Title of Invention

AN EQUIPMENT FOR LOADING BLASTED COAL/MINERAL FROM A CONVENTIONAL LONG WALL MINE PANEL

Abstract In the present invention there is provided an equipment for loading blasted coal / mineral from a conventional long wall mine panel, which is a combination of a mobile mechanical loading machine and a mobile steel shutter. The equipment consists of a large diameter screw feeder fitted to a bucket of about a ton capacity. In the bucket a water spray arrangement is incorporated for dust suppression. The prime mover is a flame-proof motor connected through a variable speed gear arrangement to the screw feeder for loading under various conditions. A remote control panel ensures that the operator works the machine remotely under safe and supported conditions. The combination of a mobile mechanical loading machine and a mobile steel shutter helps eliminate loading activity from the support side of the armoured face conveyor (AFC) and hence, the equipment will load the coal from the face side of the armoured face conveyor (AFC) only, thus resulting in increased productivity.
Full Text The present invention relates to an equipment for loading blasted coal / mineral from a conventional long wall mine panel. The present invention particularly relates to an equipment which is a combination of a mobile mechanical loading machine and a mobile steel shutter for loading of loose or blasted coal / mineral from a conventional longwall mine panel.
The equipment of the present invention provides a novel combination of a mobile mechanical loading machine and a mobile steel shutter, which will be able to load coal from the blasted face and will enable its operator to operate it from under a supported roof. This novel machine has a dust suppression system in its loading bucket and thereby will ensure a less dusty atmosphere in the panel than the conventional loading which is done by the miners using hand shovels. This novel combination of a mobile mechanical loading machine and a mobile steel shutter of the present invention will automatically ensure about 40% loading of the total blasted coal/mineral during blasting process itself and thereby eliminating the job of cleaning of coal from the support side. This will result in savings due to the requirement of less manpower, less electricity cost, less maintenance cost and also guarantee faster loading which will improve productivity and hence, the mine economics in terms of decrease in cost per tonne of coal / mineral production.
In general, extraction of coal in conventional longwall panel is done by drilling of face, blasting and loading of the blasted coal onto the armoured face conveyor (AFC). In figure 1 of the drawings accompanying this specification a block diagram of the conventional longwall panel face constituting various face equipment is depicted. The coal face (5) about 100 to 120 m in length is shown with drill holes (19) for inserting explosive cartridges to blast the face. Each round of blasting consists of about 18 to 20 number of holes in a face length of about 6 m. The full face will be blasted in about 19 to 20 shots (rounds) to cover the full 100 to 120 m face length. The blasted coal is then wetted by water spraying and after that miners with hand shovels load the coal from both sides of the armored face conveyor (4) (AFC). The loaded coal is then transported by longitudinal
movement of the conveyor flights (3). After loading is done the AFC (4) is shifted by pushing with hydraulic ram as near as possible to the face (5). After the AFC shifting is completed the supporting is done by hydraulic props (2) and the link-bar supports (1). When the span {distance between (5) and (6)} becomes more than 6.5 m or as permitted, the backside is stowed (back-filled) with sand or other filling material (6) hydraulically to provide a permanent goaf support and to prevent subsidence. Sand packing is done by providing permeable (bamboo mats or hessian / jute cloth) barricade just behind the first row of hydraulic props along the length of the face. The supports (1 & 2) are withdrawn and taken out for reuse.
The loading of the blasted loose coal is done manually by miners using hand shovels. In a face length of 100m about 55 miners are required per loading shift of 8 hours. It takes about two shifts to load the total blasted coal from both side of the AFC. Therefore the man-shift required is about 110 (2 X 55 men) to complete the loading activity in a conventional longwall cycle, which is very high and uneconomical. At the same time these men are required to load the coal near the unsupported face where about 67% of the underground accident takes place due to fall of unsupported roof. Moreover the workers or the miners working at the in-bye side (tail end) of the face are exposed to high coal dust concentration, which leads to diseases of the lungs.
