WO1983001910A1

WO1983001910A1 - Structure for continuous-line coal desulfurization reaction

Info

Publication number: WO1983001910A1
Application number: PCT/US1981/001599
Authority: WO
Inventors: F Allen Grove; Philip R Larue; Martin L Chappell; Anthony J Chinnici
Original assignee: Grove, F., Allen; Larue, Philip, R.; Chappell, Martin, L.; Chinnici, Anthony, J.
Priority date: 1981-11-30
Filing date: 1981-11-30
Publication date: 1983-06-09
Also published as: AU8003082A; EP0094935A1

Abstract

Apparatus for continuous-line coal desulfurization operations enabling fluid treatment, including gaseous treatment, of pulverant work product. Movement of the work product along a horizontally-oriented, longitudinally-extended treatment path is carried out mechanically, without requiring pressure impulsion, by a ribbon band auger (12, 102, 116) within a housing (10). Additives can be introduced from either longitudinal end (42, 44) of the housing and injection is distributed (74, 75, 78, 110) along the treatment path. The work product is raised vertically within the housing by paddles (52, 54) integral with the ribbon band auger to expand the space occupied by the work product as it is moved along the treatment path and facilitate reaction by direct impingement of injected additives. Variable speed drive (86, 106, 126) is provided to control movement rate along the treatment path and, by providing for introduction of additives and driving of the auger from either longitudinal end, substantially identical reaction chamber housings (134, 136) can be stacked one above the other for sequential reaction treatments or extension of treatment times.

Description

STRUCTURE FOR CONTINUOUS-LINE COAL DESULFURIZATION REACTION

/ This invention relates to continuous-line treat¬ ment of pulverant solids. More particularly, this inven¬ tion is concerned with apparatus defining a longitudinally- extended reaction chamber and providing for continuous move ment of work product containing pulverant coal through such chamber free of pneumatic impulsion and in a manner enablin use of fluid reactants for extraction, of sulfur from the

pulverant coal and conversion of extracted sulfur into useful by-product readily separable from the coal. Batch treatment processes and apparatus for desulfurization of coal can rely on ease of adjustment of process steps and times in adapting to variables encoun¬ tered with differing batches in order to accomplish desired results. However, batch processing, while practical for lab development purposes, has disadvantages for commercial purposes in product handling and achieving economically acceptable production rates.

The present invention enables treatment with fluids including gaseous treatment while providing for mechanically controlled continuous movement of work product eliminating product handling problems and providing for commercially economic production rates.

Prior art teachings attempting to accomplish reaction of pulverant coal and fluid materials have relied

m WHO on tortuous path structures and pressure means for moving pulverants. Also, in general, such apparatus have not been adaptable to continuous-line operations relying rather on batch handling before and after treatment. The present invention provides desired interaction of pulverant solids and fluid additives without requiring pressure for movement of solids nor complex

tortuous path structure while maintaining rate of movement. Exposure time is controlled to provide for sequential

continuous-line treatments, including gaseous extraction of sulfur from coal coupled to continuous-line treatment using a fluid reactant to convert extracted sulfur to useful by-product readily separable from the coal.

Chemical reactions involved in such extraction of sulfur and conversion treatment are disclosed in copending U.S. Application Serial No. 223,274, entitled "REMOVING SULFUR AND BΞNEFICIATING COAL", filed January 8, 1981; and continuous-line operations for producing "compliance" coal and useful by-product are disclosed in copending Applicatio Serial No. PCT/ , entitled "CONTINUOUS-LINE

OPERATIONS FOR DESULFURIZING COAL", filed concurrently herewith; the disclosures of such copending applications ar incorporated herein by reference.

Extraction of sulfur during continuous movement o raw pulverant .coal is made practicable by mechanically pro¬

viding for expansion of the space occupied by the pulverant coal during its passage through the reaction zone, by pro¬ viding for repeated direct access of fluid reactant to all surfaces of the pulverant work product without complexities of pneumatic movement or tortuous path structures, and by providing for selection of treatment times.

Direct impingement of reactant gas is provided along an elongated travel path using economic, problem-free movement measures and structures. Further, the apparatus

provides for continuous agitation and movement of the work product for subsequent conversion of extracted sulfur to separable sulfur compounds. In addition, provision is made for limiting the temperature resulting from exothermic gaseous reactions.

Other advantages and contributions of the inven- tion are set forth in describing the specific embodiments shown in the accompanying drawings. In these drawings:

FIG. 1 is an elevational view, with portions cut away and portions shown in dotted lines, of apparatus embodying the invention; FIG. 2 is a top plan view of the apparatus of FIG.

1 with portions cut away and portions shown in dotted lines;

FIG. 3 is a cross-sectional view of the apparatus of FIG. 1;

• FIG. 4 is a schematic elevational view of an interior portion of the apparatus of FIG. 1 for illustrating functional aspects of the invention; FIGS. 5 through 8 are schematic cross section views of the apparatus of FIG. -4 with the ribbon-band auger at differing angles of rotation for illustrating functional aspects of the invention; FIG. 9 is a schematic elevational view combining first and second reaction chamber structures of the embodi¬ ment of FIGS. 1-3 stacked in series for sequential treat¬ ment of work product made available by the present inventio

and FIG. 10 is a schematic perspective view showing a plurality of reaction chamber structures of the embodimen of FIGS. 1-3 in a parallel-path series-stacked combination made available with the present invention*.

The longitudinally-extended reaction chamber structure of the present invention is defined by a housing means circumscribing a helical-path ribbon band auger for conveying work product by rotation within the housing means. Both longitudinal movement of work product and a tumbling,

cascading action, transverse to such continuous-line longi- tudinal movement, are provided in a manner which facilitate reaction with additives to achieve desired results.

The housing means has a cross-sectional configura tion which provides for injecting additives along substanti ally the full length of an elongated travel path forming part of a continuous line. Provision is made for charge an discharge of work product at opposite longitudinal ends of the chamber defined by the housing means. Condition sensin means can be mounted on the housing means; temperature sensing, pH monitoring, and ozone monitoring can be carried out along the travel path. Temperature control responsive to chamber or work product temperature can be carried out during the continuous movement of work product within the housing means. in addition to ease of control of rate of movemen

of work product, a further contribution of the invention permits stacking of individual structures, one above the other, to enable continuous-line sequential treatments of work products, with various reactant fluids, utilizing identical and interchangeable apparatus, in which the auger means of stacked chamber structures are capable of moving work product in opposite directions in relation to each other while providing for selective introduction of addi¬ tives from either longitudinal end of the individual structures.

Referring to FIGS. 1, 2, and 3, housing means 10 defines a longitudinally-extended chamber circumscribing a helical-path ribbon band auger 12 which is radially spaced from axis of rotation 14 by narrow-width arms, such as 16, JL8, extending between and integral with sleeve 20 and the ribbon band 12.

As best seen in FIG. 3, rotation of the ribbon- band auger 12 presents an outer diameter cylindrical f O PI periphery 22 and an inner diameter cylindrical periphery 24, both radially spaced from axial_/sleeve 20. Longitudinally- extending passage 26, radially within the inner diameter cylindrical periphery 24, is largely unobstructed, being open except for the narrow-width support arms such as 16,

18.

The chamber-defining housing means 10 is horizon¬ tally oriented and includes a longitudinally-extending bottom wall 30 of semi-circular cross-sectional configura- tion throughout its length or a major portion of its length. A discharge opening is located contiguous to one longi¬ tudinal end. As shown, discharge opening 32 in the bottom wall 30 is defined by discharge framing means 34. The housing means further includes sidewalls 36, 38 (FIG. 3) extending tangentially from distal ends of semi-circular bottom wall 30 to define open cross-sectional space 39 above outer diameter cylindrical periphery 22. The bottom wall and sidewalls, as shown, present a U-shaped cross section. The sidewalls 36, 38 are joined at their upper ends by longitudinally extending top wall closure 40 which can be continuous throughout its length in extending between end- walls 42, 44 or provide for entrance opening 48 defined by work product entrance framing me^s 50. Charge and dischar openings contiguous to opposite longitudinal ends should provide for gravity feed of work product between stacked chambers. A plurality of paddles, such as 52, 54, are integrally mounted on ribbon band 12 in angled relationship to such band and predeterminedly distributed along its length; such angled paddles lift work product during its longitudinal movement causing a tumbling, cascading action of pulverant solids. Movement of work product by the paddles is generally transverse to the longitudinally directed continuous-line movement; this action expands the

space occupied by the work product during its passage and facilitates desired reaction within the chamber.

Bottom wall 30 is in contiguous relationship to the bottom half of outer diameter cylindrical periphery 22 defined by ribbon band 12 while sidewalls 36, 38 and top wall closure 40 help define longitudinally-extended open space 39, above the outer cylindrical periphery 22, for injecting fluid reactants and monitoring conditions longi¬ tudinally of the chamber.

In accordance with one feature of the invention, conduit connectors are provided contiguous^" to both longi- tudinal ends of the chamber defined by the housing means.

In FIGS. 1, 2, and 3, conduit connectors 60, 61, and 62 are mounted on endwall 42 and conduit connectors 64, 65, and 66 mounted on endwall 44. Provision is thus made for selective introduction of fluid reactants from opposite longitudinal ends of a single housing structure which, with selection of orientation of the housing means and direction of rotation

UI

OMPI of helical-path ribbon band 12, enables positioning of a re¬ action chamber structure to provide for right-hand entry or left-hand entry of work product; this enables position¬ ing of manifold injection means within the housing so as to avoid obstruction of work product entry means; and, provides for stacking a plurality of structurally identical treatment chambers, for sequential treatment of work product with continuous—line feed and discharge of work product.between a plurality of stacked structures. Manifold means for injecting additives within the chamber defined by the housing means extend longitudinally from the conduit connectors contiguous to a longitudinal end As shown in FIGS. 1 and 2, longitudinally-extended manifolds 70, 71, and 72 extend, respectively, from conduit connectors 60, 61 and 62; the mounting shown enables the entry opening 40 at the opposite longitudinal end of the chamber to be unobstructed. Manifold means 70, 71, and 72 can extend longitudinally throughout substantially the full length of the defined chamber while exempting a portion for work product entry when the charge opening is defined in the top wall.

Individual injectors, such as 74, 75 (FIG. 1) are distributed along the longitudinal dimension of the manifold means. Injection patterns, such as shown in dotted lines at 76, 77 of FIG..1, are determined by selection of commerci¬

ally available injection nozzles; also, injection can be angled in differing directions and flow control means, such as on/off valves, can be included in such nozzles.

With longitudinal distribution of injection nozzles, additives can be injected along selected portions of or substantially the full elongated travel path for work product; and, additives can be injected, where and as neede in transverse relationship to the continuous-line direction of movement of work product.

The number and location of injection nozzles utilized can be selected. Also, additives in differing

manifolds can be selectively mixed after introduction into the housing means but before dispersion. In using the apparatus of FIGS. 1, 2 and 3 for gaseous extraction of sulfur, a reactant gas is introduced through connector conduit 60 and manifold 70. Air can be introduced through connector 61 and manifold 71, and water can be introduced separately throug conduit connector 62 and manifold 72. However, as shown in FIG. 2, air and water manifolds 71 and 72 can be interconnected for mixing air and water within the chamber and discharge through intermediately located spray nozzles such as 78; thus, depth of water penetration within the housing means can be readily augmented with air pressure Also, a spray-mist can be provided to facilitate quench cooling while helping minimize the amount of water used when

cooling is required.

The ribbon band auger 12 is supported at both its longitudinal ends for rotation and can be driven from either longitudinal end. In tfre specific embodiment, bearing sleeve 82 is supported on endwall 42 and bearing sleeve 84 is supported on endwall 44. A variable speed drive 86 mounted contiguous to endwall 42 is connected by chain drive 88 to sprocket 89; as an alternative available w^'ith the invention, which contributes to the adaptability of the structure to stacked operations, such a drive means can be mounted at the opposite longitudinal end contiguous to wall 44 for rotatably driving the auger 12 from that longitudinal end.

Temperature sensing means are mounted on housing 10 for monitoring temperature conditions within the chamber and at the discharge end of the chamber. Pressure sensing is not generally a processing requirement since the chambers are open to atmospheric conditions at work product charge and discharge openings, but can be provided to detect unusual occurrences such as a blockage or stoppage of flow which would result in a pressure increase.^* As seen in FIG. 1, pressure sensor 90 is mounted in endwall 40 and a temperature sensor 92 is mounted conti¬ guous to discharge opening 32; the latter monitors the work product after gaseous treatment for extraction of sulfur; should work product temperatures approach 100°C. , cooling measures can be taken. Condition sensors, such as 93, for

monitoring pH or sampling chamber atmosphere for ozone f OMPI content, can be located along the length of the housing means for control purposes.

Temperature sensors such as 94 (FIG. 3) can be located in sidewall 38 for monitoring temperature conditions

along the longitudinally-extended chamber. Quench cooling can be provided, responsive to temperature monitoring, as required to maintain a reaction zone temperature below about 100°C. and avoid formation of steam in the reaction chamber or the following chamber. Quench cooling water is provided by manifold 72 and/or augmented with air pressure from manifold 71. Injection means are distributed along such chamber length; however, injector valves can be selectively operated. Preferably, quench cooling is limited to a space contiguous to the work product discharge opening, dependent on experience with a particular coal.

The action of the helical-path ribbon band 12 with associated paddles in providing longitudinal movement and a mixing, tumbling, and cascading action of work product for interaction of injected additives is shown in FIGS. 4 through 9.

As seen in the elevational view of FIG. 4, the auger moves the pulverant work product longitudinally as the paddles raise the work product within the chamber and, upon continued rotation of the auger, the work product falls

within the chamber. This raising and falling of the work product is represented in the cross-sectional views of FIGS. 5-8; paddles can take various shapes, including scoop con¬ figurations to control the amourit of lifting.

Reactant gas injected from manifold 70 is directed into contact with the coal a.s it is moved within the chamber during its tumbling cascading movement in fall¬ ing from the paddles, while on the paddles, and while in the bottom portion of the housing.

As seen in FIG. 7, cooling water and air from

manifolds 71, 72 are combined and injected in later stages as may be required to impinge on work product of elevated temperature as it is being raised within the chamber by rotation of the auger.

In the combination of treatments described in above-identified Application Serial No. PCT/ , extraction of sulfur is followed by a conversion treatment in which extracted sulfur, in the form of calcium sulfate, is converted into an ammonium sulfate which is more readily removable from the pulverant coal. The sulfur extraction reaction is a gaseous reaction of nascent oxygen with a moisture-agglomerated pulverant work product; and, the sequential conversion to an ammonium sulfate utilizes a fluid reactant. Conversion chamber structure is substanti¬ ally identical to structure (FIGS. 1, 2 and 3) as described for sulfur extraction reaction in mixing, raising and cas- cading of work, product and continuous-line movement of the work product. Manifolds can be selected for liquid and gaseous additives.

As shown in FIGS. 9 a-rid 10, with the features and adaptability provided by the present invention which enable introduction of additives from either longitudinal end, driving of the auger means from either longitudinal end, and sequential handling of work product in pulverant form for gaseous or liquid reactant treatments, substantially identical chamber structures, as shown in FIGS. 1 through 3 and described above, can be series stacked as shown in FIG. 9, or arranged in various combinations such as the parallel treatment paths shown in FIG. 10, without requir¬ ing an inventory of different types of chamber structures.

Referring to FIG. 9, a first reaction chamber structure 98 is positioned for entry of work product at entrance 100 for movement along the elongated continuous- line travel path upon rotation of ribbon-band auger 102 toward discharge opening 104. Ribbon-band auger 102 is driven by variable drive means 106 at the work product

entry end of the chamber by chain linkage between drive means 106 and drive sprocket 108. Additives are made through manifolds such as 110 extending from conduit con- • nector 112 located at the discharge end of the first reaction chamber structure 98 so that the entrance opening for work product is not obstructed by the manifold means. Entrance means 114 for second reaction chamber

structure 115 is connected to the discharge opening the first chamber structure 98. Ribbon-band auger 116 in the second chamber structure 115 moves the work product longitudinally in the direction of discharge opening .120 with additives being introduced through conduit connector means 122 located at the discharge opening end of the second chamber structure 115; manifolds such as 124 extend longi¬ tudinally along the elongated work product travel path with¬ out obstructing the entrance opening 114 of the second

chamber structure 115. Ribbon-band auger 116 within the second chamber

115 can be driven from either longitudinal end, preferably with its own drive means 126 linked to sprocket 127. It can also be driven from the drive means 106 through a chain linkage oriented to provide a direction of rotation for ribbon-band auger 116 which is opposite to the direction of rotation of ribbon band 102 of the first chamber 98. With series connected chamber structures, control of rotation is coordinated as indicated by dotted line 128, to have the work product move at a higher rate through the second chamber 115 than through the first chamber 98 when a liquid addition is made in the second chamber in order to avoid the possibility of back-up of materials within such first cham¬ ber.

■ With the structural features described, chambers can be stacked- for gaseous reaction before other reactions are undertaken, so that fluid treatment times can be

O PI extended, as may be required for high sulfur content coals, without slowing rate of movement along the continuous line.

•With the adaptability provided by the structure of FIGS. 1-3, parallel path treatments can also be carried out to expand capacities of a given line. Referring to FIG. 10, from an additive mixer chamber 130 the work product travels as indicated to flop gate chute 132 which permits

selection of one or two travel paths. As shown, each travel path includes a sulfur extraction chamber such as 134 and a chamber such as 136 for sulfate conversion treatment. The output of both parallel paths, in the combination shown, is directed to spray washing and dewatering screen structure 138 with pulverant solids being directed to separate-means such as cyclone separator 140. Typically, for desulfurization treatments of pulverant coal at rates up to about two hundred and. fifty tons per hour, a chamber length of about twenty feet is defined by the housing means, with a helical ribbon band having an outer diameter of about four feet, a forty-eight inch pitch, and an inner diameter of about thirty inches; paddles such as 52, 54, are located at selected intervals of about 60° to 120° along the helix. Housing and auger means are preferably constructed from chemical resistant material, such as stainless steel. A commercially available twenty horsepower vari¬

able speed drive motor provides a desired range of rotat: preferably a maximum RPM of about forty and a minimum RPM of about ten for each chamber; rate of movement through the chamber can thus be readily controlled by RPM selection. Ozone can be used to supply nascent oxygen for sulfur extraction. Quench cooling fluid can include water, air, or combined water and air. Conversion reactant com¬ prises ammonia which can be added as a gas plus water, or as ammonium hydroxide.

Injection nozzles can be distributed at about twelve-inch intervals longitudinally of the manifold means. Spray patterns and flow control for each can be selected from commercially available nozzles. Entrance and discharge openings should be about three-foot square or of equivalent area. While specific configurations and materials have been described, it is understood that, in the light of the present teachings, other configurations and materials could be substituted; therefore, the scope of the invention should be determined with reference to the appended claims.

Claims

1. Apparatus defining an elongated reaction chamber and providing continuous movement of work product

including pulverant coal without relying on pressure impulsion comprising auger means including a narrow-width helical-path ribbon band rotatable about a centrally-located longitudina

axis of rotation, such ribbon band being supported in radially spaced relationship from such longitudinal axis establish¬ ing an inner and outer diameter cylindrical periphery symmetrical with such axis during rotation of such ribbon band, the inner diameter cylindrical periphery defining an elongated passageway located radially inwardly of such ribbon band, such passageway extending in the longitudinal direction established by the longitudinal axis of rotation, a plurality of integral paddle means distributed along the length of the helical-path ribbon-band and dis¬ posed in transverse relationship to such ribbon-band surface to create a vertical component of movement of work product

through such passageway while the work product is being moved with a horizontal component in the direction of the

longitudinal axis provided by rotation of the helical-path ribbon band, housing means having a longitudinally-extended configuration enclosing the auger means defining a longi¬ tudinally-extended chamber with an entry means for work product contiguous to one of its longitudinal ends and a discharge means for work product contiguous to its remain¬ ing longitudinal end, such housing means being horizontally oriented an

including a bottom wall, the bottom wall defining, in a plane perpen¬ dicular to such longitudinal axis of rotation, a semi¬ circle having a radial dimension positioning the botto wall contiguous to the outer diameter cylindrical periphery defined by rotation of such ribbon band, sidewall portions integral with and extendin tangentially upwardly from such semi-circular bottom wall to establish, as viewed in a plane perpendicular to the longitudinal axis of rotation, an open cross- sectional area within such housing means which is radially exterior of the outer diameter cylindrical periphery established by rotation of such ribbon band, longitudinally-extended top wall closure means extending between and joined to such sidewall portions,

• endwall means presenting an endwall for

closing a predetermined portion of each longitudinal end of the enclosure defined by such bottom wall, sidewall portions, and top/wall closure means, bearing means contiguous to such endwall means providing for rotation of such ribbon band about

its longitudinal axis, conduit connector means contiguous to such endwall means for introducing additives within such longitudinally-extended chamber defined by the housing

means, manifold means extending longitudinally from such conduit connector means into such open cross- sectional area within the housing means radially exterior of the outer diameter cylindrical periphery established by rotation of such ribbon band, and additive injection means including a plural¬ ity of injectors predeterminedly distributed longi¬ tudinally along such- longitudinally-extended manifold means.

2. The apparatus of claim 1 in Which the conduit connector means include a plurality of individual conduit connectors con¬ tiguous to each endwall, and the manifold means includes a plurality of indivi¬ dual manifolds

with individual manifolds connected to individual

conduit connectors enabling each to supply a fluid additij

OMP within the longitudinally-extended chamber defined by the

housing means. ^/

3. The apparatus of claim 1 in which such conduit

connector means include a plurality of individual conduit connectors mounted on each endwall for selective mounting internally of such housing means of a manifold on each conduit connector.

4. The apparatus of claim 2 in which at least two individual longitudinally-extended manifolds are inter¬ connected along their lengths to permit intermixing of separate additives within the housing means for injection within the housing means.

5. The apparatus of claim 2 including means interconnecting individual manifolds for intermixing separate fluid additives for injection within the housing means, such individual interconnecting means being dis¬ tributed longitudinally along such individual manifolds and including individually operable valve means for controlling injection of such intermixed fluid additives.

6. . The apparatus of claims 1, 2, 3, 4, and 5 in which such injection means includes means for directing an additive in a direction transverse to the longitudinal direc tion of movement of work product established by rotation of

the ribbon band.

7. The apparatus of claim 1 in which the plural¬ ity of injectors distributed along the longitudinal length

of the manifold means include nozzle means for selective, operation of individua

injectors.

8. The apparatus of claim 1 in which conduit connector means are positioned contiguous to the endwall at each longitudinal end of the housing means to permit selec¬ tion of the longitudinal end of the housing means for entry

of additives.

9. The apparatus of claim 8 in which such entry means defines a charge opening for wor product in the top wall closure means, and such discharge means defines a discharge opening for work product in such bottom wall.

10. In combination, first and second reaction chamber apparatus as set forth in claims 8 and 9 stacked for sequential passage of work product, in which such first chamber apparatus is positioned vertically above such second chamber apparatus with its discharge means connected to the entry means of such second chamber apparatus, and in which the helical-path ribbon band of such first and second reaction chamber apparatus are rotatable to provide longitudinal movement of work product in opposite directions

in relation to each other.

11. The apparatus of claim 1 further including temperature sensing means mounted on such housing

means for measuring temperature level within such housing means.

12. The apparatus of claim 1 further including pressure sensing means mounted on such housing means .for measuring pressure within such housing means.

13. The apparatus of claim 1 further including

variable speed drive means connected to control rotation rate of the helical-path ribbon band.

14. The apparatus of claim 10 including drive means connected to such ribbon band within each such first and second chamber apparatus to control rotation rate of each such ribbon band.

15. The apparatus of claims 8 and 9 in which the manifold means extend from the conduit connector contiguous to the e^*ndwall at the discharge means end of the longi¬ tudinally-extended chamber defined by the housing means and have a length to avoid obstruction of the entry means for work product contiguous to the remaining opposite longi¬ tudinal end of such chamber.

O PI