US3260548A

US3260548A - Method and apparatus for continuously mining and transporting coal

Info

Publication number: US3260548A
Application number: US441412A
Authority: US
Inventors: Eric H Reichl
Original assignee: Consolidation Coal Co
Current assignee: Consolidation Coal Co
Priority date: 1965-03-11
Filing date: 1965-03-11
Publication date: 1966-07-12
Anticipated expiration: 1983-07-12

Description

July 12, 1966 E. H. RElcHL METHOD AND APPARATUS FOR CONTINUOUSLY MINING AND TRANSPORTING COAL 5 Sheets-Sheet 1 Filed March 11, 1965 FIG. I

INVENTOR.

C H. REICHL BY ERI J HIS ATTORNEY July 12, 1966 E. H. Rl-:lcHL 3,250,548

METHOD AND APPARATUS FOR CONTINUOUSLY MINING AND TRANSPORTING COAL 5 Sheets-Sheet 2 Filed. March 11, 1965 INVENTOR. ERIC H. REICHL HIS ATTORNEY July 12, 1966 E. H. RElcx-u. 3,260,548

METHOD AND APPARATUS FOR CONTINUOUSLY MINING AND TRANSPORTING COAL Filed. March 11, 1965 5 Sheets-Sheet 5 INVENTOR. ERIC f/. Ee Jef/1 eq BY his arroz/J5 Y United States Patent O 3 260,548 METHOD AND APPAlATUS FOR CONTINUOUSLY MINING AND TRANSPORTING CUAL Eric H. Reichl, Pittsburgh, Pa., assignor to Consolidation Coal Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Mar. 11, 1965, Ser. No. 441,412 12 Claims. (Cl. 299-18) This application is a continuation-in-part of copending application Serial No. 126,610, entitled Continuous Transportation of Newly Mined Coal, tiled July 25, 1961, and now abandoned.

This invention relates to a method and apparatus for continuously mining and transporting coal and more particularly to a method and apparatus for mining coal and continuously transporting the newly mined coal hydraulically from a continuous mining machine to a terminus located either within the mine or outside of the mine.

The conventional system for transporting coal from the working face to the main line haulage system is often inadequate to keep pace with the continuous mining machine. In the conventional system the coal mined by the continuous mining machine is deposited on the mine iioor behind the mining machine lor loaded into a shuttle car. If it is deposited on the mine oozr, a iloading machine gathers the coal and loads it into a shuttle car. The shuttle car conveys the coal a short distance to an endless conveyor belt and discharges the coal onto a moving endless conveyor belt. The coal is conveyed by the endless conveyor belt to a main line rail haulage system or a main line conveyor system where it is discharged from the conveyor belt into conventional rail cars or onto another endless conveyor belt. Thus, between the ytime the coal is mined and the time it leaves the underground mine, it may be loaded by a loading machine, shuttled a short distance in a shuttle car, transferred to a conveyor belt, and transferred from the conveyor belt to rail cars.

At times, some variations may be found in these usual procedures. On occasion the Imain line rail haulage system may extend sufficiently close to the area of mining so that the shuttle car can discharge the coal directly intro the rail car. Even with these variations the conventional haulage systems are not adequate to permit the continuous mining machine to operate at maximum efficiency. It is necessary to stop the mining machine at intervals to permit the haulage system to remove the coal that accumulates behind the mining machine. Improved type continuous mining machines have mining capabilities that far exceed the capabilities of the above discussed haulage systems and are idle a substantial amount of the time. There is, therefore, 'a need `for an improved haulage system that is capable of removing and transporting the mined coal from the face at the same trate that it is dis-lodged by the continuous mining machine.

There have been proposals in the past to provide extensible or articulated conveyor systems connected at one end to the mining machine and at the other end to a fixed haulage system such as an endless conveyor belt or a rail haulage terminus. The articulated or extensible conveyors were intended to replace the loading machine and shuttle car. Articulated yor extensible conveyors do not complete-ly solve the previously discussed multiple handling problems of mined coal and a majority portion of the coal haulage from the mining machine to the fixed haulage system is now being performed by the loading machine-shuttle car combination previously discussed.

The present invention contemplates a novel method and apparatus for continuously transporting coal from the mine face at substantially the same rate as that at which it is mined. The method and apparatus ofthe present invention eliminates the multiple handling of the coal be- 3,260,548 Patented July 12, 1966 Vice fore it leaves the mine and permits the continuous mining machine to operate at maximum eiciency. The invention provides a novel mining machine with a receiver positioned thereon for the coal removed from the mine face. The receiver admixes the coal with `a liquid and the admixture is transported hydraulically to a distant location. The receiver has a pump associated therewith that propels the admixture through ya conduit extending rearwardly from the mining machine. There is also provided an intermediate pump means associated with the conduit that m-ay be used alone or to provide additional propulsion to the `admixture as it is conveyed through the conduit extending rearwardly from the rmining machine.