Extensive efforts have been made for the development of suitable cutting and loading machines like shearers, road headers, dint headers. There are also developments of loading machines like Side Dump Loaders (SDL), Load Haul Dumpers (LHD), Shuttle cars, but these machines are very costly and sophisticated. Moreover these machines operate hydraulically and have to incur high maintenance cost. To highlight the continual efforts made by inventors to develop coal-loading machines, a few patent references are provided below for illustration.
Reference may be made to US patent no. 6672674, titled "Longwall Mining with Blasting" wherein the machine for underground ore extraction operations, with extraction of the product by blasting has an advancing support equipment mainly power supports and an armoured face conveyor (AFC) coupled to it as well as at least one boring device for the production of shot holes and a loading device (bucket) to supply the face conveyor with the rocks/coal loosened by blasting, whereby the boring device and the loading device are assigned to a common boring and loading machine, which can be driven along the face conveyor at right angles to the direction of mining in the direction towards the rock/coal face running parallel to the direction of mining, or away from this. The main drawbacks of this machine are that it is large in size and requires time to assemble the loading unit and drill unit separately. A further drawback of this invention is that the operator has to work under unsupported face.
Reference may be made to patent nos.: US4605119 and corresponding patent ZA8309110, entitled 'Drive arrangement for the loading arms of a loading ramp for heading machines or longwall shearing machines'. The invention relates to a drive arrangement for the loading arms of a loading ramp for a heading machine or longwall shearing machine, each loading arm is rotatably supported in off-center position on a rotary disc and extended beyond its axis of rotation by guide arm arranged so as to swivel around a bearing point on one end of a steering lever. The heading machine or longwall shearing machine has-for broadening its loading ramp-laterally outwardly swivel-able parts having arranged thereon, in a manner preventing angular movement, an arm extending beyond the pivotal axis of the extendible part. For automatic adaptation of the removal width of the loading arms to the selected working width of the loading ramp, the other end of the steering lever is hinged to the free end of the arm connected with the outwardly swivel-able part. This is a typical example of a gathering arm loader fitted with a Shearer machine or a heading machine. The main drawbacks are that the loading machine is hydraulically operated and therefore very costly and also difficult to maintain.
Reference may be made to patent no.: RU2122636, entitled 'Plow plant'. The invention relates to a plow plant and it includes face conveyor flight with guides secured to conveyor, plows installed on guides and interconnected by connecting members, and mechanism for moving the plows in the form of hydraulic cylinders located longitudinally with respect to face conveyor flight and forming a system of kinematics action and hydraulic supply of hydraulic cylinders. In this invention the plow is the cutting tool and the cut coal is loaded by the pulling action of the plow. This is a typical example of a plow machine. The main drawbacks are that here the cutting and loading machine is hydraulically operated and therefore very costly and difficult to maintain. Further drawback is that it requires a power pack to run continuously during the loading operation. Still further drawback is that it operates only in thin seams of about 2m in heights.
Reference may be made to. patent no. PL275404 also published as PL158146B (B1), entitled 'cutting head adaptable to varying cutting conditions for longwall mechanical coal miners' wherein the invention relates to a winning element of a mining machine, adaptable for variable mining conditions, which has a cylindrical shape made up of a hub with at least three coiled loading plates and a concave head shield, with mining cutters set on the edges of the loading plates and the edge of the head shield, the mining cutters on one plate being tangential cutters, and on the other plates being radial cutters, which also has cutter on the head shield, consisting in that the loading plate fitted on the edge with tangential cutters set in holders with bumpers has in cross-section a structure of a box formed by the slanting plate extending from the hub of the element to the four fourths of the loading plate, and on the concave planes of the head shield has mining cutters. This machine is essentially a Shearer, which cuts and loads the loose coal to the AFC by the helical movement of the cutter boom. This is a very sophisticated coal cutting machine but not very suitable for hard Indian coals. The drawback is that this invention requires huge investment, which is difficult for Indian coal companies. Further drawback of this invention is that the geo-mining
conditions of Indian coalfields are such that due to presence of geological irregularities like faults and dykes, these machines have failed in many places.
