US20040124555A1 - Apparatus and process for granulating dry powder materials - Google Patents
Apparatus and process for granulating dry powder materials Download PDFInfo
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- US20040124555A1 US20040124555A1 US10/373,194 US37319403A US2004124555A1 US 20040124555 A1 US20040124555 A1 US 20040124555A1 US 37319403 A US37319403 A US 37319403A US 2004124555 A1 US2004124555 A1 US 2004124555A1
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- apertured plate
- chamber
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
- B01J2/20—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by expressing the material, e.g. through sieves and fragmenting the extruded length
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/02—Making granules by dividing preformed material
- B29B9/06—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
Definitions
- the present invention relates to an apparatus and process for extruding granules.
- the granules are formed from dry powder material.
- the extruders which are currently used employ rotating single or double screws to transport a moistened and kneaded material to be granulated to a die having holes.
- the pressure of the feeding screw and the scraping action of the screw(s) forces the material to come out of the holes of the die in the form of cylindrical strands.
- FIG. 1 of the drawings A schematic representation of such an extruder is shown in FIG. 1 of the drawings accompanying this specification.
- this extruder uses a rotating screw driven by a motor to convey the material to be extruded to a die having holes. The die is aligned axially with the screw. The material to be extruded is fed through the die and forced to transfer forwardly to the front end of the extruder by means of the conveying screw. The material is pressurized and compressed to extrude out of the holes of the die.
- the compaction of the material is very high.
- a low pressure basket type extruder positioned vertically/horizontally may be employed.
- This low pressure basket type extruder is depicted in FIG. 3.
- the low pressure basket type extruder consists of a basket shape housing holding a spherical plate with multiple holes.
- the material to be extruded is fed to the extruder the material encounters a distributing plate which distributes the material uniformly.
- the extrusion blades which are mounted to the rotating axis of the extruder, push the material out of the holes of the die in the form of strands.
- no screw is provided.
- the extrusion pressure is minimized and eventually the granules are formed under low impact and pressure.
- the problem encountered in these types of extruders is that it can not extrude a powder that is not moistened with externally added water or other solvents.
- the present invention is an extruder and granulation process for producing uniformly sized granules.
- the extruder contains a chamber having a chamber inlet and an apertured plate located at a bottom of the chamber.
- a spiral worm screw is positioned within the chamber for guiding a granulation material to the apertured plate.
- the granulation material is a dry powder material that is substantially free from water and/or solvent having a low softening point.
- the spiral worm screw which includes a guiding slant terminating at a blunt edge at a distance from said apertured plate, is rotated within the chamber. When the granulation material is inserted into the chamber through the chamber inlet, the spiral worm screw is rotated.
- the blunt edge rubs the granulation material against the apertured plate resulting in an increase in pressure between the granulation material and the apertured plate.
- This increase in pressure softens the granulation material transforming it to a semi-solid material.
- the semi-solid material is then gently extruded through the apertured plate using just the required pressure.
- the granules are hardened after extrusion through the apertured plate.
- the extruder may be used in a continuous manner to produce the desired granules.
- the extruder and granules that are formed are preferred over the prior devices and compounds for a variety of reasons.
- the granulation material is a dry powdered material substantially free from water and/or solvent
- the material exiting the apertured plate is in the form of granules without the additional cutting step that is required in the prior art.
- additional cutting may be performed if the user requires a smaller granule size. Since additional water and/or solvents are not required in this granulation process, the granules that are formed do not need to be dried. However, drying of the granules may optionally be performed depending on the moisture content that is required.
- the rubbing action produced when the blunt edge pushes the granulation material against the apertured plate affects the water dispersibiltity of the granules and is preferred over previous compaction and impact granulation devices.
- the preferred diameter for the granules is 1-2 mm.
- the present extruder is useful for granulation materials in all forms, especially dry powder material, which avoids the problems encountered in the prior extruders.
- the granules that are produced are water soluble or water dispersible granules having excellent water solubility and/or water dispersing quality for essentially environmentally friendly uses.
- the present extruder may be used for preparing granules of dry powdered, water soluble, low melting compounds and compositions, such as Acephate, Lambdacyhalothrin, Chloropropham, Metalaxyl, Bifenthrin, Devrinol, Chlorpyrifos, Endosulfan, Glyphosate, IPA salt, Vamidothion, Trichloron and the like without the problems encountered in prior devices.
- dry powdered, water soluble, low melting compounds and compositions such as Acephate, Lambdacyhalothrin, Chloropropham, Metalaxyl, Bifenthrin, Devrinol, Chlorpyrifos, Endosulfan, Glyphosate, IPA salt, Vamidothion, Trichloron and the like without the problems encountered in prior devices.
