JPS60181594A - Removing device for scale in bundle of tube for heat exchanger or the like - Google Patents

Abstract

PURPOSE:To permit to remove scale thoroughly by a method wherein a gas sealing device is provided and sponge balls are dehydrated to circulate them through the inside of the bundle of tube. CONSTITUTION:When a chamber 19 is filled with gas through a gas sealing pipe 20 and a cage unit 17 is rotated, processing water is dehydrated by a centrifugal force and the gas is sealed into the inside of the ball 15. Next, the processing liquid is introduced into the chamber 19 by a pump 23 to float up the sponge balls 15 and flow them through a transfer tube 6. The sponge balls 15 pass through the bundle of tubes of the heat exchanger 2 together with the processing liquid, remove the scale, separated from the processing liquid in a strainer 9, return into the chamber 19 through a return pipe 25 and thus they are recirculated. At the initial period of circulation, the specific gravity of the ball is light due to the sealing of the gas and the ball passes through the heat transfer tube at the upper side of the bundle of tube, however, the gas is removed during repeating the circulation of the ball, the specific gravity of the ball becomes heavier and the ball passes through the heat transfer tubes at the lower side of the bundle of tube. Accordingly, the sponge balls pass all the tubes at the upper and lower parts of the bundle of tube and the scale in the tubes may be removed in all stages of the tubes.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a scale removal device for a heat exchanger, etc., which uses sponge balls to flow together with a fluid in a tube bundle of a heat exchanger, and uses the balls to remove scale attached to a tube bundle. In particular, it relates to a device for removing scale within a tube bundle, such as a heat exchanger, which allows sponge balls to pass through the tube bundle to remove scale within the tube bundle.

[Technical background of the invention and its problems] A heat exchanger has a tube bundle consisting of a large number of heat transfer tubes, and indirectly heat exchanges fluids with 11 different temperatures, but there is scale on the inner wall of the heat transfer tubes. There is a problem in that it tends to adhere (which causes a phenomenon that reduces heat transfer efficiency).

Conventionally, as a method for removing scale attached to the tube bundle of this heat exchanger, a large number of sponge balls are caused to flow together with the fluid in the tube bundle, and the sponge balls are passed through each heat transfer tube of the tube bundle.
It is known that scales can be removed using This method has the advantage that it can be carried out during operation and that the fluid in the tube bundle and the sponge balls can be easily separated, compared to the method of removing scale with chemicals or cleaning the heat transfer tubes one by one with a drill.

However, if there is a difference in specific gravity between the sponge balls and the fluid in the tube bundle, for example, if the sponge balls are lighter than the fluid, they will float due to the buoyancy of the sponge balls. The scale will flow and the scale on the lower heat exchanger tube cannot be removed. On the other hand, if the specific gravity becomes heavy, there is a problem in that scale is removed only from the lower heat exchanger tube.

For this reason, sponge balls have been formed to have the same specific gravity as the fluid, but in this case, it cannot be applied to devices in which many heat exchangers are connected in series, such as condensing heat exchangers in desalination equipment. .

In other words, the fluid in the tube bundle direction of the heat exchanger exchanges heat at each stage, so the temperature of the fluid differs in each stage, and the specific gravity differs, so if the sponge balls are adjusted to the specific gravity of the fluid in the inlet stage, the fluid in the outlet side The stage heat exchanger tube bundles cannot be adequately descaled.

[Objective of the Invention J The object of the present invention is to remove scale within a tube bundle of a heat exchanger using sponge balls.
The present invention provides a device for removing scale within a tube bundle such as a heat exchanger.

[Summary of the Invention] The present invention provides a ball supply device for mixing sponge balls into the fluid on the inlet side of a tube bundle such as a heat exchanger, and a strainer for separating the fluid and sponge balls on the outlet side of the tube bundle. At the same time, in the descaling unit in which the sponge balls separated by the strainer are returned to the ball supply device, a gas enclosing device is provided in the ball supply device to fill the sponge balls with gas. The sponge ball is dehydrated using a gas filling device, and the gas sealed inside is circulated within the tube bundle.As the sponge ball is circulated several times, the gas sealed in the sponge ball gradually becomes 1112 gas. As the specific gravity changes, scale can be removed from the top to the bottom of the tube bundle.

