JP2023000710A - Cleaning jig for outer surface of fin tube and cleaning method - Google Patents

Abstract

A cleaning jig capable of efficiently cleaning and removing deposits on the outer surface of a fin tube and a cleaning method using this cleaning jig are provided.
A cleaning jig (1) has a grip portion (2), a header portion (3) connected to one end of the grip portion (2), and a plurality of water injection pipes (4, 5, 6) extending from the header portion (3). . Each of the water injection pipes 4, 5, 6 has a straight pipe shape, and is provided with an injection port for ejecting water in the extending direction of the pipe axis of each of the water injection pipes 4, 5, 6 at its tip or side surface. The length of the water injection pipes 4, 5 and 6 is decreasing in order.
[Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a cleaning jig and a cleaning method for removing deposits adhering to the outer surface of a fin tube used in an evaporator tube or the like of a waste heat recovery boiler for power generation or the like by washing with water.

Water-soluble components such as ammonium sulfate and insoluble components such as iron oxide, calcium, and silica adhere to the fin tubes (evaporation tubes, heat transfer tubes, etc.) of waste heat boilers for power generation and gas-gas heaters during boiler operation. and deposit. As a result, the differential pressure of exhaust gas from the waste heat boiler and the gas-gas heater increases, and the heat efficiency deteriorates, resulting in deterioration of the boiler efficiency. Therefore, the boiler is periodically stopped and the fin tubes are cleaned by high-pressure water cleaning or the like.

The arrangement and structure of the fin tubes vary depending on the boiler model and manufacturer. In a boiler with narrow fin tube intervals and a staggered arrangement, the jet water for high pressure water washing did not reach the fin tubes at the back of the tube bundle, and the effect of high pressure water washing could not be obtained.

For example, when high-pressure water is jetted toward the surface of a fin tube, only the deposits on the fin tubes that are directly hit by the jet water are removed, and the high-pressure water does not reach the fin tubes at the back of the tube bundle. bad effect. A method of pouring water from the top of the fin tube and a method of spraying water are also used, but water-soluble components can be removed to some extent, but insoluble components cannot be removed.

Patent Document 1 discloses a cleaning jig and a cleaning method for fin tubes that can efficiently clean and remove deposits on fin tubes, in which a plurality of high-pressure water injection ports are provided at intervals in the longitudinal direction of the tube. A cleaning jig having a pipe, the cleaning jig being provided with the high-pressure water injection port so as to inject high-pressure water in two directions perpendicular to a plane including the tube axis of the cleaning pipe; is described.

JP 2017-133734 A

In the high-pressure water cleaning jig of Patent Document 1, even if high-pressure water is jetted to the inner part of the tube bundle and the back side of the fin tubes to remove the deposits, the amount of water is insufficient to wash away the peeled deposits. may get caught in the fins of the fin tube.

Therefore, it is necessary to wash away with a large amount of water, but since there is no gap at the top, it is a structure that prevents water from being poured from above the center part of the tube bundle. Due to the metal plates installed at regular intervals, water does not flow downward, but flows laterally along the partition plate to the outside of the tube bundle. In addition, washing away from the side is blocked by the staggered arrangement of the tubes, and water does not reach the back.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning jig capable of efficiently cleaning and removing deposits on the outer surface of a fin tube, and a cleaning method using this cleaning jig.

The cleaning jig for the outer surface of the fin tubes of the present invention is a cleaning jig having water injection pipes that are inserted between fin tubes of a bundle of fin tubes and eject water from the tip or the side surface, and includes water injection pipes of different lengths. characterized by

In one aspect of the jig for cleaning the outer surface of the fin tube of the present invention, the base end side of the water injection pipe continues to the header portion, and the pipe axial direction of each water injection pipe is parallel and arranged on the same plane. ing.

In one aspect of the jig for cleaning the outer surface of the fin tube of the present invention, the water injection pipes are arranged in order from the shortest length.

In one aspect of the jig for cleaning the outer surface of the fin tubes of the present invention, the length difference between the adjacent water injection tubes having different lengths is substantially the same as the arrangement interval of the fin tubes.

The cleaning method for the outer surface of the fin tube of the present invention is a cleaning method using such a cleaning jig of the present invention.

In one aspect of the cleaning method of the present invention, a plurality of fin tube bundles in which the fin tubes are arranged horizontally are arranged vertically in a plurality of stages, and a horizontal partition plate is arranged between the fin tube bundles, Water is jetted along the upper surface of the partition plate, and the jetted water sweeps away the peeled matter that has fallen on the partition plate and removes it from the partition plate.

In one aspect of the cleaning method of the present invention, cleaning waste water is subjected to solid-liquid separation treatment and then supplied to the cleaning jig again.

According to the cleaning jig and cleaning method of the present invention, a plurality of water injection pipes having different lengths are inserted into narrow gaps between fin tubes, and a large amount of water is injected from the tip or side of each water injection pipe, Solids can be exfoliated and washed away. Further, in one aspect of the present invention, in order to prevent solid matter from accumulating on the lower partition plate, water can be sprayed along the upper surface of the partition plate to wash away the solid matter in the lateral direction.

