JP5320052B2 - Soot blower and operation method thereof - Google Patents

Description

The present invention relates to a soot blower that removes fly ash adhering to a heat transfer tube by spraying steam on the heat transfer tube of a boiler, and in particular, has a double-pipe structure in which a lance pipe is detachably arranged on the outside of a feed pipe. TECHNICAL FIELD The present invention relates to a so-called long draw soot blower that introduces steam supplied to a pipe into a lance pipe and blows steam from a nozzle at the tip of the lance pipe to a heat transfer pipe of a boiler to remove fly ash adhering to the heat transfer pipe and an operation method thereof. .

  In the present invention, “fly ash” is a general term for soot, ash, dust, and the like that float in the boiler and adhere to the heat transfer tube of the boiler.

  Boilers, especially boilers used in waste treatment facilities, receive a large amount of fly ash together with high-temperature exhaust gas, and fly ash adheres to the heat transfer tubes of the boiler, so that the boiler can be operated efficiently and safely. Therefore, it is necessary to remove the fly ash adhering to the heat transfer tube periodically or as necessary.

  To remove such deposits, a soot blower using a lance pipe is generally used. However, in order to remove fly ash adhering to the heat transfer pipe of a boiler, a long blow with a long lance pipe is used. A differential soot blower is used.

  FIG. 3 is an explanatory diagram showing the basic configuration and operation of a conventional long-drawing soot blower. As shown in FIG. 3A, the long-drawing soot blower has a double-pipe structure in which a lance pipe 2 is detachably arranged on the outside of the feed pipe 1. Among these, the feed pipe 1 is fixed, and the lance pipe 2 can advance and retreat (can be inserted and removed) along its longitudinal direction, and can rotate around a longitudinal axis. A gap between the base end of the lance pipe 2 and the outer peripheral surface of the feed pipe 1 is sealed with a seal member 3.

  An inlet valve 4 is attached to the proximal end of the feed pipe 1, and steam is supplied from the main steam line 5 to the feed pipe 1 by opening the inlet valve 4. The steam supplied to the feed pipe 1 is introduced into the lance pipe 2 and injected from the nozzle 2a at the tip of the lance pipe.

  When removing the fly ash adhering to the heat transfer tube by actually spraying steam on the heat transfer tube of the boiler, the lance pipe 2 is advanced and inserted into the boiler B as shown in FIG. While rotating 2, steam is injected from the nozzle 2 a. When the fly ash removal operation is completed, as shown in FIG. 3A, the lance pipe 2 is retracted to the standby position outside the boiler B, the inlet valve 4 is closed, and the supply of steam is stopped.

  In this way, the long pull-out soot blower positions the lance pipe at the standby position outside the boiler during standby and stops the supply of steam. Therefore, during standby, the feed pipe 1 and the lance pipe 2 are cooled, and each pipe is cooled. Drain remains inside. In addition, since steam is supplied in a completely cooled state at the next start-up, a large amount of drain is generated while the feed pipe 1 and the lance pipe 2 are warmed up with steam. This drain is injected into the boiler, a drain attack occurs, and the heat transfer tubes and the like are damaged.

  In order to prevent the occurrence of this drain attack, Patent Document 1 discloses an intermediate stop position in FIG. 3B, which is in the middle of the blow position in FIG. 3C from the standby position in FIG. Low pressure steam is supplied to the feed pipe 1 with the nozzle 2a at the tip of the lance pipe positioned in the vicinity of the boiler outer wall B1 in the boiler B, and the drain in the feed pipe 1 and the lance pipe 2 is discharged at the intermediate stop position at the nozzle 2a. A technique for warming up the soot blower while discharging from the factory is disclosed.

However, according to a test conducted by the present inventor, even when low-pressure steam is supplied at an intermediate stop position as shown in FIG. 3B, the drain accumulated in the portion where the feed pipe 1 and the lance pipe 2 are overlapped is It was found that it was not discharged and remained as drain D as shown in FIG. Therefore, when steam is supplied by advancing the lance pipe 1 from the intermediate stop position in FIG. 3 (b) to the blow position in FIG. 3 (c), the drain D that has not been discharged at the intermediate stop position in FIG. Injected from the nozzle 2a, a train attack occurs.
Japanese Patent Laid-Open No. 11-63466

The problem to be solved by the present invention is to provide a soot blower capable of reliably discharging the drainage accumulated in each pipe of the soot blower and an operating method thereof .

