PROCESSING APPARATUS FOR EFFECTING INTERACTION BETWEEN, AND SUBSEQUENT SEPARATION OR GASEOUS AND SOLID OR LIQUID PARTICULATE SUBSTANCES
United States Patent 3600817
An apparatus for drying or otherwise processing solid or liquid particulate substances comprises an axially elongated vessel which forms a cylindrical vortex chamber, an inlet duct communicating with the chamber at one otherwise closed end for supplying the particulate substance in a direction substantially tangential to the vortex chamber and inclined toward the other end of the vessel. The cylindrical portion of the vessel is provided with a number of further inlets for the supply of active medium such as hot air for drying the particulate substance. The entering direction of the further inlets is tangential and inclined in the same direction as the inlet duct for the particulate material. A gas outlet duct protrudes coaxially into the vortex chamber near the other end of the vessel and has a smaller diameter than the chamber so that an annular gap space is formed around the mouth portion of the gas outlet duct. The dried or otherwise processed particulate material passes through the gap space to be collected at, or discharged from, the other end of the vessel. The inlets for the active medium such as drying air are distributed peripherally and lengthwise of the vessel and conjointly form an array which comprises inlets that communicate with the annular gap space at localities between the mouth of the gas outlet duct and the other vessel end. An annular plate member surrounds the gas outlet duct in fixed relation thereto and is axially spaced from the duct mouth to form a constricted annular passage between the plate member and the vessel at a locality within the region of the array of inlets.
US Patent References:
Method of and apparatus for providing material in finely divided form
Andrews - March 1936 - 2032827
Method and apparatus for drying liquid containing materials
Peebles - September 1936 - 2054441
Method of and apparatus for clinkering cement raw materials and the like
Witt - April 1953 - 2634116
METHOD AND APPARATUS FOR CARRYING OUT PHYSICAL AND CHEMICAL REACTIONS
Geiger et al. - February 1970 - 3494047
Method of and apparatus for providing material in finely divided form
Andrews - March 1936 - 2032827
Method and apparatus for drying liquid containing materials
Peebles - September 1936 - 2054441
Method of and apparatus for clinkering cement raw materials and the like
Witt - April 1953 - 2634116
METHOD AND APPARATUS FOR CARRYING OUT PHYSICAL AND CHEMICAL REACTIONS
Geiger et al. - February 1970 - 3494047
Application Number:
05/005580
Publication Date:
08/24/1971
Filing Date:
01/26/1970
View Patent Images:
Export Citation:
Assignee:
Aktiengesellschaft; Siemens
Primary Class:
Other Classes:
96/372
International Classes:
B04C3/00; F26B17/10
Field of Search:
34/57E,10 263/29 55/261 302/17
Primary Examiner:
Matteson, Frederick L.
Assistant Examiner:
Dua, Robert A.
Claims:
I claim
1. Processing apparatus for effecting interaction between, and subsequent separation of, gaseous and solid or liquid particulate substances, comprising a vessel forming an axially elongated cylindrical vortex chamber and having near one end an inlet duct means for particulate substance to be processed, said inlet duct means having an entering direction substantially tangential to said cylindrical chamber and inclined toward the other end of the vessel, said vessel having a cylindrical portion provided with a number of further, lateral inlets for active medium, said further inlets having an entering direction tangential and inclined in substantially the same sense as said inlet duct means, a gas outlet duct protruding from the outside into said vessel near said other vessel end, said gas outlet duct having a smaller diameter than said chamber and having a mouth portion extending coaxially to said chamber, an annular gap space being formed around said duct portion for the passage of processed particulate substance to the other end of said vessel, said active-medium inlets being distributed lengthwise of said vessel in an array which comprises inlets in communication with said chamber at localities of said annular gap space between the mouth of said outlet duct and said other vessel end.
2. In processing apparatus according to claim 1, said one end of said vessel being closed, and said inlet duct means entering from the side through the cylindrical wall of said chamber near said closed end and in axially spaced relation to said array of further inlets.
3. Processing apparatus according to claim 1, comprising an annular plate member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said plate member and the wall of said chamber, said plate member being located near those of said further inlets that are near said other end of said vessel.
