersing the material in particulate form in a liquid to form the slurry.

6. A method of processing material which comprises: providing a reciprocating piston in a cylindrical bore and a pressure chamber which forms a continuation of the cylindrical bore; reciprocating the piston in the cylindrical bore in alternating forward pressurizing strokes and return strokes; feeding the material to the pressure chamber and cylindrical bore, while the piston is retracted; pressurizing the material in the cylindrical bore with the forward pressurizing strokes of the piston and forcing the material by the forward pressurizing strokes of the piston from the cylindrical bore, directly through the pressure chamber into a passageway at a pressure of 200 bar or above through a passageway having a diameter of between 0.05 mm and 8 mm, causing the material to flow from the passageway through a passage comprising a plurality of sections including at least a first section and a second section, each of said sections having an inlet and an outlet and said sections being at an angle with respect to the section which precedes it, said method being performed on apparatus comprising a first part that defines surfaces and a second part that defines surfaces corresponding to the surfaces of the first part, said passage being formed between said corresponding surfaces of the first and second parts: urging the second part towards the first part with a bias mechanism, so that the material changes direction as it flows from one of said sections to the next, and providing an impact wall at the outlet end of each section so that the material, as it emerges from each section, impacts on the impact wall at the end of that section, changes direction and flows into the next section of the passage.

7. The method according to claim 6, wherein the bore diameter is between 0.1 mm and 6 mm and the pressure is between 350 and 1200 bar.

8. The method according to claim 7, wherein the material is forced through a bore which has two end-to-end sections, the upstream section being of larger diameter than the downstream section.

9. The method according to claim 6, which includes the prior steps of forming a slurry of the material by reducing the material to particulate form and dispersing the material in particulate form in a liquid to form the slurry.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

(2) FIG. 1 is an axial section through apparatus in accordance with the present invention for processing organic products and other materials;

(3) FIG. 2 is an axial section, to a larger scale, through part of the apparatus of FIG. 1; and

(4) FIG. 3 is an axial section which additionally shows the inlet valve structure.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) The apparatus 10 illustrated in FIG. 1 comprises a barrel 12 which is attached to a body 14 of the apparatus. The barrel 12 is externally threaded and the body 14 has internal threading compatible with the external threading of the barrel. In view of the pressures generated in the apparatus, the barrel and body are linked together by, for example, a nut and a castellated spring washer with an internal tab to prevent it rotating. These components are generally designated 16 and the slot along which the tab of the spring washer slides is designated 18. Any other means for ensuring that the body and barrel cannot shift with respect to one another in use, such as a split clamp, can be used.

(6) The barrel is formed internally with a cylindrical bore 24 which is a constant diameter throughout its length except at the right-hand end as viewed in FIG. 1 where it has a short-flared section 26.

(7) A piston 28 slides in the bore 24. Axially spaced sealing rings 30, 32 positioned in grooves 34, 36 encircle the piston 28. The rings 30, 32 seal between the outer surface of the piston 28 and the surface of the bore 24.

(8) An operating rod 38 is secured by a bolt 40 to the piston 28. The operating rod is the rod of a hydraulic cylinder (not shown) which reciprocates the piston 28 in the bore 24 as will be described below.

(9) The body 14 defines a pressure chamber 42 which is co-axial with, and forms a continuation of, the bore 24 of the barrel 12. The diameter of the cylinder equals the maximum diameter of the flared section 26.

(10) There is an inlet 44 to the chamber 42. The valve structure which controls flow of material to be processed from an inlet pipe (not shown) to the chamber 42 will be described below with reference to FIG. 3.

(11) A block 46 is secured by a ring of bolts (not shown) to the body 14. The block 46 has a passageway 48 therethrough one end of which communicates with the chamber 42.

(12) A circular recess 50 is formed in the surface of the block 46 remote from the chamber 42 and the passageway 48 opens into this recess.

(13) An insert 52 (see particularly FIG. 2) comprising a cylindrical body 54 and a flange 56 is held in place by a circular retainer 58. The retainer 58 has a stepped central opening 60 the shape of which matches the shape of the insert 52. The body 54 of the insert 52 projects from the recess 50 and is located in a bore 62 of an outlet structure generally designated 64. The insert 52 has an axially extending passageway 66 through it which is smaller in diameter than the passageway 48 and in axial alignment with it.

(14) The outlet structure 64 comprises a block 68 in which the bore 62 is formed. Within the block 68 there is a cylindrical central cavity 70 into which the bore 62 opens. The bore 62 and cavity 70 are co-axial and there is a wall 72 which forms one end of the cavity 70. The bore 62 passes through the wall 72.

(15) There is a sleeve 74 of a hard abrasion resistant material in the cavity 70, one end of the insert being against the wall 72.

(16) The sleeve 74 is internally stepped so as to provide a series of three circular surfaces 76 which face away from the wall 72 and, alternating with the surfaces 76, four cylindrical surfaces 78 the diameters of which increase from left to right.

(17) A freely rotatable bobbin 80 of hard abrasion resistant material is located in the sleeve 74. The bobbin has a stepped shape which matches that of the sleeve 74. Three circular surfaces of the bobbin 80 press, in one operating condition, against the corresponding surfaces 76 of the sleeve 74. Four external cylindrical surfaces of the bobbin lie radially inwardly of the surfaces 78. The bobbin thus has four sections the diameters of which sections increase from left to right as viewed in FIG. 2.

(18) The smallest diameter part of the bobbin 80 is extended to the left by a cone 82 the shape of the apex of which matches the shape of the end of the passageway 66.

(19) The largest diameter section of the bobbin has skew grooves 84 in the surface thereof. The function of these will be described below. The larger diameter section of the bobbin is extended to the right, as viewed in FIG. 2, by a cylinder 86 which has a dome-shaped free end.