- FIG. 1 is a general schematic view of a screw-type extruder known in the prior art
- FIG. 2 is a general schematic view of a screw-type radial extruder known in the prior art
- FIG. 3 is a general schematic view of a low pressure basket type extruder known in the prior art
- FIG. 4 is a schematic view of the front elevation of the present extruder along with a stand and a motor;
- FIG. 5 is an enlarged schematic view of the chamber of the present extruder
- FIG. 6 is a schematic view of the cross section of the spiral worm screw taken through the chamber
- FIG. 7 is a schematic front view of the present extruder
- FIG. 8 is a schematic side view of the present extruder
- FIG. 9 is a graph showing the effect of pressure exerted to the chamber of the present extruder.
- FIG. 10 is a sketch of the present extruder whereby various points in the extruder correspond with the pressure measurements indicated in FIG. 9.
- FIG. 4 shows a schematic view of the front elevation of the extruder 14 along with a preferred stand 16 and the motor 18 .
- the extruder 14 comprises a chamber 20 provided with a chamber inlet 22 preferably at a suitable position near the top of the chamber 20 for charging the granulation material.
- the chamber 20 is preferably a jar-type chamber.
- the chamber inlet 22 is preferably a feed hopper.
- dry powder material substantially free from solvents and/or water is the preferred granulation material, the extruder 14 may also be used to form granules from moist starting material.
- the dry powder material preferably has a low softening point of 70° C. or less.
- the dry powder material has a low softening point in the range of 40-70° C. Also, the preferred dry powder material contains less than 1 wt. % moisture.
- the chamber 20 has a bottom provided with an apertured plate 24 .
- the design of the apertured plate 24 is important in obtaining uniform granules and is discussed in further detail below.
- the apertured plate 24 is preferably attached to the chamber 20 using a holding frame 38 .
- the holding frame 38 has appropriate hooks for clamping the apertured plate 24 to the chamber 20 .
- the hooks are preferably positioned at 120° to each other.
- the chamber 20 also houses a rotatable spiral worm screw 26 having a guiding slant 28 , the edge of which is a blunt edge 30 .
- the spiral worm screw 26 is positioned inside the chamber 20 so that the blunt edge 30 is a distance from the apertured plate 24 .
- the distance between the blunt edge 30 of the spiral worm screw 26 and the apertured plate 24 is preferably maintained in the range of 0.5 to 5.0 mm, most preferably between 1.0 to 2.5 mm.
- the chamber 20 and the spiral worm screw 26 may be preferably made of a thick metal block, such as Rhode of MS or SS or suitable alloy.
- an interior wall surface of the chamber 20 is wear resistant by preferably vacuum coating the chamber 20 with titanium.
- the preferred embodiment of the extruder 14 depicted in FIG. 4 shows a stand 16 and a motor 18 attached to the extruder 14 .
- the stand 16 comprises a base 32 provided with a horizontal portion 34 , the height of which is capable of adjustment.
- One side of the horizontal portion 34 has a motor 18 and the other side has the extruder 14 .
- the motor 18 rotates the spiral worm screw 26 .
- the apertured plate 24 has a plurality of holes that are configured in such a manner to produce the desired high quality granules.
- the apertured plate 24 has holes which are uniquely spaced according to the diameter of the granules desired.
- the holes in the apertured plate 24 are arranged in an equilateral triangular relationship to one another. It is additionally preferred that the spacing or pitch between the centers of the holes is approximately twice the diameter of the holes.
- the apertured plate 24 is not a die as it is neither semi-solid nor drilled.
- the thickness of the apertured plate 24 is significantly less than the thickness of a die.
- the holes can be engineered to suit particular requirements.
- the thickness of the apertured plate 24 is adequately balanced to its diameter for just required plasticizing of the granulation material. When the holes are properly designed, the problems in the prior art associated with blocking or choking are overcome. Also, the apertured plate 24 thickness is balanced specifically in comparison to the diameter of the holes and distance between holes so that the friction produced by the rubbing of the granulation material against the apertured plate 24 is just enough to soften the granulation material. The softening of the granulation material results in the formation of smaller granules.
- the holes of the apertured plate 24 are preferably made by punching to ensure uniform diameter.
- the granules are formed by inserting a granulation material into the extruder 14 .
- the granulation material enter the chamber 20 of the extruder 14 through the chamber inlet 22 .
- the spiral worm screw 26 rotates, the granulation material present in the chamber 20 is guided to the bottom of the chamber 20 via the guiding slant 28 .
- the blunt edge 30 of the spiral worm screw 26 rubs the granulation material against the apertured plate 24 increasing the pressure between the granulation material and the apertured plate 24 . This increase in pressure elevates the temperature of the granulation material near the apertured plate 24 and softens the granulation material transforming it to a semi-solid material.
- the blunt edge 30 of the spiral worm screw 26 which is in contact with the semi-solid material, exerts just the required pressure by rubbing action to push the semi-solid material though the apertured plate 24 .
- the force of gravity also aids in extruding the semi-solid material through the apertured plate 24 and the semi-solid material exits the apertured plate 24 under its own dead weight.
- the material exiting the apertured plate 24 is hardened to form the desired granules.
- the granulation material is a dry powder material substantially free from water and/or solvents, the semi-solid material hardens upon extrusion through the apertured plate 24 in the form of granules, and not strands, due to the decrease in pressure and temperature.
