WO1988008759A1

WO1988008759A1 - Mobile exhaust extractor

Info

Publication number: WO1988008759A1
Application number: PCT/GB1988/000364
Authority: WO
Inventors: Trevor Willis; Brian Rogers
Original assignee: Bt Sales And Services Limited
Priority date: 1987-05-12
Filing date: 1988-05-11
Publication date: 1988-11-17
Also published as: GB8925651D0; GB8711168D0; AU1714988A; GB2228770B; GB2228770A

Abstract

There is provided an exhaust extractor (10) for coupling with an exhaust pipe of an internal combustion engine (13, 14) in order to convey the exhaust gases to a safe discharge point. The extractor comprises a wheel-supported frame (16, 17) to render the extractor mobile, and an extractor fan unit (18) is mounted on the frame having an electric motor coupled with a suction fan, in which the unit is sealed to meet flameproof requirements for the particular operating environment. An intake fitting (19) is mounted on the frame (16) and takes the form of a slide plate (26) slidably mounted on the frame and having one or more inlet fittings (27) for receiving the ends of one or more flexible inlet pipes (15) coupled with respective exhaust pipes, and a gas output fitting (22) of the extractor (10) is coupled with an output of the suction fan and adapted to receive one end of a flexible outlet pipe for discharging the extracted gases to a safe discharge position.

Description

MOBILE EXHAUST EXTRACTOR

This invention relates to a mobile exhaust extractor for coupling with an exhaust pipe of an internal combustion engine in order to convey the exhaust gases away from the immediate environment of the engine.

The invention has been developed primarily, though not exclusively, in relation to a mobile exhaust extractor for use with engines which are operating in confined areas, such as workshops, in order to remove the exhaust gases therefrom, so as to render the area safe for operatives to work on and around the engines. A typical situation may be a military workshop for equipment, such as tanks and armoured vehicles and ground support equipment for use with aircraft, and on which testing and maintenance work is to be carried out.

This can involve the operation of the engines for extended periods, which in the absence of an exhaust extractor system would rapidly render the operating environment, at the very least, unpleasant to work in and, if it is a particularly confined area, may cause a build-up of fumes to a harmful and possibly even toxic level.

Therefore, it is known to provide exhaust extractor systems, which involve the use of flexible pipes which are coupled via suitable "hoods" onto the ends of the exhaust pipes, and which extend to a suitable discharge position at which the exhaust gases" can be safely vented to atmosphere. These pipes may be taken along the floor of the workshop, following manual coupling-up with an exhaust pipe, or may form part of a fixed installation which extends upwardly from the shop floor and through the roof covering the operating area.

The use of fixed installations extending upwardly from the shop floor has the advantage of keeping the pipes out of the way, but the disadvantage that an engine will have to be positioned suitably close to an inlet pipe of the installation. Also, these systems are necessarily quite expensive to install, requiring suitably strong overhead mounting of the installation from which the inlet pipe is suspended. The use of pipes taken over the shop floor has the advantage that the pipes can be moved to suit the position of a particular vehicle, rather than vice versa, but if the exhaust system merely comprises a flexible pipe of a suitable material, with no suction generator associated therewith, there will be a limit to the length of pipe which can be used to convey the exhaust gases, without imposing too great a back pressure feeding-back to the engine which would inhibit its proper operation, and therefore also prevent correct tuning or testing of its operation. Also, the limitation on the length of the pipe may mean that the exhaust gases cannot be conveyed to a discharge po'sition to atmosphere and outside the building forming the operating area.

There is therefore a need to provide an exhaust extractor which is readily mobile to bring it within easy coupling distance of the exhaust pipe of an engine, and which incorporates an extractor fan for applying suction so as to assist the extraction of the' exhaust gases from the exhaust pipe, which will supplement the extraction action produced by the propulsion of the exhaust gases by the piston(s) of the engine during the exhaust stroke.

According to the invention there is provided an exhaust extractor for coupling with an exhaust pipe of an internal combustion engine in order to convey the exhaust gases away from the immediate operating environment of the engine, in which the extractor comprises: a wheel-supported frame to render the extractor mobi le; an extractor fan unit mounted on the frame and having an electric motor coupled with a suction fan, the unit being sealed to meet flameproof requirements for the operating environment; an intake fitting mounted on the frame and coupled with an input of the suction fan, the fitting being adapted to receive one end of a flexible inlet pipe of which the other end is intended to be coupled with an end of an exhaust pipe; and a gas output fitting coupled with an output of the suction fan and adapted to receive one end of a flexible outlet pipe of which the other end is intended to be taken to a safe gas-discharging distance from the engine.

Preferably, the intake fitting comprises a slide plate which is slidably mounted on the frame and which is provided with at least one inlet pipe stub for receiving said one end of the flexible inlet pipe. Conveniently, the pipe stub includes a manually operable detent arrangement for engaging releasably in a holding groove provided at said one end of the inlet pipe, thereby to provide for easy coupling and uncoupling of the inlet pipe.

The slide plate is preferably provided with at least two inlet pipe stubs, which may be of sufficient size to receive the exhaust gases issuing from heavy duty engines, such as tank engines. Usually, a tank has a main engine for propelling the tank, and an auxiliary engine for powering the ancillary components, and the slide plate can therefore receive the exhaust gases of both engines, there being a suitable manifold for conveying the gases to the suction fan.

For use with smaller engines, an alternative or additional slide plate may be provided, having up to six inlet pipe stubs, so that three vehicles (each having two engines) can be operated simultaneously and have their exhausts conveyed away from the operating area via a single exhaust extractor according to the invention.