(20) Each section of the bobbin 80 is smaller in diameter than the part of the sleeve 74 into which it fits. There is consequently an annular gap between each bobbin section and the cylindrical surface of the insert which lies radially outwardly of that section. The widths of the annular gaps decrease from left to right as viewed in the drawing. Thus, the gap between the smallest diameter section of the bobbin and the cylindrical surface which lies radially outwardly of it is larger than the gap between the next section and the surface which lies radially outwardly of it, and so on.

(21) The sleeve 74 is held in place by a tube 88, and the tube 88 is held in place by an end plate 90 which is secured by bolts (not shown) to the block 68. One of the recesses for receiving a bolt head is shown at 92.

(22) A spring-loaded rod 94 passes through the end plate 90 into the cavity 70. The end of the rod 94 which is in the cavity is turned down and threaded and a cylindrical bearing housing 96 is screwed onto the end of the rod. A thrust bearing 98 is located in the housing 96 at the end of the threaded section which into which the rod 94 is screwed. The right-hand race of the bearing is fixed and the left hand race is free to turn. The dome of the cylinder 86 of the insert 52 is in contact with the rotatable race of the thrust bearing 98. The spring which loads the rod 94 can be replaced by a pneumatic or hydraulic cylinder.

(23) The rod 94 carries a stop (not shown) which co-operates with a fixed abutment to limit movement of the rod to the right. The rod 94 can only move a distance which is sufficient to open the exit from the passageway 66 and separate the axially facing surfaces of the sections of the bobbin 80 from the surfaces 76 of the sleeve 74.

(24) It will be understood that the cavity 70 forms an annular exit chamber between the tube 88 on the one hand and the rod 94 and the parts carried by it on the other hand. An outlet port 100 of the block 68 communicate with the cavity 70.

(25) Whilst in the preferred form of the invention the sleeve 74 and the bobbin 80 are cylindrical it is possible for other shapes to be used. For example, the sections could be square or triangular.

(26) The ball valve structure between the inlet 44 and the source of organic material to be processed has an open position and a closed position. When the valve is opened chopped pieces of the organic material are pumped into the pressure chamber. After a timed interval the valve closes isolating the pressure chamber 42 from the source of organic material.

(27) The piston 28 is shown in its fully retracted position in FIG. 3. The valve structure is open and the organic material to be processed is at this time being pumped into the pressure chamber 42. There is no pressure in the passageways 48, 66, and consequently the spring or pressure cylinder acting on the rod 94 forces the apex of the cone 82 into the exit end of the passageway 66.

(28) Once the pressure chamber 42 has been filled, the valve of the valve structure closes and the piston 28 begins to move to the right so that the pressure in the chamber 42 steadily increases. The movement of the piston 28 to the right is limited so that the right-hand seal 30 is always to the left of the flared section 26.

(29) The pressure in the chamber 42 causes organic product to flow along the passageways 48, 66 and towards the cone 82 which at this stage is closing the exit end of the passageway 66. The pressure builds at the exit end of the passageway 66 until it overcomes the closing force exerted by the spring or cylinder. The bobbin 80 then moves to the right, opening the exit end of the passageway 66 and separating the circular surfaces of the bobbin from those surfaces of the sleeve 74 against which they were pressed by the spring.

(30) Organic material flows from the passageway 48 into the narrower passageway 66 with a commensurate increase in the speed at which it is flowing. The speed can be between 500 and 6000 kph and is preferably in the range 2000 to 4000 kph. The material under high pressure and at high speed is spread by the cone 82 so that it flows radially outwardly in all directions into the annular gap between the smallest section of the bobbin 80 and the smallest inwardly facing surface of the sleeve 74. This gap constitutes the inlet end of the first section. The material impacts on the circular impact surface which is between the smallest section of the bobbin and the adjacent section of the bobbin and which is consequently at the outlet end of the first section. It then flows outwardly again impacting on the surface of the sleeve 74 that encircles the second smallest bobbin section. The material impacts multiple times on surfaces of the bobbin and the sleeve as it travels from section to section until it flows into the exit chamber constituted by the cavity 70. From this chamber it flows through the outlet port 100.

(31) Once the piston 28 reaches the end of its travel, no further pressurisation is possible and the piston is retracted (to the left as illustrated). Only once the piston has commenced to retract, and the pressure in the pressure chamber 42 has been relieved, does the ball of the valve structure in the inlet rotate to open the inlet and allow the next charge of organic material to flow into the pressure chamber 42.

(32) Material being processed which flows along the grooves 84 causes the bobbin 80 to turn at the rate of a few (say 2 or 3) rpm. Experimental work has shown that this avoids uneven wear on the bobbin.

(33) Pressure, flow rate and size parameters are:

(34) Maximum pressure in the pressure chamber −200 to 2000 bar, preferably to 1600 bar, and more preferably 350 to 1200 bar.

(35) Diameter of the passageway 66—0.05 mm to 8 mm preferably 0.1 to 6 mm

(36) Annular gaps between the bobbin 80 and the insert 72—100 micron, 100 micron, 75 micron, 50 micron, 25 micron

(37) Maximum movement of the bobbin 100 micron

(38) With appropriate selection of the parameters discussed, it is possible to process organic material with a viscosity of up to 250000 centipoise.

(39) To treat metal bearing ores, the ore is initially crushed and then reduced to particulate form in a ball mill or the like. The particles are dispersed in an inert liquid such as water to form a slurry which is then fed through the apparatus as is described above. It is also possible to disperse the particles in the leaching acid so that the extraction process takes place whilst the particle size is being reduced.