- Granules formed in this manner do not stick and clump together.
- the semi-solid material extruded through the apertured plate 24 may require additional processing steps, such as drying, in order to produce solid granules. There is minimal contact of the semi-solid material with the spiral worm screw 26 and the apertured plate 24 prior to granulation
- the extruder 14 and granules that are formed have several advantageous properties.
- the material extruded from the extruder 14 is in the form of granules without an additional cutting step.
- surface conditioning and/or cutting may be performed if the user requires a smaller granule size. Since additional water and/or solvents are not included in this preferred granulation process, the granules that are formed do not need to be dried. However, drying of the granules may optionally be performed depending on the moisture content that is required.
- the material exiting the apertured plate 24 may need additional conditioning, such as drying, to obtain the desired granules.
- additional conditioning such as drying
- the output of the granules directly depends upon the percent openings (%) of the apertured plate 24 .
- Percent openings can be anywhere between 12-40% and more preferably 2530%. However, this can be altered depending on the size of the granules desired, the output desired, and the pressure which the apertured plate 24 can withstand.
- the relationship between extruding force and drag force could alter the percent openings of the apertured plate 24 .
- the percent openings is directly proportional to the extruding force and inversely proportional to the drag force.
- the present extruder 14 is utilized for the continuous processing of granulation material to produce agglomerated granules of a desired spherical diameter.
- the enhanced uniformity of granules produced by the present extruder 14 makes it useful for granulating compositions where it is particularly important that there is minimal range of variation in granule size, shape, density and compositions.
- FIGS. 5 - 8 show additional schematic views of the extruder.
- FIG. 5 is an enlarged schematic view of the chamber 20 of the extruder 14 .
- FIG. 5 shows the addition of a heating element 40 and a cooling element 42 on an outside wall of the chamber 20 .
- FIG. 6 is a schematic cross-sectional view of the spiral worm screw 26 taken through the chamber 20 .
- FIG. 7 is a schematic front view of the extruder 14 .
- FIG. 8 is a schematic side view of the extruder 14 .
- FIG. 9 is a graph showing the effect of pressure exerted at various points within the chamber 20 of the extruder 14 .
- FIG. 10 is a sketch of the extruder 14 indicating the points within the chamber 20 corresponding to the pressure measurements indicated in FIG. 9. As shown in FIG. 9, the pressure near the top of the chamber 20 is small and increases near the bottom of the chamber 20 as the material begins to enter the apertured plate 24 . This increase in pressure causes the granulation material to soften into the semi-solid material. As soon as the semi-solid material passes through the apertured plate 24 , the pressure drops to zero and the granules are formed.
- the present extruder 14 is useful for granulation materials in all forms, especially dry powder material.
- the granules that are produced are water soluble or water dispersible granules having excellent water solubility and/or water dispersing quality for essentially environmentally friendly uses.
- granules containing insecticides are produced using the present extruder 14 and granulation method.
- the present extruder 14 may be used for preparing granules of dry, powdered, water soluble, low melting compounds and compositions, such as Acephate, Lambdacyhalothrin, Chloropropham, Metalaxyl, Bifenthrin, Devrinol, Chlorpyrifos, Endosulfan, Glyphosate, IPA salt, Vamidothion, Trichloron and the like.
- granules of phosphoroamidothioate are prepared using the present extruder 14 .
- the granules are preferably formed using the process disclosed in the co-pending U.S. application Ser. No. 10/126,965 filed on Apr. 22, 2002, which is hereby incorporated by reference.
- the co-pending application generally describes a process for preparing a chemically stable, dry flow, low compact dust free soluble granule of phosphoroamidothioates.
- Acephate is one of the important commercial insecticides within this class of compounds, which is a systemic insecticide of moderate persistence with residual activity lasting about 10-15 days.
- % acephate and preferably 95-98 wt. % acephate, are preferably formed using the present extruder 14 and granulation process.
- the granules of phosphoroamidothioate are generally prepared by the following process:
- the granules of phosphoroamidothioate are essentially chemically stable, dry flow, low compact, dust free, soluble granules of phosphoroamidothioate having a length of 1.5-3.0 mm and a diameter of 0.5 to 1.50 mm. These granules of phosphoroamidothioate are characterized by an aging stability of a minimum of two years.
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Abstract
Description
- This application claims the benefit, under 35 U.S.C. 119(e), of U.S. Provisional Application No. 60/437,006 filed Dec. 31, 2002, the contents of which are incorporated herein by reference.
- 1. Field of the Invention
- The present invention relates to an apparatus and process for extruding granules. Preferably, the granules are formed from dry powder material.
- 2. Description of Related Art
- The extruders which are currently used employ rotating single or double screws to transport a moistened and kneaded material to be granulated to a die having holes. The pressure of the feeding screw and the scraping action of the screw(s) forces the material to come out of the holes of the die in the form of cylindrical strands.
