Cleaning tool and cleaning method for the outer surface of a fin tube

Abstract

To provide a washing jig that can efficiently wash and remove deposit of an outside surface of fin tube, and to provide a washing method using the washing jig.SOLUTION: A washing jig 1 includes: a grip part 2; a header part 3 continuing to one end of the grip part 2; and a plurality of water jetting pipes 4, 5, 6 extending from the header part 3. Each of the water jetting pipes 4, 5, 6 has a straight pipe shape and is provided with a jetting port for jetting water in a tube axis extension direction of each of the water jetting pipes 4, 5, 6 at the tip or lateral surface thereof. The water jetting pipes 4, 5, 6 have lengths that are each shortened in this order.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cleaning tool and a cleaning method for removing deposits adhering to the outer surfaces of fin tubes used in evaporator tubes of waste heat recovery boilers for power generation, etc., by washing with water. [Background technology]

[0002] Water-soluble components such as ammonium sulfate and insoluble components such as iron oxide, calcium, and silica adhere to and accumulate on the fin tubes (evaporation tubes, heat transfer tubes, etc.) of waste heat boilers for power generation and gas-gas heaters during boiler operation. This increases the exhaust gas pressure difference in the waste heat boiler or gas-gas heater, and reduces the thermal efficiency, resulting in a decrease in boiler efficiency. For this reason, the boiler is periodically stopped and the fin tubes are washed with high-pressure water, etc.

[0003] The arrangement and structure of fin tubes vary depending on the boiler model and manufacturer. In boilers with narrow fin tube spacing and a staggered arrangement, the high-pressure water cleaning jets could not reach the fin tubes at the back of the tube bundle, and the high-pressure water cleaning was not effective.

[0004] For example, when high-pressure water is sprayed onto the surface of the fin tube, only the deposits on the fin tube that the sprayed water directly hits are removed, and the high-pressure water does not reach the fin tubes deep inside the tube bundle, so the effect of removing the deposits is poor. Methods such as pouring water over the top of the fin tube or spraying water are also used, but although they can remove water-soluble components to a certain extent, they cannot remove insoluble components.

[0005] Patent Document 1 describes a cleaning tool and cleaning method for fin tubes that can efficiently clean and remove deposits from fin tubes. The cleaning tool has a cleaning pipe with multiple high-pressure water jet nozzles spaced apart in the longitudinal direction of the pipe, and the high-pressure water jet nozzles are arranged to jet high-pressure water in two directions perpendicular to a plane including the axis of the cleaning pipe, and the cleaning method uses this cleaning tool. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-133734 A Summary of the Invention [Problem to be solved by the invention]

[0007] With the high-pressure water cleaning tool in Patent Document 1, even if high-pressure water is sprayed at the back of the tube bundle or the back side of the fin tube to remove the deposits, the amount of water is insufficient to wash away the removed deposits, and the deposits may get caught between the fins of the lower fin tube.

[0008] This requires a large amount of water to be used for washing, but because there are no gaps in the top tier, water cannot be poured from above onto the center of the tube bundle, and because of the metal plates called partitions that are installed horizontally at regular intervals between the tube bundles, the water does not flow downward, but flows sideways along the partitions to the outside of the tube bundle. Also, washing from the side is hindered by the staggered arrangement of tubes, so water does not reach the back.

[0009] An object of the present invention is to provide a cleaning jig capable of efficiently cleaning and removing deposits from the outer surface of a fin tube, and a cleaning method using this cleaning jig. [Means for solving the problem]

[0010] The cleaning jig for the outer surface of a fin tube of the present invention is a cleaning jig that is inserted between the fin tubes of a fin tube bundle and has water injection tubes that spray water from the tips or sides, and is characterized by having water injection tubes of different lengths.

[0011] In one aspect of the cleaning jig for the outer surface of a fin tube of the present invention, the water injection pipes are connected at their base ends to a header portion, and the pipe axes of each water injection pipe are parallel to each other and arranged on the same plane.

[0012] In one aspect of the cleaning jig for the outer surface of a fin tube of the present invention, the water injection pipes are arranged in order of length from shortest to longest.

[0013] In one aspect of the cleaning jig for the outer surfaces of fin tubes of the present invention, the difference in length between adjacent water injection tubes of different lengths is approximately the same as the arrangement spacing of the fin tubes.

[0014] The method for cleaning the outer surface of a fin tube of the present invention is a cleaning method that uses the cleaning jig of the present invention.

[0015] In one aspect of the cleaning method of the present invention, fin tube bundles in which the fin tubes are arranged horizontally are arranged in multiple tiers one above the other, and horizontal partition plates are arranged between the fin tube bundles. Water is sprayed along the upper surface of the partition plate, and the sprayed water washes away any peeled material that has fallen onto the partition plate, removing it from the partition plate.

[0016] In one embodiment of the cleaning method of the present invention, the cleaning wastewater is subjected to solid-liquid separation and then supplied again to the cleaning jig. Effect of the Invention

[0017] According to the cleaning tool and cleaning method of the present invention, multiple water injection pipes of different lengths are inserted into the narrow gaps between the fin tubes, and a large amount of water is injected from the tip or side of each water injection pipe to peel off and wash away the solid matter. In one aspect of the present invention, in order to prevent solid matter from accumulating on the partition plate at the bottom, water can be injected along the upper surface of the partition plate to push the solid matter sideways.

[0018] In the cleaning method of the present invention, a large amount of water is injected, but by recovering, treating and reusing the water, the amount discharged outside the system can be reduced. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a plan view of the cleaning jig according to the embodiment. [Diagram 2]FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 1A to 1C are vertical cross-sectional views illustrating a cleaning method according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment will be described with reference to FIGS.

[0021] 1 to 3 show a cleaning jig 1 according to an embodiment. This cleaning jig 1 has a grip section 2, a header section 3 connected to one end of the grip section 2, and a plurality of water injection pipes 4, 5, and 6 extending from the header section 3. Each of the water injection pipes 4, 5, and 6 is straight and has an injection port at its tip for ejecting water in the axial extension direction of each of the water injection pipes 4, 5, and 6. The water injection pipes 4, 5, and 6 are arranged parallel to one another on the same plane along the longitudinal direction of the header section 3. Also, they are arranged in order from shortest to longest.

[0022] In this embodiment, a total of seven water injection pipes are installed: three long water injection pipes 4, two short water injection pipes 6, and two water injection pipes 5 whose length is intermediate between the two, but the number of water injection pipes of two or more lengths may be two or four or more. Also, the number of water injection pipes of each length may be other than the above.

[0023] In this embodiment, it is preferable that the difference in length between water injection pipes 4 and 5 and the difference in length between water injection pipes 5 and 6 are approximately the same as the arrangement spacing of the fin tubes 8 (for example, approximately 0.8 to 1.2 times), but is not limited to this.

[0024] A method for cleaning the outer surfaces of the fin tubes using this cleaning jig 1 will be described with reference to FIG.

[0025] 4, a large number of fin tubes 8 are installed in parallel with the tube axis direction horizontal. Horizontal partition plates 9 are arranged between bundles 7 of a predetermined number of fin tubes 8.

[0026] A pressure-resistant hose (not shown) extending from a pump (not shown) is connected to the grip portion 2. The operator holds the cleaning jig 1 in his / her hand, inserts the cleaning jig 1 between the fin tubes 8, and sprays water from the tip or side of each of the water injection pipes 4 to 6 while moving the cleaning jig 1 in the insertion direction and in the longitudinal direction of the fin tubes 8 to thoroughly clean each fin tube 8.

[0027] Matter adhering to the fin tubes that hits the water jetted from each of the water jet tubes 4-6 is peeled off and crushed from the fin tubes 8, and falls onto the partition plate 9. In order to remove the peeled off material from the partition plate 9, a cleaning jig 1 is placed so as to jet water along the upper surface of the partition plate 9, and the water jetted from this cleaning jig 1 washes away the peeled off material on the partition plate 9.

[0028] A large amount of washing water is sprayed from the washing jig 1, so the washing wastewater that falls from the fin tube bundle 7 and the partition plate 9 is collected, and is subjected to chemical treatment (for example, flocculation treatment by adding a flocculant) and solid-liquid separation treatment (for example, sedimentation treatment) 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 wastewater discharged outside the system.

[0029] The above description is merely an example of the present invention, and the present invention may be embodied in other forms than those described above. [Explanation of symbols]

[0030] 1 Cleaning tool 2 Grip section 3. Header section 4,5,6 water injection pipe 7 Fin tube bundle 8 Fin Tube 9 Partition

Claims

1. A cleaning tool having a water jet tube that is inserted between the fin tubes of a fin tube bundle and jets water from the tip or side, A cleaning tool for the outer surface of a fin tube equipped with water jet tubes of different lengths, The water injection pipes are connected at their base ends to the header section, and the pipe axes of the water injection pipes are parallel to each other and arranged on the same plane. A cleaning tool for the outer surface of a fin tube, characterized in that the water injection pipes are arranged in order of length from shortest to longest.

2. A cleaning tool having a water jet tube that is inserted between the fin tubes of a fin tube bundle and jets water from the tip or side, A cleaning tool for the outer surface of a fin tube equipped with water jet tubes of different lengths, The water injection pipes are connected at their base ends to the header section, and the pipe axes of the water injection pipes are parallel to each other and arranged on the same plane. A cleaning jig for the outer surface of a fin tube, characterized in that the difference in length between adjacent water injection tubes of different lengths is approximately the same as the arrangement spacing of the fin tubes.

3. A cleaning tool having a water jet tube that is inserted between the fin tubes of a fin tube bundle and jets water from the tip or side, A method for cleaning the outer surface of a fin tube using a cleaning tool for the outer surface of a fin tube having water jet tubes of different lengths, comprising: The water injection pipes of the cleaning jig for the outer surface of the fin tube are connected to a header portion at their base ends, and the pipe axes of the water injection pipes are parallel to each other and arranged on the same plane. A method for cleaning the outer surface of a fin tube, wherein the water injection pipes are arranged in order of length from shortest to longest.

4. A cleaning tool having a water jet tube that is inserted between the fin tubes of a fin tube bundle and jets water from the tip or side, A method for cleaning the outer surface of a fin tube using a cleaning tool for the outer surface of a fin tube having water jet tubes of different lengths, comprising: The water injection pipes of the cleaning jig for the outer surface of the fin tube are connected to a header portion at their base ends, and the pipe axes of the water injection pipes are parallel to each other and arranged on the same plane. A method for cleaning the outer surfaces of fin tubes, characterized in that the difference in length between adjacent water injection tubes of different lengths is approximately the same as the arrangement spacing of the fin tubes.

5. The fin tube bundles in which the fin tubes are horizontally arranged are arranged in a plurality of stages vertically, and horizontal partition plates are arranged between the fin tube bundles, A method for cleaning the outer surface of a fin tube as described in claim 3 or 4, characterized in that water is sprayed along the upper surface of the partition plate, and the sprayed water washes away any peeling material that has fallen onto the partition plate, thereby removing it from the partition plate.

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