Another embodiment of the present invention includes a mobile slurry preparation terminal that is adapted to be connected to the mining machine and move with the mining machine -as it advances into the coal face. The coal is conveyed directly from the mine face to the mobile slurry preparation terminal by the endless conveyor on the mining machine. In the mobile slurry preparation terminal the coal may be reduced in size to a predetermined .maximum top size. The coal at the preselected size is mixed with a carrier liquid and the admixture pumped by means of a pump in the mobile slurry preparation terminal to an underground relay station through flexible conduits which connect the relay station with the mobile slurry preparation terminal. At the central underground relay st-ation the slurry transported through the flexible conduits from the mobile slurry preparation terminal may be reprocessed and conveyed from the relay station either hydraulically or by more conventional methods, such as rail haulage or the like.

The transportation system of the present invention is preferably completely hydraulic in that the coal can be processed at `the central relay station in a quality controlled slurry plant to prepare a relatively fixed consistency slurry. This slurry can then be transported more economically through xed conduits from the central underground relay station to a coal preparation plant yor other facility at the surface where the coal will be utilized. The relatively short distance that the coal is transported from the mining machine to the central underground relay station through ilexible conduits provides economic short distance haulage. The preparation Iof the coal for hydraulic transportation at the Imine face is maintained at a minimum. The principal requisite in the preparation of the coal `at the mine face is to lim-it the size of the coal particles to a preselected top size. With the boring type mining machine as illustrated in FIGURES 3 and 4, substantially all the coal dislodged from the mine face has a particle size which -is suitable for hydraulic transportation 4over the relatively short distance to the central underground relay station. Where other types of mining machines are employed, suitable comminuting facilities may be provided to obtain coal particles of a size that can be transported in the flexible conduits.

Because of the desirability of performing a minimum amount of preparation at the coal face before the coal is pumped through the flexible conduits, no substantial effort is made to prepare `a coal slurry that has optimum pressure drop characteristics for hydraulic transportation through the ilexible conduits to the underground relay station. The underground relay station is, therefore, located at a minimum distance from the working face and a slurry is prepared adjacent the mining machine that is hydraulically transportable from the mining machine to the central underground relay station. At the central underground relay station more preparation can be perfor-med on the mined coal to prepare a slurry more suitable for pumping economically at a reduced pressure drop through conduits that extend for longer distances than the flexible conduits 2E between the mining machine and the central underground relay station.

At least a portion of the conduits that extend between the mining machine 4and the central underground relay station are extensible, for example, the conduits may be formed of a ilexible material such as rubber or the like. The conduits may be extended by addition of sections during those periods ywhen the mining machine is not in operation, as, for example, when the mining machine is retracting from a room and being repositioned in fthe mine passa-ge rfor developing another room. The conduit may be formed so that it is longer than the distance between the central underground relay station and the mine working lface. The conduit may be positioned so that the flexible portions have sinuous curves between the mobile slurry preparation terminal and the central underground relay station. The sinuous curved portions in effect provide for storage of additional lengths of conduit. As the mining machine progresses into the working face and away from the central `underground relay station, the sinuous portion of the conduit will be straightened to thereby extend the over-all effective length of the flexible conduit. The flexible conduit thus forms la con-tinuous extensible connection between the mobile slurry preparation terminal and the central underground relay station. Other arrangements may be used to store the flexible conduit in a previously developed mine room or in an unused mine passageway adjacent to the path of the flexible conduit.

In the spresent invention the coal is mixed with a carrier liquid adjacent the mining machine. This carrier liquid 'may be water or it may be a mixture of tine coal and water which has -an apparent specific gravity higher than the specic gravity of water and therefore more readily suspends the larger coal particles as lthey are transported through the conduit. The term a carrier liquid as used herein is intended to generically encompass any suitable liquid capable of transporting larger particles of coal as the admixture orf the coal particles and carrier liquid is pumped through the flexible conduits. Either water or a mixture of very line coal particles or other heavy, inely divided solids and water are suitable carrier liquids.

With `the fore-going considerations in mind, it is a primary object of the present invention to provide an improved transportation system for conveying newly mined coal away from a continuous mining machine.

Another object of this invention is to provide a transportation system in which coal particles are transported in a carrier liquid away from a continuous mining machine.

Another object of this invention is to provi-de a transportation system in which relatively coarse coal particles are conveyed away from a continuous mining machine :for -a short distance and then reprooessed for further transportation.

Another object of this invention is to provide a transportation system which permits the continuous mining machine to -be operated at maximum eiciency without delays caused by problems of removing mined coal lfrom the vicinity of the mining machine.

Another object of this invention is to provide a continuous mining machine that has associated therewith a receiver for the newly mined coal where the coal particles are admixed with a carrier liquid and transported hydraulicailly away from the mining machine.

Another object of this invention is to provi-de auxiliary pump means positioned in the conduit for transporting the coal hydraulically through the conduits.