4. Processing apparatus according to claim 1, comprising a jacket structure coaxially surrounding said cylindrical vessel and forming a plenum chamber with which all of said further inlets communicate, and duct means connected with said jacket structure for supplying active medium to said further inlets through said plenum chamber.
5. Processing apparatus according to claim 1, comprising a jacket structure coaxially surrounding said cylindrical vessel and forming a plurality of axially adjacent plenum chambers having respective duct means for supplying active medium, axially adjacent sets of said further inlets being in communication with said respective plenum chambers to receive said medium therefrom.
6. Processing apparatus according to claim 1, comprising an annular member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said member and the wall of said chamber, said member being located near those of said further inlets that are near said other end of said vessel, a jacket structure surrounding said vessel and communicating with said further inlets and having duct means for the supply of active medium.
7. Processing apparatus for the drying of particulate solid or liquid substance, comprising a processing vessel forming an axially elongated cylindrical vortex chamber and having at one end inlet duct means for supplying the substance to be dried, said inlet duct means having relative to said chamber a substantially tangential direction of delivery inclined relative to the chamber axis toward the other end of the vessel, said vessel having a cylindrical portion provided with a number of drying gas inlets having a gas-entering direction, tangential and inclined in substantially the same direction as said inlet means, a gas outlet duct protruding from the outside into said vessel near said other vessel end, said outlet duct having a smaller diameter than said chamber and having a mouth portion extending coaxially to said chamber, an annular gap space being formed around said duct portion for the passage of the dried substance, said hot-gas inlets being distributed lengthwise of said vessel in an array which comprises inlets in communication with said chamber at localities of said annular gap space between the mouth of said outlet duct and said other vessel end, and an annular plate member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said plate member and the wall of said chamber in the region of said array of gas inlets.
8. In processing apparatus according to claim 7, said vessel having a substantially vertical axis, the top end of said vessel being closed, said inlet duct means entering from the side through the cylindrical wall of said chamber near said closed end and in axially spaced relation to say array of further inlets, the bottom end of said vessel having below said plate member a downwardly tapering funnel shape for collection of dried substance and having a normally closed bottom opening for removal of the collected substance.
9. In processing apparatus according to claim 8, said gas outlet duct having an upwardly widening mouth above and spaced from said plate member, the largest diameter of said mouth being smaller than that of said plate member.
1. Processing apparatus for effecting interaction between, and subsequent separation of, gaseous and solid or liquid particulate substances, comprising a vessel forming an axially elongated cylindrical vortex chamber and having near one end an inlet duct means for particulate substance to be processed, said inlet duct means having an entering direction substantially tangential to said cylindrical chamber and inclined toward the other end of the vessel, said vessel having a cylindrical portion provided with a number of further, lateral inlets for active medium, said further inlets having an entering direction tangential and inclined in substantially the same sense as said inlet duct means, a gas outlet duct protruding from the outside into said vessel near said other vessel end, said gas outlet duct having a smaller diameter than said chamber and having a mouth portion extending coaxially to said chamber, an annular gap space being formed around said duct portion for the passage of processed particulate substance to the other end of said vessel, said active-medium inlets being distributed lengthwise of said vessel in an array which comprises inlets in communication with said chamber at localities of said annular gap space between the mouth of said outlet duct and said other vessel end.
2. In processing apparatus according to claim 1, said one end of said vessel being closed, and said inlet duct means entering from the side through the cylindrical wall of said chamber near said closed end and in axially spaced relation to said array of further inlets.
3. Processing apparatus according to claim 1, comprising an annular plate member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said plate member and the wall of said chamber, said plate member being located near those of said further inlets that are near said other end of said vessel.
4. Processing apparatus according to claim 1, comprising a jacket structure coaxially surrounding said cylindrical vessel and forming a plenum chamber with which all of said further inlets communicate, and duct means connected with said jacket structure for supplying active medium to said further inlets through said plenum chamber.
5. Processing apparatus according to claim 1, comprising a jacket structure coaxially surrounding said cylindrical vessel and forming a plurality of axially adjacent plenum chambers having respective duct means for supplying active medium, axially adjacent sets of said further inlets being in communication with said respective plenum chambers to receive said medium therefrom.
