GB2062802A - Tube cleaning device - Google Patents

Abstract

The invention relates to (condenser 1) tube cleaning devices utilising cleaning balls 2, wherein if, e.g., water passing through tubes contains fibrous material having passed a preliminary sieve the fibres clog a sieve forming part of the cleaning device thereby preventing the passage of the balls. The sieve must therefore be flushed frequently which can cause substantial loss of cleaning balls. This problem is overcome by a device comprising a sieve attachment 4 mounted in the outlet 3 (from the condenser 1), incorporating a V- shaped sieve formed by two hinged sieves 5 followed by a sieve box 6, a cleaning ball return pipe 7 containing a pump 8 being connected to the sieve 5 and leading through a sluice 9 to the (condenser) inlet, the sluice 9 separating the cleaning balls 2 from fibrous material, by a hydrocycline sieve 11 with a tangential inlet union 12, the hydrocycline sieve 11 being connected to the cleaning ball return pipe water and fibrous material passing through the hydrocycline sieve to a valved 15 cooling water return pipe 17 connected in the outlet pipe 16 (from the condenser) at a point beyond the first sieve attachment 4. <IMAGE>

Description

SPECIFICATION Tube cleaning device This invention relates to devices for cleaning tubes, particularly tubes in power station condensers, with the aid of cleaning balls, and having a sieve attachment mounted in the outlet pipe from the condenser, incorporating V-shaped separating sieves followed in the direction of flow by a sieve box, a cleaning ball return pipe containing a return pump being connected to the sieve box and leading through a cleaning ball sluice to the condenser inlet.

In known devices of this type, the cleaning ball sluice functions simply as a sluice for the cleaning balls. It is constructed as a pot into which the cleaning balls sink and from which they can be recovered, and for this purpose, the sluice is provided with a removable cover. Cleaning balls can also be introduced into the cleaning system through the sluice. In the working conditions for tube cleaning, the cleaning balls are transferred from the cleaning ball sluice to the cleaning system or introduced directly into the cleaning system, and when they reach the condenser inlet, they are recovered from the cooling water in the sieve attachment and returned through the cleaning ball return pipe. When cleaning is not in progress, the cleaning balls remain in the sluice or are removed therefrom, the return pipe being blocked off in this condition.The entire device is preceded by preliminary cleaning sieves for the cooling water. The sieve attachment as such can be cleaned by flushing out, and suitable fittings are usually provided. During flushing operations, the dirt which has been deposited in the sieve attachment is carried away with the cooling water used for flushing into the outlet pipe, and, for example, returned to the watercourse from which the cooling water is initially taken.

However, problems can arise if the cooling water is unusually heavily contaminated with grass stalks and other fibrous material, and if substantial amounts of such fibres pass through the preliminary cleaning sieves for the cooling water and enter the pipe cleaning system, the fibres are deposited in the sieve attachment and may also prevent cleaning balls from passing through it. Therefore, the sieve attachment must be flushed out frequently, and in the process substantial numbers of cleaning balls are lost.

The object of the invention is to improve and modify a device of the type in question, so that fibres and the like deposited in the sieve attachment can be removed without losses of cleaning balls.

According to the present invention a device for cleaning tubes with the aid of cleaning balls comprises a sieve attachment mounted in the outlet pipe from the condenser, incorporating Vshaped separating sieves followed in the direction flow by a sieve box, and a cleaning ball return pipe containing a return pump being connected to the sieve box and leading through a cleaning ball sluice to the condenser inlet, the cleaning ball sluice being adapted as a separator to separate the cleaning balls from fibrous material, by providing a separating sieve of the hydrocyclone type together with a tangential separator inlet union, the inner compartment of the separating sieve being connected back to the cleaning ball return pipe while its outer compartment is connected through a valve device beyond the separating sieve to a cooling water return pipe inserted in the outlet pipe from the condenser at a point beyond the sieve attachment.

Thus, all deposits in the sieve attachment are diverted during flushing out through the cleaning ball return pipe and into the separator. It is selfevident that a suitable volume of return-flow water must be used for this purpose. In this connection, it is preferred within the invention to adapt the cleaning ball return pipe to function simultaneously as a flushing pipe, dimensioning the return pump accordingly. In the separator, the deposits are separated from the cleaning balls, and the cleaning balls are returned to the condenser inlet, so that they can continue their cleaning action. The fibres or other deposits are returned to the outlet pipe from the condenser at a point beyond the sieve attachment.To ensure that all the deposits can be released from the separating sieves during flushing operations, it is preferred that the separating sieves are swivellable about a horizontal axle near the sieve box, so that they can be flushed out. In order to flush out the sieve box as well, it is further preferred that the sieve attachment has adjustable guides, which also function as closure vanes, mounted between the separating sieves and the sieve box.

One embodiment of the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a schematic side elevation of a device of the invention for cleaning the tubes in power-station condensers; Figure 2 shows the sieve attachment of the device of Figure 1, on a much larger scale and partly in vertical section; and Figure 3 shows the separator of the device of Figure 1, on the same scale as Figure 2 and again in vertical section.