These and other objects and advantages of this inven- #tion will become apparent as this description proceeds in conjunction with the accompanying drawings.

In the drawings:

FIGURE 1 is a diagrammatic plan view of the transportation system of the present invention in a coal mine.

FIGURE 2 is a diagrammatic view of apparatus that will be employed in the transportation system illustrated in FIGURE 1.

FIGURE 3 is a top plan View of a continuous mining machine having apparatus for ladmixing the coal particles with a carrier liquid for hydraulic transportation through a conduit connected thereto.

FIGURE 4 is a view in elevation of the mining machine illustrated in FIGURE 1.

FIGURE 5 is a detailed vertical sectional view of the receiver -and pump positioned on the mining machine.

Referring to FIGURE 1 there is represented in plan view a section of a coal mine having interconnected mine passages 10. A series of rooms 12 are developed laterally from the mine passages 10 as the coal is removed from the seam. A ripper type mining machine 14 is shown within a partially developed room 12 in position to remove coal from the working face. As used herein the term working face is intended to designate that portion of the mine where the continuous mining machine is dislodging coal from the seam.

Adjacent the mobile mining machine 14 within the room 12 is a mobile slurry preparation terminal 16 which is adapted to move with Ithe mining machine 14 and closely follow it. Several passages removed from the room 12 in which the mining machine 14 and slurry preparation terminal 16 are located, a central underground relay station 18 is located to receive the coal mined by mining machine 14 and processed in preparation terminal 16. The central underground relay station 18 contains equipment to reprocess coal delivered to the station 18 from the preparation terminal 16 through -a conduit 20. Conduit 20 may be formed from a rigid conduit section 20a and a flexible conduit section 20b which are connected together to form the continuous conduit 2t). The rigid conduit -section 20a is preferably longer than the flexible conduit section 20b. The distance between the central relay station and the working face where the coal is being dislodged is preferably less than 500 feet.

The coal mined by the ripper type mining machine 14 is crushed within the preparation terminal 16 and added to a carrier liquid to be conducted through conduit 20. At the central underground relay station 1S, the coal is removed from the carrier liquid and reprocessed. The carrier liquid is returned through conduit 22 to the molbile slurry preparation terminal 16. Conduit 22 is similar to conduit 2i) and is formed with =a rigid section 22a and a flexible section 22b. As indicated in FIGURE 1, couplings 24 are provided at the mobile slurry preparation terminal 16 to connect the conduit sections 20h Iand 22b to `the preparation terminal 16. Couplings 24 are also provided to connect the flexible conduit sections 2lb land 20h to the respective rigid conduit sections 22a and 20a. A third set of couplings 24 are provided at the central underground relay station 18 to connect the conduit sections 22a and 20a to the relay station 18. With the couplings so provided, additional sections of llexible conduit may be added between the rigid sections 20a and 22a and `their respective

flexible sections

20b and 22b to lengthen the ilexible portion of the condui-ts.

As shown in FIGURE 1, the llexible sections 20h and 22b of

conduits

20 and 22 are positioned with sinuous curves therein so that the mining machine 14 and terminal 16 may move further away from relay station 18 and still have a continuous connection between the mobile terminal 16 and relay station 18. As the mobile terminal 16 moves with the mining machine, the sinuous curves in the flexible conduits 20b and 22h lare straightened. As shown in FIGURE 1, the sinuous curves are located `within -a passage 10 of the coal mine. It is within the scope of the present invention to extend the flexible sections Ztlb and 2212 sinuously into a room 12 which has already been mined so 'that the excess conduit will 'be clear of a passage.

As shown in FIGURE l, the central underground relay station has a conduit 26 extending therefrom through which the reprocessed coal may be conveyed in a carrier liquid. The reprocessed coal may be separated from the carrier liquid at a terminal 27 located outside of the mine and returned through a return conduit 28 to the central rel-ay station. While pipeline transportation of the reprocessed coal from central relay station 18 is shown in FIGURE l, it is within the scope of the present invention to utilize any type of transportation means to move the reprocessed coal from relay station 18 to a point outside the mine itself.

In FIGURE 2 the elements of FIGURE 1 are shown in more detail. The mining machine 14 has an endless chain type cutter element 30 which removes coal from the coal seam. The coal removed by cutter element 30 is deposited on a longitudinally extending conveyor 32 that extends the length of a mining machine 14. The mining machine 14 is mounted on endless 'tracks 34 so that it can continuously advance tas the coal i5 removed from the mine face.

As shown in FIGURE 2, the mobile slurry preparation terminal 16 also has endless tracks 36 which support the terminal chassis 38. A crusher unit 40 is mounted on chassis 38 and is disposed lat the forward end of the chassis 38 so that it may be positioned under, and receive coal from, the conveyor 32 of the mining machine 14, The Crusher 40 may be any suitable type which receives solid material and reduces it in size by the rotation of one or more elements within the crusher. In selecting a Crusher for use on the mobile slurry preparation terminal, some consideration must be given to the overall height of the unit since the height of the coal seam will control the maximum height of the crusher element. The Crusher should be such that it fits conveniently beneath the conveyor 32 of the mining machine and yet has suicient capacity to receive :and process the quantity of coal being mined by the mining machine.