6. Processing apparatus according to claim 1, comprising an annular member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said member and the wall of said chamber, said member being located near those of said further inlets that are near said other end of said vessel, a jacket structure surrounding said vessel and communicating with said further inlets and having duct means for the supply of active medium.
7. Processing apparatus for the drying of particulate solid or liquid substance, comprising a processing vessel forming an axially elongated cylindrical vortex chamber and having at one end inlet duct means for supplying the substance to be dried, said inlet duct means having relative to said chamber a substantially tangential direction of delivery inclined relative to the chamber axis toward the other end of the vessel, said vessel having a cylindrical portion provided with a number of drying gas inlets having a gas-entering direction, tangential and inclined in substantially the same direction as said inlet means, a gas outlet duct protruding from the outside into said vessel near said other vessel end, said outlet duct having a smaller diameter than said chamber and having a mouth portion extending coaxially to said chamber, an annular gap space being formed around said duct portion for the passage of the dried substance, said hot-gas inlets being distributed lengthwise of said vessel in an array which comprises inlets in communication with said chamber at localities of said annular gap space between the mouth of said outlet duct and said other vessel end, and an annular plate member surrounding said gas outlet duct in fixed relation thereto and axially spaced from said duct mouth, a constricted annular passage being formed between said plate member and the wall of said chamber in the region of said array of gas inlets.
8. In processing apparatus according to claim 7, said vessel having a substantially vertical axis, the top end of said vessel being closed, said inlet duct means entering from the side through the cylindrical wall of said chamber near said closed end and in axially spaced relation to say array of further inlets, the bottom end of said vessel having below said plate member a downwardly tapering funnel shape for collection of dried substance and having a normally closed bottom opening for removal of the collected substance.
9. In processing apparatus according to claim 8, said gas outlet duct having an upwardly widening mouth above and spaced from said plate member, the largest diameter of said mouth being smaller than that of said plate member.
Description:
My invention relates to apparatus of the vortex or tornado-flow type for effecting an exchange of substance and/or heat such as for the purpose of drying a liquid or particulate solid material or for performing chemical reactions. Known apparatus of this type, when employed for the processing of solid or liquid particulate substances which, for example, are to be dried or to be subjected to some other physical or chemical reaction, involve the problem that the dwell time of the individual particles within the reaction chamber can be adjusted only inaccurately if a selective adjustment is possible at all.
It is therefore a general object of my invention, relating to processing apparatus of the type mentioned, to afford guiding the particles in the processing chamber on accurately ascertainable paths for a definite or controllable dwell time, thus affording a more precise control of the drying or other desired operation.
In principle, such an accurate guidance of the particles through a processing vessel is attainable with the aid of equipment operating in accordance with the tornado-flow principle known, for example, from U.S. Pats. No. 3,199,268, No. 3,199,270 or No. 3,226,165. As more fully explained in these patents, a suitable tornado flow can be produced in a rotationally symmetrical vortex chamber, also called tornado-flow chamber, and comprises a helically progressing circulatory flow which occurs in the chamber region near the cylindrical wall which occurs in the chamber region near the cylindrical wall and essentially constitutes a potential flow and has a corresponding axial component in the direction in which the flow progresses on the helical path along the chamber. Near one end region of the vortex chamber, this course of the flow becomes deflected with the formation of a cortex sink and passes along spiral-shaped paths toward the axis of the vortex chamber. Near the axis the flow converts into a rotational flow comparable to the vortex filament of a tornado which retains the rotational sense of the outer helical, potential flow but whose axial component points in the opposite direction. This vortex filament thus is directed back toward the other end of the vortex chamber. The tornado-flow phenomenon, just mentioned, can be generated, for example, with the aid of nozzles arranged in the cylindrical surface of the vortex chamber and having an injecting direction substantially tangential to the vortex chamber and inclined to the chamber axis, also as more fully described in the above-mentioned patents.
It is a more specific object of my invention to improve the utilization of the phenomenon and forces involved in such a tornado flow for the purpose of securing an improved treatment by interaction of gas with solid or liquid particle material.
