US3253777A - Collecting and conveying mechanism - Google Patents

Description

May 31, 1966 J. JONAKIN COLLECTING AND CONVEYING MECHANISM Filed May 8, 1963 ATTORNEY United States Patent 3,253,777 COLLECTING AND CONVEYING MECHANISM James Jonakin, Simsbury, Conn., assignor to Combustion Engineering, Inc., Windsor, Conn., a corporation of Delaware Filed May 8, 1963, Ser. No. 278,880

2 Claims. (Cl. 233-46) This invention relates to collecting and conveyor mechanism and particularly to mechanism for collecting partially dewatered coal discharged from a centrifuge and conveying the discharged coal to a point of use such as a pulverizing mill or cyclone furnace.

In a system for handling a liquid-solid slurry and particularly in a system for handling a pumpable slurry of crushed coal and water wherein it is desired to provide a continuous and regulated supply of mechanically dewatered solids, it is necessary that the various components of the system including the mechanical dewatering device be able to operate continuously, performing its desired functions without interruption over relatively long periods of time. With a slurry such as the pumpable coal slurry which may originally have had a water concentration of 50% and where the mechanical dewatering reduces this concentration to approximately 20%, special precautions must be taken with regard to the handling of the thus concentrated slurry, which is a pasty material similar to a thick mud, so that a steady flow is maintained and that plugging or stoppage is not encountered. The present invention is directed to a method and system employing a centrifuge dewatering device of particular construction for the handling and dewatering of a liquid-solid slurry (such as a pumpable coal slurry) and with the method and organization being such as to provide more sustained operation over long periods.

An object of the present invention is a method and mechanism for collecting the pasty discharge from a centrifuge and conveying it at a uniform rate to a point of use.

Other and additional objects will .be apparent from the following specification and claims and the attached drawings in which:

FIG. 1 is a side view partly in section showing the invention applied to a centrifuge and a bowl mill pulverizer; and

FIG. 2 is an end view partly in section of the mechanism of FIG. 1 with the bowl mill removed.

In the coal firing of furnaces it is highly desirable to have a continuous and uniform supply of coal to the furnace in order to provide a steady and efficient combustion of the coal in the furnace. One of the problems in collecting and transporting dewatered coal slurry from the centrifuge to the furnace'has been the tendency of the dewatered coal, because of its pasty nature, to collect irregularly in the collector and chute directing the discharged coal slurry to the point of use such as a pulverizing mill or a cyclone furnace. After some build-up the collected or adhering slurry might let go irregularly and discharge a slug of coal at one time to provide too much coal at that time for eificient combustion and during the build-up period supply insufficient coal for efiicient combustion. It is an object of applicants'invention to overcome this problem.

In the handling of pipeline coal and the supplying of this coal to a furnace for burning therein, as for example the furnace of a vapor generator, the coal slurry as it is conveyed through the long pipe line is of a consistency which renders it desirable to remove a portion of the water prior to introducing the slurry into a firing system of a furnace. This concentration of the coal slurry to provide a coal slurry concentrate of partially dewatered coal icg may be effected by means ofa centrifuge dewatering device, and the concentrate egressing from the centrifuge may be conveyed to a furnace, such as a cyclone furnace, for burning therein or to a pulverizing mill and thence to a furnace. For the details with relation to such systems for the handling and burning of coal thus transported through a pipe line, including the uniform and continuous supply of slurry to a centrifuge, reference may be made to US. application Serial No. 159,600, filed December 15, 1961, by James Jonakin and Robert C. Tulis for Drying and Burning of Pipeline Coal, US. application Serial No. 159,603, filed December 15, 1961, by James J'onakin for Method and Apparatus for Handling and Burning Fuel, and U.S. application Serial No. 215,203, filed August 6, 1962, now Patent No. 3,211,369, issued Oct. 12, 1965, by Harry B. Jones and Donald J. Frey for Method and Apparatus for Handling Pipeline Coal.

