GB2028459A

GB2028459A - Pipe Descaling Machine

Info

Publication number: GB2028459A
Application number: GB7928973A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-20
Filing date: 1979-08-20
Publication date: 1980-03-05

Abstract

A machine for descaling the interior of pipes 10 has a rotatable member on which flexible flail elements are mounted and which is driven by e.g. an air motor 14. The machine is supported from the pipe by a sledge 11 so that the axis of rotation of the rotatable member is at the axis of the pipe. Preferably the flail elements are chains 21 with weights 22 attached to the ends. The machine may be winched through the pipe or inserted at the end of a bar. Air vented from the motor 14 may blow away debris. <IMAGE>

Description

SPECIFICATION Pipe Descaling Machine This invention relates to a machine for removing scale or other deposits adhering to the interior walls of pipes particularly but not exclusively, relatively large diameter pipes.

Various methods are used for descaling pipes including brushes, shot blasting and the like but in some applications, for example, pipes having a lining of concrete, it is difficult to remove the deposit. In addition pipes to which relatively soft deposits adhere can be difficult to deal with by existing methods. For example outflow sewage pipes can pose problems in removing the soft materials adhering thereto.

An object of the invention is to provide a machine capable of effectively removing both hard and soft deposits from the interior of pipe walls.

According to the invention, a pipe descaling machine comprises a rotatable member, two or more flail elements arranged to extend outwardly of the member upon rotation thereof so that the outer ends of the elements circumscribe a circle corresponding in diameter to the size of'pipe, support means for the member for movably supporting the member in the pipe with its axis of rotation substantially at the axis of the pipe, and drive means for rotating the rotatable member.

Preferably the flail elements are in the form of chains and the chains may each carry a weight at its outer end which acts as an abrading or descaling element by engaging the deposit on the pipe and releasing it from the pipe wall.

Further features of the invention will appear from the following description of an embodiment of the invention given by way of example only and with reference to the drawings in which: Fig. 1 is a side elevation of the machine in situ in a pipe, and Fig. 2 is an end elevation in the direction of arrow A in Fig. 1 to a smaller scale.

Referring to the drawings a pipe descaling machine is shown in a pipe 10 of relatively large diameter, for example 12 to 18 inches. The machine includes a sledge 11 by which the machine is mounted to move along the pipe. The sledge 11 includes a base member 12 to the outer edges of which are attached runners 13 in the form of cylindrical rods or tubes of which the ends are bent upwards and inwards. It will be noted that the base member 12 leaves a space below the machine and deposits removed from the pipe will tend to gather in this space to enable the machine to pass over the deposits during progress along the pipe.

The machine is normally moved during operation in the direction of arrow X so that progress of the machine is over pipe which has been cleaned of deposits.

Bolted to the base member 12 is an air operated motor 14 mounted about a horizontal axis and having an output shaft 15, the runners 13 being positioned in relation to the axis of the motor such that the axis is at the axis of the pipe 10.

A sieeve 1 7 is engaged over the end of the shaft 1 5 and is formed with a disc 18. A further larger diameter disc 1 9 is replaceably attached to the disc 1 8 for rotation therewith on operation of the motor and the disc 19 has a plurality of fixing holes, preferably six, in each of which a shackle 20 can be fixed for attaching a length of chain 21.

At the other end of each length of chain 21 a weight 22 is attached, the weight being selected according to the nature of the deposit to be removed from the pipe wall.

The chains 21 are the same length and the outer ends of the weights are each at the same distance from the axis of the shaft 1 5 when the motor is operated and circumscribe a circle when the disc is rotating. The circle has a diameter substantially equal to or slightly greater than the internal diameter of the pipe 10. Thus during rotation any deposit on the wall of the pipe is contacted by the weights and removed. This applies even if the deposits are hard, such as concrete, or soft, such as deposits in sewage pipes.

Air from the air motor 14 is led to the machine from the downstream side of the machine through a pipe 23 and exhaust air is vented through a pipe 24. The pipe 24 may be directed towards the rotating chains to carry dust released during operation away from the machine.

Alternatively to reuse the exhaust air the pipe 24 may be connected to introduce the air into the inlet air pipe 23.

It has been found that for hard deposits on a pipe having a diameter in the range 12 to 18 inches a rotational speed of 500-2,500 revolutions per minute is effective in removing the deposits. For soft deposits the speed may be slower. In such a machine a motor rate at 11 h.p.

has been found satisfactory.

The size of the disc 1 9 may be increased or decreased according to the size of pipe and the air motor, although particularly advantageous under the conditions prevailing in pipes, may be replaced by an electric motor.

To draw the machine through the pipe a winch or winches may be used with the winch rope or wire attached to the disc 1 9 through a bearing to prevent the rope being rotated.

Alternatively, when access to the end of the pipe makes it possible, a rigid bar (not shown) may be attached to the rear of the machine to extend out of the end of the pipe to be held manually and used to push the machine along the pipe.

Although the machine is shown with three chains 21 and associated weights, it will be appreciated that two, four or six lengths of chain can be used, provided they are fitted in a balanced orientation, according to the nature of the deposit to be removed.

In operation a torque reaction due to the impact of the flails on the pipe deposit will be created. With soft materials this may be insufficient to affect the stability of the machine, but with hard deposits it is desirable to provide means for resisting the torque reaction. In one arrangement the machine is fitted with radially direct members or shoes which engage the pipe wall under spring bias.

Claims

1. A pipe descaling machine comprising a rotatable member, two or more flexible flail elements arranged to extend outwardly of the member upon rotation thereof so that the outer ends of the elements circumscribe a circle corresponding in diameter to the size of pipe, support means for the member for movably supporting the member in the pipe with its axis of rotation substantially at the axis of the pipe, and drive means for rotating the rotatable member.

2. A machine according to Claim 1 wherein the flail elements are in the form of chains.

3. A machine according to Claim 2 wherein the chains each carry a weight at its outer end to act as an abrading or descaling element.

4. A machine according to any one of the preceding claims wherein the support means includes a sledge having runners slidably engageable with the walls of the pipe.

5. A machine according to any one of the preceding claims comprising attachment means for attaching traction means for moving the machine along the pipe.

6. A pipe descaling machine substantially as described with reference to the drawings.