JP6736936B2 - Boiler repair method - Google Patents

Boiler repair method Download PDF

Info

Publication number
JP6736936B2
JP6736936B2 JP2016061247A JP2016061247A JP6736936B2 JP 6736936 B2 JP6736936 B2 JP 6736936B2 JP 2016061247 A JP2016061247 A JP 2016061247A JP 2016061247 A JP2016061247 A JP 2016061247A JP 6736936 B2 JP6736936 B2 JP 6736936B2
Authority
JP
Japan
Prior art keywords
panel
pipe
tube group
group
shaped
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
JP2016061247A
Other languages
Japanese (ja)
Other versions
JP2017172918A (en
Inventor
昇 木田
昇 木田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tokyo Electric Power Co Inc
Original Assignee
Tokyo Electric Power Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tokyo Electric Power Co Inc filed Critical Tokyo Electric Power Co Inc
Priority to JP2016061247A priority Critical patent/JP6736936B2/en
Publication of JP2017172918A publication Critical patent/JP2017172918A/en
Application granted granted Critical
Publication of JP6736936B2 publication Critical patent/JP6736936B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Description

本発明は、ボイラ内のパネル状管群を補修するボイラ補修方法に関する。 The present invention relates to a boiler repairing method for repairing a panel-shaped tube group in a boiler.

例えば、火力発電所のボイラの火炉は、多数の管を連結部で連結した角筒状のパネル状管群にて形成されている。パネル状管群の角筒の内部が火炉であり、この火炉でバーナーにより燃料を燃焼させる。そして、火炉内で燃やされた燃料の燃焼ガスの熱と管の中を流れる給水(水)とで熱交換し蒸気を発生させる。同様に、ボイラの後伝部においても壁の一部がパネル状管群で形成され、火炉から出た燃焼ガスの熱と管の中を流れる給水とで熱交換をし給水を加熱している。従って、パネル状管群の内側部は燃焼ガスに曝され、外側部は燃焼ガスに曝されない。 For example, a furnace of a boiler of a thermal power plant is formed of a rectangular tube-shaped panel-shaped tube group in which a large number of tubes are connected by a connecting portion. The inside of the rectangular tube of the panel-shaped tube group is a furnace, and the burner burns the fuel in this furnace. Then, heat is exchanged between the heat of the combustion gas of the fuel burned in the furnace and the feed water (water) flowing in the tube to generate steam. Similarly, in the rear transmission part of the boiler, a part of the wall is formed by a panel-shaped tube group, and heat is exchanged by the heat of the combustion gas discharged from the furnace and the feed water flowing in the tube to heat the feed water. .. Therefore, the inner portion of the panel-shaped tube group is exposed to the combustion gas, and the outer portion is not exposed to the combustion gas.

このことから、パネル状管群の内側部の劣化が激しく、パネル状管群の外側部は事実上劣化はない。そこで、ボイラの停止時において、劣化が激しいパネル状管群の内側部の管の健全性を確認している。この管の健全性の確認は管の減肉やき裂などの劣化状態を点検し、管の劣化状態が取替基準に達しているか否かを判断し、管の劣化状態が取替基準に達しているときは管の取り替えを行っている。管の取り替えは、管の劣化部分を部分的に切り取り、切り取り部分に新品の管を溶接して修理している。また、管の取替範囲が多い場合には、管ごとに代えてパネル状管群の劣化部分を部分的に切り取り、切り取り部分に新品のパネル状管群を溶接して修理している。 Therefore, the inner portion of the panel-shaped tube group is severely deteriorated, and the outer portion of the panel-shaped tube group is practically not deteriorated. Therefore, when the boiler is stopped, the soundness of the inner tube of the panel-shaped tube group, which is severely deteriorated, is confirmed. To confirm the soundness of this pipe, check the deterioration state of the pipe such as thinning and cracks, judge whether the deterioration state of the pipe has reached the replacement standard, and the deterioration state of the pipe has reached the replacement standard. When I am, I am replacing the pipe. When replacing a pipe, the deteriorated part of the pipe is partially cut off, and a new pipe is welded to the cut out part for repair. When the replacement range of the pipe is large, the deteriorated portion of the panel-shaped pipe group is partially cut out instead of each pipe, and a new panel-shaped pipe group is welded to the cut-out portion for repair.

ここで、排ガスと熱交換を行う熱交換器を補修するものとして、複数のチューブバンドルを備える熱交換器の少なくとも一つのチューブバンドルを取り外し、取り外したチューブバンドルの複数の伝熱管のうち少なくとも一部の伝熱管を修理し、修理したチューブバンドルを他のチューブバンドルと置き換えるようにし、コストを低減するとともに、作業時間を短縮するようにしたものがある(特許文献1参照)。この特許文献1のものでは、伝熱管の修理の際には、減肉の少ない伝熱管においては排ガス上流側と下流側とを交換するように伝熱管を180°反転させることによって、伝熱管の再利用を可能とし修理時のコストを低減するようにしたり、排ガスの最上流系列と最下流系列のうち、より高温となるチューブバンドルの置換頻度を、より低温となるチューブバンドルの置換頻度よりも高くするようにしたりしている。 Here, as a repair of the heat exchanger that exchanges heat with the exhaust gas, at least one tube bundle of the heat exchanger including a plurality of tube bundles is removed, and at least a part of the plurality of heat transfer tubes of the removed tube bundle is removed. Of the above heat transfer tube, the repaired tube bundle is replaced with another tube bundle to reduce the cost and the working time (see Patent Document 1). In this patent document 1, when the heat transfer tube is repaired, the heat transfer tube is reversed by 180° so that the exhaust gas upstream side and the downstream side are exchanged in the heat transfer tube with less wall thinning. It enables reuse and reduces repair costs, and replaces the tube bundle that has a higher temperature than the one that has a higher temperature than the replacement frequency of a tube bundle that has a lower temperature in the most upstream and downstreammost exhaust gas series. I try to raise it.