In the embodiment illustrated to explain the present invention a centrifuge having a rotating drum 10, similar to that shown in the above cited applications, is fed wit-h a continuous stream of pipeline slurry and discharges dewatered slurry through the discharge orifices 12 in a continuous and uniform stream from each orifice. The bowl 10 which may rotate at 1000 or 2000 r.p.m. imparts a centrifugal force to the concentrate which provides the radial outward component to the tangentially discharged concentrate. A collector 14 surrounds the discharge openings 12 and provides a stationary surface in the path of the discharged coal and against which the discharged coal impinges. 'Ihis collector has a semi-circular portion 16 concentric with the axis of rotation of the bowl 10 and two tangential extensions 18 and 20 inclined downwardly and away from said axis and forming a converging chute having an open end 22 providing an opening through which coal may be discharged into the pulverizer 24 and its bowl 26. The collector has side plates 28 and 30 forming enclosures for the axially extending surfaces 32 of the collector. The collector thus provides an enclosure having one end formed of a semicircular shape with a linear axially extending surface and a converging chute extending from the open side of the semi-circle and having linear axially extending surfaces and terminating in an open discharge end. This collector may be supportedin any suitable manner, such as by bolts (not shown) from the centrifuge housing 34 a flange 36 is secured to the open end of the collector 14 and serves as a means for fastening the collector to the pulverizer mill 24 in a position to deliver the discharge from the collector to the pulverizer bowl 26. A pair of spaced chains 38 and 40 are threaded over sprockets 42 and 44 driven by a motor 46. Scraper blades 48 have one end secured to a link in chain 38 and the other end secured to a corresponding link in chain 40 and extend outwardly from the chain and along the linear axially extending surface of the collector 14 in an axially extending direction. The chains 38 and 40 which act as holders for the scraper blades 48 are supported on and guided .by sprockets 50 so as to position the scraper blades 48 adjacent the interior surface of the collector 14 including both the semi-circular and the tangential chute portions. As the chains are driven in unison by the sprocket 42 and 44 secured in fixed relation on the driven shaft 52 they will carry the scraper blades 48 along the interior surface of the collector 14. The scraper blades 48 traveling over and along the interior surface of the collector 14 will dislodge any material that may tend to stick to the surface of the collector and either push it along in front of the scraper blades or cause the material to drop or fall down onto a lower surface of the collector such as the tangential portion 18 forming the lower surface of the discharge chute. The spaced scraper blades 48 serve to divide the the mill to the furnace.

concentrate collected on the interior surfaces of .the collector 14 into comparatively small pockets orsegments which are pushed along the surface 18 of the discharge chute and delivered in a uniform and continuous stream through the open end 22 of the discharge chute and into the rotating pulverizer bowl 26. Each individual scraper blade presents such a small surface to the concentrate and in operation is vibrated sufliciently so that there is little or no tendency for the concentrate to build up on the individual blades. If desired, some combustion air can be introduced near the lower end of the surface 18 adjacent the point where the scraper blade leaves the surface for the beginning of its return trip along the surface 20 to prevent any collection of concentrate in this area. After delivery into the pulverizing mill 26 the coal will be pulverized by the usual pulverizing roll and transported in the usual manner by a stream of air passing through The concentrate in being discharged from the centrifuge forms an outwardly radiating disc of discharging concentrate which is intercepted by the collector and confined within the collector chamber and is transported to the open discharge end of the collector chamber by the axially extending scraper blades 48 mounted on the endless conveyor 38 and 40 rotating around the axis of the discharge disc and the bowl 10. Thus an irregular accumulation of concentrate in the collector 14 is prevented and the concentrate is delivered in a continuous and uniform stream to the point of discharge which in the illustrated embodiment is a pulverizer mill.

While I have illustrated and described a preferred embodiment of my invention, it is to be understood that such is merely illustrative and not restricted and that variations and modifications may be made therein without departing from the spirit and scope of the invention. I therefore do not wish to be limited to the precise details set forth but desire to avail myself'of such changes as fall within the purview of my invention as defined in the following claims.