Also mounted on the terminal chassis 38 is a chain conveyor 42 which receives crushed coal from the crusher 48 'and conveys it upwardly into a receiver or reservoir 44 mounted on the chassis 38. The receiver 44 is of relatively large capacity and has `an inlet port 46 connected to conduit 22. The inlet port 46 admits carrier liquid from conduit 22 into the receiver 44 where the carrier liquid is mixed with crushed coal from Crusher 40 to prepare a coal slurry for transportation to the central relay station 18. The receiver 44 has :a slurry outlet port 48 which is connected to a pump 50 by a pump inlet conduit 52. The slurry from receiver 44 is drawn through conduit 52 yby pump 50 and then is pumped through conduit 20 to the relay station 18.

Pump Si) may be of any suitable construction for pumping a relatively coarse slurry. As shown in FIGURE 2, the pump outlet conduit 54 is connected to conduit 20 by a coupling 24 so that the slurry passing through pump 50 will be forced under pressure through conduit 20. The pump 50 is driven by a pump motor 56 also mounted on chassis 38. A slurry preparation terminal motor 58 is shown mounted on chassis 38 to drive the Crusher 40 and the chain conveyor 42 together with the tracks 36 of the slurry preparation terminal which is self propelled. While a single motor 58 is shown to drive all of these elements, it will be appreciated that individual motors may be provided for each of the elements.

The

conduits

20 and 22 are indicated schematically in FIGURE 2. A section 20h of conduit 20 is shown in a sinuous loop merely to indicate that the section 2Gb is flexible and may be sinuously positioned so that the mobile preparation terminal 16 can advance and the conduit 20 can move with it without the necessity of breaking the conduit 20. The

conduits

20 and 22 extend to the central underground relay station 18.

Within central underground relay station 18 there is a drag tank 60 of conventional construction. Drag tank 60 receives the mixture of coal and carrier liquid from receiver 44 that is pumped through conduit 20. A mixture of coal and carrier liquid is allowed to settle within drag tank 60 and the coal is removed by means of a chain conveyor 62 extending along the bottom of drag tank 60 and upwardly out of the tank as shown in FIGURE 2. The carrier liquid remains above the coal within drag tank 60 and is removed through removal conduit 64 which leads to a return pump 66. Pump 66 forces the carrier liquid from conduit 64 into conduit 22 through valve 68 and returns the carrier liquid to receiver 44 so that it may there be mixed with additional coal for conveyance to central relay station 18. The control valve 68 is provided in conduit 22 so that conduit 22 may be closed and the carrier liquid may be removed through conduit 64 and pump 66 and pumped out of the mine as will be explained.

Also within the central relay station 18 is mounted a Crusher unit 70 which is adapted to receive coal from the drag tank chain conveyor 62 and further crush it to reduce its top size. The coal from drag tank 60, which has already been crushed in crusher 40, is recrushed in crusher 70 so that it may be utilized to form a more stable coal water `slurry that may be pumped over longer distances at a minimum cost. The coal from crusher 70, hereinafter referred to as the recrushed coal, is conducted into a reservoir 72 where it is mixed with a second carrier liquid. Carrier liquid is pumped into reservoir 72 from a point outside the mine (not shown) through conduit 28 shown in both FIGURES 1 and 2.

A slurry formed by the mixture of the second carrier liquid and the recrushed coal within the reservoir 72 leaves the reservoir 72 through an outlet conduit 74 connected to a coal slurry pump 76. Coal slurry pump 76 connects to the conduit 26 which extends to a point outside the mine. The pump 76, =as well as the pump 66, may be of any suitable construction for pumping coal slurry, in the case of pump 76, or carrier liquid in the case of pump 66.

An inter-connecting conduit 78 is provided between conduit 22 and conduit 26. The control valve 80 within interconnecting conduit 78 ordinarily maintains this conduit closed so that no flow may occur therethrough. On occasion, however, it is necessary to renew the supply of carrier liquid that flows from drag tank 60 to reservoir 44 and carries the crushed coal from reservoir 44 to drag tank 60. After extended periods of use, the carrier liquid will accumulate tine coal particles that do not settle within drag tank 60. Upon extended accumulation of these particles, carrier liquid will become more ditiicult to pump and require excess pumping energy. In these instances, the control valve 68 within conduit 22 is yclosed and the control valve 80 within inter-connecting conduit 78 is opened iso that the carrier liquid may be pumped from drag tank 60 through conduit 64, pump 66, inter-connecting conduit 78, and out of the mine through conduit 26. A new quantity of carrier liquid may then be pumped into drag tank 60, and control valve 80 will be closed and control valve 68 will be opened for resumption of the normal ow pattern.