Reference may be made to patent no. US4620748 also published as GB2140060(A) and ES8600457(A), entitled 'Method of and arrangement for loosening, loading and transporting of stratified minerals in underground elongated front longwalls' wherein this invention relates to a method of and an arrangement for loosening, loading and transporting of stratified minerals includes a single continuously rotating and forcibly guided pulling organ, a plurality of loosening elements integrated in the pulling organ in its working run extending in a longitudinal direction of a longwall, and a plurality of transporting elements also integrated in the same single pulling organ at its transporting run located behind the working run at a back filling side, wherein the loosening elements perform loosening and loading functions, whereas the transporting elements perform the transporting functions in an opposite longitudinal direction of the longwall. This is again a Plow machine therefore the drawback is that the cutting and loading machine is hydraulically operated and therefore very costly. Further drawback of this invention is that it operates only in thin seams of about 2m heights only.
Hence, it is clear from the hitherto known prior art that no attempt has yet been made to use a simple loading machine to load coal / mineral from a conventional blasted longwall face where the face height may vary from 1.8m to 3m. The existing loading machines operate hydraulically and therefore are costly and moreover these machines are to be imported and difficult to maintain due to irregular supply of spares. Most of these machines are not suitable for Indian geo-mining conditions.
The main object of the present invention is to provide an equipment for loading blasted coal / mineral from a conventional long wall mine panel, which will obviate the drawbacks of the hitherto known prior art as detailed above.
Another object of the present invention is to provide an equipment which is a combination of a mobile mechanical loading machine and a mobile steel shutter for loading of loose or blasted coal / mineral from a conventional longwall mine panel, which will obviate the drawbacks of the hitherto known prior art as detailed above.
Yet another object of the present invention is to provide a simple and cheap mechanical loading machine to load and transfer the blasted coal from a conventional longwall face to an armoured face conveyor (AFC).
Still another object of the present invention is to provide a conventional longwall loading machine to improve the productivity of the Indian coal mines.
Still yet another object of the present invention is to provide a mechanical loading machine, which can load safely from the blasted conventional longwall face as the normal manual loading involves about 110 men to work under unsafe unsupported roof condition as because the supporting of roof can be done only after loading of coal / mineral is completed.
A further object of the present invention is to provide an equipment which will not expose the miners / workers to high dust concentration.
In the present invention there is provided an equipment for loading blasted coal / mineral from a conventional long wall mine panel, which is a combination of a mobile mechanical loading machine and a mobile steel shutter. The equipment consists of a large diameter screw feeder fitted to a bucket of about a ton capacity. In the bucket a water spray arrangement is incorporated for dust suppression. The prime mover is a flame-proof motor connected through a variable speed gear arrangement to the screw feeder for loading under various conditions. A remote control panel ensures that the operator works the machine remotely under safe and supported conditions. The combination of a mobile
mechanical loading machine and a mobile steel shutter helps eliminate loading activity from the support side of the armoured face conveyor (AFC) and hence, the equipment will load the coal from the face side of the armoured face conveyor (AFC) only, thus resulting in increased productivity.
Accordingly the present invention provides an equipment for loading blasted coal / mineral from a conventional long wall mine panel, which comprises in combination a mobile mechanical loading machine and a mobile steel shutter capable of being placed on either side of an armoured face conveyor (AFC) in a conventional long wall mine panel; wherein the mobile mechanical loading machine consists of a variable speed prime mover powered horizontally placed large diameter screw feeder mounted at the side of a bucket by means of an axle and bearings on both sides, the said bucket and the said screw feeder having means for providing top water spray; the said mobile mechanical loading machine being provided with a mobile steel shutter placed on the other side of the armoured face conveyor (AFC).
