GB2162278A

GB2162278A - Ventilation ducting for underground passageways

Info

Publication number: GB2162278A
Application number: GB8517280A
Authority: GB
Inventors: Gordon Elliott; Stephen Elliott; Frank Elliott
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-07-25
Filing date: 1985-07-08
Publication date: 1986-01-29
Also published as: GB2162278B; GB8517280D0; GB8418932D0

Abstract

Ventilation ducting for use in underground passageways consists of a series of lengths of ducting (2,4), each of which lengths comprises a pair of opposed, semi-cylindrical portions (6,8) of a rigid material. Sealing means (12) are provided between the adjacent longitudinal edges of each pair of portions (6,8), said longitudinal edges being sealed together by said sealing means (12) as a result of tensioned coupling means (14) surrounding each length of ducting (2,4), while further coupling means (16) sealingly interconnect adjacent lengths of ducting (2,4). <IMAGE>

Description

SPECIFICATION Improved ventilation ducting for underground passageways This invention relates to ventilation ducting for underground passageways and more particularly to such ducting for use in auxiliary ventilation systems provided in underground mine roadways and like situations to supplement the primary ventilation therein.

In the formation of underground roadways, and as the roadway progresses further from the shaft, the primary systems provided to ventilate the underground workings eventually become incapable of feeding sufficient volume of air under pressure to regions that are further than a predetermined distance from the shaft.

Accordingly, it has become common practice to supplement these primary systems with auxiliary ventilation systems comprising fans and ducting at these remote locations.

For forced ventilation purposes-i.e. when supplying fresh air at positive pressure-it is convenient for the ducting of the auxiliary systems to be of the flexible lay-flat type because such ducting can be readily transported in compact form to the necessary locations.

However, if the auxiliary systems are to be used for exhaust purposes where the interior of ducting is subjected to negative pressures, the ducting itself must be of a circumferentially rigid nature to withstand those negative forces, and it is clearly not possible to use the flexible lengths desirable for forced ventilation. The transportation of rigid lengths of ducting to remote locations underground is much more difficult and time-consuming than with the flexible lengths, although the rigid ducting does have the advantage of superior performance, in that the smooth internal wall keeps to a minimum the resistance to air flow along the ducting.This can be compared with the undulating form of the internal walls of the alternative exhaust ducting, namely spiralreinforced flexible tubing the configuration of the internal walls of which results in relatively inefficient transfer of air therealong.

It would be desirable to be able to provide ducting for auxiliary ventilation systems which incorporated the superior performance of smooth-walled rigid ducting but which was sufficiently compact to be readily transportable to remote locations in underground roadways.

According to the present invention there is provided ventilation ducting for use in underground passageways, the ducting consisting of a series of interconnected lengths of ducting each of which is of a rigid material and comprises a pair of substantially identical opposed portions each of generally semi-cylindrical shape, sealing means extending along diametrically-opposed longitudinal edges of each portion, first coupling means extending circumferentially of each length of ducting and tensioned to effect a seal between adjacent longitudinal edges of the opposed portions, and further coupling means sealingly interconnecting adjacent lengths of ducting.

The provision of lengths of ducting in two semi-cylindrical halves enables said lengths to be transported to the desired locations underground with the half portions stacked one in the other, thus obviating many of the problems associated with conventional rigid ducting whilst maintaining the smooth inner walls of said conventional ducting.

Conveniently, the further coupling means are the same as, and are therefore interchangeable with, the coupling means tensioning the two portions of each length of ducting, said coupling means preferably each comprising a band of neoprene or like resilient material provided with tensioning means in the form of over-centre mechanisms, toggle mechanisms or the like.

It will be appreciated that the provision of lengths of ducting comprising two identical portions and coupling means which can be used either to interconnect the two portions of a length of ducting or to interconnect two adjacent lengths of ducting ensures that the number of different components comprising the overall system is kept to a minimum.

The sealing means are each preferably a longitudinal strip of H-section neoprene or like material adhered to one edge of the associated duct portion, each strip, in use, receiving therein the other edge of the adjacent duct portion.

A preferred length of ducting is of glass fibre-reinforced plastic, the portions of each length of ducting conveniently being separately preformed of said material.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Figure 1 is a side view of part of ducting according to the invention showing the junction between two adjacent lengths; Figure 2 is a transverse section through the ducting of Fig. 1, and Figure 3 shows portions of the ducting of Figs. 1 and 2 stacked for transport.