特開2015−34651号公報JP, 2015-34651, A

しかし、従来のように、劣化が激しいパネル状管群を部分的に切り取り、切り取った部分に新品の管やパネル状管群を溶接して取り替える取替方法では、切り取った大きさの新品の管やパネル状管群を用意しなければならない。従って、切り取った大きさの新品の管やパネル状管群の製作に時間が掛かりコストも高くなり、さらには、工事工程も長期間となる。 However, as in the conventional method, the panel-shaped tube group that is severely deteriorated is partially cut, and a new pipe or panel-shaped tube group is welded to the cut portion to replace it. A panel tube group must be prepared. Therefore, it takes time and cost to manufacture a new pipe or a panel-shaped pipe group of a cut size, and the construction process also takes a long time.

また、特許文献1のものでは、複数のチューブバンドルを備えた熱交換器であることからチューブバンドルでの取り替えが可能であるが、ボイラの場合は、管がパネル状管群で一体となっておりチューブバンドルを形成していないので、高温となるチューブバンドルの置換頻度を低温となるチューブバンドルの置換頻度よりも高くするといったチューブバンドル単位での置換を行うことができない。 Further, in Patent Document 1, since it is a heat exchanger having a plurality of tube bundles, it can be replaced with a tube bundle, but in the case of a boiler, the tubes are integrated into a panel-shaped tube group. Since the cage tube bundle is not formed, it is not possible to perform replacement on a tube bundle-by-tube basis such that the replacement frequency of the high temperature tube bundle is higher than the replacement frequency of the low temperature tube bundle.

また、特許文献1の伝熱管は、減肉の少ない伝熱管について排ガス上流側と下流側とを交換するように伝熱管を180°反転させて伝熱管の再利用を可能とすることができるが、ボイラの場合はパネル状管群であり、燃焼ガスの上流側と下流側の管を180°反転させても意味がない。 Further, the heat transfer tube of Patent Document 1 can be reused by reversing the heat transfer tube by 180° so as to exchange the exhaust gas upstream side and downstream side with respect to the heat transfer tube with less wall thinning. In the case of a boiler, it is a panel-shaped tube group, and it is meaningless to invert the upstream and downstream tubes of combustion gas by 180°.

本発明の目的は、低コストで工事工程を短縮でき、しかも新品と同等にボイラのパネル状管群を補修できるボイラ補修方法を提供することである。 An object of the present invention is to provide a boiler repair method that can reduce the construction process at low cost and can repair the panel tube group of the boiler in the same manner as a new product.

請求項1の発明に係るボイラ補修方法は、 ボイラの内部で燃料を燃焼させた燃焼ガスの熱とボイラ内のパネル状管群の管の中を流れる給水もしくは蒸気とで熱交換させる前記パネル状管群の点検の際に前記パネル状管群の前記燃焼ガスに曝される内側の劣化状態を判定し、 前記パネル状管群の劣化状態が取替基準に達しているときはその管またはパネル状管群を部分的に切り取り、 部分的に切り取った管またはパネル状管群を裏返して前記燃焼ガスに曝される内側と前記燃焼ガスに曝されない外側との位置を反転させ、 部分的に切り取って位置を反転させた管またはパネル状管群を切り取り部分に嵌め込み溶接してボイラのパネル状管群を補修するにあたり、劣化状態が予め定めた取替基準に達している箇所の管またはパネル状管群に歪みがあるときは、管またはパネル状管群を部分的に切り取る際に、切り取った管またはパネル状管群の管口を前記切り取り部分の管口に合わせて溶接できる大きさに分割して切り取り、切り取った管またはパネル状管群を裏返した後に、管またはパネル状管群の管口が前記切り取り部分の管口位置に合うように修正加工し、修正加工した管またはパネル状管群を前記切り取り部分に嵌め込み溶接することを特徴とする。 The boiler repairing method according to the invention of claim 1 is the panel shape in which the heat of the combustion gas in which the fuel is burned inside the boiler and the feed water or steam flowing in the tube of the panel tube group in the boiler are heat-exchanged. When inspecting the tube group, the deterioration state of the inside of the panel tube group exposed to the combustion gas is determined, and when the deterioration state of the panel tube group reaches the replacement standard, the tube or panel. The pipe group is partially cut off, and the partially cut pipe or panel-shaped pipe group is turned over to reverse the positions of the inside exposed to the combustion gas and the outside not exposed to the combustion gas, and partially cut away. When repairing the boiler panel-like tube group by fitting a pipe or panel-like tube group whose position has been reversed into the cut-out portion and welding it, the pipe or panel-like shape of the part where the deterioration state has reached the predetermined replacement standard If the tube group is distorted, when the tube or panel-shaped tube group is partially cut, divide the cut pipe or panel-shaped tube group into a size that can be welded according to the cut-out portion. After turning over the cut tube or panel-shaped tube group, the tube or panel-shaped tube group is corrected so that the tube mouth of the tube or panel-shaped tube group fits the position of the cut-out portion, and the corrected tube or panel-shaped tube The group is fitted into the cutout portion and welded .

請求項1の発明によれば、ボイラのパネル状管群の劣化状態が取替基準に達しているときは、その管またはパネル状管群を部分的に切り取り、部分的に切り取った管またはパネル状管群を裏返して燃焼ガスに曝される内側と燃焼ガスに曝されない外側との位置を反転させ、ボイラのパネル状管群を補修するので、新品の管やパネル状管群を用意する必要がなく、コストの低減及び工事工程を短縮できる。また、燃焼ガスに曝される内側と燃焼ガスに曝されない外側との位置を反転させるので、補修後に燃焼ガスに曝される内側の管やパネル状管群は、燃焼ガスに曝されていない外側のものとなり、劣化のない新品と同様の管やパネル状管群となる。従って、管やパネル状管群の寿命は事実上2倍に延びる。 According to the invention of claim 1, when the deterioration state of the panel-shaped tube group of the boiler has reached the replacement standard, the tube or panel-shaped tube group is partially cut, and the partially cut-off tube or panel. It is necessary to prepare a new tube or panel-shaped tube group because the panel-shaped tube group of the boiler is repaired by turning over the tube-shaped tube group and reversing the positions of the inside exposed to the combustion gas and the outside not exposed to the combustion gas. The cost can be reduced and the construction process can be shortened. Further, since the positions of the inside exposed to the combustion gas and the outside not exposed to the combustion gas are reversed, the inner pipes or panel-shaped pipes exposed to the combustion gas after repair are not exposed to the combustion gas. The pipes and panel-shaped pipes will be the same as new ones without deterioration. Therefore, the life of the tube or tube bundle is effectively doubled.