The device shown in the Figures is intended for cleaning the tubes in a power-station condenser 1 with the aid of cleaning balls 2. A few of the cleaning balls 2 are shown in the Figures on a larger than natural scale, for ease of tracing the path they follow. The device has a sieve attachment 4 mounted in the outlet pipe 3 from the condenser 1, incorporating a V-shaped set of separating sieves 5, flat in the embodiment shown and followed in the direction of flow by a sieve box 6.

A cleaning ball return pipe 7 containing a return pump 8 is connected to the sieve box 6 and leads through a cleaning ball sluice 9 to the condenser inlet 10. A comparison of Figures 1 and 3 shows in particular that the cleaning ball sluice is adapted as a separator 9 to separate the cleaning balls from fibrous material, and incorporates a separating sieve 11 of the hydrocyclone type, together with a tangential separator inlet union 12. The inner compartment 13 of the separating sieve 11 is connected to the cleaning ball return pipe, while its outer compartment 14 is connected through a valve device 15 to a cooling water return pipe 17 inserted in the outlet pipe 16 from the condenser 1 at a point beyond the sieve attachment 4.In Figure 1, the section of the cleaning ball return pipe 7 leading back from the inner compartment 13 of the separating sieve 11 to the condenser inlet 10 is only indicated by dashed lines.

A comparison of Figures 1 and 2 shows that the separating sieves 5 are swivellable about a horizontal axle 1 8 near the sieve box 6, so that they can be flushed out. The scrap view on a larger scale, included in Figure 1, shows that in the preferred embodiment of the invention, the sieve attachment 4 has adjustable guides 1 9 mounted between the separating sieves 5 and the sieve box 6. They are adapted to act simultaneously as closure vanes. The cleaning ball return pipe 7 simultaneously functions as a flushing line and the return pump 8 is dimensioned accordingly.

As a result, any dirt, mainly of a fibrous nature, that collects in the sieve attachment 4 is removed along with the cleaning balls 2 from the sieve attachment 4 to the separator 9, which simultaneously functions as the sluice, and is there separated from the cleaning balls 2.

Consequently, losses of cleaning balls 2 for the reasons referred to in the introduction can no longer occur.

The sieve attachment 4 of the invention, as shown in the Figures, differs from that of prior art in that the separating sieves 5 can swivel as described about a horizontal axle 1 8. As a result, all the deposits collected on the sieve faces are emptied during the flushing operations into the sieve box 6. For this purpose, the two separating sieves 5 are successively and/or repeatedly swivelled into a flushing position, as shown by dashed lines in Figure 2. The wdith of the sieve box 6 is suitably increased. By virtue of the guides 19, which simultaneously act as closure vanes, the sieve box 6 can be flushed out without difficulty. The volume of cooling water diverted from the sieve attachment 4 during flushing operations is quite substantial, and is returned by special pumps to the outlet pipe from the condenser 1, at a point beyond the sieve attachment 4. The separator 9 functions by initially setting up a strong rotary current, from the tangential feed, and this prevents any blockage of the separating sieve 11 by fibres or the like, and separates the cleaning balls 2 from dirt of this nature.

Under cleaning conditions, the cleaning balls 2 are recovered from the separator, along with a much smaller volume of water than has been used for the flushing operations, and returned to the condenser inlet 10. The valve 20 in the condenser outlet can be used to obtain "ball recovery" operating conditions, under which the cleaning balls 2 remain in the separator 9. They can be removed or inspected after opening the cover 21.

Balls 2 can also be introduced once again through the separator 9, which in this connection still functions, in the device of the invention, as the cleaning ball sluice.

Claims (5)

1. A device for cleaning tubes with the aid of cleaning balls comprising a sieve attachment mounted in the outlet pipe from the condenser, incorporating V-shaped separating sieves followed in the direction of flow by a sieve box, and a cleaning ball return pipe containing a return pump being connected to the sieve box and leading through a cleaning ball sluice to the condenser inlet, the cleaning ball sluice being adapted as a separator to separate the cleaning balls from fibrous material, by providing a separating sieve of the hydrocyclone type together with a tangential separator inlet union, the inner compartment of the separating sieve being connected back to the cleaning ball return pipe, while its outer compartment is connected through a valve device beyond the separating sieve to a cooling water return pipe inserted in the outlet pipe from the condenser at a point beyond the sieve attachment.

2. A device as in Claim 1, wherein the separating sieves are swivellable about a horizontal axle near the sieve box, so that they can be flushed out.

3. A device as in Claim 1 or Claim 2, wherein the sieve attachment has adjustable guides, which also function as closure vanes, mounted between the separating sieves and the sieve box.

4. A deivce as in any of Claims 1 to 3, wherein the cleaning ball return pipe is adapted to function simultaneously as a flushing pipe, and the return pump is dimensioned accordingly.

5. A device for cleaning tubes with the aid of cleaning balls substantially as hereinbefore described with reference to the accompanying drawings.