JPH0417355B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a heat exchanger tube with a storage container or a retainer at both ends, and the inside of the tube is cleaned by moving a cleaning material such as a brush. This relates to a tube cleaning device for a heat exchanger that cleans the inner wall of the tube by reciprocating the cleaning material while changing the direction of fluid flow between forward and reverse directions at any time using a valve provided at the inlet and outlet of the heat exchanger. be.

[Prior Art] A heat exchanger transfers heat between two fluids flowing inside and outside a tube whose ends are fixed to a tube plate, cooling one fluid and heating the other fluid. Foreign matter tends to accumulate on the inner wall,
The accumulation of foreign matter significantly reduces the efficiency of heat exchange.

Therefore, a tube cleaning material is stored in a container or a holder provided at both ends of the tube of the heat exchanger, and the cleaning material is moved back and forth within the tube periodically or at any time using the power of the internal fluid. It is common to wash or clean the inner walls of the tube.

For example, as shown in FIG. 3, the tubes 3 in the heat exchanger 1 are attached to the tube plate 2 by a method such as tube expansion. There are water chambers 4 at both ends of the heat exchanger, and fluid flows into the water chambers 4, passes through the tubes 3, and exits from the opposite water chamber. A basket-shaped storage container 5 is attached to both ends of the tube by a holding plate 7, and a tube cleaning material 6 is stored in the storage container 5. In FIG. 3, the cleaning material is stored in the right storage container 5 because the flow direction of the fluid in the tube is to the right when facing the drawing. Further, the flow flows from the left side to the right side in the figure, flows from the tube 3 to the storage container 5, and flows out from the small hole 51 of the storage container into the water chamber 4 on the right side. (The water chamber on the left side is not shown.) A valve is connected to the inlet of the heat exchanger water chamber, and the flow direction is switched by switching the valve. For example, the fourth
As shown in the figure, a valve piping 30 consisting of four valves 31 to 34 is provided at the inlet and outlet nozzles of the heat exchanger water chamber 4 (in Figure 4, the outlined valves 31 and 33 are in the open state). , and the black valves 32 and 34 are in the closed state.) By switching each valve of this valve piping 30, the direction of the flow supplied from the pump 35 changes from a solid line to a broken line, and the cleaning material 6 (see FIG. 3) leaves the container 5, flows while washing the inner wall of the tube, and is retained in a container attached to the opposite end of the tube.

[Problem that the invention seeks to solve]

The purpose of the tube cleaning device is to keep the tubes of the heat exchanger clean at all times and to eliminate maintenance such as normal manual tube cleaning. However, this type of tube cleaning device is weak against fluids containing filamentous foreign matter, and if filamentous foreign matter such as hair, fibers, etc. enter the fluid,
The cleaning material 6 becomes tangled in the storage container 5 and becomes clogged within the storage container 5, making it inoperable, resulting in the disadvantage that maintenance must be performed quite frequently.

Therefore, when using fluid containing such foreign substances, this type of tube cleaning device cannot be used.

The present invention solves the above problems, and even when a fluid containing filamentous foreign matter is used, the cleaning material does not become inoperable, and the inside of the tube can always be kept clean, and the filter can be kept clean at all times. An object of the present invention is to provide a tube cleaning device for a heat exchanger that can be kept clean.

[Means for solving problems]

The present invention provides a holder for tube cleaning material at both ends of the tube of the heat exchanger to hold the same number of cleaning materials as the tube, and connects a flow path switching valve to the water chamber inlet/outlet nozzle of the heat exchanger, In the tube cleaning device that cleans the inner wall of the tube by reciprocating the cleaning material within the tube using the flow of internal fluid accompanying switching of the flow path, the flow path switching valve is configured as a four-way valve, A four-way valve is connected to the water chamber inlet/outlet nozzles on the upstream side and downstream side of the heat exchanger, and the flow between the upstream side of the heat exchanger or this and the water chamber inlet/outlet nozzle on the downstream side is connected. The tube cleaning device is characterized in that a filter is provided in the channel, and the flow filtered by the filter is directed to the water chamber inlet/outlet nozzle.

〔Example〕

Hereinafter, the present invention will be described in more detail based on examples. As shown in FIG. There is a water chamber 4, and fluid flows into the water chamber 4, passes through the tube 3, and flows out from the water chamber on the opposite side. A basket-shaped storage container 5 is attached to both ends of the tube 3 by a holding plate 7, and inside the storage container 5 is a tube cleaning material 6.
are contained in each. In FIG. 3, the flow direction of the fluid in the tube is in the direction of the arrow, that is, in the tube 3.
The water flows from the water into the container 5 and flows out into the water chamber 4 through a small hole 51 in the container.