In the cleaning method of the present invention, the amount of sprayed water is large, but by recovering, treating, and reusing the water, the amount of water discharged outside the system can be reduced.

1 is a plan view of a cleaning jig according to an embodiment; FIG. FIG. 2 is a view taken along line II-II of FIG. 1; FIG. 2 is a view taken along line III-III in FIG. 1; It is a longitudinal section explaining the washing method concerning an embodiment.

Embodiments will be described below with reference to FIGS.

1 to 3 show a cleaning jig 1 according to an embodiment. This cleaning jig 1 has a grip portion 2 , a header portion 3 connected to one end of the grip portion 2 , and a plurality of water injection pipes 4 , 5 , 6 extending from the header portion 3 . Each of the water injection pipes 4, 5, 6 has a straight pipe shape, and is provided at its tip with an injection port for injecting water in the extension direction of the pipe axis of each of the water injection pipes 4, 5, 6. The water injection pipes 4 , 5 , 6 are arranged parallel to each other on the same plane along the longitudinal direction of the header portion 3 . Also, they are arranged in order from the shortest to the longest.

In this embodiment, there are three long water injection pipes 4, two short water injection pipes 6, and two intermediate water injection pipes 5, totaling seven water pipes. Although the injection pipe is installed, the length may be two or four or more. Also, the number of water injection pipes of each length may be other than the above.

In this embodiment, the length difference between the water injection pipes 4 and 5 and the length difference between the water injection pipes 5 and 6 are approximately the same as the arrangement intervals of the fin tubes 8 ( For example, it is preferably about 0.8 to 1.2 times), but it is not limited to this.

A method of cleaning the outer surface of the fin tube using this cleaning jig 1 will be described with reference to FIG.

As shown in FIG. 4, a large number of fin tubes 8 are installed in parallel with the tube axis direction being horizontal. A horizontal partition plate 9 is arranged between bundles 7 of a predetermined number of fin tubes 8 .

A pressure hose (not shown) extending from a pump (not shown) is connected to the grip portion 2 . An operator holds the cleaning jig 1 by hand, inserts the cleaning jig 1 between the fin tubes 8, and jets water from the tips or side surfaces of the water injection pipes 4 to 6, and inserts the cleaning jig 1 in the insertion direction. And, it is moved in the longitudinal direction of the fin tubes 8 to wash each fin tube 8 evenly.

Fin tube deposits hit by water jetted from each of the water jet pipes 4 to 6 are separated from the fin tube 8 and pulverized, and fall onto the partition plate 9 . In order to remove the peeled material from the partition plate 9 , the cleaning jig 1 is arranged so as to spray water along the upper surface of the partition plate 9 , and the partition plate 9 is cleaned by the water sprayed from the cleaning jig 1 . Sweep away the flakes on top.

Since a large amount of washing water is ejected from the washing jig 1, the washing waste water dropped from the bundle of fin tubes 7 and the partition plate 9 is collected and subjected to chemical treatment (for example, coagulation treatment by adding a coagulant) and solid-liquid separation treatment ( sedimentation) to separate the supernatant water and sediment, and the supernatant water is returned to the pump and reused for washing. This reduces the amount of waste water discharged outside the system.

The above description is merely an example of the present invention, and the present invention may be embodied in forms other than those described above.

REFERENCE SIGNS LIST 1 cleaning jig 2 grip portion 3 header portion 4, 5, 6 water injection pipe 7 fin tube bundle 8 fin tube 9 partition plate

Claims (7)

A cleaning jig having a water jet pipe that is inserted between fin tubes of a fin tube bundle and jets water from the tip or side,
A cleaning jig for the outer surface of a fin tube, comprising water injection pipes of different lengths. 2. The fin tube according to claim 1, wherein the water injection pipes are connected to the header portion on the base end side, and arranged on the same plane with the axial directions of the respective water injection pipes parallel to each other. External cleaning jig. 3. The jig for cleaning the outer surface of a fin tube according to claim 2, wherein said water injection pipes are arranged in order from the shortest length. 4. The jig for cleaning the outer surface of a fin tube according to claim 2, wherein the length difference between adjacent water jet pipes having different lengths is substantially the same as the arrangement interval of the fin tubes. A method for cleaning the outer surface of a fin tube using the jig for cleaning the outer surface of a fin tube according to any one of claims 1 to 4. A plurality of fin tube bundles in which the fin tubes are arranged horizontally are arranged vertically in a plurality of stages, and a horizontal partition plate is arranged between the fin tube bundles,
6. The fin tube according to claim 5, wherein water is jetted along the upper surface of the partition plate, and the jetted water sweeps away the peeled substances that have fallen on the partition plate and removes them from the partition plate. External cleaning method. 7. The method for cleaning the outer surface of a fin tube according to claim 5 or 6, wherein cleaning drainage is subjected to a solid-liquid separation treatment and then supplied to the cleaning jig again.

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