In an embodiment of the present invention, the bucket is provided with peripheral teeth to collect the blasted coal.
In another embodiment of the present invention, the bucket and the axle mounted screw feeder is at a vertical height matching the armoured face conveyor (AFC) for conveying the loaded coal / mineral.
In yet another embodiment of the present invention, the variable speed prime mover is a flame-proof electrical motor attached to a gear box through a coupling fitted with an over-load prevention shear-pin.
In still another embodiment of the present invention, the variable speed prime mover is a flame-proof electrical motor capable of being operated by means such as control panel connected through a cable or a cable less remote control.
In still yet another embodiment of the present invention, the means for providing top water spray, in the said bucket and the said screw feeder, is a water sprinkling system such as suitably perforated pipe(s) connected to a pressurized water source.
In a further embodiment of the present invention, the mobile mechanical loading machine is provided with means such as wheels or crawler mounted wheels powered through a gear-box connected prime mover such as a flame proof motor.
In still further embodiment of the present invention, the movable steel shutter, placed opposite to the blasting face on the other side of the armoured face conveyor (AFC), is provided with means such as wheels or crawler mounted wheels powered through a gear-box connected prime mover such as a flame proof motor.
The present invention is illustrated in the form of schematic diagrams in figures 2 to 5 of the drawings accompanying this specification. In the drawings like reference numbers / letters indicate corresponding parts in the various figures.
In figure 2 (plan) and figure 3 (elevation) of the drawings accompanying this specification are shown the plan and elevation, respectively, of the equipment of the present invention which is a combination of a mobile mechanical loading machine and a mobile steel shutter. It consists of a bucket (7) with peripheral teeth to collect the blasted coal. The large diameter screw feeder (8) mounted at the back of the bucket by means of an axle (9) and bearings (15) on both sides, transports the blasted coal / mineral to the armored face conveyor (AFC) (4). The prime mover of this whole system is a flame-proof electrical motor (12) attached to a gear box (10) by a coupling (11) fitted with a shear pin (not shown) to prevent over loading of the motor. The forward and backward movement of the loading machine along the face is done by means of a pair of wheel or crawler mounted wheels (17). A device (16) fitted in front of the AFC (4) will act as a
guide to the loading machine so that it does not crawl over the AFC (4). A water spray arrangement (20) is provided in the bucket (7) to prevent the coal dust to get air-borne. The control panel (14) is connected to the loading machine by a cable (13) or it may be operated by a cable less remote control also.
In figure 4 of the drawings is depicted the mobile steel shutter (18) which is placed on the other side of the armored face conveyor (AFC) (4). It will ensure that about 40 percent of the blasted material post blasting will fall directly onto the AFC which is moving. Blasting operation will progress from the tail-gate side towards the main-gate side. A round of blasting (consisting of about 18-20 holes) will be done while the AFC (4) is moving so that about 40 percent of the coal is transported during the blasting cycle. This will also avoid the loading operation from the support side of the AFC, which is required to be done in the normal conventional longwall loading system. The combination of the mobile mechanical loading machine and mobile steel shutter (18) will be slid to adjacent blasting area toward the main gate for next round.
As depicted in figure 5 of the drawings accompanying this specification, an operator (21) who will walk safely in parallel along with the machine under the first row of hydraulic supports, will be operating the loading machine is by the remote control panel (14).
The present invention provides an equipment which is a combination of a mobile mechanical loading machine and a mobile steel shutter for loading of loose or blasted coal / mineral from a conventional longwail mine panel. During blasting the movable steel shutter placed just opposite to the face helps in loading about 40% of blasted coal / minerals automatically, in addition it also involves the mechanical loading machine which consists of a bucket with a large diameter screw feeder mounted at the back by means of an axle which conveys the loaded coal / mineral onto the armoured face conveyor. Moreover, a water sprinkling system is en suited in the bucket for dust suppression during loading. Furthermore, this entire equipment can be operated through a remote control
device by an operator walking in parallel to the face along with the machine under the supported roof.
