GB2405664A

GB2405664A - Galvanic isolation in longwall equipment

Info

Publication number: GB2405664A
Application number: GB0418742A
Authority: GB
Inventors: Jens Titschert; Jurgen Tschoepe; Wilfried Weigel; Norbert Schwarz
Original assignee: DBT Automation GmbH
Current assignee: Caterpillar Global Mining Europe GmbH
Priority date: 2003-09-08
Filing date: 2004-08-23
Publication date: 2005-03-09
Also published as: RU2004126966A; CN1605714B; AU2004205126A1; US20050053430A1; DE20314011U1; PL369880A1; CN1605714A; GB0418742D0; PL213034B1; RU2358112C2

Abstract

Longwall face equipment for extraction use in underground mining includes electrohydraulically operated support units each having a support controller 6, with at least one power unit 11 being provided, that supplies the support controllers 6 of differing support units with power. A bi-directional coupler 12 is connected between the power unit 11 and the support controllers 6 and provides galvanic isolation between the power unit 11 and the support controllers 6 and/or groups I, II of the support controllers 6. The couplers permit communication between the support controllers 6 and/or groups I, II of the support controllers 6. In order to simplify the arrangement of the face, the coupler 12 is integrated into the power unit 11 or is flanged directly onto the housing of the power unit 11.

Description

LONGWALL FACE EQUIPMENT

The present invention relates to longwall face equipment for extraction use performed in underground mining.

Longwall face equipment having several support units is known from German patent application DE 195 28 644 Al. Each support unit has assigned to it a support controller which is linked with a control strip for valves and sensors. All support controllers, or alternately individual support controllers, are equipped with an 0 integrated module in the form of a computer unit, in order, by way of the control strip, to be able to evaluate the signals from the sensors and to carry out functions of the support units such as drawing or setting props, advancing, and moving the conveyor, by means of the valves and hydraulic components of the support units. In addition, every support unit features a lamp serving to illuminate the face, which is installed in a housing with flameproof or special-protection enclosure. In the case of group control, the integrated computer module is assigned to one of the support units, with the computer module being located together with the lamp in a flameproof or specialprotection housing. The computer module is connected to a power unit which is also located in the housing, which power unit transforms the input voltage of 230 V present at the lamp, which may be implemented in the form of an energy-saving lamp having a supply voltage of 230 V, to 12 V, since Mines Inspectorate rules stipulate that such controllers may only be operated as intrinsically safe units at a voltage such as 12 V. The housings assigned to the individual support units, or the power units or lamps located within them, are connected together by a 230 V power supply cable and suitable flameproof or special-protection plug systems for transmitting power and data. In the case of group control, the superordinate computer module is connected with the downstream support controllers by wires for data transmission and power supply.

In other longwall face equipment used in underground mining, a superordinate computer is placed upstream of groups of support controllers equipped with a computer module, with this superordinate computer providing for the galvanic isolation between a power unit and the support controllers or groups of support controllers which is required in order to make the longwall face equipment intrinsically safe. In this type of arrangement the individual support controllers are dependent on the superordinate computer, which may negatively affect support control. In addition, there is a high hardware need, since not only computer modules for the individual support controllers but also a superordinate computer are required. s

The object of the present invention is to longwall face equipment which simplifies the layout described above According to the invention there is provided Longwall face equipment for lo extraction use in underground mining, comprising: support controllers for respective electrohydraulically operated support units, at least one power unit for supplying at least two support controllers of differing support units with power, and a bi-directional coupler connected between the power unit and the at least two support controllers and providing galvanic isolation between the power unit and the support controllers and/or groups (I, II) of support controllers and permitting communication between the two support controllers and/or groups (I, II) of support controllers, wherein the coupler is integrated into the power unit or is flanged directly onto the housing of the power unit.

The integration of the bi-directional coupler into the power unit or into the housing of the power unit makes it possible to eliminate the power supply lines which otherwise would be needed to make the connection between the outputs of the power unit and the bi-directional coupler. In addition, a separate bi-directional coupler as such can be eliminated, since integration of the coupler into the power unit can be achieved without impact on the price. The support controllers can be connected directly with the power unit, with the bi-directional coupler then allowing communication between the groups of support controllers connected to the coupler, these being galvanically isolated from one another. In this arrangement the bi- directional coupler integrated into the power unit or flanged directly onto the housing of the power unit provides for the galvanic isolation between the support controllers or groups of support controllers supplied with electrical power by the power unit.