When forming underground roadways, for example in coal mines, it is of course desirable for the tunnels to be prepared as quickly as possible. However the faster the rate of advance of the face of the tunnel, the quicker must the auxiliary equipment associated with the advance be transported to the working area. In the case of the supply of ventilating air to the working area and/or the removal of dust and the like from the working area, it is necessary to continuously extend the ducting associated therewith. As mentioned above, conventional rigid cylindrical ducting as is necessary for exhaust purposes is bulky and has proved extremely difficult and time-consuming to transport over substantial distances underground.

Referring to the drawings there is illustrated ducting of a rigid material but which is much more readily transportable then heretofore.

More particularly, the ducting comprises a series of interconnected lengths of which parts of two such lengths are shown at 2 and 4 in Fig. 1. Each length comprises two identical halves 6,8 each of semicylindrical shape, the halves 6,8 being separately preformed of glass fibre-reinforced plastic (as opposed to comprising two halves of a split cylinder) and a lip 10 being formed round each end of each half.

A longitudinal strip seal 12 of H-section neoprene or like resilient material is adhered along one longitudinal edge of each half 6,8 as best seen in Fig. 3.

A ducting is assembled by first of all locating the two halves 6,8 of each length opposite one another to provide a cylindrical tube, with the strip seal 12 on each half 6,8 receiving therein the free longitudinal edge of the other half 8,6 as seen in Fig. 2. Circumferential coupling means in the form of, for example, neoprene bands 14 are located around the assembled halves 6,8 and are tensioned to effect longitudinal seals between the two halves. Said bands 14 may consist of a layer of soft neoprene or the like inside and an outer layer of harder neoprene or the like surrounding said inner layer and incorporating for example an over-centre mechanism to effect said tensioning.

Adjacent lengths of ducting 2,4 are interconnected by further coupling means 16 which also effect a seal between the ends of said lengths. Conveniently these coupling means 16 are the same as the coupling means 14, the softer inner band of neoprene seating on the lips 10 and the harder band of neoprene surrounding said lips and inner band to ensure, when tensioned, a seal between the two ends as well as providing a joint between the two lengths.

It will be appreciated that, as clearly shown in Fig. 3, the duct halves 6,8 can be stacked one on the other in an extremely compact manner for transportation to desired locations underground and can then be readily assembled into the required ducting with a minimum of components involved, the resultant ducting being of a rigid nature capable of serving exhaust or forced ventilation purposes and having a smooth internal wall to ensure efficient air transfer therealong.

The provision of duct halves 6,8 of an identical nature means that there is no handling of the two halves necessary prior to installation, while the provision of identical coupling means 14 and 16 enables increased interchangeability of parts and at the same time keeps manufacturing costs to a minimum. These two features additionally combine to keep the number of components in the overall system to a mimimum.

Claims

1. Ventilation ducting for use in underground passageways, the ducting consisting of a series of interconnected lengths of ducting each of which is of a rigid material and comprises a pair of substantially identical opposed portions each of generally semi-cylindrical shape, sealing means extending along diametrically-opposed longitudinal edges of each portion, first coupling means extending circumferentially of each length of ducting and tensioned to effect a seal between adjacent longitudinal edges of the opposed portions, and further coupling means sealingly interconnecting adjacent lengths of ducting.

2. Ventilation ducting as claimed in claim 1 in which the further coupling means are the same as, and are interchangeable with, the coupling means tensioning the two portions of each length of ducting.

3. Ventilation ducting as claimed in claim 2 in which the coupling means each comprise a band of resilient material provided with tensioning means therein.

4. Ventilation ducting as claimed in claim 3 in which the resilient material is neoprene and the tensioning means each comprise an over-centre mechanism or a toggle mechanism.

5. Ventilation ducting as claimed in any one of claims 1 to 4 in which the sealing means each comprise a longitudinal strip of resilient material of generally H-shape in transverse section adhered to one edge of the associated duct portion, each strip, in use, receiving therein the other edge of the adjacent duct portion.

6. Ventilation ducting as claimed in any one of claims 1 to 5 in which each length of ducting is of glass fibre-reinforced plastic.

7. Ventilation ducting as claimed in claim 6 in which the two opposed portions of each length of ducting are separately preformed.

8. Ventilation ducting substantially as described with reference to and as illustrated by the accompanying drawings.