The loading machine is provided with a bucket fitted with a large diameter screw feeder mounted at the back by means of an axle which conveys the loaded coal/mineral into the armored face conveyor.
The bucket is equipped with a water sprinkling system for dust suppression during loading operations.
An operator standing safely under the supported roof can remotely operate the control unit.
The loading unit moves in parallel to the face by means of two wheels operated mechanically by gear arrangement with the flame proof motor which is the main prime mover of this loading unit.
The movable steel shutter placed opposite to the blasting face helps in loading about 40% of the coal/mineral automatically.
The features and advantages of the present invention will be set forth in part in the description, and in part will come to be understood by those skilled in the art by the reference to the following description of the invention and referenced drawings.
In figure 1 of the drawings accompanying this specification represents a conventional face of about 100m length. Drill holes (19) are made in the coal face (5) by coal drill machines in an inclined direction as shown in the figure 1 or as approved by the statute. To complete this activity in a faster pace two or more drill machines are required to cover the total face length of 100m. A row of supports are installed / erected near the face just beyond the AFC (4). this
supporting activity is done just after advancing of AFC (4) as near as possible to the face. After the drilling activity is done the holes are cleaned by water jet and the face is wetted to suppress the coal dust. Presence of methane or other inflammable gas is checked by detectors as per existing Indian statute. After this statutory check up the explosive cartridges along with detonators are inserted into the drill holes and then stemmed with sand/clay capsules. The detonating cords are connected to an exploder in series and several warning signal is blowed to alert the workers to keep a safe distance. The steel shutter (18) is brought and kept opposite to the blasting face and secured properly with the hydraulic supports. The AFC(4) is kept in running condition. A face length of about 5 to 6 m is blasted at a time. After blasting some portion (about 40%) of the blasted coal is transported by the AFC automatically. The steel shutter (18) will prevent the throw of coal on the other side, this will save lot of manpower to clean the coal from the support side of the AFC. After the blasting fumes are removed by the ventilating air current, the roof is dressed to remove any loose coal/rock. Then again the blasting process continues in the adjacent portion of the face.
When the full face is blasted the roof is checked and dressed for any loose rock mucking / loading operation starts. Here again the present invention comes in the picture. An operator starts loading the coal from the main gate side of the face.
It will take about a full shift of 8 hours to load the total blasted coal from the face-side of the armored face conveyor (AFC) by this device of the present invention.
The novelty of the equipment of the present invention for loading blasted coal / mineral from a conventional long wall mine panel, resides in its usefulness for loading coal/minerals with increased productivity by only one operator from a remote position, in a conventional longwall panel, through simple cost effective constructional features, simplicity of manufacture and working.
The novelty of the equipment of the present invention for loading blasted coal / mineral from a conventional long wall mine panel, has been realized by the non-obvious inventive steps comprising a combination of a mobile mechanical loading machine and a mobile steel shutter capable of being placed on either side of an armoured face conveyor (AFC) in a conventional long wall mine panel. The large size screw feeder fitted to the loading bucket increases the rate of transfer of the coal/mineral to the AFC directly from the face. The steel shutter blocks the throw of the blasted coal and directs the coal to get loaded onto the AFC automatically and this step helps in loading about 40% of the coal directly to the running AFC, after blasting without much effort wherein the loading cycle is also eliminated from loading the coal manually from the support side of the AFC, thus saving time and man-power. The water sprinkling arrangement works as an effective dust suppression system, all through the loading operation. Furthermore, the operator is capable of controlling the operation from a remote location by walking in parallel to the face along with the machine under the supported roof. In the hitherto known prior art, there are no such uses of a steel shutter during blasting and the use of a loading machine having a bucket fitted with a large diameter screw feeder along with a water spraying system/mechanism in the loading bucket itself.