[Embodiments of the Invention] Hereinafter, a preferred embodiment of the apparatus for removing scale within a tube bundle such as a heat exchanger according to the present invention will be described with reference to the accompanying drawings.

The attached drawings show an example in which the scale removing apparatus of the present invention is applied to a seawater desalination apparatus, and the desalination apparatus is composed of a large number of flash evaporation chambers 1 arranged in parallel. Evaporation chamber 1
A heat exchanger 2 consisting of a tube bundle of a large number of heat transfer tubes is provided, and the fluid flowing inside the heat exchanger 2 is preheated by the vapor of the processing liquid 3 accumulated in the evaporation chamber 1, and the vapor is condensed.

Processing liquid such as seawater is transferred from the supply pipe 4 to the pump 5 and transfer pipe 6.
It flows through the heat exchanger 2 at the front stage of the heat recovery section 7 through the heat exchanger 2 of the heat recovery section 7, sequentially flows through the heat exchanger 2 of each evaporation chamber 1, is heated by the heater 8, and passes through the strainer 9 and the pipe 10 to the heat recovery section. It flows into the evaporation chamber 1 in the latter stage of the evaporation chamber 7, and then flows to the evaporation chamber 1 in the former stage while undergoing flash evaporation there. The processing liquid 3 flowing into each evaporation chamber 1 flash-evaporates there, preheats the processing liquid flowing through the upper heat exchanger 2, and condenses. Although the condensate is not shown, it is collected as fresh water in a saucer or the like.

The processing liquid 3 that has left the front stage of the heat recovery section 7 flows through the connecting pipe 11 to the evaporation chamber 1 of the heat radiation section 12, where it similarly heats the heat exchanger 2 while undergoing flash evaporation.

The fluid flowing through the heat exchanger 2 of this heat radiation section 12 is transferred to the heat recovery pipe 1
3 and sent to other systems. Mata 1! ! ! The liquid 3 is discharged from the discharge pipe 14, and a part of the liquid 3 is discharged from the supply pipe 4. It is mixed with the liquid and transferred to the heat recovery section 7 again.

Each heat exchanger 2 in the heat recovery section 7 is connected in series, and the evaporation temperature of the processing liquid 3 in each stage is different, being lower in the former stage and higher in the latter stage, and similarly The temperature is low (but gets higher in the later stages).

A scale removing apparatus of the present invention for removing scale adhering to the inside of the tube bundle of the heat exchanger 2 in the heat recovery section 11 will be described.

First, a ball supply device 16 for supplying sponge balls 15 is connected between the transfer pipe 6 on the inlet side of the heat exchanger 2 and the strainer 9 on the outlet side.

This ball supply device @16 includes a basket portion 17 that accommodates the sponge balls 15, and a drive device that rotates the basket portion 17.
18, and an enclosed gas introduction pipe 20 for introducing gas into the cavity 19 in which the cage portion 17 is accommodated.

The sponge balls 15 of the ball supply device 16 are transferred to the heat exchanger 1.
In order to mix the liquid into the inlet side fluid, for example, connect a pipe 22 to the transfer pipe 6, connect a pump 23 for ball circulation to the pipe 22, and supply the processing liquid introduced by the pipe 22 and pump 23. The sponge balls 15 are introduced into the lower chamber 19a of the basket section 17 in the chamber 19 of the device 16, floated through the basket section 17 into the upper chamber 191), and the sponge balls 15 are transferred from the supply pipe 24 together with the processing liquid into the transfer pipe 6. is mixed into the flowing processing liquid.