- One of the earliest extruders was an axial extruder which has either a single screw or a double screw. A schematic representation of such an extruder is shown in FIG. 1 of the drawings accompanying this specification. Generally, this extruder uses a rotating screw driven by a motor to convey the material to be extruded to a die having holes. The die is aligned axially with the screw. The material to be extruded is fed through the die and forced to transfer forwardly to the front end of the extruder by means of the conveying screw. The material is pressurized and compressed to extrude out of the holes of the die. Hence, in these types of extruders, the compaction of the material is very high.
- An improved version of the above-described extruder was fabricated to overcome the problem of high pressure and low production capacity of small sized granules found in the earlier types of extruders. This improved version is known as a screw-type radial extruder as depicted in FIG. 2. Generally, the raw material which is to be extruded is conveyed and compressed by a conveying screw axially within the screw housing. The material is then forced radially outward through a semi cylindrical die by means of an extracting screw. In this case, the extruding pressure changes its direction from axial flow to radial flow. Hence, the impact on the material employing this type of extruder is lower than the previously described extruder. However, the internal pressure generated by the conveying screw cannot be fully employed for the extrusion of the material through the die because the material changes its direction from axial to radial. This again leads to lower production capacity resulting in making the device uneconomical.
- Alternatively, a low pressure basket type extruder positioned vertically/horizontally may be employed. This low pressure basket type extruder is depicted in FIG. 3. Generally, the low pressure basket type extruder consists of a basket shape housing holding a spherical plate with multiple holes. In this type of extruder, when the material to be extruded is fed to the extruder the material encounters a distributing plate which distributes the material uniformly. The extrusion blades, which are mounted to the rotating axis of the extruder, push the material out of the holes of the die in the form of strands. In this type of extruder, no screw is provided. Hence, the extrusion pressure is minimized and eventually the granules are formed under low impact and pressure. The problem encountered in these types of extruders is that it can not extrude a powder that is not moistened with externally added water or other solvents.
- The present invention is an extruder and granulation process for producing uniformly sized granules. The extruder contains a chamber having a chamber inlet and an apertured plate located at a bottom of the chamber. A spiral worm screw is positioned within the chamber for guiding a granulation material to the apertured plate. In a preferred embodiment, the granulation material is a dry powder material that is substantially free from water and/or solvent having a low softening point. The spiral worm screw, which includes a guiding slant terminating at a blunt edge at a distance from said apertured plate, is rotated within the chamber. When the granulation material is inserted into the chamber through the chamber inlet, the spiral worm screw is rotated. Upon rotation of the spiral worm screw, the blunt edge rubs the granulation material against the apertured plate resulting in an increase in pressure between the granulation material and the apertured plate. This increase in pressure softens the granulation material transforming it to a semi-solid material. The semi-solid material is then gently extruded through the apertured plate using just the required pressure. The granules are hardened after extrusion through the apertured plate. The extruder may be used in a continuous manner to produce the desired granules.
- The extruder and granules that are formed are preferred over the prior devices and compounds for a variety of reasons. When the granulation material is a dry powdered material substantially free from water and/or solvent, the material exiting the apertured plate is in the form of granules without the additional cutting step that is required in the prior art. However, additional cutting may be performed if the user requires a smaller granule size. Since additional water and/or solvents are not required in this granulation process, the granules that are formed do not need to be dried. However, drying of the granules may optionally be performed depending on the moisture content that is required. The rubbing action produced when the blunt edge pushes the granulation material against the apertured plate affects the water dispersibiltity of the granules and is preferred over previous compaction and impact granulation devices. Although a wide range of granules may be formed using the present extruder, the preferred diameter for the granules is 1-2 mm.
- The present extruder is useful for granulation materials in all forms, especially dry powder material, which avoids the problems encountered in the prior extruders. In a preferred embodiment, the granules that are produced are water soluble or water dispersible granules having excellent water solubility and/or water dispersing quality for essentially environmentally friendly uses. Most preferably, the present extruder may be used for preparing granules of dry powdered, water soluble, low melting compounds and compositions, such as Acephate, Lambdacyhalothrin, Chloropropham, Metalaxyl, Bifenthrin, Devrinol, Chlorpyrifos, Endosulfan, Glyphosate, IPA salt, Vamidothion, Trichloron and the like without the problems encountered in prior devices.
- The features and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, in which:
- FIG. 1 is a general schematic view of a screw-type extruder known in the prior art;
- FIG. 2 is a general schematic view of a screw-type radial extruder known in the prior art;
- FIG. 3 is a general schematic view of a low pressure basket type extruder known in the prior art;
- FIG. 4 is a schematic view of the front elevation of the present extruder along with a stand and a motor;
- FIG. 5 is an enlarged schematic view of the chamber of the present extruder;
- FIG. 6 is a schematic view of the cross section of the spiral worm screw taken through the chamber,
- FIG. 7 is a schematic front view of the present extruder;
- FIG. 8 is a schematic side view of the present extruder;
- FIG. 9 is a graph showing the effect of pressure exerted to the chamber of the present extruder; and
- FIG. 10 is a sketch of the present extruder whereby various points in the extruder correspond with the pressure measurements indicated in FIG. 9.