To this end, and in accordance with the invention, a processing apparatus for effecting interaction between, and subsequent separation of, gaseous and solid or liquid particulate substances is provided with a processing vessel which forms an axially elongated cylindrical vortex chamber. Near one end the vessel has inlet means for the supply of the particulate substance to be treated, the supply direction relative to the cylindrical chamber being substantially tangential and inclined to the chamber axis toward the other end of the vessel. The cylindrical portion of the vessel is provided with an array of further, lateral, inlets for active or reactive medium such as gas or hot air for drying the particulate material. These further inlets have each an entering direction which is tangential and inclined in the same sense as the inlet means for the particulate material. A gas outlet duct protrudes into the vessel near the other end and has a mouth portion which extends coaxially to the cylindrical chamber and has a smaller diameter than the chamber so as to form an annular gap space for the passage of the processed particulate substance. It is essential that the array of active-medium inlets is distributed along the processing vessel over such an area that some of the further inlets, for example for the purpose of supplying drying air, communicate with the annular gap space at localities between the mouth opening of the gas outlet duct and the adjacent vessel end.
According to another feature of my invention, an annular member, such as a plate, surrounds the gas outlet duct in fixed relation thereto and axially spaced from the mouth opening, thus forming a constricted annular passage between the plate member and the chamber wall, the annular member being still located near the gas inlets of the array.
The particulate liquid or solid substance to be processed may be directly injected into the vortex chamber without the aid of appreciable amounts of carrier medium, although it is generally preferable to entrain the particulate substance in a flow of air or other gas. Upon mixing of the substance with gas coming from the further inlets, the particles are gas entrained in a carrier medium constituted by the gas injected through the gas inlets and, as the case may be, by the amount of original carrier gas used for entering the particulate substance into the vortex chamber. It is, of course, also within the contemplation of my invention to supply a smaller or larger amount of the active or reactive gas through the material inlet together with the particulate material to be treated and/or to supply some of the particulate substance together with the air or other gas through the other inlets.
The particulate substance supplied through the inlet duct becomes subjected to the effect of the reaction medium, such as the drying gas which is blown into the chamber through the gas inlets along the cylindrical wall of the reaction chamber and by virtue of this effect the particles are guided on a helical path in the vicinity of the chamber wall. When this helical flow or particle-laden carrier medium enters into the vicinity of the annular gap space, the particulate material, due to the fact that its mass is larger than that of the carrier medium, is flung into the annular gap and then reaches the other end of the vessel from which the collected particulate substance can be discharged. The reaction medium, thus liberated from processed particulate material passes from the wall region toward the center of the voltage chamber, this deflection being caused or augmented by the above-mentioned annular plate member. Thereafter, the medium travels to the mouth of the gas outlet duct.
Preferably the active or reactive medium, for example the drying gases to the inlets located along the cylindrical chamber wall is effected through a plenum chamber which is formed within a jacket structure that surrounds the processing vessel, the plenum chamber being in communication with all or groups of the gas inlets. The jacket structure may also be provided with several plenum chambers for respective ring groups of gas inlets, each of these plenum chambers having its own gas supply to permit stepwise a different drying effect in different respective zones of the vortex chamber.
The invention will be further described with reference to embodiments of processing apparatus according to the invention schematically illustrated by way of example on the accompanying drawings, in which:
FIG. 1 is a longitudinally sectional view of a processing apparatus equipped with a plenum chamber common to all of the lateral inlets for the active or reactive medium; and
FIG. 2 is a longitudinally sectional view of a similar processing apparatus whose jacket structure is subdivided into several plenum chambers for respective groups of gas inlets.
The same reference numerals are applied in both illustrations for corresponding components respectively.