さらには、劣化状態が予め定めた取替基準に達している管またはパネル状管群に歪みがあるときは、管またはパネル状管群を部分的に切り取る際に、切り取った管またはパネル状管群の管口を前記切り取り部分の管口に合わせて溶接できる大きさに分割して切り取り、切り取った管またはパネル状管群を裏返した後に、管またはパネル状管群の管口が前記切り取り部分の管口位置に合うように修正加工し、修正加工した管またはパネル状管群を前記切り取り部分に嵌め込み溶接するので、管やパネル状管群に歪みがあっても、切り取った管またはパネル状管群を容易に切り取り部分に嵌め込むことができる。
Furthermore, when the pipe or panel-like pipe group whose deterioration state has reached a predetermined replacement standard is distorted, the cut-out pipe or panel-like pipe pipe is cut when partially cutting the pipe or panel-like pipe group. The pipe mouth of the tube or panel-like tube group is turned over after cutting the pipe mouth of the group into a size that can be welded in accordance with the pipe mouth of the cutout portion, and turning over the cut pipe or panel-like tube group. Since the modified pipe or panel-shaped pipe group is fitted and welded to the cutout part so that it fits the pipe mouth position of the pipe, even if there is distortion in the pipe or panel-shaped pipe group, the cut pipe or panel-shaped The tube group can be easily fitted into the cutout portion.

本発明の第1実施形態に係るボイラ補修方法の工程を示すフローチャート。The flowchart which shows the process of the boiler repair method which concerns on 1st Embodiment of this invention. 本発明の第1実施形態で対象とする火力発電所のボイラの一例を示す概念図。The conceptual diagram which shows an example of the boiler of the thermal power station made into object in 1st Embodiment of this invention. 本発明の第1実施形態におけるボイラのパネル状管群の斜視図。The perspective view of the panel-shaped tube group of the boiler in 1st Embodiment of this invention. 本発明の第1実施形態において部分的に切り取ったパネル状管群を裏返して切り取り部分に嵌め込み溶接する場合の説明図。FIG. 3 is an explanatory view of a case where the panel-shaped tube group that is partially cut out is turned over and fitted into the cut-out portion and welded in the first embodiment of the present invention. 本発明の第2実施形態に係るボイラ補修方法の工程を示すフローチャート。The flowchart which shows the process of the boiler repair method which concerns on 2nd Embodiment of this invention. 本発明の第2実施形態において管またはパネル状管群に歪みがある場合に部分的に切り取ったパネル状管群を裏返して切り取り部分に嵌め込み溶接する場合の説明図。Explanatory drawing in the case of distorting a pipe or a panel-shaped tube group in the second embodiment of the present invention, in which a panel-shaped tube group partially cut out is turned over and fitted into the cut-out portion and welded.

本発明に至った経緯を説明する。特許文献1には、伝熱管を180°反転させることによって、伝熱管の再利用を可能とする技術的思想が示されている。本発明においても、管またはパネル状管群を裏返しさせる(180°反転させる)ことによって、管またはパネル状管群の再利用を可能とするので、その点では一致する。しかし、特許文献1が対象とする伝熱管は減肉が少ない伝熱管であるが、本発明の対象とする管またはパネル状管群は、逆に、減肉やき裂(劣化)の激しい(内側が取替基準に達している)管またはパネル状管群である点で相違する。 The background of the present invention will be described. Patent Document 1 discloses a technical idea that enables the heat transfer tube to be reused by reversing the heat transfer tube by 180°. Also in the present invention, by reversing the tube or panel-like tube group (reversing by 180°), it becomes possible to reuse the tube or panel-like tube group, and therefore the points are the same. However, although the heat transfer tube targeted by Patent Document 1 is a heat transfer tube with little wall thinning, the tube or panel-shaped tube group targeted by the present invention, conversely, has severe wall thinning and severe cracking (deterioration) (inside). Have reached the replacement standard) or a panel-shaped tube group.

これは、特許文献1の伝熱管は、伝熱管自体が排ガス中に曝されており、伝熱管の下流側であっても減肉していることから、上流側で減肉が少ない伝熱管ならば、伝熱管を180°反転させることによって、まだ、使用できるというものである。一方、本発明の管またはパネル状管群は、燃焼ガスに曝される内側と燃焼ガスに曝されない外側とがあり、燃焼ガスに曝されるのは内側のみであるというボイラの特質に基づくものである。つまり、ボイラでは、燃焼ガスに曝されていない外側のものは、劣化のない新品と同様のものであるという特質に基づくものである。この特質に基づき、本発明は、特許文献1のように、減肉が少ない管を対象とするのではなく、逆に、減肉やき裂(劣化)の激しい(内側が取替基準に達している)管またはパネル状管群であっても、管またはパネル状管群の再利用を可能としたものである。 This is because the heat transfer tube of Patent Document 1 is exposed to the exhaust gas in the exhaust gas itself and the wall thickness is reduced even on the downstream side of the heat transfer tube. For example, it can still be used by reversing the heat transfer tube by 180°. On the other hand, the tube or panel-like tube group of the present invention has an inside exposed to combustion gas and an outside not exposed to combustion gas, and is based on the characteristic of the boiler that only the inside is exposed to combustion gas. Is. In other words, the boiler is based on the characteristic that the outer one not exposed to the combustion gas is the same as a new one without deterioration. Based on this characteristic, the present invention does not target a pipe with a small amount of metal thinning as in Patent Document 1, but, conversely, has a large amount of metal thinning and cracks (deterioration) (the inside reaches a replacement standard. Existing pipes or panel-like tube groups, it is possible to reuse the tube or panel-like tube groups.

以下、本発明の実施形態を説明する。図1は本発明の第1実施形態に係るボイラ補修方法の工程を示すフローチャート、図2は本発明の第1実施形態で対象とする火力発電所のボイラの一例を示す概念図である。 Hereinafter, embodiments of the present invention will be described. FIG. 1 is a flowchart showing steps of a boiler repairing method according to a first embodiment of the present invention, and FIG. 2 is a conceptual diagram showing an example of a boiler of a thermal power plant which is a target of the first embodiment of the present invention.

図2において、火力発電所のボイラ11は火炉部11aと後伝部11bとから構成される。給水系統から送水されてきた水は、後伝部11bの節炭器12に導かれ、節炭器12にてボイラ11の火炉部11aから出た燃焼ガスと熱交換され加熱される。節炭器12で加熱された水は、第1連結配管13及び第1管寄せ14を介してボイラ11の火炉部11aを構成するパネル状管群15に供給される。また、図示は省略するが、後伝部11b内側の壁の一部にはパネル状管群が形成され、後伝部11bの内側において、火炉部11aから出た燃焼ガスの熱とパネル状管群の管の中を流れる給水とで熱交換をして給水を加熱し、火炉部11aのパネル状管群15に供給される。 In FIG. 2, the boiler 11 of the thermal power plant is composed of a furnace section 11a and a rear transmission section 11b. The water sent from the water supply system is guided to the economizer 12 of the rear transmission part 11b, and is heat-exchanged with the combustion gas emitted from the furnace part 11a of the boiler 11 in the economizer 12 to be heated. The water heated by the economizer 12 is supplied to the panel-shaped tube group 15 forming the furnace part 11 a of the boiler 11 via the first connecting pipe 13 and the first header 14. Although illustration is omitted, a panel-shaped tube group is formed on a part of the inner wall of the rear transmission part 11b. Inside the rear transmission part 11b, the heat of the combustion gas emitted from the furnace part 11a and the panel-shaped tube are formed. The feed water is heated by exchanging heat with the feed water flowing through the tube of the group, and is supplied to the panel-shaped tube group 15 of the furnace part 11a.

次に、火炉部11aのパネル状管群15はボイラ11内において角筒状に配置され、パネル状管群15の内部が火炉となる。すなわち、パネル状管群15の内部でバーナーにより燃料を燃焼させ、燃焼ガスの熱とパネル状管群15の管の中を流れる給水とで熱交換することで蒸気を発生させ、発生した蒸気は第2管寄せ16及び第2連絡配管17を介して過熱器18に供給され、過熱器18から図示省略の蒸気タービンに導かれる。 Next, the panel-shaped tube group 15 of the furnace portion 11a is arranged in a square tube shape inside the boiler 11, and the inside of the panel-shaped tube group 15 serves as a furnace. That is, the burner burns fuel inside the panel-shaped tube group 15, and heat is exchanged between the heat of the combustion gas and the feed water flowing through the tubes of the panel-shaped tube group 15 to generate steam, and the generated steam is It is supplied to the superheater 18 via the second header 16 and the second connecting pipe 17, and is guided from the superheater 18 to a steam turbine (not shown).

また、火炉部11aから出た燃焼ガスは過熱器18及び節炭器12に流れ熱交換して、ボイラ11外に排ガスとして排出される。図示は省略するが、火炉部11aのパネル状管群15は、保熱材で包囲されているので、火炉部11aから出た燃焼ガスはパネル状管群15の外側には流れない。従って、火炉部11aのパネル状管群15や図示省略の後伝部11bの壁のパネル状管群の内側部は燃焼ガスに曝され、外側部は燃焼ガスに曝されない。 Further, the combustion gas emitted from the furnace portion 11a flows into the superheater 18 and the economizer 12 for heat exchange, and is discharged to the outside of the boiler 11 as exhaust gas. Although illustration is omitted, since the panel-shaped tube group 15 of the furnace part 11a is surrounded by the heat insulating material, the combustion gas emitted from the furnace part 11a does not flow to the outside of the panel-shaped tube group 15. Therefore, the inner part of the panel-like tube group 15 of the furnace part 11a and the panel-like tube group of the wall of the rear transmission part 11b (not shown) is exposed to the combustion gas, and the outer part is not exposed to the combustion gas.

以下の説明では、ボイラ11の火炉部11aのパネル状管群15を補修する場合について説明する。図1において、本発明の第1実施形態に係るボイラ補修方法では、まず、ボイラのパネル状管群の燃焼ガスに曝される内側の劣化状態を判定する(S1)。ボイラ11のパネル状管群15の点検は、ボイラ11を停止した状態で点検員がパネル状管群15の内側に入り、目視または超音波探傷装置を用いて点検する。 In the following description, the case of repairing the panel-shaped tube group 15 of the furnace part 11a of the boiler 11 will be described. Referring to FIG. 1, in the boiler repair method according to the first embodiment of the present invention, first, the deterioration state inside the panel-shaped tube group of the boiler exposed to the combustion gas is determined (S1). When inspecting the panel-shaped tube group 15 of the boiler 11, an inspector enters the inside of the panel-shaped tube group 15 with the boiler 11 stopped and is inspected visually or using an ultrasonic flaw detector.

図3はボイラ11のパネル状管群15の斜視図である。図3ではパネル状管群15に接続される第1管寄せ14及び第2管寄せ16の図示は省略している。図3に示すように、パネル状管群15は、複数の管19を連結板20で連結して角筒状に形成されている。このような角筒状のパネル状管群15の内側にバーナーが位置するようにボイラ11内に配置される。パネル状管群15の点検の際には、点検員がパネル状管群15の内側に入り、パネル状管群15の内側の劣化状態が予め定めた取替基準に達しているか否かを判定する。 FIG. 3 is a perspective view of the panel-shaped tube group 15 of the boiler 11. In FIG. 3, the illustration of the first header 14 and the second header 16 connected to the panel-shaped tube group 15 is omitted. As shown in FIG. 3, the panel-shaped tube group 15 is formed into a rectangular tube shape by connecting a plurality of tubes 19 with a connecting plate 20. The burner is arranged in the boiler 11 so that the burner is located inside the square tubular panel-shaped tube group 15. When inspecting the panel-shaped tube group 15, an inspector enters inside the panel-shaped tube group 15 and determines whether the deterioration state inside the panel-shaped tube group 15 has reached a predetermined replacement criterion. To do.

次に、図1において、パネル状管群15の内側の劣化状態が予め定めた取替基準に達している箇所があるか否かを判定する(S2)。劣化状態が予め定めた取替基準に達している箇所がない場合は処理を終了する。一方、劣化状態が予め定めた取替基準に達している箇所があるときは、劣化状態が予め定めた取替基準に達している箇所の管またはパネル状管群15を部分的に所定の大きさで切り取る(S3)。 Next, in FIG. 1, it is determined whether or not there is a portion where the deterioration state inside the panel-shaped tube group 15 has reached a predetermined replacement standard (S2). If there is no part where the deterioration state has reached the predetermined replacement standard, the process is terminated. On the other hand, when there is a portion whose deterioration state has reached the predetermined replacement standard, the pipe or panel-like tube group 15 at the portion whose deterioration state has reached the predetermined replacement standard is partially of a predetermined size. Cut it off (S3).

点検員による点検で、劣化状態が予め定めた取替基準に達している箇所があるときは、図3に示すように、その劣化状態箇所21を部分的に所定の大きさで、例えばグラインダーで切り取る。所定の大きさは切り取った管またはパネル状管群の取り替え作業が火炉内で行える程度の大きさである。例えば、数メートル四方の範囲に入る大きさである。劣化状態箇所21が数メートル四方の範囲に入らない場合は分割して切り取ることになる。なお、図3では管ではなくパネル状管群15の一部を切り取る場合を示している。 In the inspection by the inspector, when there is a part where the deterioration state has reached a predetermined replacement standard, as shown in FIG. 3, the deterioration state part 21 is partially of a predetermined size, for example, by a grinder. cut out. The predetermined size is such that a cut tube or a panel-shaped tube group can be replaced in a furnace. For example, the size is within a range of several meters square. When the deteriorated state portion 21 does not fall within the range of several meters square, it is divided and cut. Note that FIG. 3 shows a case where a part of the panel-shaped tube group 15 is cut out instead of the tube.

次に、切り取った管またはパネル状管群を裏返す(S4)。すなわち、部分的に切り取った管またはパネル状管群を半回転させて表裏を入れ替え、燃焼ガスに曝される内側と燃焼ガスに曝されない外側との位置を反転させる。そして、裏返した管またはパネル状管群を切り取り部分に嵌め込み溶接する(S5)。 Next, the cut tube or panel-shaped tube group is turned over (S4). That is, a partially cut tube or a panel-shaped tube group is rotated by half a turn to replace the front and back sides, and the positions of the inside exposed to the combustion gas and the outside not exposed to the combustion gas are reversed. Then, the turned-up tube or panel-shaped tube group is fitted into the cut-out portion and welded (S5).

図4は、部分的に切り取ったパネル状管群を裏返して切り取り部分に嵌め込み溶接する場合の説明図である。図4では部分的にパネル状管群を切り取った場合を示している。図4に示すように、パネル状管群15のうち、劣化状態が予め定めた取替基準に達している劣化状態箇所21を切り取る。 FIG. 4 is an explanatory diagram of a case where the panel-shaped tube group that is partially cut out is turned over and fitted into the cut-out portion and welded. FIG. 4 shows a case where the panel-shaped tube group is partially cut out. As shown in FIG. 4, in the panel-shaped tube group 15, the deteriorated state portion 21 whose deteriorated state has reached a predetermined replacement standard is cut out.

切り取ったパネル状管群15a1は、パネル状管群15の内側に位置していた部分が劣化している。これは、燃焼ガスに曝されていたからである。この切り取ったパネル状管群15a1を裏返すと、パネル状管群15の外側に位置していた部分が前面となったパネル状管群15a2となる。このパネル状管群15a2の背面は劣化しているが、前面は燃焼ガスに曝されない外側であるので、劣化のない新品と同様の管やパネル状管群である。このパネル状管群15a2の前面がパネル状管群15の内側になるように、切り取りしていないパネル状管群15の切り取り部分(劣化状態箇所21)に溶接して取り付ける。 The cut-out panel-shaped tube group 15a1 is deteriorated at a portion located inside the panel-shaped tube group 15. This is because it was exposed to the combustion gas. When the cut panel-shaped tube group 15a1 is turned upside down, a portion located outside the panel-shaped tube group 15 becomes a panel-shaped tube group 15a2 having a front surface. Although the rear surface of the panel-shaped tube group 15a2 is deteriorated, the front surface is the outside which is not exposed to the combustion gas, and therefore is the same tube or panel-shaped tube group as the new one that is not deteriorated. The panel-shaped tube group 15a2 is welded and attached to the cut-out portion (deteriorated state portion 21) of the panel-shaped tube group 15 so that the front surface of the panel-shaped tube group 15a2 is inside the panel-shaped tube group 15.

これにより、パネル状管群15の内側のパネル状管群は劣化のない新品と同様のパネル状管群となり、パネル状管群の寿命は事実上2倍に延びる。以上の説明では、パネル状管群として切り取る場合について説明したが、管だけを切り取る場合も同様である。 As a result, the panel-shaped tube group inside the panel-shaped tube group 15 becomes the same panel-shaped tube group as a new one without deterioration, and the life of the panel-shaped tube group is effectively doubled. In the above description, the case of cutting out as a panel-shaped tube group has been described, but the same applies to the case of cutting out only tubes.

次に、本発明の第2実施形態を説明する。図5は本発明の第2実施形態に係るボイラ補修方法の工程を示すフローチャートである。この第2実施形態は、図1に示した第1実施形態に対し、ステップS11〜ステップS15を追加して設け、管またはパネル状管群に歪みがあるときは、管またはパネル状管群を部分的に切り取る際に、切り取った管またはパネル状管群の管口を切り取り部分の管口に合わせて溶接できる大きさに分割して切り取り、切り取った管またはパネル状管群を裏返した後に、管またはパネル状管群の管口が切り取り部分の管口位置に合うように修正加工し、切り取った管またはパネル状管群を前記切り取り部分に嵌め込み溶接するようにしたものである。図1と同一ステップには同一符号を付し重複する説明は省略する。 Next, a second embodiment of the present invention will be described. FIG. 5 is a flowchart showing steps of the boiler repair method according to the second embodiment of the present invention. In the second embodiment, steps S11 to S15 are additionally provided to the first embodiment shown in FIG. 1, and when the pipe or panel-shaped tube group is distorted, the tube or panel-shaped tube group is When partially cutting, divide the pipe opening of the cut pipe or panel-like pipe group into a size that can be welded according to the pipe opening of the cut portion and cut it, after turning over the cut pipe or panel-like pipe group, The pipe or panel-like pipe group is modified so that the pipe mouth is aligned with the pipe mouth position of the cutout portion, and the cut pipe or panel-like pipe group is fitted into the cutout portion and welded. The same steps as those in FIG.

図5において、ステップS2の判定で、パネル状管群15の内側の劣化状態が予め定めた取替基準に達している箇所があるときは、劣化状態が予め定めた取替基準に達している箇所に歪みがあるか否かを判定する(S11)。劣化状態が予め定めた取替基準に達している箇所に歪みがないときは、図1に示したステップS3〜ステップS5と同様の処理を行う。 In FIG. 5, when it is determined in step S2 that the deterioration state inside the panel-shaped tube group 15 has reached the predetermined replacement standard, the deterioration state has reached the predetermined replacement standard. It is determined whether or not there is distortion at the location (S11). When there is no distortion at the place where the deterioration state has reached the predetermined replacement standard, the same processing as steps S3 to S5 shown in FIG. 1 is performed.

一方、劣化状態が予め定めた取替基準に達している箇所に歪みがあるときは、その箇所の管またはパネル状管群を切り取ったときに、切り取った管またはパネル状管群の管口を切り取り部分の管口に合わせて溶接できる大きさに分割して切り取る(S12)。そして、切り取った管またはパネル状管群を裏返し(S13)、管またはパネル状管群の管口が切り取り部分の管口位置に合うように修正加工し(S14)、修正加工した管またはパネル状管群を前記切り取り部分に嵌め込み溶接する(S15)。 On the other hand, when there is distortion at the place where the deterioration state has reached the predetermined replacement standard, when cutting the pipe or panel-like tube group at that place, make sure that the pipe opening of the cut-out tube or panel-like tube group is The cut portion is cut into pieces that can be welded according to the pipe mouth (S12). Then, the cut tube or panel-shaped tube group is turned upside down (S13), and the tube or panel-shaped tube group is subjected to correction processing so that the tube opening of the tube or panel-shaped tube group matches the tube opening position of the cut portion (S14). The tube group is fitted into the cutout portion and welded (S15).

これは、切り取った管またはパネル状管群を切り取り部分に嵌め込み溶接する場合に、切り取りしていない管またはパネル状管群に適切に連結できるようにするためである。すなわち、切り取った管またはパネル状管群を裏返すことから、火炉の内側と外側とが入れ替わり、管またはパネル状管群の管口が切り取り部分の管口位置に合うように修正加工しないと、切り取りしていない管またはパネル状管群に適切に連結できなくなるからである。 This is so that when the cut pipe or panel-shaped pipe group is fitted into the cut portion and welded, it can be properly connected to the non-cut pipe or panel-shaped pipe group. That is, since the cut tube or panel-shaped tube group is turned over, the inside and outside of the furnace are switched and the pipe or panel-shaped tube group must be modified so that the pipe mouth does not match the pipe mouth position of the cut portion. This is because it becomes impossible to properly connect to a pipe or a panel-shaped pipe group that has not been formed.

図6は、管またはパネル状管群に歪みがある場合に部分的に切り取ったパネル状管群を裏返して切り取り部分に嵌め込み溶接する場合の説明図である。図6では部分的にパネル状管群を切り取った場合を示している。 FIG. 6 is an explanatory view of a case where a panel-shaped tube group partially cut out is turned over and fitted into the cut-out portion and welded when the tube or the panel-shaped tube group is distorted. FIG. 6 shows a case where the panel-shaped tube group is partially cut out.

パネル状管群15のうち、劣化状態が予め定めた取替基準に達している劣化状態箇所21を切り取るにあたり、劣化状態箇所21に歪みがあるときは、切り取ったパネル状管群の大きさが、切り取った管またはパネル状管群の管口を切り取り部分の管口に合わせて溶接できる大きさに分割して切り取る。図6ではパネル状管群15が内側に凸に歪んでいる場合を示している。 When the deterioration state portion 21 of the panel-shaped tube group 15 whose deterioration state has reached the predetermined replacement standard is distorted, when the deterioration state portion 21 is distorted, the size of the cut panel-shaped tube group is , Cut the cut pipe or panel-shaped pipe group into a size that can be welded according to the pipe port of the cut part and cut it. FIG. 6 shows a case where the panel-shaped tube group 15 is distorted so as to be convex inward.

切り取ったパネル状管群15b1は、パネル状管群15の内側に位置していた部分が劣化している。これは、燃焼ガスに曝されていたからである。この切り取ったパネル状管群15b1を裏返すと、パネル状管群15の外側に位置していた部分が前面となったパネル状管群15b2となる。このパネル状管群15b2の背面は劣化しているが、前面は燃焼ガスに曝されない外側であるので、劣化のない新品と同様の管やパネル状管群である。 The cut-out panel-like tube group 15b1 is deteriorated at the portion located inside the panel-like tube group 15. This is because it was exposed to the combustion gas. When the cut panel-shaped tube group 15b1 is turned upside down, a portion located outside the panel-shaped tube group 15 becomes a panel-shaped tube group 15b2 having a front surface. Although the rear surface of the panel-like tube group 15b2 is deteriorated, the front surface is the outside which is not exposed to the combustion gas, and therefore is the same tube or panel-like tube group as a new one without deterioration.

このパネル状管群15b2の前面がパネル状管群15の内側になるように、切り取りしていないパネル状管群15の切り取り部分(劣化状態箇所21)に溶接して取り付けるわけであるが、パネル状管群15b1は内側に凸に歪んでいることから、パネル状管群15b1を裏返したパネル状管群15b2は内側に凹に歪んだものとなる。 The panel-shaped tube group 15b2 is welded and attached to the cut portion (degraded state portion 21) of the panel-shaped tube group 15 so that the front surface of the panel-shaped tube group 15b2 is inside the panel-shaped tube group 15. Since the tube-shaped tube group 15b1 is distorted inwardly convex, the panel-shaped tube group 15b2 obtained by turning the panel-shaped tube group 15b1 upside down is distorted inwardly.

そこで、パネル状管群15b1を裏返したパネル状管群15b2に対し、その管口が切り取り部分(劣化状態箇所21)の管口位置に合うように修正加工する。パネル状管群15b2を修正加工させるにあたっては、パネル状管群15b2の上下端部において、管19間の連結板20に切り込み22を入れる。そして、パネル状管群15b2の上下端の連結板20を、管19またはパネル状管群15の管口が切り取り部分の管口位置に合うように修正加工する。 Therefore, the panel-shaped tube group 15b2, which is the panel-shaped tube group 15b1 turned upside down, is modified so that the tube opening matches the tube opening position of the cutout portion (deteriorated state portion 21). When the panel-shaped tube group 15b2 is modified, the notch 22 is formed in the connecting plate 20 between the tubes 19 at the upper and lower ends of the panel-shaped tube group 15b2. Then, the connecting plates 20 at the upper and lower ends of the panel-shaped tube group 15b2 are modified so that the tube opening of the tube 19 or the panel-shaped tube group 15 is aligned with the tube opening position of the cutout portion.

図6の修正加工したパネル状管群15b3において、管19間の上下端部の連結板20の先端部は切り込み22により2分割される。管19aと管19bとの間の上端部の連結板20は、先端部が連結板片20a1と連結板片20a2とに2分割され、同様に、管19bと管19cとの間の連結板20は、切り込み22により先端部が連結板片20b1と連結板片20b2とに2分割され、管19cと管19dとの間の連結板20は、切り込み22により先端部が連結板片20c1と連結板片20c2とに2分割される。また、管19間の下端部においても、符号の図示は省略するが、同様に連結板20の先端部は2分割される。 In the panel-shaped tube group 15b3 that has been modified as shown in FIG. 6, the tip ends of the connecting plates 20 at the upper and lower ends between the tubes 19 are divided into two by the notches 22. The upper end of the connecting plate 20 between the pipes 19a and 19b is divided into two parts, a connecting plate piece 20a1 and a connecting plate piece 20a2, and similarly, a connecting plate 20 between the pipes 19b and 19c. Is divided into two parts by a notch 22 into a connecting plate piece 20b1 and a connecting plate piece 20b2. The connecting plate 20 between the pipes 19c and 19d has a notch 22 so that the leading end part is connected to the connecting plate piece 20c1. It is divided into two pieces 20c2. Further, also at the lower end portion between the pipes 19, although illustration of the reference numeral is omitted, similarly, the leading end portion of the connecting plate 20 is divided into two.

そして、パネル状管群15b2の上下端の連結板20を、管19またはパネル状管群15の管口が切り取り部分の管口位置に合うように修正加工すると、図6の修正加工したパネル状管群15b3となる。このパネル状管群15b3を切り取りしていないパネル状管群15の切り取り部分(劣化状態箇所21)に嵌め込み溶接して取り付ける。 Then, the connecting plates 20 at the upper and lower ends of the panel-shaped tube group 15b2 are corrected so that the tube opening of the tube 19 or the panel-shaped tube group 15 matches the tube opening position of the cut portion. It becomes a tube group 15b3. The panel-shaped tube group 15b3 is fitted and welded to the cut-out portion (deteriorated state portion 21) of the panel-shaped tube group 15 which is not cut.

すなわち、切り取った管またはパネル状管群の管口と切り取り部分の管口との間、切り込み22を入れた連結板20の切り込み部分が重なり合っている箇所を溶接する。これにより、管やパネル状管群に歪みがあっても、切り取った管またはパネル状管群を容易に切り取り部分に嵌め込むことができる。以上の説明では、パネル状管群として切り取る場合について説明したが、管だけを切り取る場合も同様である。 That is, between the cutout pipe or the pipe mouth of the panel-shaped pipe group and the cutout pipe mouth, a portion where the cut portion of the connecting plate 20 having the cut 22 overlaps is welded. Thereby, even if the pipe or the panel-shaped pipe group is distorted, the cut pipe or the panel-shaped pipe group can be easily fitted into the cut portion. In the above description, the case of cutting out as a panel-shaped tube group has been described, but the same applies to the case of cutting out only tubes.

ここで、切り取った管またはパネル状管群の管口を切り取り部分の管口に合わせて溶接できる大きさとは、図6の修正加工したパネル状管群15b3において、パネル状管群15b3の修正加工した上下端の連結板20が重なり合う大きさである。すなわち、切り取った管またはパネル状管群の管口を、切り取り部分の管口に合わせるように修正加工したとき、パネル状管群15b3の修正加工した上下端の連結板20が重なり合う大きさである。上下端の連結板20が重なり合っていれば、溶接が可能であるからである。 Here, the size of the cut pipe or the pipe mouth of the panel-like pipe group that can be welded in accordance with the pipe mouth of the cut portion means that the panel-like pipe group 15b3 of FIG. The connecting plates 20 at the upper and lower ends overlap each other. That is, when the cut pipe or the pipe mouth of the panel-like pipe group is modified so as to match the pipe mouth of the cut-out portion, the corrected processed upper and lower connecting plates 20 of the panel-like pipe group 15b3 overlap each other. .. This is because welding is possible if the connecting plates 20 at the upper and lower ends overlap.

以下の説明では、ボイラ11の火炉部11aのパネル状管群15を補修する場合について説明したが、ボイラ11の後伝部11bのパネル状管群を補修する場合についても同様に適用できる。 In the following description, the case of repairing the panel-shaped tube group 15 of the furnace part 11a of the boiler 11 has been described, but the same can be applied to the case of repairing the panel-shaped tube group of the rear transmission part 11b of the boiler 11.

以上、本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。 Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the scope of equivalents thereof.