- FIG. 4 shows a schematic view of the front elevation of the extruder14 along with a
preferred stand 16 and themotor 18. The extruder 14 comprises achamber 20 provided with achamber inlet 22 preferably at a suitable position near the top of thechamber 20 for charging the granulation material. Thechamber 20 is preferably a jar-type chamber. Thechamber inlet 22 is preferably a feed hopper. Although dry powder material substantially free from solvents and/or water is the preferred granulation material, the extruder 14 may also be used to form granules from moist starting material. The dry powder material preferably has a low softening point of 70° C. or less. Most preferably, the dry powder material has a low softening point in the range of 40-70° C. Also, the preferred dry powder material contains less than 1 wt. % moisture. Thechamber 20 has a bottom provided with anapertured plate 24. The design of theapertured plate 24 is important in obtaining uniform granules and is discussed in further detail below. Theapertured plate 24 is preferably attached to thechamber 20 using a holdingframe 38. The holdingframe 38 has appropriate hooks for clamping theapertured plate 24 to thechamber 20. The hooks are preferably positioned at 120° to each other. Thechamber 20 also houses a rotatablespiral worm screw 26 having a guidingslant 28, the edge of which is ablunt edge 30. Thespiral worm screw 26 is positioned inside thechamber 20 so that theblunt edge 30 is a distance from theapertured plate 24. The distance between theblunt edge 30 of thespiral worm screw 26 and theapertured plate 24 is preferably maintained in the range of 0.5 to 5.0 mm, most preferably between 1.0 to 2.5 mm. Thechamber 20 and thespiral worm screw 26 may be preferably made of a thick metal block, such as Rhode of MS or SS or suitable alloy. In a preferred embodiment, an interior wall surface of thechamber 20 is wear resistant by preferably vacuum coating thechamber 20 with titanium. - The preferred embodiment of the extruder14 depicted in FIG. 4 shows a
stand 16 and amotor 18 attached to the extruder 14. However, one of ordinary skill in the art would readily ascertain additional means for holding the extruder 14 and this invention should not be limited to thisparticular stand 16 andmotor 18 configuration. Thestand 16 comprises a base 32 provided with ahorizontal portion 34, the height of which is capable of adjustment. One side of thehorizontal portion 34 has amotor 18 and the other side has the extruder 14. Themotor 18 rotates thespiral worm screw 26. - As discussed above, the
apertured plate 24 has a plurality of holes that are configured in such a manner to produce the desired high quality granules. Theapertured plate 24 has holes which are uniquely spaced according to the diameter of the granules desired. In a preferred embodiment, the holes in theapertured plate 24 are arranged in an equilateral triangular relationship to one another. It is additionally preferred that the spacing or pitch between the centers of the holes is approximately twice the diameter of the holes. Theapertured plate 24 is not a die as it is neither semi-solid nor drilled. Preferably, the thickness of theapertured plate 24 is significantly less than the thickness of a die. However, to get a smooth surface finish, the holes can be engineered to suit particular requirements. A blind space where there are no holes in theapertured plate 24 bears the pressure of extrusion and aids in increasing the density of the resulting granules. Unlike other prior extruders, there is minimal differential pressure that occurs while operating the present extruder. The thickness of theapertured plate 24 is adequately balanced to its diameter for just required plasticizing of the granulation material. When the holes are properly designed, the problems in the prior art associated with blocking or choking are overcome. Also, theapertured plate 24 thickness is balanced specifically in comparison to the diameter of the holes and distance between holes so that the friction produced by the rubbing of the granulation material against theapertured plate 24 is just enough to soften the granulation material. The softening of the granulation material results in the formation of smaller granules. The holes of theapertured plate 24 are preferably made by punching to ensure uniform diameter. - The granules are formed by inserting a granulation material into the extruder14. The granulation material enter the
chamber 20 of the extruder 14 through thechamber inlet 22. When thespiral worm screw 26 rotates, the granulation material present in thechamber 20 is guided to the bottom of thechamber 20 via the guidingslant 28. Theblunt edge 30 of thespiral worm screw 26 rubs the granulation material against theapertured plate 24 increasing the pressure between the granulation material and theapertured plate 24. This increase in pressure elevates the temperature of the granulation material near theapertured plate 24 and softens the granulation material transforming it to a semi-solid material. Theblunt edge 30 of thespiral worm screw 26, which is in contact with the semi-solid material, exerts just the required pressure by rubbing action to push the semi-solid material though theapertured plate 24. In a preferred embodiment, the force of gravity also aids in extruding the semi-solid material through theapertured plate 24 and the semi-solid material exits theapertured plate 24 under its own dead weight. The material exiting theapertured plate 24 is hardened to form the desired granules. When the granulation material is a dry powder material substantially free from water and/or solvents, the semi-solid material hardens upon extrusion through theapertured plate 24 in the form of granules, and not strands, due to the decrease in pressure and temperature. Granules formed in this manner do not stick and clump together. When moist material is extruded, the semi-solid material extruded through theapertured plate 24 may require additional processing steps, such as drying, in order to produce solid granules. There is minimal contact of the semi-solid material with thespiral worm screw 26 and theapertured plate 24 prior to granulation - The extruder14 and granules that are formed have several advantageous properties. In the preferred embodiment, when the granulation material is a dry powder material, the material extruded from the extruder 14 is in the form of granules without an additional cutting step. However, surface conditioning and/or cutting may be performed if the user requires a smaller granule size. Since additional water and/or solvents are not included in this preferred granulation process, the granules that are formed do not need to be dried. However, drying of the granules may optionally be performed depending on the moisture content that is required. Additionally, if the granulation material is not a dry powdered material, the material exiting the