According to FIG. 1, the illustrated processing apparatus comprises an elongated cylindrical vessel which forms an upright cylindrical vortex (tornado-flow) chamber 8 and whose top is closed by a cover 2. An inlet duct 3 for supplying the particulate substance to be treated is provided near the vessel top and has an entering direction extending tangentially to the cylindrical vortex chamber and in a downwardly inclined direction. The vessel is surrounded by a cylindrical jacket structure 4 which forms a plenum chamber and is connected with a duct 5 and connecting ducts 6 for supplying the active or reactive medium, for example the hot air or gas used for drying the particulate substance entering through the inlet duct 3. From the plenum chamber surrounding the major cylindrical portion of the vessel 1, the active medium passes through further inlets 7 which are arranged in the cylindrical wall portion of the processing vessel 1 and have an entering direction inclined and tangential in the same sense as the inlet duct 3. A number of such further inlets 7 are distributed about and along the vessel 1 so as to conjointly form an array which downwardly extends substantially to the end of the active portion of the vortex chamber, as will be more fully explained hereinafter.
Due to the active medium, such as hot air, the particles injected through the inlet duct 3 are guided on helical paths, such as the one schematically shown at 9, in the region near the vortex chamber wall and pass along such helical paths to the lower portion of the vortex chamber. A tubular gas outlet duct 10 of smaller diameter than the vessel 1 protrudes from below into the processing chamber 8 of the vessel 1. The resulting annular gap space 11 between the mouth-adjacent portion of the tubular duct 10 and the inner wall of the vessel 1 is partially closed by an annular diaphragm or plate member 12 which is located in the region of the lowermost inlets 7 and hence still within the active region of the array of gas inlets. The annular diaphragm 12 is a rigid plate member which is fastened to the gas outlet tube 10 in spaced relation to the mouth 18. A narrow outlet gap 13 is thus formed between the plate member 12 and the inner wall surface of the processing vessel 1. Below the plate member 12 and below the lowermost gas inlet nozzle 7, the end portion of the processing vessel 1 tapers downwardly and forms a bunker 14 of frustoconical shape whose bottom opening is normally closed by a cover lid 15. As explained, the particles introduced through the inlet duct 3 and guided along helical paths 9 become entrained in the gaseous carrier medium and at the bottom of the processing chamber, shortly above the plate numbered 12, are flung into the annular gap space 11 and through the annular constriction 13 into the bunker 14 from which they can be discharged from time to time by opening the lid 15. The lid may also be substituted by a cell-wheel lock or any other closeable outlet.
Above the plate 12 the gaseous carrier medium while now liberated from dried or otherwise processed particulate material, travels on a spiral path 16 inwardly. The carrier medium or the spent reactive medium then passes from the spiral path 16 on a helical path 17' upwardly to the mouth 18 of the tubular outlet duct 10. This inner helical path corresponds to the vortex filament according to the tornado-flow phenomenon described and explained in the above-mentioned patents. In the region immediately above the outlet mouth 18, the direction of the flow is reversed, due to suction applied to the external portion of the outlet duct, for example with the aid of a blower (not shown). In this manner, for example, any humidified air resulting from the drying operation can be exhausted through the outlet duct 10.
The apparatus described thus affords contacting the reactive or active medium with the particulate substance to be processed, while guiding the particulate substance on an accurately predetermined path within the vortex chamber and securing a particularly intensive contact with the gaseous medium. The annular diaphragm member 12 further secures a reliable separation of the processed particles from the drying or otherwise reactive medium.
It is in some cases desirable to permit a still more precise control of the drying operation, particularly for very sensitive particulate substances. In such cases, and as exemplified by the embodiment according to FIG. 2, individual and axially sequential regions of the vortex chamber can be supplied with drying gas of differently hot temperatures respectively. The apparatus shown in FIG. 2 corresponds in other respects to that of FIG. 1 so that it need not be again described with respect to identical details. However, the external jacket 4 in FIG. 2 is subdivided by horizontal partitions 19 into a number, for example, four plenum chambers 20 to 23. Each of these chambers has its own gas supply duct 21 to 27 so that it can be supplied with hot drying air having a different temperature from the air supplied to the next adjacent chamber. For example, the temperature may thus be gradually increased as the material passes from the inlet duct 3 to the bunker 14. Generally, an apparatus of the type shown in FIG. 2 affords blowing into the reaction chamber 8 a drying gas whose temperature can be adjusted in accordance with the particular degree of drying desired in the respective sequential regions.
The active or reactive medium supplied through the further inlet 7 along the cylindrical wall of the processing chamber would alone be sufficient to reliably guide the particulate substance on the predetermined helical paths. Hence, in both illustrated embodiments, the substance to the dried may be directly injected or blown into the vortex chamber 8 without the use of gaseous carrier medium or without supplying an appreciable quantity of gas at this locality, although if desired, the substance to be dried or processed may also be supplied while suspended or otherwise entrained in a gas flow. As mentioned, it is preferable, as a rule, to connect the gas outlet 10 to a blower or other suction device. The described apparatus thus permit, for example, the drying of particulate substances on predetermined paths during a predetermined dwell time in the reaction chamber to a reliably predetermined degree of dryness and to subsequently effect a satisfactory separation of the processed particles from the drying medium. In most cases, no subsequent separating operation is needed. The same apparatus also permits the performance of other processes, for example cooling operations or chemical reactions with the particulate substances.
While the illustrated embodiments show apparatus in which the cylindrical vortex chambers extend vertically, it will be understood that the apparatus may also be mounted in horizontal or slanting position without impairing the operability, although the horizontal arrangement may make it desirable to provide for a correspondingly different arrangement or discharge of the bunker.
To those skilled in the art it will be obvious upon a study of this disclosure that such and other modifications are readily available without departing from the essential features of my invention and within the scope of the claims annexed hereto.
It is therefore a general object of my invention, relating to processing apparatus of the type mentioned, to afford guiding the particles in the processing chamber on accurately ascertainable paths for a definite or controllable dwell time, thus affording a more precise control of the drying or other desired operation.
In principle, such an accurate guidance of the particles through a processing vessel is attainable with the aid of equipment operating in accordance with the tornado-flow principle known, for example, from U.S. Pats. No. 3,199,268, No. 3,199,270 or No. 3,226,165. As more fully explained in these patents, a suitable tornado flow can be produced in a rotationally symmetrical vortex chamber, also called tornado-flow chamber, and comprises a helically progressing circulatory flow which occurs in the chamber region near the cylindrical wall which occurs in the chamber region near the cylindrical wall and essentially constitutes a potential flow and has a corresponding axial component in the direction in which the flow progresses on the helical path along the chamber. Near one end region of the vortex chamber, this course of the flow becomes deflected with the formation of a cortex sink and passes along spiral-shaped paths toward the axis of the vortex chamber. Near the axis the flow converts into a rotational flow comparable to the vortex filament of a tornado which retains the rotational sense of the outer helical, potential flow but whose axial component points in the opposite direction. This vortex filament thus is directed back toward the other end of the vortex chamber. The tornado-flow phenomenon, just mentioned, can be generated, for example, with the aid of nozzles arranged in the cylindrical surface of the vortex chamber and having an injecting direction substantially tangential to the vortex chamber and inclined to the chamber axis, also as more fully described in the above-mentioned patents.
It is a more specific object of my invention to improve the utilization of the phenomenon and forces involved in such a tornado flow for the purpose of securing an improved treatment by interaction of gas with solid or liquid particle material.
To this end, and in accordance with the invention, a processing apparatus for effecting interaction between, and subsequent separation of, gaseous and solid or liquid particulate substances is provided with a processing vessel which forms an axially elongated cylindrical vortex chamber. Near one end the vessel has inlet means for the supply of the particulate substance to be treated, the supply direction relative to the cylindrical chamber being substantially tangential and inclined to the chamber axis toward the other end of the vessel. The cylindrical portion of the vessel is provided with an array of further, lateral, inlets for active or reactive medium such as gas or hot air for drying the particulate material. These further inlets have each an entering direction which is tangential and inclined in the same sense as the inlet means for the particulate material. A gas outlet duct protrudes into the vessel near the other end and has a mouth portion which extends coaxially to the cylindrical chamber and has a smaller diameter than the chamber so as to form an annular gap space for the passage of the processed particulate substance. It is essential that the array of active-medium inlets is distributed along the processing vessel over such an area that some of the further inlets, for example for the purpose of supplying drying air, communicate with the annular gap space at localities between the mouth opening of the gas outlet duct and the adjacent vessel end.
According to another feature of my invention, an annular member, such as a plate, surrounds the gas outlet duct in fixed relation thereto and axially spaced from the mouth opening, thus forming a constricted annular passage between the plate member and the chamber wall, the annular member being still located near the gas inlets of the array.
The particulate liquid or solid substance to be processed may be directly injected into the vortex chamber without the aid of appreciable amounts of carrier medium, although it is generally preferable to entrain the particulate substance in a flow of air or other gas. Upon mixing of the substance with gas coming from the further inlets, the particles are gas entrained in a carrier medium constituted by the gas injected through the gas inlets and, as the case may be, by the amount of original carrier gas used for entering the particulate substance into the vortex chamber. It is, of course, also within the contemplation of my invention to supply a smaller or larger amount of the active or reactive gas through the material inlet together with the particulate material to be treated and/or to supply some of the particulate substance together with the air or other gas through the other inlets.
The particulate substance supplied through the inlet duct becomes subjected to the effect of the reaction medium, such as the drying gas which is blown into the chamber through the gas inlets along the cylindrical wall of the reaction chamber and by virtue of this effect the particles are guided on a helical path in the vicinity of the chamber wall. When this helical flow or particle-laden carrier medium enters into the vicinity of the annular gap space, the particulate material, due to the fact that its mass is larger than that of the carrier medium, is flung into the annular gap and then reaches the other end of the vessel from which the collected particulate substance can be discharged. The reaction medium, thus liberated from processed particulate material passes from the wall region toward the center of the voltage chamber, this deflection being caused or augmented by the above-mentioned annular plate member. Thereafter, the medium travels to the mouth of the gas outlet duct.
Preferably the active or reactive medium, for example the drying gases to the inlets located along the cylindrical chamber wall is effected through a plenum chamber which is formed within a jacket structure that surrounds the processing vessel, the plenum chamber being in communication with all or groups of the gas inlets. The jacket structure may also be provided with several plenum chambers for respective ring groups of gas inlets, each of these plenum chambers having its own gas supply to permit stepwise a different drying effect in different respective zones of the vortex chamber.
The invention will be further described with reference to embodiments of processing apparatus according to the invention schematically illustrated by way of example on the accompanying drawings, in which:
FIG. 1 is a longitudinally sectional view of a processing apparatus equipped with a plenum chamber common to all of the lateral inlets for the active or reactive medium; and
FIG. 2 is a longitudinally sectional view of a similar processing apparatus whose jacket structure is subdivided into several plenum chambers for respective groups of gas inlets.
The same reference numerals are applied in both illustrations for corresponding components respectively.
According to FIG. 1, the illustrated processing apparatus comprises an elongated cylindrical vessel which forms an upright cylindrical vortex (tornado-flow) chamber 8 and whose top is closed by a cover 2. An inlet duct 3 for supplying the particulate substance to be treated is provided near the vessel top and has an entering direction extending tangentially to the cylindrical vortex chamber and in a downwardly inclined direction. The vessel is surrounded by a cylindrical jacket structure 4 which forms a plenum chamber and is connected with a duct 5 and connecting ducts 6 for supplying the active or reactive medium, for example the hot air or gas used for drying the particulate substance entering through the inlet duct 3. From the plenum chamber surrounding the major cylindrical portion of the vessel 1, the active medium passes through further inlets 7 which are arranged in the cylindrical wall portion of the processing vessel 1 and have an entering direction inclined and tangential in the same sense as the inlet duct 3. A number of such further inlets 7 are distributed about and along the vessel 1 so as to conjointly form an array which downwardly extends substantially to the end of the active portion of the vortex chamber, as will be more fully explained hereinafter.
Due to the active medium, such as hot air, the particles injected through the inlet duct 3 are guided on helical paths, such as the one schematically shown at 9, in the region near the vortex chamber wall and pass along such helical paths to the lower portion of the vortex chamber. A tubular gas outlet duct 10 of smaller diameter than the vessel 1 protrudes from below into the processing chamber 8 of the vessel 1. The resulting annular gap space 11 between the mouth-adjacent portion of the tubular duct 10 and the inner wall of the vessel 1 is partially closed by an annular diaphragm or plate member 12 which is located in the region of the lowermost inlets 7 and hence still within the active region of the array of gas inlets. The annular diaphragm 12 is a rigid plate member which is fastened to the gas outlet tube 10 in spaced relation to the mouth 18. A narrow outlet gap 13 is thus formed between the plate member 12 and the inner wall surface of the processing vessel 1. Below the plate member 12 and below the lowermost gas inlet nozzle 7, the end portion of the processing vessel 1 tapers downwardly and forms a bunker 14 of frustoconical shape whose bottom opening is normally closed by a cover lid 15. As explained, the particles introduced through the inlet duct 3 and guided along helical paths 9 become entrained in the gaseous carrier medium and at the bottom of the processing chamber, shortly above the plate numbered 12, are flung into the annular gap space 11 and through the annular constriction 13 into the bunker 14 from which they can be discharged from time to time by opening the lid 15. The lid may also be substituted by a cell-wheel lock or any other closeable outlet.
Above the plate 12 the gaseous carrier medium while now liberated from dried or otherwise processed particulate material, travels on a spiral path 16 inwardly. The carrier medium or the spent reactive medium then passes from the spiral path 16 on a helical path 17' upwardly to the mouth 18 of the tubular outlet duct 10. This inner helical path corresponds to the vortex filament according to the tornado-flow phenomenon described and explained in the above-mentioned patents. In the region immediately above the outlet mouth 18, the direction of the flow is reversed, due to suction applied to the external portion of the outlet duct, for example with the aid of a blower (not shown). In this manner, for example, any humidified air resulting from the drying operation can be exhausted through the outlet duct 10.
The apparatus described thus affords contacting the reactive or active medium with the particulate substance to be processed, while guiding the particulate substance on an accurately predetermined path within the vortex chamber and securing a particularly intensive contact with the gaseous medium. The annular diaphragm member 12 further secures a reliable separation of the processed particles from the drying or otherwise reactive medium.
It is in some cases desirable to permit a still more precise control of the drying operation, particularly for very sensitive particulate substances. In such cases, and as exemplified by the embodiment according to FIG. 2, individual and axially sequential regions of the vortex chamber can be supplied with drying gas of differently hot temperatures respectively. The apparatus shown in FIG. 2 corresponds in other respects to that of FIG. 1 so that it need not be again described with respect to identical details. However, the external jacket 4 in FIG. 2 is subdivided by horizontal partitions 19 into a number, for example, four plenum chambers 20 to 23. Each of these chambers has its own gas supply duct 21 to 27 so that it can be supplied with hot drying air having a different temperature from the air supplied to the next adjacent chamber. For example, the temperature may thus be gradually increased as the material passes from the inlet duct 3 to the bunker 14. Generally, an apparatus of the type shown in FIG. 2 affords blowing into the reaction chamber 8 a drying gas whose temperature can be adjusted in accordance with the particular degree of drying desired in the respective sequential regions.
The active or reactive medium supplied through the further inlet 7 along the cylindrical wall of the processing chamber would alone be sufficient to reliably guide the particulate substance on the predetermined helical paths. Hence, in both illustrated embodiments, the substance to the dried may be directly injected or blown into the vortex chamber 8 without the use of gaseous carrier medium or without supplying an appreciable quantity of gas at this locality, although if desired, the substance to be dried or processed may also be supplied while suspended or otherwise entrained in a gas flow. As mentioned, it is preferable, as a rule, to connect the gas outlet 10 to a blower or other suction device. The described apparatus thus permit, for example, the drying of particulate substances on predetermined paths during a predetermined dwell time in the reaction chamber to a reliably predetermined degree of dryness and to subsequently effect a satisfactory separation of the processed particles from the drying medium. In most cases, no subsequent separating operation is needed. The same apparatus also permits the performance of other processes, for example cooling operations or chemical reactions with the particulate substances.
While the illustrated embodiments show apparatus in which the cylindrical vortex chambers extend vertically, it will be understood that the apparatus may also be mounted in horizontal or slanting position without impairing the operability, although the horizontal arrangement may make it desirable to provide for a correspondingly different arrangement or discharge of the bunker.
To those skilled in the art it will be obvious upon a study of this disclosure that such and other modifications are readily available without departing from the essential features of my invention and within the scope of the claims annexed hereto.