As discussed previously, the carrier liquid which carries coal from terminal 1.6 to the central relay station 18, and the carrier liquid which carries coal from central relay station 18 to the point outside the mine may be either water =or a mixture of very fine coal particles with water. If the mixture of very line coal particles is utilized with water, the apparent specic ygravity of the carrier liquid is higher than water and the coal particles are suspended in the carrier liquid. When very tine coal particles `are utilized in the water as a carrier liquid, it will still become necessary, on occasion, to purge the drag tank 60 since additional tine coal particles will enter the reservoir 44 with the newly mined coal .and cause excessive amounts of ne coal to be entrained `in the carrier liquid. When the carrier -liquid is purged through interconn-ecting conduit 78, the ne coal particles in the carrier liquid are conveyed to the point outside the mine where they may be mixed with the coal pumped out of the mine.

As an example of the capacity of the present system, it is designed to receive an average of 300 tons per hour of coal from the mining machine 14. For extended periods the system may receive at an instantaneous rate of 500 tons per hour from mining machine 14. The coal removed from the seam Iby mining machine 14 is conducted into crusher 40 and is reduced in size so that it has a maximum top size of about six inches. The coal from crusher 14 is mixed within receiver 44 with the carrier liquid and is pumped through conduit 20 which has a diameter of approximately 14 inches. The concentr-ation `of the coal within the carrier liquid will vary as the instantaneous output of miner 14 varies since, as the coal is pumped into the receiver 44, it is continuously withdrawn therefrom by pump 50. The receiver 44 contains sufficient liquid so that twenty seconds of pumping can be accomplished without return flow into the reservoir through conduit 22. The coal from crusher 40 as it enters receiver 44, is mixed with the carrier liquid and is conveyed as a slurry through the conduit 20.

The

conduits

20 and 22 are maintained as short as practicable since the energy requirements to transport the coal therethrough are relatively high. The energy requirements are high because of the relatively large size coal particles. The energy requirements may be expressed as the pumping energy required to move the large size coal particles as a slurry through the conduit 20. This high pumping energy can be tolerated over relatively short distances since the ease of handling of the mined coal more than compensates for the high pumping energy.

Once the coal is received within the relay station 18, it may be reprocessed by further crushing within crusher 70. Maximum top size of the coal may be reduced to approximately 8 mesh so that a relatively stable slurry of coal and water may be mixed in reservoir 72. This more stable slurry can be pumped at substantially lower pumping costs than the slurry transported in conduit 20.

In FIGURES 3, 4 and 5 there is illustrated another embodiment of the invention wherein a receiver or feeder generally designated by the numeral 100 forms a part of the continuous mining machine 102 and processes the coal mined by the mining machine and feeds the coal to a pump 104 connected to the bottom of the feeder 100. The mining machine 102 is a boring type mining machine similar to the Marietta Continuous Miner manufactured and sold by National Mine Service Company. The mining machine 102 has a pair of

cutter arms

106 and 108 that have cutter bits extending forwardly therefrom. The arms 106 and 10S are rotatably mounted on the machine frame 110 and are driven by

motors

112 and 114. The

motors

112 and 114 rotate the arms so that the cutter bits extending forwardly therefrom form circular kerfs in the mine face and dislodge coal therefrom. The arrangement of the cutter bits and breakers positioned therebetween dislodges the coal so that substantially all of the coal particles are smaller than and a substantial amount of the coal particles have a size less than Vs. The coal as it is dislodged from the face is directed, due to the direction of rotation of the

cutter arms

106 and 108, toward the center of the mining machine. The machine frame 110 has an opening adjacent the front end with a relatively broad throat 116 that receives the coal dislodged by the

cutter arms

106 and 108. An endless conveyor 118 extends into the throat 116 and is arranged to convey the coal from the throat 116 to the rear portion of the mining machine frame 110. The frame 110 is mounted on endless tracks 120 that permit the mining machine 102 to continuously advance into the mine face as the coal is dislodged therefrom. The machine frame 110 has a rearwardly extending portion 122 that supports the feeder 100 and pump 104. The endless conveyor 118 discharges the mined coal into the receiver 100. A grid 124 is positioned over the inlet opening to the receiver and controls the maximum top size of the coal that passes into the receiver 100.

The receiver 100 has a conically shaped body 126 with a top opening 128 and a bottom opening 130. The receiver body 126 has a radially extending ange 132 adjacent the bottom opening 130 that secures the receiver 126 to the pump housing 134. The body 126 has a plurality of apertures 136 therein adjacent the top opening 128. The'apertures 136 extend around the peripheral portion of the body 126 in substantially the same horizontal plane. A conduit 138 extends around the external portion of the feeder body 126 and has a plurality of feeder conduits 140 extending through the apertures 136 in the feeder body 126. The conduits 140 are arranged tangentially to the circular configuration of the feeder body 126 to thereby impart a swirling motion to a liquid passing through conduits 140 into the inner portion of the feeder 100. The conduit 138 is connected to a liquid carrier conduit 142 that is similar to conduit 22b illustrated in FIGURE l. The carrier liquid entering the feeder 100 through the apertures 136 has a swirling action imparted thereto within the receiver conical body 126 and is admixed with the coal particles discharged into the receiver 100 from conveyor 118. The admixture ows through the bottom outlet 130 into the axial center or eye of pump 104 positioned therebelow. The receiver body portion 126 has an inturned lip 144 adjacent the top opening 128 to minimize spillage of the carrier liquid supplied by conduit 142.