Also, from the transfer pipe 6 through each heat exchanger 2 of the heat recovery section 7,
The sponge balls 15 that have passed through the heater 8 are separated from the processing liquid by the strainer 9, returned to the upper chamber 19b of the supply device 16 through the return pipe 25, and returned onto the basket portion 17.

A gas vent pipe 26 is connected to the upper part of the chamber 19.
A drain pipe 27 for draining the processing liquid in the container 9 is connected. Further, the surplus processing liquid during circulation through the sponge ball 15 is returned from the pipe 28 to the pipe 10 at the processing liquid outlet of the strainer 9.

In addition, 29.30, 31.3.2 in the figure are sponge balls 1
A valve 33 is installed in the gas inlet pipe 20, and a valve 34 is installed in the gas outlet pipe 26.

Next, the present invention will be explained in detail.

When removing scale in the tube bundle of the heat exchanger 2, the processing liquid in the chamber 19 of the ball supply device 16 is drained into the drain pipe 27.
and fill the chamber 19 with gas from the gas filling tube 20,
When the cage portion 17 of the gas enclosing device 21 is rotated in this state, the treated water contained in the sponge balls 15 is centrifugally dehydrated, gas is enclosed within the balls 15, and the specific gravity thereof becomes lighter. Next, the processing liquid in the transfer pipe 6 is introduced into the chamber 19 through the pipe 22 by the pump 23, and the sponge ball 1 is
5 floats up and flows into the transfer pipe 6 via the pipe 24. The sponge balls 15 mixed into the transfer tube 6 flow into the heat exchanger 2 together with the processing liquid in the tube 6, where they pass through the tube bundle of the heat exchanger 2 to remove scale within the tube bundle, and then pass through the strainer 9. The liquid is separated from the processing liquid, returned to the chamber 19 via the return pipe 25, and circulated again as described above.

At the beginning of the circulation of the sponge ball 15, the specific gravity is light because the sponge ball 15 is filled with gas.
The sponge balls 15 pass through the heat transfer tubes at the top of the tube bundle of each heat exchanger 2, but as the circulation is repeated, the sponge balls 15
The gas sealed inside is gradually degassed and the specific gravity becomes heavier.
It passes through the heat transfer tubes at the bottom of the tube bundle of each heat exchanger 2.

Therefore, due to this change in the specific gravity of the sponge balls 15, the sponge balls 15 pass over and over the tube bundle of each heat exchanger 2, and scale within the tube bundle is removed at all stages.

[Effects of the Invention] As is clear from what has been described in detail below, the present invention exhibits the following excellent effects.

(1) A gas enclosing device is installed to remove scale from the tube bundle of the heat exchanger. The sponge balls are dehydrated and filled with gas. By repeatedly circulating the sponge balls filled with the gas, the gas is sealed during the circulation. gas is released,
Because the specific gravity is heavy, all scale within the tube bundle can be removed.

(2) Since the sponge balls are gradually degassed, the passing distribution of the balls in each tube bundle can be uniform, so that scale can be removed efficiently and a good heat exchange rate can be maintained even during operation.

[Brief explanation of the drawing]

The accompanying drawings are diagrams showing one embodiment of the apparatus for removing scale within a tube bundle such as a heat exchanger according to the present invention. In the figure, 2 is a heat exchanger, 9 is a strainer, 15 is a sponge ball, 16 is a ball supply device, and 21 is a gas enclosure device. Patent applicant: Patent attorney representing Ishikawajima-Harima Heavy Industries Co., Ltd.
Nobuo Kinuya

Claims (1)

[Claims] A ball supply device is provided on the inlet side of the fluid in a tube bundle such as a heat exchanger to mix sponge balls into the fluid, and a strainer is provided on the outlet side of the tube bundle to separate the fluid and sponge balls. A tube bundle for a heat exchanger or the like, characterized in that a scale removing device returns sponge balls to the ball supply device, and the ball supply device is provided with a gas entrapment device for dehydrating the sponge balls and enclosing gas therein. Internal scale device.