apertured plate 24 may need additional conditioning, such as drying, to obtain the desired granules. Although a wide range of granules may be formed using this extruder 14, the preferred diameter for the granules is 1-2 mm. - The output of the granules directly depends upon the percent openings (%) of the
apertured plate 24. Percent openings can be anywhere between 12-40% and more preferably 2530%. However, this can be altered depending on the size of the granules desired, the output desired, and the pressure which theapertured plate 24 can withstand. The relationship between extruding force and drag force could alter the percent openings of theapertured plate 24. The percent openings is directly proportional to the extruding force and inversely proportional to the drag force. - In operation, the present extruder14 is utilized for the continuous processing of granulation material to produce agglomerated granules of a desired spherical diameter. The enhanced uniformity of granules produced by the present extruder 14 makes it useful for granulating compositions where it is particularly important that there is minimal range of variation in granule size, shape, density and compositions.
- FIGS.5-8 show additional schematic views of the extruder. FIG. 5 is an enlarged schematic view of the
chamber 20 of the extruder 14. FIG. 5 shows the addition of aheating element 40 and acooling element 42 on an outside wall of thechamber 20. FIG. 6 is a schematic cross-sectional view of thespiral worm screw 26 taken through thechamber 20. FIG. 7 is a schematic front view of the extruder 14. FIG. 8 is a schematic side view of the extruder 14. - FIG. 9 is a graph showing the effect of pressure exerted at various points within the
chamber 20 of the extruder 14. FIG. 10 is a sketch of the extruder 14 indicating the points within thechamber 20 corresponding to the pressure measurements indicated in FIG. 9. As shown in FIG. 9, the pressure near the top of thechamber 20 is small and increases near the bottom of thechamber 20 as the material begins to enter theapertured plate 24. This increase in pressure causes the granulation material to soften into the semi-solid material. As soon as the semi-solid material passes through theapertured plate 24, the pressure drops to zero and the granules are formed. - The present extruder14 is useful for granulation materials in all forms, especially dry powder material. In a preferred embodiment, the granules that are produced are water soluble or water dispersible granules having excellent water solubility and/or water dispersing quality for essentially environmentally friendly uses. Preferably, granules containing insecticides are produced using the present extruder 14 and granulation method. Most preferably, the present extruder 14 may be used for preparing granules of dry, powdered, water soluble, low melting compounds and compositions, such as Acephate, Lambdacyhalothrin, Chloropropham, Metalaxyl, Bifenthrin, Devrinol, Chlorpyrifos, Endosulfan, Glyphosate, IPA salt, Vamidothion, Trichloron and the like.
- According to another preferred embodiment of the present invention, granules of phosphoroamidothioate are prepared using the present extruder14. The granules are preferably formed using the process disclosed in the co-pending U.S. application Ser. No. 10/126,965 filed on Apr. 22, 2002, which is hereby incorporated by reference. The co-pending application generally describes a process for preparing a chemically stable, dry flow, low compact dust free soluble granule of phosphoroamidothioates. Acephate is one of the important commercial insecticides within this class of compounds, which is a systemic insecticide of moderate persistence with residual activity lasting about 10-15 days. Granules containing 40-98 wt. % acephate, and preferably 95-98 wt. % acephate, are preferably formed using the present extruder 14 and granulation process. The granules of phosphoroamidothioate are generally prepared by the following process:
- (1) preparing a dry premix by mixing 95-99% of the phosphoroamidothioate, preferably acephate, 0.5-5. % dispersing agent, 0.1-3.0% wetting agent, 0.1-0.3% binding agent, 0.03-0.08% antifoaming agent, 0.5-10.0% disintegrating agent, 0.05-1.0% stabilizer and fillers, all ingredients are in the form of solids without the addition of water or solvent to make 100% (w/w) in a premixer,
- (2) grinding the resulting mixture in a microniser to obtain 5 microns to 10 microns particle size,
- (3) mixing the ground mixture in a post mixer and then charging the mixture through a rotary feeder into the extruder14 through
chamber inlet 22 ofchamber 20 shown in FIG. 4, - (4) rotating the
chamber 20 and thespiral worm screw 26 in such a way to convert the dry mix into a semi-solid material wherein theblunt edge 30 of thespiral worm screw 26, which is in contact with the semi-solid material, guides the semi-solid material through theapertured plate 24 by a rubbing action, exerting just the required amount of pressure, thereby forming the low compact granules, - (5) collecting the resulting granules to obtain dry, semi-solid, low compact, dust free, soluble granules of the phosphoroamidothioate,
- (6) passing the granules through a hot air chamber for surface conditioning,
- (7) passing the resultant dry granules through an oscillating cutter and thereafter sieving to obtain granules, and
- (8) collecting the resulting granules to obtain dry, semi-solid, low compact, dust free, soluble granules of phosphoroamidothioate. The granules of phosphoroamidothioate are essentially chemically stable, dry flow, low compact, dust free, soluble granules of phosphoroamidothioate having a length of 1.5-3.0 mm and a diameter of 0.5 to 1.50 mm. These granules of phosphoroamidothioate are characterized by an aging stability of a minimum of two years.