The pump 104 has a housing 134 with an inlet 146 arranged coaxially with the outlet of receiver 100 and discharge outlet 148 extending horizontally therefrom. Positioned within the pump housing 134 is an impeller 150 that is connected to shaft 152 for rotation therewith. Suitable seal means are provided in the pump housing 134 to prevent leakage of the carrier liquid between the shaft 152 and housing 134. Within the pump housing 134 there is a 4chamber 154 in which the impeller 150 is positioned. The chamber 154 has a peripheral volute that gathers the material discharged by the impeller 150 and directs the material to the outlet opening 148. The impeller 150 has a plurality of vertically extending vanes spaced from each other to provide a plurality of liquid impelling passageways therebetween. The passageways are of sufficient size to permit the various sized coal particles entering the receiver 100 to pass through the pump 104 and be transported under pressure through outlet 148. A conduit 156 is connected to the flange of pump outlet 148 and is arranged to transport hydraulically the admixture of carrier liquid and coal particles from the mining machine 102 rearwardly toward an underground relay station. The conduit 156 is similar in many respects to conduit 20b previously described. A motor 158 is connected by means of suitable shafting to pump drive shaft 152 to rotate the same at a velocity sufficient to transport `the admixture of coal particles and liquid carrier away from the mining machine 102 to the relay station.

The mining mach-ine has a rated capacity of between 6 and l0 ton per minute so that the feed `rate to the feeder 100 will vary -between 0 and 10 ton per minute. The amount of liquid carrier supplied through conduit 142 to feeder 100 should be adequate to provide an admixture of coal particles and liquid carrier having a maximum solids concentration of about 50%. The discharge pressure of the pump 104 should be adequate to convey the coalliquid carrier mixture at a sufficient velocity to maintain a substantial portion of the coal particles suspended in the liquid carrier. It is believed where the pump has a discharge rate of about 5,000 gallon per minute and a discharge pressure .of less than 40 pounds per square inch the system will have sufficient flexibility to handle between 0 and l0 ton per minute of newly mined c-oal, and a coal-liquid carrier slurry having a maximum solids con- 9 centration of `about 50% by weight may be transported from the continuous mining machine 102 to the central relay station located at about 500 feet from the mining machine 102.

In the described embodiments of the present invention a Itwo stage slurry pumping system is shown to the extent that the coal is removed from the mine and pumped to a central underground relay station in a relatively coarse slurry over a relatively short distance. The coal is then reprocessed at the central underground relay station and pumped as a finer slurry to a desired desitnation outside the mine. It will be appreciated that the present invention may 'be practiced without the second stage of transporation. Once the coal is delivered to the underground Irelay station 18, the reprocessing there may consist of dewatering the coal so that it may be carried by more coventional transportation such as rail haulage or conveyor beltsto the desired point outside the mine. The present invention is primarily concerned with the rapid, eicient removal of the coal from a mining machine so that the capacity of the mining machine is not limited by the haulage system that transports the coal awlay from the mining machine.

In the presen-t invention the slurry pump systems are shown as two separate and distinct systems each having its own carrier liquid. Thus, the sho-rt loop between the mining machine and the central underground relay stati-on is a closed circuit with its own carrier liquid and the longer line coal slurry pumping system -from the relay station to a location outside the mine is provided with its own closed circuit for carrier liquid. In some instances it may be desirable :to utilize the same carrier liquid by pumping it from a location outside the mine directly to the receiver adjacent the mine face and thereafter pumping the slurry from the receiver adjacent the mine face to the central underground relay station where it is reprocessed -as a slurry and pumped to a location outside the mine. It is within the scope of the present invention to provide such a transportation system.

According to the provisions of the patentv statutes, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated and described what I now consider to `represent its best embodiments. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specically illustrated and described.

What is claimed is:

1. A method of continuously transportig mined coal from a continuously advancing mobile mining machine comprising the steps of,

continuously dislodging coal from a working face in an underground mine, admixing said mined coal with a carrier liquid to form a mixture adjacent to said working face,

pumping said mixture away from said working face through a conduit to a central underground relay station located within said mine,

separating a substantial portion of said coal from said carrier liquid, and

returning said carrier liquid to a location adjacent to said working face thereby making said carrier liquid available to transport additional coal from said working face.

