JP2016090059A - Inspection method for soundness of boiler refractory material anchor and inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method for soundness of boiler refractory material anchor and an inspection device in which a holding state of water-cooled wall refractory material of a furnace for a boiler is inspected conveniently within a short time and removal and drop of the refractory material can be prevented in advance.SOLUTION: One terminal earth rod 4a of a tester 4 is connected to a free end 3a of an anchor 3 for holding a refractory material arc-welded to a water pipe 1 that is exposed at a surface of the refractory material as the free end 3a. The other terminal earth rod 4b of the tester 4 is connected to a tongue piece plate 5 connected to a fin part 1a at a part not covered with the refractory material of the water pipe 1 welded and attached with the anchor 3. The tester 4 is operated to inspect an electrical conduction state between the water pipe 1 and the anchor 3 so as to assure a soundness of welded state between the fin part 1a of the water pipe 1 and the anchor 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a boiler refractory material anchor for inspecting whether or not an anchor for holding the refractory material is welded and fixed to the water tube in order to cover the water tube with a furnace water-cooled wall refractory material of the boiler. The present invention relates to a soundness inspection method and an inspection apparatus.

  A water-cooled wall structure is used for a furnace wall of a fluidized bed boiler or the like, and a part of the wall surface has a structure in which a water pipe is covered with a refractory material. The refractory material is held by an anchor welded to the water pipe by arc welding. There is a possibility that the strength of welding of the anchor may be lowered due to secular change or the like.

  If the welding strength of the anchor is lowered, the anchor may be detached from the water pipe, and the refractory material may fall off. For this reason, it is necessary to inspect that the anchor holding the refractory material is securely welded to the water pipe. This inspection is desirably performed, for example, by periodically stopping the operation of the boiler every six months. If the refractory material falls off during operation of the boiler and the boiler stops, productivity may be reduced, so this inspection should be performed carefully to ensure that the welded state of the anchor is known. Therefore, it is desirable to check the integrity of the anchor.

  Conventionally, the integrity of the welded state of such an anchor has not been confirmed, and the presence or absence of peeling of the refractory material on the water-cooled wall is only investigated by a hammering test. If the anchor soundness is to be inspected for each anchor by hitting sound, the number of anchors is large, so it takes a lot of time, and in some cases, it is necessary to cut the water-cooled wall refractory material. There is a risk of becoming expensive.

  By the way, various methods for inspecting the suitability of the welding strength have been proposed. For example, Patent Document 1 proposes a nondestructive inspection method for welded members that can guarantee the total number of weld strengths without destroying the welded members. Patent Document 2 proposes a spot welding strength evaluation method and apparatus useful for nondestructive inspection of a spot welding strength of a metal material easily and accurately. Further, Patent Document 3 includes a method for evaluating a welded portion by nondestructive inspection that can be performed with simple processing without incurring an increase in cost and device space.

JP-A-7-130293 JP 2008-254005 A JP 2011-177722 A

In the nondestructive inspection method for a welded member disclosed in Patent Document 1, a resistance value is measured by contacting a probe with a four terminal against one surface near the welded portion of the welded member, and the same member as the above member is obtained in advance. The nugget diameter of the member is calculated from the relationship between the resistance value and the nugget diameter, and the pass / fail of the welding strength is determined based on the nugget diameter.
The spot welding strength evaluation method disclosed in Patent Document 2 detects a potential generated on the surface of the metal material by a pair of electrode needles that apply a predetermined current between any two points on the surface of the metal material, and the current. Using a probe having a pair of voltage electrode needles, the probe probe is brought into contact with a welded region of a spot-welded metal material to measure the electrical resistance of the welded region, and the welded region of the metal material The probe probe is brought into contact with a non-welded area away from the surface, the electric resistance of the non-welded area is measured, and the joint strength of the welded area is evaluated based on the ratio of these electric resistances. .
In addition, in the method for evaluating a joining state of a welded portion disclosed in Patent Document 3, a pair of electrodes are brought into contact with two superimposed metal plates, and a current is passed between the pair of electrodes to cause the two metal plates to contact each other. In resistance welding for welding plates, a method for evaluating the joining state of a welded portion, which is based on the method of decreasing the resistance value between electrodes when a welding current is passed between the electrodes. Is to be evaluated.

  Since the inventions disclosed in these Patent Documents 1 to 3 are all intended to evaluate the welding strength by performing an inspection at the time of completion of welding or the like, for example, an inspection device facing the finished product conveyance path. Is installed, or is carried into an inspection room or the like in the factory to work, and the inspection work is performed while visually checking the welded portion.

  On the other hand, when inspecting the welding state between the anchor and the water pipe in the furnace water cooling wall of the boiler, as described above, it is necessary to stop the operation of the boiler, and the worker must enter the boiler to perform the work. Equipment and equipment necessary for inspection must also be carried into the boiler. For this reason, the inspection apparatus of the welding strength disclosed by patent documents 1-3 cannot be used for the inspection of the welding of the boiler water-cooled wall anchor.