In a preferred embodiment, the power unit includes a component such as a computer module, which has a data link with the support controllers, in order to route information to the latter on the electricity consumption, current peaks, voltages, etc. at any given moment. Based on the information on the power available at the time, the support controllers then can actively adapt their control, providing load management at the face.

It is preferable if the power unit is assigned to a support unit, in which case the lo power unit together with a lamp to illuminate the face may be located in a housing with flameproof, explosion-proof or specialprotection enclosure. The lamp or the power unit is preferably connected to a power supply having a 230 V input voltage.

The power unit transforms the voltage to 12 V, so that the bi-directional coupler and the support controllers receive an intrinsically safe power supply of 12 V. To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a block diagram of longwall face equipment according to the present invention having a power unit with an integrated bi-directional coupler; and Figure 2 is a similar block diagram of longwall face equipment known from

the prior art.

Referring to Figure 1 there is shown a double unit 11 according to the present invention with a bi-directional coupler 12 integrated into the power unit 11 to supply power to the groups I, II of support controllers 6. As can be seen by comparison with Figure 2, the integration of the coupler 12 into the power unit 11 makes it possible to eliminate the two connection cables 3 which are required in the prior art, together with appropriate special connecting plugs. The double power unit 11 is designed to supply intrinsically safe power to two lines or groups I, II of support controllers 6. An input voltage of 230 V is present at a power connection 4 of power unit 11, and this is transformed in power unit 1 1 to an intrinsically safe voltage, in this case 12 V. l The bi-directional coupler 12 is connected through wires 5 with two groups I, II of support controllers 6 in differing electrical supply lines of the double power unit 11. With each support controller 6 the sensor systems and hydraulic systems of an electrohydraulic support unit, not shown here, can be evaluated or activated, with s each support controller 6 being connected for this purpose to a control strip, also not shown, for the sensors and valves of the related support unit.

Via the bi-directional coupler 12, the controllers 6 of the two groups I, II are supplied intrinsically safely with power at a voltage of 12 V from power unit 11. The lo two wires 5 both supply power and transmit data and the bi-directional coupler 12 permits communication between the support controllers 6 of the two groups I, II, via the wires 5. In this arrangement the bi-directional coupler 12 simultaneously provides the function of galvanic isolation between power unit 11 and support controllers 6 or groups I, II of support controllers 6.

Each group I, II of support controllers 6 includes further connected support controllers, through the power supply and data transmission wires 7 shown as dotted lines, with the result that several support controllers 6 are connected with the related power unit 11 by means of the bidirectional coupler 12. The individual support controllers 6 or groups I, II are autonomous and galvanically isolated from the power unit 1 1.

It is preferable if the power unit 1 I with the bi-directional coupler 12 is located in a housing 8 with a flameproof or special-protection enclosure.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, the bi-directional coupler may also be eliminated as a separate component andlor may be integrated through circuitry directly in the power unit or only be flanged directly onto the housing of the power unit. Further the power unit may be equipped with intelligence, such as, in particular, a computer module, in order to be able to transmit to the support controllers information on the power consumption, current peaks, voltages, etc. at any given moment so that the support controllers may exercise active control. s

Claims

CLAIMS: 1. Longwall face equipment for extraction use in underground

mining, comprising: support controllers for respective electrohydraulically operated support units, at least one power unit for supplying at least two support controllers of differing support units with power, and a bi-directional coupler connected between the power unit and the at least two support controllers and providing galvanic isolation between the power unit and the support controllers and/or groups (I, II) of support controllers and permitting communication between the two support controllers and/or groups lo (I, II) of support controllers, wherein the coupler is integrated into the power unit or is flanged directly onto the housing of the power unit.
2. Longwall face equipment as claimed in Claim 1, wherein the power unit includes a component having a data link with the support controllers in order to transmit to the support controllers information on the power consumption, current peaks, voltages or similar at any given moment.
3. Longwall face equipment as claimed in Claim 1 or Claim 2, wherein the power unit is located in a housing with a flameproof, explosion-proof or special-protection enclosure.
4. Longwall face equipment as claimed in Claim 1, wherein the power unit together with a lamp, which is used to illuminate the face, is located in the housing and/or is implemented in the form of a double power unit.
5. Longwall face equipment substantially as hereinbefore described with reference to Figure 1 of the accompanying drawing.