Fig. 1 shows an example in which the flow direction of the fluid in the heat exchanger is constant (the upper water chamber 4' serves as the inlet), and the cleaning with the cleaning material is performed in one reciprocation unit. During operation, the cleaning material is always stored in the holder installed in the lower water chamber 4''.When cleaning the tube, the pump 35 is used to change the flow direction of the fluid.
A four-way valve 30' is provided which communicates with the discharge side of the
A filter 40 is provided between the four-way valve 30' and the water chamber 4' on the inlet side of the heat exchanger. The filter 40 can have a simple structure because it is specifically designed to capture only filamentous foreign matter. For example, a strainer such as punched metal, sand, or gravel can also be used. Four-way valve 30'
It is preferable to automate this in order to facilitate maintenance, and there is a method in which a timer is used to make one reciprocating operation at a fixed time interval, or a pressure loss before and after the filter 40 is detected by a differential pressure switch 45 and the control panel and motor 47 are activated. or a combination of both methods.

According to this embodiment, filamentous foreign matter is captured by the filter 40 and a fluid containing no foreign matter is introduced into the heat exchanger 1, so that the conventional problems with storage containers and cleaning materials are solved.

On the other hand, the filamentous foreign matter accumulated in the filter 40 is backwashed when switching the four-way valve 30', and
It is discharged without passing through.

However, in this embodiment, since a filter is not provided on the water chamber 4'' side, fluid that is not purified by the filter will flow.Therefore, in FIG. It is necessary to shorten the time as much as possible.

Next, Fig. 2 shows the present invention, which is adopted when the flow direction of the fluid is not constant, that is, when the heat transfer performance does not change much no matter which nozzle of the upstream or downstream water chamber 4' or 4'' becomes the inlet. This is a second embodiment of the invention.

In this embodiment, in addition to the filter 40 in FIG. 1, a filter 41 is also provided in the downstream water chamber 4''. It is something that only functions when it flows.

By periodically operating the four-way valve 30', the tube 3 is cleaned with the cleaning material 6 inside the heat exchanger 1, and the filter 40 or 41 on the outlet side of the heat exchanger 1 is backwashed. It can be cleaned by

〔Effect of the invention〕

The present invention configures the flow path switching valve as a four-way valve, and connects the four-way valve to the water chamber inlet/outlet nozzle located upstream and downstream of the heat exchanger, and A filter is provided in the flow path between this and the water chamber inlet/outlet nozzle on the downstream side, and the flow filtered by the filter is directed toward the water chamber inlet/outlet nozzle. It can accurately prevent foreign matter from entering the heat exchanger, and the cleaning material can be reciprocated within the tube by changing the flow direction of the fluid, automatically cleaning the inner wall of the tube periodically or at any time. By trapping filamentous foreign matter that is about to flow in by the filter, it is possible to solve the conventional problem in which the foreign matter becomes entangled with the cleaning material and the holder, making it impossible to clean. In addition, backwashing allows the filter to be cleaned to its full potential. Therefore, the present invention aims to reduce the operating cost of the heat exchanger by making the heat exchanger maintenance-free, and by making it possible to use the tube automatic cleaning device for fluids containing filamentous foreign matter, which could not be used conventionally. I can do it.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing two embodiments of the tube cleaning device of the present invention, Figure 3 is an enlarged sectional view of the main part of a heat exchanger, and Figure 4 is a conventional tube cleaning device for a heat exchanger. FIG. 1... Heat exchanger, 2... Tube plate, 3... Tube, 4, 4', 4''... Water chamber, 5... Basket-shaped storage container,
6... Cleaning material, 7... Holding plate, 30... Valve piping, 30'... Four-way valve, 31, 32, 33, 34
... Valve, 35 ... Pump, 40, 41 ... Filter, 45 ... Differential pressure switch, 46 ... Control panel,
47...Motor, 51...Small hole.

Claims (1)

[Claims] 1. A holder for tube cleaning material is provided at both ends of the tube of the heat exchanger to hold the same amount of cleaning material as the tube, and a flow path switching valve is connected to the water chamber inlet/outlet nozzle of the heat exchanger to control the flow path. In the tube cleaning device for cleaning the inner wall of the tube by reciprocating the cleaning material within the tube using the flow of internal fluid accompanying switching, the flow path switching valve is configured as a four-way valve, and the four-way valve is configured to Connected to the water chamber inlet/outlet nozzles on the upstream and downstream sides of the heat exchanger, and in a flow path between the upstream side of the heat exchanger or between this and the water chamber inlet/outlet nozzles on the downstream side. A tube cleaning device comprising a filter, and a flow filtered by the filter is directed to the water chamber inlet/outlet nozzle.