11…ボイラ、11a…火炉部、11b…後伝部、12…節炭器、13…第1連結配管、14…第1管寄せ、15…パネル状管群、16…第2管寄せ、17…第2連絡配管、18…過熱器、19…管、20…連結板、21…劣化状態箇所、22…切り込み DESCRIPTION OF SYMBOLS 11... Boiler, 11a... Furnace part, 11b... Rear transfer part, 12... Economizer, 13... 1st connection piping, 14... 1st tube gathering, 15... Panel tube group, 16... 2nd tube gathering, 17 ...Second communication pipe, 18...superheater, 19...pipe, 20...connecting plate, 21...degraded location, 22...cut

Claims (1)

ボイラの内部で燃料を燃焼させた燃焼ガスの熱とボイラ内のパネル状管群の管の中を流れる給水もしくは蒸気とで熱交換させる前記パネル状管群の点検の際に前記パネル状管群の前記燃焼ガスに曝される内側の劣化状態を判定し、
前記パネル状管群の劣化状態が取替基準に達しているときはその管またはパネル状管群を部分的に切り取り、
部分的に切り取った管またはパネル状管群を裏返して前記燃焼ガスに曝される内側と前記燃焼ガスに曝されない外側との位置を反転させ、
部分的に切り取って位置を反転させた管またはパネル状管群を切り取り部分に嵌め込み溶接してボイラのパネル状管群を補修するにあたり、
劣化状態が予め定めた取替基準に達している箇所の管またはパネル状管群に歪みがあるときは、管またはパネル状管群を部分的に切り取る際に、切り取った管またはパネル状管群の管口を前記切り取り部分の管口に合わせて溶接できる大きさに分割して切り取り、切り取った管またはパネル状管群を裏返した後に、管またはパネル状管群の管口が前記切り取り部分の管口位置に合うように修正加工し、修正加工した管またはパネル状管群を前記切り取り部分に嵌め込み溶接することを特徴とするボイラ補修方法。
When inspecting the panel-shaped tube group, the heat of the combustion gas produced by burning the fuel in the boiler and the feed water or steam flowing in the tube of the panel-shaped tube group in the boiler exchange heat. Determine the deterioration state of the inside exposed to the combustion gas of,
When the deterioration state of the panel-shaped tube group has reached the replacement standard, the tube or the panel-shaped tube group is partially cut off,
The partially cut out tube or panel-like tube group is turned over to reverse the positions of the inside exposed to the combustion gas and the outside not exposed to the combustion gas,
When repairing a panel-shaped tube group of a boiler by fitting a welded tube or panel-shaped tube group whose position has been partially cut and the position reversed ,
When the pipe or panel-shaped pipe group is distorted in a location where the deterioration state has reached a predetermined replacement standard, when cutting the pipe or panel-shaped pipe group partially, the cut pipe or panel-shaped pipe group After cutting the pipe opening of the pipe into a size that can be welded in accordance with the pipe opening of the cut portion and turning over the cut pipe or panel-like tube group, A method for repairing a boiler , which is modified so as to match a pipe opening position, and the modified pipe or panel-shaped pipe group is fitted into the cutout portion and welded .
JP2016061247A 2016-03-25 2016-03-25 Boiler repair method Active JP6736936B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016061247A JP6736936B2 (en) 2016-03-25 2016-03-25 Boiler repair method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016061247A JP6736936B2 (en) 2016-03-25 2016-03-25 Boiler repair method

Publications (2)

Publication Number Publication Date
JP2017172918A JP2017172918A (en) 2017-09-28
JP6736936B2 true JP6736936B2 (en) 2020-08-05

Family

ID=59970821

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016061247A Active JP6736936B2 (en) 2016-03-25 2016-03-25 Boiler repair method

Country Status (1)

Country Link
JP (1) JP6736936B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6871662B1 (en) * 2020-11-10 2021-05-12 日本エネルギーパートナーズ株式会社 Boiler heat transfer tube wall thickness estimation method, boiler heat transfer tube wall thickness estimation device, boiler heat transfer tube wall thickness estimation program and boiler heat transfer tube management method based on the method

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4807076B2 (en) * 2005-12-28 2011-11-02 Dowaテクノロジー株式会社 Heat transfer tube, heat transfer tube manufacturing method, and fluidized bed furnace
JP2012110943A (en) * 2010-11-25 2012-06-14 Mitsubishi Heavy Ind Ltd Build-up welding device and method
JP6244606B2 (en) * 2013-08-07 2017-12-13 三菱日立パワーシステムズ環境ソリューション株式会社 Heat exchanger repair method

Also Published As

Publication number Publication date
JP2017172918A (en) 2017-09-28

Similar Documents

Publication Publication Date Title
JP6357706B2 (en) Heat exchanger
TW201341700A (en) Steam generator heating tube repair means and repair method
CA2687885C (en) Repair welding method for waterwall tubes
CN101398274B (en) Heat exchanger tube assembly welded by laser
JP6736936B2 (en) Boiler repair method
JP6453323B2 (en) Replacement method of boiler and its heat transfer tube
CN107738039B (en) Steel membrane type tube panel sealing welding method
JP2011002115A (en) Method of repairing pipe of heat exchanger
JP2011179781A (en) Heat exchanger
JPWO2017170661A1 (en) Stoker waste incinerator equipped with a waste heat recovery boiler
KR100810131B1 (en) Welding method of boiler tubes assembly
JP6862986B2 (en) How to operate the gas preheater
KR101552858B1 (en) Flue tube-smoke tube composite type hot water boiler
JP3180377U (en) Heat exchanger
JP6671146B2 (en) Repair method for economizer, boiler and heat transfer tube
CA2507821C (en) Method for producing a continuous steam generator and a continuous steamgenerator
US10527278B2 (en) Radiant to convection transition for fired equipment
JP6632438B2 (en) Repair method of waste heat recovery boiler
US10955201B2 (en) Heat exchanger, boiler, and setting method for heat exchanger
KR101508755B1 (en) A HRSG of mono drum type
Amador et al. Application of unifuse overlay tubes in the convection section of waste-to-energy boilers
KR20160111287A (en) Recuperator
JP2007064608A (en) Membrane panel for boiler system, and boiler system using the same
CN105387445A (en) Anti-flushing structure for water feeding inlet of high-pressure heater
JP2007147159A (en) Membrane wall for boiler, and boiler device using it

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20190204

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20191218

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20200107

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20200206

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20200616

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20200629

R150 Certificate of patent or registration of utility model

Ref document number: 6736936

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150