  Moreover, since the working environment in the boiler is not good, it is not preferable to lengthen the working time, and it is desirable to complete the inspection work in as short a time as possible because of the relationship with the boiler shutdown time.

  Therefore, the present invention provides a soundness inspection method and an inspection apparatus for a boiler refractory material anchor that can easily inspect the state of welding between an anchor holding a refractory material of a furnace water cooling wall of a boiler and a water pipe. It is intended to provide.

  As a technical means for achieving the above object, a method for inspecting the soundness of an anchor for a boiler refractory material according to the present invention includes an anchor for holding the refractory material and a water pipe for covering the water tube of the boiler with the refractory material. In the method for inspecting the soundness of a boiler refractory material anchor for inspecting the welded state between the free end of the anchor and the portion exposed from the surface of the refractory material, and the water pipe to which the anchor is connected It is characterized by measuring the resistance value.

  In other words, if there is an energization between the water pipe and the anchor, it can be determined that the anchor is welded to the water pipe. If there is no energization, the water pipe and the anchor are separated from each other, so that the anchor is not sound and the refractory material may fall off the water pipe together with the anchor. For this reason, it can grasp | ascertain that it is necessary to repair etc. about this anchor.

  In addition, the boiler refractory material anchor inspection device according to the present invention includes a boiler refractory material that covers the water pipe of the boiler with the refractory material and inspects the welded state between the anchor that holds the refractory material and the water tube. In the inspection device for the soundness of the anchor for an object, the anchor whose free end protrudes from the surface of the refractory material is to be inspected, and is connected to a portion where the refractory material of the water pipe to which the anchor is welded is not attached. A tongue plate is welded to an appropriate fin portion, a cable connected to one terminal of the tester is connected to the free end portion of the anchor, and the other end portion of the tester is connected to the tongue piece plate. A cable is connected, the current state between the water pipe and the anchor is inspected by the tester, and the welded state between the water pipe and the anchor is inspected.

  A tester is used to check whether or not the water pipe and the anchor are energized to determine whether or not the welded state between the water pipe and the anchor is sound. The tongue plate is joined to the water pipe so that the presence / absence of energization can be reliably confirmed, and the grounding rod for the terminal of the tester can be stably connected.

  The “appropriate fin portion” is a fin portion connecting a water pipe to which a target anchor is welded or an adjacent water pipe, and any fin portion may be used.

  According to the inspection method and inspection device for the soundness of the boiler refractory anchor according to the present invention, whether or not the anchor to be inspected and the water pipe are reliably joined can be easily determined in a short time, Inspection work at the time of stoppage at the time of periodic inspection of the boiler can be reliably performed. For this reason, dropping off of the refractory material on the water cooling wall of the furnace can be prevented as much as possible. Therefore, it is possible to perform continuous operation of the boiler without any trouble.

It is a figure which shows the test | inspection apparatus of the soundness of the anchor for boiler refractory materials which concerns on this invention. It is a perspective view which shows the test | inspection condition by the inspection apparatus of the soundness of the boiler refractory material anchor which concerns on this invention, and has shown a part of water cooling wall. It is a perspective view of the model explaining the structure of a furnace water cooling wall. It is a table | surface which shows the result of having measured the presence or absence of electricity supply, ie, the magnitude | size of resistance value, changing the welding state of a water pipe and an anchor using the model shown in FIG.

  Hereinafter, based on the preferred embodiment illustrated, the soundness inspection device for the boiler refractory material anchor according to the present invention will be described in detail.

  As shown in FIG. 2, the portion of the inner wall of the boiler furnace that is exposed to a high temperature is formed by fixing the refractory material 2 to the water pipe 1. As shown in FIG. 1, this refractory material 2 is held by an anchor 3 whose base is welded to a water pipe 1 by arc welding. The free end 3a side of the anchor 3 is formed in a Y shape or the like to prevent the refractory material 2 from being accidentally dropped from the anchor 3. The refractory material 2 is a part of the water pipe 1 and is attached to a necessary part such as a lower peripheral wall of a boiler furnace. Further, the water pipes 1 are connected to each other by adjacent fins 1a.

  FIG. 1 shows an outline of a soundness inspection apparatus for a boiler refractory anchor according to the present invention. This inspection apparatus mainly determines whether or not the anchor 3 is maintained in a welded state with respect to the water pipe 1, that is, the soundness of the anchor 3. Since the anchor 3 holds the refractory material 2, the free end 3 a of the anchor 3 is buried in the refractory material 2 at the beginning of the construction of the boiler, and the anchor 3 is securely welded to the water pipe 1. Yes. When a considerable period of time elapses after construction, the surface of the refractory material 2 may be worn and the free end 3a of the anchor 3 may be exposed from the refractory material 2. Therefore, the welded state of the anchor 3 with the free end 3a exposed from the surface of the refractory material 2 is inspected with the water pipe 1.