2. A method of continuously transporting mined coal from a continuously advancing mobile mining machine comprising the steps of,

continuously dislodging coal ffrom a working face in an underground mine, Iadmixing said mined coal with a carrier liquid to form a mixture adjacent to said working face,

.pumping said mixture away from said working face through a conduit to a central underground relay station located within said mine,

comminuting said coal in said mixture at said central underground relay station to reduce its size, and

transporting a mixture of said comminuted coal and a carrier liquid from said central underground relay station to a terminal outside of said mine at a reduced pressure drop.

3. A method of continuously transporting mined coal from a continuously advancing mobile mining machine comprising the steps of, i

pumping said mixture away :from said working face through a conduit to a central underground relay station located within said mine,

separating a substantial portion of said coal from said carrier liquid,

comminuting said coal at said central relay station to reduce its size,

returning at least a portion of said carrier liquid to a location adjacent to said working -ace thereby making said carrier liquid available to transport additional coal from said working face,

admixing said comminuted coal at said relay station with a second carrier liquid to form a second mixture, and

pumping said second mixture through a conduit from said second relay station to a terminal outside of said mine.

4. A method of continuously transporting mined coal from a continuously advancing mobile mining machine comprising the steps of,

transferring the mined coal from said mobile mining machine to =a mobile preparation terminal,

comminuting at least a portion of said mined coal in a crusher positioned on said mobile preparation terminal,

transferring said comminuted coal to a receiver positioned on said mobile preparation terminal, feeding a carrier liquid to said receiver,

mixing said comminuted coal and carrier liquid in said receiver to form a mixture,

feeding said mixture to a pump positioned on said mobile preparation terminal,

pumping said mixture away from said mobile preparation terminal,

through said conduit to a central underground relay station, separating a substantial portion of said comminuted coal `from said carrier liquid at said relay station, and

returning said carrier liquid to said mobile preparation terminal thereby making said carrier liquid available to transport additional coal -f-rom said mobile preparation terminal.

5. A method of continuously transporting coal f-rom a mobile mining machine within a mine to a terminal outside of said mine which comp-rises,

transferring the mined coal from said mobile mining machine to a mobile preparation terminal,

`transferring said comminuted coal to a receiver positioned on said mobile prepa-ration terminal, feeding a carrier liquid to said receiver,

vfeeding said mixture to a pump positioned on said mobile preparation terminal,

pumping said mixture lthrough la conduit to a central relay station located underground within said mine, returning said carrier liquid to said mobile preparation terminal thereby makin-g said carrier liquid available to transport additional coal from said mobile preparation terminal,

recomminuting said comminuted coal -at said relay station to further reduce its size,

mixing said recomminuted coal with a second carrier liquid at said relay station, and

pumping said mixture through a conduit from said relay station to a terminal outside said mine.

6. Tine method of continuously transporting coal from a mobile mining machine within a mine to a terminal outside of said mine as set forth in claim which includes, separating s-aid recomminuted coal from said second carrier liquid at said terminal outside said mine, and returning said second carrier liquid to said relay station within said mine thereby making said second carrier liquid available to transport additional coal from said relay station within said mine to said terminal outside of said mine.

7. Apparatus for continuously conveying mined coal from a continuous mining machine within a mine to an area outside of said mine comprising,

a continuous mining machine operable to continuously `dislodge coal from the Working face and convey said dislodged coal toward the rear portion of said mining machine,

a receiver connected to said mining machine and movable therewith as said mining machine advances into the working face, said receiver positioned to receive said dislodged coal conveyed rearwardly on said mining machine,

first conduit means connected to said receiver and extending therefrom to a central underground relay station located within said mine, said first conduit means arranged to supply carrier liquid from said central underground relay station located Within said mine to said receiver connected to said mining machine, and

pump means connected to said receiver, said pump means operable to pump a mixture of said dislodged coal and said carrier liquid through a second conduit from said receiver to said central underground relay station.

8. Apparatus for continuously conveying mined coal from a continuous mining machine within a mine to an area outside of said mine as set forth in claim 7 in which said central underground relay station includes,

means to separate said dislodged coal from said carrier liquid, and

pump means to convey said carrier liquid from said underground relay station to said receiver located adjacent said working face.

9. Apparatus for continuously conveying mined coal from a continuous mining machine within a mine to an area outside of said mine as set forth in claim 7 in which said central underground relay station includes,

Crusher means to comminute said dislodged coal to reduce the size consist of said dislodged coal,

a mixing vessel to admix said comminuted coal from said crusher means and a carrier liquid, and

other pump means fo-r pumping said mixture of said comminuted coal and carrier liquid through another conduit from said central underground relay station located within said mine to a location outside of said mine.