One embodiment of exhaust extractor according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective illustration of an exhaust extractor according to the invention, and coupled-up with the exhaust pipes of the engines of two vehicles; -and,

Figure 2 is an enlarged perspective illustration of the embodiment of exhaust extractor according to the invention.

Referring first to Figure 1 of the drawings, a mobile exhaust extractor according to the invention is designated generally by reference 10 and is adapted for coupling with at least one exhaust pipe of an internal combustion engine in order to convey the exhaust gases away from the immediate operating environment of the engine. As shown in Figure 1, vehicles 11 and 12 have engines 13 and 14 respectively, and the exhaust pipe of each engine is coupled-up with the exhaust extractor 10 via a respective flexible inlet pipe 15 of a suitable heat resistant material .

When the exhaust extractor 10 is intended for use in a military workshop, in which many of the vehicles undergoing repair and routine maintenance have two engines, (namely a main propelling engine and an auxiliary engine for operating ancillary equipment), the exhaust extractor 10 can discharge the gases from both engines of one or more vehicles, provided that an intake fitting of the extractor 10 has a suitable number of inlet pipe stubs, as will be described in more detail below.

The extractor 10 has a frame 16 supported by wheels 17, so as to render the extractor readily mobile to bring it within easy coupling distance of each engine. An extractor fan unit 18 is mounted on the frame 16 and has an electric motor coupled with a suction fan (not shown) , the unit 18 being sealed internally and externally, so as to meet frameproof requirements for the operating environment. For use with military equipment, this requires the provision of flameproof motors and fittings to zone 2 standard. An intake fitting 19 is mounted on the frame 16 and is coupled with an input of the suction fan via an inlet manifold 20. The intake fitting 19 is adapted to receive one end 21 of at least one flexible inlet pipe (15) , the other end of which is coupled via any suitable hood or other type coupling with the end of the exhaust pipe of the engine (13 or 14) .

A gas output fitting 22 is coupled with an output of the suction fan and is adapted to receive one end 23 of a flexible outlet pipe 24 of which the other end 25 is intended to be taken to a safe gas-discharge position from the engines 13 and 14, which will usually be to a suitable position well away from the operating area for discharge to atmosphere.

The intake fitting 19 comprises a slide plate 26 which is slidably mounted on the frame 16 and which is provided with at least one inlet pipe stub 27 for receiving the end 21 of the flexible inlet pipe 15. Each pipe stub 27 includes a manually operable detent arrangement (not shown) for engaging releaεably in a holding groove (also not shown) provided at the end 21 of each flexible inlet pipe 15, thereby to provide for easy coupling and uncoupling of the inlet pipe.

As shown in Figure 1, two inlet pipe stubs 27 are provided, which are of sufficient size to receive the exhaust gases issuing from heavy duty engines. However, for use with smaller engines, an alternative or additional slide plate may be provided (not shown in Figure 1), having up to six inlet pipe stubs, so that three vehicles (each having two engines) can be operated simultaneously and have their exhaust gases conveyed away via a single exhaust gas extractor 10.

The extractor 10 is shown to an enlarged scale in Figure 2, and parts corresponding with those already described with reference to the schematic illustration of Figure 1 are designated by the same reference numerals. In Figure 2, there is shown a slide plate 26 provided with a pair of large inlet pipe stubs 27, but there is also shown on top of the unit an alternative slide plate 26a which is provided with six smaller inlet pipe stubs 28.

Also, although not shown, there will be provided a mobile hose stowage basket 29 in which are stored a number of inlet and outlet pipes for use with the exhaust gas extractor.

To promote the cooling of the exhaust gases, an inlet fitting (not shown) may be provided at the upstream end of the inlet pipe, which permits ambient cooling air to be drawn into the pipe by a suction effect generated by the discharge of the exhaust gases into the pipe via the fitting.

An exhaust gas extractor according to the invention may be provi-ded with an interchangeable set of exhaust inlet manifolds (20) . to accommodate special flexible high temperature hoses, for a wide range of aircraft ground support equipment and motor transport vehicles.

An exhaust gas extractor according to the invention may also be used to extract harmful gases from other sources, such as those produced during welding.

Although not shown, the slide plate of the intake fitting (19) may be provided with one or more sockets (in place of the pipe stubs 27) to receive respective ends of flexible inlet pipes leading to a source of gas which requires extraction and delivery to a safe discharge point.

Claims

CLA I MS

1. An exhaust extractor for coupling with an exhaust pipe of an internal combustion engine in order to convey the exhaust gases away from the immediate operating environment of the engine, in which the extractor comprises: a wheel-supported frame to render the extractor mobi le; an extractor fan unit mounted on the frame and having an electric motor coupled with a suction fan, the unit being sealed to meet flameproof requirements for the operating environment; an intake fitting mounted on the frame and coupled with an input of the suction fan, the fitting being adapted to receive one end of a flexible inlet pipe of which the other end is intended to be coupled with an end of an exhaust pipe; and a gas output fitting coupled with an output of the suction fan and adapted to receive one end of a flexible outlet pipe of which the other end is intended to be taken to a safe gas-discharging distance from the engine.

2. An exhaust extractor according to Claim 1, in which the intake fitting comprises a slide plate which is slidably mounted on the frame and which is provided with at least one inlet pipe stub for receiving said one end of the flexible inlet pipe.

3. An exhaust extractor according to Claim 2, in which the pipe stub includes a manually operable detent arrangement for engaging releasably in a holding groove provided at said one end of the inlet pipe.

4. An exhaust extractor according to Claim 2 or 3, in which the slide plate is provided with two or more inlet pipe stubs.

5. An exhaust extractor according to Claim 1, in which the intake fitting comprises a slide plate which is slidably mounted on the frame and which is provided with at least one socket for receiving said one end of the flexible inlet pipe.