I claim:

1. In combination with a rotating centrifuge member having discharge outlets and rotating about a horizontal axis and separating liquid from a pumpable coal slurry and substantially continuously centrifugally discharging partially dewatered coal as a pasty mass radially outward from said discharge outlets in said rotating centrifuge member, a stationary collector in the form of a semicircle,

concentric with said axis, wit-h extending portions, at

least one of which is tangential, forming a downwardly extending converging chute at the ends of said semicircle,

said collector surrounding said outlets and having an axially extending collector surface in the path of said mass as discharged, side plates forming, with said surface and centrifuge a substantially closed enclosure enclosing said discharge outlets and forming .a discharge opening for said enclosure at the end of said extensions and side plates remote from said semicircle, an endless chain conveyor extending along the inner surface of said collector, a plurality of scrapers mounted on and spaced along, said chain. conveyor, means guiding said conveyor and scrapers along the inner surface of said collector with said scrapers closely adjacent substantially the entire length of the inner surface of said semicircle and extending portions, said scrapers located between said discharge outlets of said centrifuge and said collector surface and dividing the pasty mass as discharged from said centrifuge and collected on said collector surface into a plurality of segments along said collector surface and continuously pushing said segments along said chute away from said axis and through said discharge opening, sprocket means for driving said conveyor and scrapers.

2. In combination with rotating mechanism rotating about a horizontal axis and centrifugally delivering a substantially uniform, continuous stream of pasty material radially outward from and completely around the axis of rotation of said mechanism, a stationary collector having a collecting surface around said axis in the path of said stream, said surface having a substantially semicircular portion with said axis as its center and having tangential extensions extending downwardly away from said axis and forming a chute terminating in an open discharge end, said portion and extensions having an axially extending surface, a travelling scraper extending in an axial direction across said surface, an endless chain conveyor holding said scraper, a plurality of rotary sprockets including drive sprocket means supporting and directing said scraper in a path adjacent said collecting surface including said extensions, said scraper continuously removing material collected on and adhering to said surface and conveyingsaid material away from said axis along one of said extensions to said open discharge end.

References Cited by the Examiner UNITED STATES PATENTS 775,320 11/1904 Van Kirk 2337 1,195,000 8/1916 Labrador 210-372 2,104,162 1/1938 Macklind 233-47 X 2,600,372 6/1952 Milliken et al. 2337 2,685,369 8/1954 Crossley. 2,704,704 3/1955 Ogorzaly 302-66 X MARTIN P. SCHWADRON, Acting Primary Examiner,

T. KLINKSIEK, Examiner

Claims (1)

1. IN A COMBINATION WITH A ROTATING CENTRIFUGE MEMBER HAVING DISCHARGE OUTLETS AND ROTATING ABOUT A HORIZONTAL AXIAL AND SEPARATING LIQUID FROM A PUMPABLE COAL SLURRY AND SUBSTANTIALLY CONTINUOUSLY CENTRIFUGALLY DISCHARGING PARTIALLY DEWATERED COAL AS A PASTY MASS RADIALLY OUTWARD FROM SAID DISCHARGE OUTLETS IN SAID ROTATING CENTRIGUGE MEMBER, A STATIONARY COLLECTOR IN THE FORM OF A SEMICIRCLE, CONCENTRIC WITH SAID AXIS, WITH EXTENDING PORTIONS, AT LEAST ONE OF WHICH IS TANGENTIAL, FORMING A DOWNWARDLY EXTENDING CONVERGING CHUTE AT THE ENDS OF SAID SEMICIRCLE, SAID COLLECTOR SURROUNDING SAID OUTLETS AND HAVING AN AXIALLY EXTENDING COLLECTOR SURFACE IN THE PATH OF SAID MASS AS DISCHARGED, SIDE PLATES FORMING, WITH SAID SURFACE AND CENTRIFUGE A SUBSTANTIALLY CLOSED ENCLOSURE ENCLOSING SAID DISCHARGE OUTLETS AND FORMING A DISCHARGE OPENING FOR SAID ENCLOSURE AT THE END OF SAID EXTENSIONS AND SIDE PLATES REMOTE FROM SAID SEMICIRCLE, AN ENDLESS CHAIN CONVEYOR EXTENDING ALONG THE INNER SURFACE OF SAID COLLECTOR,

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