- Although the present invention has been disclosed in terms of a preferred embodiment, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention as defined by the following claims:
Claims (29)
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/373,194 US6752943B1 (en) | 2002-12-31 | 2003-02-26 | Apparatus and process for granulating dry powder materials |
CA002511977A CA2511977A1 (en) | 2002-12-31 | 2003-07-09 | An improved apparatus and process for granulating dry powder materials |
KR1020057012353A KR20050113601A (en) | 2002-12-31 | 2003-07-09 | An improved apparatus and process for granulating dry powder materials |
PCT/IB2003/002716 WO2004058470A1 (en) | 2002-12-31 | 2003-07-09 | An improved apparatus and process for granulating dry powder materials |
AU2003303340A AU2003303340B2 (en) | 2002-12-31 | 2003-07-09 | An improved apparatus and process for granulating dry powder materials |
MXPA05007220A MXPA05007220A (en) | 2002-12-31 | 2003-07-09 | An improved apparatus and process for granulating dry powder materials. |
BR0317214-7A BR0317214A (en) | 2002-12-31 | 2003-07-09 | Method for forming uniform sized granules in an extruder |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US43700602P | 2002-12-31 | 2002-12-31 | |
US10/373,194 US6752943B1 (en) | 2002-12-31 | 2003-02-26 | Apparatus and process for granulating dry powder materials |
Publications (2)
Publication Number | Publication Date |
---|---|
US6752943B1 US6752943B1 (en) | 2004-06-22 |
US20040124555A1 true US20040124555A1 (en) | 2004-07-01 |
Family
ID=32474196
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/373,194 Expired - Lifetime US6752943B1 (en) | 2002-12-31 | 2003-02-26 | Apparatus and process for granulating dry powder materials |
Country Status (7)
Country | Link |
---|---|
US (1) | US6752943B1 (en) |
KR (1) | KR20050113601A (en) |
AU (1) | AU2003303340B2 (en) |
BR (1) | BR0317214A (en) |
CA (1) | CA2511977A1 (en) |
MX (1) | MXPA05007220A (en) |
WO (1) | WO2004058470A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9272468B1 (en) * | 2008-04-03 | 2016-03-01 | Purdue Research Foundation | Apparatus and method for producing biobased carriers from byproducts of biomass processing |
TWI608798B (en) * | 2013-03-26 | 2017-12-21 | 日本曹達股份有限公司 | Method for producing granular agent for agricultural and horticultural use |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ITMI20051138A1 (en) * | 2005-06-17 | 2006-12-18 | Sipcam Spa | PROCESS TO PREPARE AMMONIC GLYPHOSATE GRANULES |
US8221776B1 (en) | 2006-05-19 | 2012-07-17 | Sander William A | Phosphoroamidothioate granules and methods of manufacture thereof |
CN111604003B (en) * | 2020-04-30 | 2022-02-15 | 宜兴市聚能超细粉碎设备有限公司 | Pesticide powder suitable for spraying of unmanned aerial vehicle, preparation method and production equipment thereof |
CN114768677B (en) * | 2022-06-24 | 2022-08-23 | 山东百农思达生物科技有限公司 | Prilling granulator is used in germicide preparation |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6582638B1 (en) * | 1998-01-23 | 2003-06-24 | Crop Care Australasia Pty. Ltd. | Method of making granules and the granulator |
Family Cites Families (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3716600A (en) | 1970-02-24 | 1973-02-13 | Chevron Res | N-acyl derivatives of phosphoroamidothioates |
US3845172A (en) | 1971-05-28 | 1974-10-29 | Chevron Res | N-hydrocarboyl phosphoroamido-thioates and phosphoroamidodithioates |
US3914417A (en) | 1972-12-21 | 1975-10-21 | Chevron Res | Insectidical N-hydrocarboyl phosphoroamidothioates and phosphoroamidodithioates |
US4218444A (en) | 1978-06-05 | 1980-08-19 | Chevron Research Company | Insecticidal formulation |
US4544553A (en) | 1981-06-24 | 1985-10-01 | Rohm And Haas Company | Pesticidal phosphoroamido (di) thioates |
JPS5867603A (en) | 1981-10-16 | 1983-04-22 | Nissan Chem Ind Ltd | Wettrable powder for agriculture and gardening |