The main advantages of the equipment of the present invention for loading blasted coal / mineral from a conventional long wall mine panel are:
1. The loading unit has a very simple engineering design.
2. It is economical compared to the existing loading machines.
3. Enables reduction in man-power requirement to load the coal in AFC.
4. Ensures less consumption of loading time than otherwise taken by 110 workers in two loading shifts. This will improve the production as well as productivity of the mine.
5. Ensures less electricity cost, as an order of 50HP motor will be able to do the loading job.
6. Ensures safe working of the operator of the machine, under a safe supported roof with the help of control panel.
7. Ensures continuous water spraying over the bucket during the loading operation, hence there is very less chance of the coal dust getting air borne. This will enable the workers to work in a healthy environment.
8. Ensures automatic 40% loading of blasted coal/minerals by using of the steel shutter during blasting operation, in the armored face conveyor automatically. This will help in elimination of an activity of cleaning the support side of the AFC. Thus a "shift" gain is achieved in this process to reduce the longwall cycle time.
9. Ensures less maintenance cost than the hydraulic loading machines, as the device of the present invention comprises of only mechanical parts.



We claim:
1. An equipment for loading blasted coal / mineral from a conventional long wall mine panel, which is characterised by combination a mobile mechanical loading machine and a mobile steel shutter so as to place on either side of an armoured face conveyor (AFC) in a conventional long wall mine panel; wherein the mobile mechanical loading machine consists of a variable speed prime mover powered horizontally placed large diameter screw feeder mounted at the side of a bucket by means of an axle and bearings on both sides, the said bucket and the said screw feeder having means for providing top water spray; the said mobile mechanical loading machine being provided with a mobile steel shutter placed on the other side of the armoured face conveyor (AFC).
2. An equipment as claimed in claim 1, wherein the said bucket is provided with peripheral teeth.
3. An equipment as claimed in claim 1-2, wherein the said bucket and the axle mounted screw feeder is at a vertical height matching the armoured face conveyor (AFC) for conveying the loaded coal / mineral.
4. An equipment as claimed in claim 1-3, wherein the said variable speed prime mover is a flame-proof electrical motor attached to a gear box through a coupling fitted with an overĀ¬load prevention shear-pin.
5. An equipment as claimed in claim 1-4, wherein the said variable speed prime mover is a flame-proof electrical motor capable of being operated by means such as control panel connected through a cable or a cable less remote control.
6. An equipment as claimed in claim 1-5, wherein the said means for providing top water spray, in the said bucket and the said screw feeder, is a water sprinkling
system such as suitably perforated pipe(s) connected to a pressurized water source.
7. An equipment as claimed in claim 1-6, wherein the said mobile mechanical loading
machine is provided with means such as wheels or crawler mounted wheels powered through
a gear-box connected prime mover such as a flame proof motor.
8. An equipment as claimed in claim 1-7, wherein the said movable steel shutter, placed opposite to the blasting face on the other side of the armoured face conveyor (AFC), is provided with means such as wheels or crawler mounted wheels powered through a gear-box connected prime mover such as a flame proof motor.

Documents:


Patent Number 258763
Indian Patent Application Number 762/DEL/2005
PG Journal Number 06/2014
Publication Date 07-Feb-2014
Grant Date 05-Feb-2014
Date of Filing 31-Mar-2005
Name of Patentee COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
Applicant Address ANUSANDHAN BHAWAN, RAFI MARG, NEW DELHI-110 001, INDIA
Inventors:
# Inventor's Name Inventor's Address
1 PAUL BISWAJIT CENTRAL MINING, RESEARCH INSTITUTE BARWA ROAD, DHANBAD, JHARKHAND, INDIA-826001
PCT International Classification Number E21C 35/20
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA