GB2124279A

GB2124279A - Apparatus for shallow seam mining

Info

Publication number: GB2124279A
Application number: GB08320276A
Authority: GB
Inventors: Gordon Bertram Dawson
Original assignee: Anderson Strathclyde PLC
Current assignee: Anderson Strathclyde PLC
Priority date: 1982-07-30
Filing date: 1983-07-27
Publication date: 1984-02-15
Also published as: GB8320276D0

Abstract

A shallow seam mining machine has a coal cutter unit (10) behind which a thrust support structure is attached. This structure is formed of a plurality of thrust members (11) added to or removed from the structure as the machine forms and advances into or retreats from a driveway. The thrust members and cutter unit have skids which are hollow and air impellers and air outlets are provided on the cutter unit. Thus, air can pass along the thrust support structure to exit at the cutter and dilute any methane gas which may have collected at that end. The air/methane then vents back along the driveway. <IMAGE>

Description

SPECIFICATION Mining machines This invention relates to mining machines particularly for use in highwall and trench mining.

In highwall mining shallow seams are exposed in an outcrop above ground level and in trench mining shallow seams are exposed by cutting a trench from the surface to a depth of up to 400 feet.

In each case a roadway is formed parallel to the seams and driveways of up to 600 feet length are cut into the seams laterally of the roadway.

The cutting machine is remoteiy controlled and moved forward by a thrust unit, drawing behind it a support structure for a conveyor unit. One form of apparatus for moving the machine is disclosed in U.K. Patent No. 1565980 and one form of machine is disclosed in U.K. Patent No. 1 566432, (both in the name of Atlow Mining Development Consultants Limited).

Whenever coal is mined some methane is released. The amount is dependent upon the amount present naturally and the amount which has drained from the seam to the surface of other workings.

In practice it is usually found that working coal near an outcrop is virtually gas-free, so for highwall mining it is not necessary to incorporate a ventilation system.

In trench mining however, even though the seams are shallow, the natural drainage of methane is not so certain and if coal is to be mined at a high production rate with an electrically driven machine a means of ventilation to dilute the methane released will be desirable if not vital.

It is therefore one object of this invention to provide mining apparatus which incorporates a ventilation means.

According to the present invention there is provided apparatus for shallow seam mining comprising a coal cutting machine for forming and advancing into a driveway and a thrust support structure attached to the rear of the machine and progressively lengthened or reduced as the machine moves into or out of the driveway, said structure comprising a plurality of thrust members each incorporating or carrying a duct portion, adjacent duct portions being connectable in a substantially air tight manner when a thrust member is attached to the rearmost thrust member of the structure attached to the cutting machine, and means for inducing air flow in the ducting to the vicinity of the cutting machine for ventilating the driveway.

Preferably, the innermost end of the ducting extends into or onto the machine and incorporates outlet means.

Preferably also, the means for inducing air flow is located in the part of the ducting in or on the cutting machine.

Preferably also, each thrust member includes a pair of parallel longitudinal tubular skid members which comprise the duct portions.

Preferably also, said skid members are crossbraced at longitudinal intervals and carry conveyor support means.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a side view of a mining machine according to one aspect of the present invention, shown in a driveway of a shallow seam mine; Fig. 2 is a sectional end view on the line A-A' of Fig. 1; Referring to the drawings, the apparatus comprises a coal cutting machine 10 to the rear of which is attached a plurality of thrust members 11; these are added one at a time as the rearmost member 11 passes over a launching platform 12 in the roadway off which a driveway 1 3 is to be formed by the machine 1 0. Each thrust member 11 comprises a pair of hollow skids 14 which are longitudinal tubular members cross-braced and with support idlers 1 5 for a conveyor 1 6.

The cutting machine includes cutting heads 20, lower and upper cutting discs 22 and hollow skids 23 the forward ends of which have louvred outlets 24. At the rear end of the skids 23 are fans 25 for inducing air flow through the ducts to exit through the outlets 24.

In use, air is drawn into the ventilation ducts at the entrance to the driveway and the ducts increase in length as the machine moves further into the driveway. The air exists through outlets 24 in the leading skids and moves back along the driveway diluting and carrying away methane gas which may have accumulated at the cutter end of the machine. The arrows in Fig. 1 illustrate air/ventilation flow.

The means for thrusting the machine forward is located at the launching platform 12 and may comprise any known mechanism such as retractable rams. However the thrust means may be of the type disclosed in my co-pending application No. filed , in which a pair of pinion wheels are fixedly disposed horizontally on the roadway floor at the entrance to the driveway and each thrust member has an outwardly facing horizontal rack on each skid. The pinions engage the racks and feed each thrust member into the driveway in a steady continual movement.

Claims

1. Apparatus for shallow seam mining comprising a coal cutting machine for forming and advancing into a driveway and a thrust support structure attached to the rear of the machine and progressively lengthened or reduced as the machine moves into or out of the driveway, said structure comprising a plurality of thrust members each incorporating or carrying a duct portion, adjacent duct portions being connectable in a substantially air tight manner when a thrust member is attached to the rearmost thrust member of the structure attached to the cutting machine, and means for inducing air flow in the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Mining machines This invention relates to mining machines particularly for use in highwall and trench mining. In highwall mining shallow seams are exposed in an outcrop above ground level and in trench mining shallow seams are exposed by cutting a trench from the surface to a depth of up to 400 feet. In each case a roadway is formed parallel to the seams and driveways of up to 600 feet length are cut into the seams laterally of the roadway. The cutting machine is remoteiy controlled and moved forward by a thrust unit, drawing behind it a support structure for a conveyor unit. One form of apparatus for moving the machine is disclosed in U.K. Patent No. 1565980 and one form of machine is disclosed in U.K. Patent No. 1 566432, (both in the name of Atlow Mining Development Consultants Limited). Whenever coal is mined some methane is released. The amount is dependent upon the amount present naturally and the amount which has drained from the seam to the surface of other workings. In practice it is usually found that working coal near an outcrop is virtually gas-free, so for highwall mining it is not necessary to incorporate a ventilation system. In trench mining however, even though the seams are shallow, the natural drainage of methane is not so certain and if coal is to be mined at a high production rate with an electrically driven machine a means of ventilation to dilute the methane released will be desirable if not vital. It is therefore one object of this invention to provide mining apparatus which incorporates a ventilation means. According to the present invention there is provided apparatus for shallow seam mining comprising a coal cutting machine for forming and advancing into a driveway and a thrust support structure attached to the rear of the machine and progressively lengthened or reduced as the machine moves into or out of the driveway, said structure comprising a plurality of thrust members each incorporating or carrying a duct portion, adjacent duct portions being connectable in a substantially air tight manner when a thrust member is attached to the rearmost thrust member of the structure attached to the cutting machine, and means for inducing air flow in the ducting to the vicinity of the cutting machine for ventilating the driveway. Preferably, the innermost end of the ducting extends into or onto the machine and incorporates outlet means. Preferably also, the means for inducing air flow is located in the part of the ducting in or on the cutting machine. Preferably also, each thrust member includes a pair of parallel longitudinal tubular skid members which comprise the duct portions. Preferably also, said skid members are crossbraced at longitudinal intervals and carry conveyor support means. An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a side view of a mining machine according to one aspect of the present invention, shown in a driveway of a shallow seam mine; Fig. 2 is a sectional end view on the line A-A' of Fig. 1; Referring to the drawings, the apparatus comprises a coal cutting machine 10 to the rear of which is attached a plurality of thrust members 11; these are added one at a time as the rearmost member 11 passes over a launching platform 12 in the roadway off which a driveway 1 3 is to be formed by the machine 1 0. Each thrust member 11 comprises a pair of hollow skids 14 which are longitudinal tubular members cross-braced and with support idlers 1 5 for a conveyor 1 6. The cutting machine includes cutting heads 20, lower and upper cutting discs 22 and hollow skids 23 the forward ends of which have louvred outlets 24. At the rear end of the skids 23 are fans 25 for inducing air flow through the ducts to exit through the outlets 24. In use, air is drawn into the ventilation ducts at the entrance to the driveway and the ducts increase in length as the machine moves further into the driveway. The air exists through outlets 24 in the leading skids and moves back along the driveway diluting and carrying away methane gas which may have accumulated at the cutter end of the machine. The arrows in Fig. 1 illustrate air/ventilation flow. The means for thrusting the machine forward is located at the launching platform 12 and may comprise any known mechanism such as retractable rams. However the thrust means may be of the type disclosed in my co-pending application No. filed , in which a pair of pinion wheels are fixedly disposed horizontally on the roadway floor at the entrance to the driveway and each thrust member has an outwardly facing horizontal rack on each skid. The pinions engage the racks and feed each thrust member into the driveway in a steady continual movement. Claims

1. Apparatus for shallow seam mining comprising a coal cutting machine for forming and advancing into a driveway and a thrust support structure attached to the rear of the machine and progressively lengthened or reduced as the machine moves into or out of the driveway, said structure comprising a plurality of thrust members each incorporating or carrying a duct portion, adjacent duct portions being connectable in a substantially air tight manner when a thrust member is attached to the rearmost thrust member of the structure attached to the cutting machine, and means for inducing air flow in the ducting to the vicinity of the cutting machine for ventilating the driveway.

2. Apparatus as claimed in claim 1 in which, the innermost end of the ducting extends into or onto the machine and incorporates outlet means.

3. Apparatus as claimed in claim 1 or 2, in which the means for inducing air flow is located in the part of the ducting in or on the cutting machine.

4. Apparatus as claimed in any one of claims 1 to 3, in which each thrust member includes a pair of parallel longitudinal tubular skid members which comprise the duct portions.

5. Apparatus as claimed in claim 4, in which said skid members are cross-braced at longitudinal intervals and carry conveyor support means.

6. Apparatus for shallow seam mining substantially as hereinbefore described with reference to the accompanying drawings.