GB2222422A

GB2222422A - Cooling system for use in tunnelling installations

Info

Publication number: GB2222422A
Application number: GB8919047A
Authority: GB
Inventors: Herbert Heitkamp; Klaus Linde
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1988-08-31
Filing date: 1989-08-22
Publication date: 1990-03-07
Anticipated expiration: 2009-08-22
Also published as: GB2222422B; FR2635820A1; DE3829531C2; GB8919047D0; FR2635820B1; DE3829531A1

Description

1 i 2222422 "COOLING SYSTEM FOR USE IN TUNNEL DRIVING INSTALLATIONS" The

present invention relates to a cooling system usable in tunnel driving installations or the like.

In tunnel driving a cutting appliance such as a wheel or drill head is driven by hydraulic or electric motors to detach material from a working face. The cutting operation takes place at the front of an advanceable support shield. To assist the cutting work, it is known to convey liquid, such as water or a thixotropic fluid such as a bentonite suspension, to the face to perform a flushing and support function. An extraction chamber behind the cutting appliance receives the flushing and supporting agent pumped in from a reconditioning plant above ground where solid spoil is removed from the carrier liquid. Slurry is withdrawn from the chamber by suction and pumped up to the separation plant.

Since the cutting operation generates considerable heat it is desirable to subject the motors and bearings to cooling. Hitherto the cooling plant necessary for this purpose is complex and costly.

In tunnel driving, it is also desirable to cool hydraulic pressure medium, usually oil or an oil-in-water emulsion, used to operate the varioushydraulic consumers such as rams and control devices in the installation. Again cooling plant for this purpose tends to be complex 2 and costly.

A general object of the invention is to provide an improved cooling system which is simple and economic yet performs efficiently.

According to the invention, an improved cooling system utilises a heat exchanger through which coolant and/or hydraulic pressure medium is circulated for cooling. To absorb heat from the coolant and/or hydraulic pressure medium the heat exchanger uses the flushing and support medium which is passed to the face as discussed hereinbefore. The flushing and support agent or medium which flows in large quantities permits efficient cooling in an economic manner since no separate cooling plant is needed.

The necessary heat exchanger is preferably connected in-line with the supply pipe conveying the reconditioned flushing and support agent to the face. It is however possible to have the heat exchanger connected in-line with the return pipe through which the liquid with the particulate extracted material is withdrawn from the face or in a by-pass line parallel to the supply or return pipes.

The heat exchanger can be located in the tunnel itself and in a preferred embodiment the heat exchanger has a box-like housing equipped with connections for connecting the associated pipe conveying the flushing and support fluid to the interior of the housing. A series of parallel heat exchange elements can be suspended 3 from an upper wall of the housing to be immersed in the fluid passing between the connectors. The elements can be sinuous pipes or flat plates for example joined with pipe couplings to supply and return pipes for circulating the coolant and/or hydraulic pressure medium. One or more pumps can be used to force the coolant and/or. hydraulic pressure medium to circulate through the heat exchange elements. The elements can be mounted on plates fitted in the upper wall of the housing which is preferably hinged or detachable. Separate sets or banks of elements can be provided for the coolant and the hydraulic pressure medium.

To enable dirt which accumulates in the housing to be removed it is desirable to have a closable outlet in the housing.

The invention may be understood more readily and various other features of the invention may become apparent, from consideration of the following description.

An embodiment of the invention, will now be described, by way of example only, with reference to the accompanying drawings, wherein:

Figure 1 is a schematic diagram depicting a tunnel driving installation equipped with a cooling system constructed in accordance with the invention; and - Figure 2 is a perspective view of a heat exchanger which can be used in the cooling system constructed in accordance with the invention.

4 As shown in Figure 1, a tunnel driving installation employs a drive shield which is operated in a conventional manner with hydraulic rams (not shown) to advance the tunnel 2. As represented, the installation has a cutting head 5 rotatably mounted on a partition wall 3 at the front of the shield. The head 5 can be thrust forwards with one or more hydraulic rams.

The wall 3 is hollow to create an extraction chamber 4 as is known. The rotary drive for the head 5 is provided by several drive motors 6 mounted to the rear side of the wall 3. During use, a flushing and support fluid usually water or a bentonite suspension is passed into the chamber 4 via a feed line 11.

If desired the working fluid can be supplemented by a compressed air cushion and in this case an air line also leads to the chamber 4. The material detached from the working face by the rotating head 5 mixes with the flushing and support fluid and is removed as a slurry via an extraction line 7. The line 7 connects with a pump of a pump unit 8 disposed in the tunnel and a further line 9 passes the slurry to a separation plant 10 on the surface. In the plant 10 the solid material is separated from the fluid and the cleaned or reconditioned fluid is returned back to the feed line 11. If the fluid is bentonite the plant 10 can regenerate the fluid by adding fresh bentonite. The plant 10 also employs a pump to charge the feed line 11 and hence the chamber 4 with the reconditioned fluid.

c P j In addition to the rams used to advance the shield 1 and the head 5, the installation may have a number of other hydraulic consumers including one or more control devices. The hydraulic pressure fluid used to operate the various hydraulic appliances is provided by a separate pump conveniently mounted in a unit 12. A storage vessel for the hydraulic fluid is also mounted in the unit 12. The hydraulic fluid can take the form of oil or a water/oil emulsion.

The head 5 is normally driven with high power and this necessitates efficient cooling of the motors 6 and the bearings for the head 5. To effect such cooling, coolant is circulated via a heat exchanger 13 which can also be used optionally to cool the hydraulic pressure fluid.