10. Apparatus for continuously conveying mined coal from a mobile mining machine Within a mine to an area outside said mine comprising,

a mobile slurry preparation terminal adapted tov prepare said mined coal for hydraulic transportation, said slurry preparation terminal including a mobile chassis, a first Crusher mounted on said chassis and adapted to receive said mined coal from said mining machine to reduce the size of said mined coal,

a receiver mounted on said chassis to receive incoming first liquid carrier for said mobile terminal,

a conveyor means mounted on said chassis to convey crushed coal from said first Crusher to said receiver,

first pump means associated with said receiver to pump a mixture of said first liquid carrier and said crushed coal out of said receiver and through first conduit means extending from said slurry preparation terminal,

said first conduit means extending between said mobile preparation terminal and a central underground relay station and being flexible so that said mobile preparation terminal can move with said mining machine as said mining machine operates to mine coal,

said central underground relay station including separating means to receive said crushed coal and said first liquid carrier from said first conduit means,

said separating means operable to remove said crushed coal from said first liquid carrier and deposit said crushed coal in a second crusher means,

said second crusher means operable to recrush said crushed coal to further reduce its size,

a mixing vessel for mixing said recrushed coal from said second crusher means and a second liquid carrier, and

second pump means for pumping a mixture of said recrushed coal and said 'second liquid carrier from said mixing vessel through second conduit means, said second conduit means connecting said central underground relay station to said area outside said mine.

11. A continuous mining machine for continuously mining coal and transporting the mined coal away from the working face comprising,

a frame member with movable cutting elements extending forwardly therefrom,

a conveyor positioned on said frame and extending longitudinally from the front of said frame adjacent said cutting elements toward the rear of said frame,

said movable cutting elements operable .to dislodge coal from the working face and direct said coal toward said conveyor,

said conveyor operable to convey said dislodged coal rearwardly on said frame,

a receiver secured to the rear portion of said frame,

said receiver having a top opening positioned below said conveyor rear end portion and arranged to receive said dislodged coal conveyed rearwardly by said conveyor,

said receiver having a plurality of side openings,

a conduit extending around the external portion of said receiver and yconnected to said openings, said conduit operable to supply a carrier liquid to said receiver for admixture therein said dislodged coal,

pump means having an inlet opening and an outlet opening,

said receiver having a bottom opening connected to said pump means inlet opening so that the admixture of dislodged coal and carrier liquid formed in said receiver is fed into said pump means inlet opening, and

a second conduit connected to said pump outlet opening to convey said admixture from said pump means to a location spaced from said mining machine.

12. A continuous mining machine for continuously mining coal and transporting the mined coal away from the working face comprising,

a frame member with movable cutting elements extending forwardly therefrom,

said movable cutting elements operable to dislodge coal from the working face and direct said coal toward said conveyor,

said conveyor operable to convey said dislodged coal rearwardly on said frame, a receiver having a con- 13 ically shaped chamber with a top opening and a bottom opening,

said chamber having an inturned lip adjacent said top opening,

said receiver positioned below said conveyor rear end portion and arranged to receive said dislodged coal conveyed rearwardly by said conveyor,

said receiver having a plurality of openings into said chamber adjacent said top opening, said opening extending around said chamber in substantially the same horizontal plane,

a main conduit extending around the external portion of said receiver body portion and arranged to supply carrier liquid to said receiver for admixture in said chamber with said dislodged coal,

a plurality of branch conduits extending from said main conduits through said openings in said body portion,

said branch conduits arranged tangentially to said conical chamber to provide a swirling motion to said carrier liquid within said chamber,

a pump member having an axial inlet opening and a tangential outlet opening,

said pump member axial inlet opening connected to said receiver bottom opening so that an admixture of dislodged coal and carrier liquid flows by gravity from said receiver chamber into said pump inlet,

said pump having an impeller with vertical vanes operable upon rotation to discharge an admixture of said dislodged coal and carrier liquid through said pump outlet, and

a second conduit connected to said pump outlet opening to convey said admixture from said pump member to a location spaced from said mining machine.

References Cited by the Examiner UNITED STATES PATENTS 2,528,748 11/ 1950 Greene 299-56 FOREIGN PATENTS 167,176 2/ 1954 Australia. 599,284 3/ 1948 Great Britain. 961,295 6/ 1964 Great Britain.

ERNEST R. PURSER, Primary Examiner.

CHARLES E. OCONNELL, Examiner.

Claims

2. A METHOD OF CONTINUOUSLY TRANSPORTING MINED COAL FROM A CONTINUOUSLY ADVANCING MOBILE MINING MACHINE COMPRISING THE STEPS OF, CONTINUOUSLY DISLODGING COAL FROM A WORKING FACE IN AN UNDERGROUND MINE, ADMIXING SAID MINED COAL WITH A CARRIER LIQUID TO FORM A MIXTURE ADJACENT TO SAID WORKING FACE, PUMPING SAID MIXTURE AWAY FROM SAID WORKING FACE THROUGH A CONDUIT TO A CENTRAL UNDERGROUND RELAY STATION LOCATED WITHIN SAID MINE, COMMINUTING SAID COAL IN MIXTURE AT SAID CENTRAL UNDERGROUND RELAY STATION TO REDUCE ITS SIZE, AND