US5650163A (en) | 1986-11-24 | 1997-07-22 | American Cyanamid Company | Safened pesticidal resin compositions for controlling soil borne pests and process for the preparation thereof |
EP0304492B1 (en) | 1987-03-13 | 1994-12-07 | Sumitomo Chemical Company, Limited | Stable solid pesticidal preparation |
US5443764A (en) | 1987-07-01 | 1995-08-22 | Ici Australia Operations Propietary Limited | Water-dispersible granules |
US5464623A (en) | 1989-08-18 | 1995-11-07 | Chevron Research Company | Process for pelletizing insecticidal N-hydrocarboyl phosphoroamidothioates and phosphoroamidodithioates |
US5075058A (en) | 1990-01-30 | 1991-12-24 | Chevron Research And Technology Company | Process for preparing pellets comprising insecticidal n-hydrocarboyl phosphoroamidothioates and/or phosphoroamidodithioates, and fungicides, herbicides, fertilizers or other insecticides |
US5100667A (en) | 1990-03-12 | 1992-03-31 | Chevron Research And Technology Company | Process for pelletizing insecticidal N-hydrocarboyl phosphoroamidothioates and phosphoroamidodithioates |
WO1992016107A1 (en) | 1991-03-25 | 1992-10-01 | Valent U.S.A. Corporation | Chemically stable granules containing insecticidal phosphoroamidothioates |
US5352674A (en) | 1991-03-25 | 1994-10-04 | Valent U.S.A. | Chemically stable granules containing insecticidal phosphoroamidothioates |
JPH0692803A (en) | 1992-07-31 | 1994-04-05 | Takeda Chem Ind Ltd | Water-soluble granule of agricultural chemical and its production |
ES2105954B1 (en) | 1993-12-20 | 1998-07-01 | Sumitomo Chemical Co | METHOD FOR STABILIZING ACEPHATE AND A DRY PESTICIDE FORMULATION CONTAINING STABILIZED ACEPHATE |
JP3424304B2 (en) | 1994-02-10 | 2003-07-07 | 住友化学工業株式会社 | Liquid pesticide composition |
JPH09124406A (en) | 1995-11-06 | 1997-05-13 | Takeda Chem Ind Ltd | Granulated water dispersible powder |
CN1915016B (en) | 1995-11-08 | 2010-12-22 | 默沙东公司 | Pesticidal formulation |
US6013272A (en) | 1996-12-19 | 2000-01-11 | Valent U.S.A. Corporation | Chemically stable, insecticidally active phosphoroamidothioate pellet compositions and methods for their manufacture |
AU748736B2 (en) * | 1998-01-23 | 2002-06-13 | Crop Care Australasia Pty Ltd | Granulator |
-
2003
- 2003-02-26 US US10/373,194 patent/US6752943B1/en not_active Expired - Lifetime
- 2003-07-09 WO PCT/IB2003/002716 patent/WO2004058470A1/en not_active Application Discontinuation
- 2003-07-09 MX MXPA05007220A patent/MXPA05007220A/en active IP Right Grant
- 2003-07-09 CA CA002511977A patent/CA2511977A1/en not_active Abandoned
- 2003-07-09 AU AU2003303340A patent/AU2003303340B2/en not_active Ceased
- 2003-07-09 KR KR1020057012353A patent/KR20050113601A/en not_active Application Discontinuation
- 2003-07-09 BR BR0317214-7A patent/BR0317214A/en not_active IP Right Cessation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6582638B1 (en) * | 1998-01-23 | 2003-06-24 | Crop Care Australasia Pty. Ltd. | Method of making granules and the granulator |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9272468B1 (en) * | 2008-04-03 | 2016-03-01 | Purdue Research Foundation | Apparatus and method for producing biobased carriers from byproducts of biomass processing |
US20160135449A1 (en) * | 2008-04-03 | 2016-05-19 | Purdue Research Foundation | Apparatus and method for producing biobased carriers from byproducts of biomass processing |
US10051858B2 (en) * | 2008-04-03 | 2018-08-21 | Purdue Research Foundation | Apparatus and method for producing biobased carriers from byproducts of biomass processing |
TWI608798B (en) * | 2013-03-26 | 2017-12-21 | 日本曹達股份有限公司 | Method for producing granular agent for agricultural and horticultural use |
Also Published As
Publication number | Publication date |
---|---|
WO2004058470A1 (en) | 2004-07-15 |
US6752943B1 (en) | 2004-06-22 |
BR0317214A (en) | 2005-11-01 |
MXPA05007220A (en) | 2005-09-12 |
AU2003303340A1 (en) | 2004-07-22 |
KR20050113601A (en) | 2005-12-02 |
CA2511977A1 (en) | 2004-07-15 |
AU2003303340B2 (en) | 2009-07-30 |
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