The heat exchanger 13 is disposed in-line with the supply pipe 11 connecting the separation plant 10 to the extraction chamber 4. The coolant is circulated and flows through pipes 22,23,25,26 leading to and from the motors 6 and the cutting head 5 and to and from the heat exchanger 13.

Figure 2 depicts the construction of the heat exchanger 13 in more detail. The heat exchanger 13 takes the form of a sealed rectangular box-like housing 14 with connectors 15,16 at opposite ends for coupling to the pipe line 11.

The flushing and support fluid passes between the connectors 15,16 within the housing 14 and flows around 6 as a number of heat exchange elements 17 disposed inside the housing 14. sinuous copper.

These elements 17 can take the form of pipes or simple plates preferably made from The elements 17 are suspended from an upper wall 21 of the housing 14 by removably mounting plates 20. The elements 17 divides the interior of the housing 14 into parallel chambers through which the flushing and support fluid is forced to flow. This promotes efficient cooling of the elements 17. The wall 21 is conveniently hinged or detachable. Each mounting plate 20 has input and output couplings or connection pipes 18,19 leading to the heat exchange element 17. The input connection pipes 19 are connected to a common coolant supply line 26 while the output connection pipes 18 are connected to a common coolant return line 25. Coolant is supplied under pressure,to the supply line 26 by means of a pump 24 which is preferably in the form of a multi-stage centrifugal pump. The coolant can be stored in a vessel in the unit 12 and is then drawn from the vessel via the pump 24 and the supply line 26 and is returned back to the vessel by way of the return line 25. Coolant is then circulated in a separate circuit via the pipe lines 22,23 to the motors 6 and the cutting head and another pump on the unit 8 can serve to circulate the coolant to and from the storage vessel and via the motors 6 and cutting head 8.

Alternatively, as shown in the chain dotted lines in Figure 1, the pipe lines 22,23 can be linked to the lines W 7 25,26 and the storage vessel is then omitted. The coolant is then simply recirculated by means of the pump 24 through the elements 17 in the heat exchanger housing 14 and via the pipe lines 25,26.

If the pressure fluid in the unit 12 is to be cooled also it is desirable to provide an auxiliary bank of heat exchanger elements fed by the pressure fluid. Valves can be provided to control the flow. The cooling system permits selective cooling of the cutting head 5 and the motors 6 and/or the hydraulic pressure fluid used to operate the hydraulic appliances.

It is advisable to provide valves at the connectors 15,16 or in the pipe line 11 upstream and downstream of the heat exchanger 13 to and the heat exchanger 13 can then be isolated to permit the flushing and support fluid to be shut off when the pipe line 11 is to be extended to follow the tunnelling progress. When the pipe line 11 is extended it is preferable to move the heat exchanger 13 to follow the shield. This facility to isolate the heat exchanger 13 also permits the heat exchanger housing to be cleaned.

It is also useful to provide the housing 14 with closable outlet on the base wall to permit removal of dirt.

8

Claims

A cooling system for cooling coolant and/or hydraulic pressure medium in a tunnelling installation; said system including a heat exchanger through which the coolant and/or hydraulic pressure fluid is passed for cooling wherein fluid used as a flushing and support medium for the tunnelling operation is passed through the heat exchanger to effect the cooling.
2. A system according to claim 1, wherein the heat exchanger is connected in-line with supply pipe which conveys reconditioned flushing and support medium to an extraction chamber of a tunnel drive shield.
3. A system according to claim 2, wherein the heat exchanger is composed of a housing equipped with connectors for joining to the supply pipe and leading to the interior of the housing and a plurality of heat exchange elements which extend into the interior of the housing and through which the coolant and/or pressure fluid is circulated.
4. A system according to claim 2, wherein the heat exchanger elements are supported by mountings detachably fitted to the housing and pipe couplings are provided on the exterior of the mountings for passing the coolant and/or pressure fluid to and from the heat exchange 9 elements.
A system according to claim 4, wherein the pipe couplings connect with respective common supply and return pipe lines and one or more pumps force the coolant and/or pressure medium to circulate.
6. A system according to claim 3,4 or 5 wherein the heat exchange elements are suspended from an upper wall of the housing which is hinged or detachable.
7. A system according to any one of claims 3 to 6 wherein the heat exchange elements are in the form of sinuous pipes or plates.
8. A system according to any one of claims 3 to 7, wherein the heat exchange elements are arranged in sets one set having the coolant passing therethrough and the other set having the pressure medium passing therethrough.
9. A system according to any one of claims 3 to 8, wherein the housing is provided with a closable outlet for removal of dirt.
10. A system according to any one of claims 2 to 9, wherein valves are provided in the supply pipe for isolating the heat exchanger.
A system according to any one of claims 1 to 10, wherein the heat exchanger is disposed within the tunnel created by the installation.
12. A cooling system substantially as described with reference to, and as illustrated in the accompanying drawings.
13. A cooling system incorporating a heat exchanger substantially as described, and as illustrated in, Figure 2 of the accompanying drawings.
14. A tunnelling installation substantially as described with reference to, and as illustrated in, the accompanying drawings.

1 PUbllmhed 1990 at The Patent Office. State House.813;7 I FighHolburn, London WCIR 4TP. Further copies maybe obtLInedtVGM The Patent OMC463186 Branch, St Mary Cray. Orpington. Kent. MRS 3RD. Printed by Multiplex techniques ltd. St MLrY CraYt Kent, COn- 3.187