  One terminal grounding rod 4a of the tester 4 is connected to the free end 3a of the anchor 3 which protrudes from the surface due to wear of the refractory material 2. At this time, the free end portion 3a of the anchor 3 is appropriately polished so that the metal portion of the anchor 3 is exposed in order to remove impurities such as wrinkles. And the metal part is not covered with the refractory material 2 of the fin part 1a linking the water pipe 1 to which the anchor 3 to which the free end part 3a is exposed and the adjacent water pipe 1 are connected. The tongue piece plate 5 is welded. At this time, it is preferable that the surface of the fin portion 1a is appropriately polished to remove impurities to expose the metal portion. Then, the other terminal grounding rod 4 b of the tester 4 is connected to the tongue plate 5. Further, the fin portion 1a to which the tongue piece plate 5 is welded is electrically connected via the water pipe 1 or other fin portion 1a to which the anchor 3 to which the free end portion 3a is exposed should be welded. The fin portion 1a may be used. When the free ends 3a of the plurality of anchors 3 are exposed, the wall surface including these anchors 3 may be provided with a tongue piece plate 5 at one place as shown in FIG. 2, which will be described later. It may be provided at an appropriate position in consideration of workability.

  As described above, one terminal grounding rod 4a is connected to the free end 3a of the anchor 3, and the other terminal grounding rod 4b is connected to the tongue plate 5 to operate the tester 4. If the anchor 3 is welded to the water pipe 1, the water pipe 1 and the anchor 3 are energized. Therefore, the resistance value indicated by the pointer of the tester 4 is small and stable, and the pointer has a constant resistance value. I'll pan. On the other hand, when the weld between the water pipe 1 and the anchor 3 is disconnected, the current is interrupted between them, so that no current is supplied, or an unstable current-carrying state occurs and the resistance is not stable with a large resistance value. In addition, the needle is not shaken and no localization is achieved.

  That is, it is possible to grasp the welding state between the anchor 3 and the water pipe 1 to which the terminal grounding rods 4a and 4b are connected by the operation of the tester 4. In particular, when the needle of the tester 4 indicates a large resistance value, it is not energized, and the anchor 3 is detached from the water pipe 1 and the refractory material 2 held by the anchor 3 is peeled off from the water pipe 1. It can be judged that it is in a state of being repaired.

  When the inspection is completed, the tongue plate 5 is removed, the welded portion is polished, and metal spraying is performed as necessary to restore the boiler so that it does not hinder the operation. Is preferred.

  Using this boiler refractory anchor anchorage inspection device, the welded state of the anchor holding the refractory material in the lower part of the furnace of the circulating fluidized bed boiler was investigated. The investigation was conducted on the anchor 3 with the free end 3a exposed, as described above, with respect to the four walls on the left and right sides of the lower part of the furnace. Such anchors 3 are present on four sides at 317 locations. When these were investigated, the soundness of one of the front walls and two of the left walls was suspected, that is, welding with the water pipe 1 It was estimated that the condition was abnormal. This determination of soundness is abnormal for the anchors 3 that can be estimated to be healthy other than the above three, whereas the guideline of the tester 4 showed a stable resistance value of 0.2 to 0.6Ω. For the estimated anchor 3, the pointer was instructed while swinging between 14-18Ω.

  In addition, prior to actually inspecting the refractory anchor of the boiler water-cooled wall, the water-cooled wall model shown in FIG. 3 was subjected to a confirmation test of the operation of the inspection apparatus, as shown in FIG. The guideline of the tester 4 indicated a stable value of about 0.2Ω for the anchor 3 welded to the water pipe 1, whereas the anchor for the non-welded anchor indicated a resistance value of 200 kΩ or more and the pointer was stable. There wasn't. This result shows almost the same tendency as the actual inspection result, and it can be said that it can be used for the inspection of the welded state of the refractory anchor of the boiler water-cooled wall. For the measurement performed on this model, a tester with FLUKE (Made in USA) and model number 175 TRUE RMS MULTI METER was used.

  According to the inspection method and inspection apparatus for the boiler refractory material anchor according to the present invention, the anchor soundness can be inspected easily and in a short time, so that the operating efficiency of the boiler is reduced. This contributes to maintaining productivity.

1 Water pipe 2 Refractory material 3 Anchor
3a Free end 4 Tester 5 Tongue plate

Claims (2)

In the method for inspecting the soundness of the boiler refractory material anchor for inspecting the welded state between the water pipe and the anchor for holding the refractory material for covering the water tube of the boiler with the refractory material,
Measuring the resistance value between the free end portion of the anchor exposed from the surface of the refractory material and the water pipe connected to the anchor, the integrity of the boiler refractory material anchor Inspection method. In the inspection device for the soundness of the boiler refractory material anchor for inspecting the welded state between the water pipe and the anchor for holding the refractory material for covering the water tube of the boiler with the refractory material,
An anchor whose free end protrudes from the surface of the refractory material is an inspection target,
A tongue plate is welded to an appropriate fin portion connected to a portion where the refractory material of the water pipe to which the anchor is welded is not attached,
Connect the cable connected to one terminal of the tester to the free end of the anchor,
A cable connected to the other end of the tester is connected to the tongue plate,
An inspection device for the soundness of an anchor for a boiler refractory material, wherein the tester tests the current-carrying state between the water pipe and the anchor and checks the welded state between the water pipe and the anchor.

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