The soot blower of the present invention has a double pipe structure in which a lance pipe can be inserted and removed from the outside of the feed pipe, introduces steam supplied to the feed pipe into the lance pipe, and heats the tube from the nozzle at the tip of the lance pipe. In the soot blower that blows steam on the heat transfer tube to remove fly ash, a drain discharge pipe is provided in the feed pipe, and its tip is a nozzle at the tip of the lance pipe for warming up the soot blower and discharging the drain in the soot blower. the state of being positioned in the boiler outer wall vicinity in the boiler (hereinafter, the position of this state is referred to as "intermediate stop position".) communicates with the lower region of the lance pipe in, proximal end in communication with outside the feed pipe, the intermediate Due to the internal pressure of the steam supplied to the feed pipe at the stop position, the lower area of the lance pipe The awaiting drain, characterized by discharging from its proximal end to the outside of the boiler from the tip of the drain exhaust pipe via the drain discharge pipe. Further, the soot blower operating method of the present invention is the soot blower operating method of the present invention, wherein steam is supplied to the feed pipe at the intermediate stop position and accumulated in a lower region of the lance pipe by the internal pressure of the steam. The drain is discharged from the front end of the drain discharge pipe through the drain discharge pipe to the outside of the boiler.

With this configuration, when low-pressure steam is supplied at the intermediate stop position , the drain that does not discharge from the nozzle at the tip of the lance pipe accumulates in the overlapping portion of the feed pipe and the lance pipe. Thus, the water is discharged from the drain discharge pipe from the base end of the drain discharge pipe via the inside of the drain discharge pipe. Other drainage is discharged from the nozzle at the tip of the lance pipe. Therefore, the drain accumulated in each pipe of the soot blower can be reliably discharged, and the occurrence of the drain attack and the damage to the heat transfer tube of the boiler due to the drain attack can be prevented.

  In the present invention, it is preferable that the distal end of the drain discharge pipe communicates with the lower region of the proximal end portion of the lance pipe at the intermediate stop position. As a result, the drain accumulated in the portion where the feed pipe and the lance pipe overlap can be more reliably discharged via the drain discharge pipe.

  ADVANTAGE OF THE INVENTION According to this invention, the drain collected in each pipe of a soot blower can be discharged | emitted reliably, and generation | occurrence | production of a drain attack and damage to the heat exchanger tube of a boiler by a drain attack can be prevented.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  FIG. 1 is an explanatory view showing the configuration and operation of the soot blower of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG.

  The basic structure of the soot blower of the present invention is the same as that of the conventional long-drawing soot blower described with reference to FIG. 3, and has a double pipe structure in which the lance pipe 2 is detachably disposed outside the feed pipe 1. Among these, the feed pipe 1 is fixed, and the lance pipe 2 can advance and retreat (can be inserted and removed) along its longitudinal direction, and can rotate around a longitudinal axis. A gap between the base end of the lance pipe 2 and the outer peripheral surface of the feed pipe 1 is sealed with a seal member 3.

  An inlet valve 4 is attached to the proximal end of the feed pipe 1, and steam is supplied from the main steam line 5 to the feed pipe 1 by opening the inlet valve 4. The steam supplied to the feed pipe 1 is introduced into the lance pipe 2 and injected from the nozzle 2a at the tip of the lance pipe.

  When removing the fly ash adhering to the heat transfer pipe by actually spraying steam on the heat transfer pipe of the boiler, as shown in FIG. 1 (c), the lance pipe 2 is advanced and inserted into the boiler B. While rotating 2, steam is injected from the nozzle 2 a. When the fly ash removal operation is completed, as shown in FIG. 1A, the lance pipe 2 is retracted to the standby position outside the boiler B, the inlet valve 4 is closed, and the supply of steam is stopped.

  Also, in the soot blower of the present invention, in order to warm up the soot blower and discharge the drain in the soot blower while the lamp pipe 2 is being advanced from the standby position of FIG. 1A to the blow position of FIG. At the intermediate stop position in FIG. 1 (b), the low pressure steam is supplied to the feed pipe 1. This low-pressure steam may be supplied by making the opening degree of the inlet valve 4 smaller than that during normal operation. Although not shown, a bypass line is provided so as to straddle the inlet valve 4. An on-off valve and a pressure reducing means may be provided and supplied via this bypass line. Instead of supplying low pressure steam, the inlet valve 4 may be fully opened to supply normal pressure steam.

  Here, the intermediate stop position shown in FIG. 1B is a position where the nozzle 2a at the tip of the feed pipe is positioned in the vicinity of the boiler outer wall B1 in the boiler B for warming up the soot blower and draining the drain in the soot blower as described above. In other words, even if the drain is injected from the nozzle 2a, the drain attack generated thereby does not substantially damage the heat transfer tube of the boiler. Specifically, the distance L from the nozzle 2a to the inner surface of the boiler outer wall B1 is in the range of about 150 mm to 300 mm.

  In the soot blower of the present invention having the above basic configuration, even if low pressure steam is supplied at the intermediate stop position, it is not discharged from the nozzle 2a at the tip of the lance pipe, and the feed pipe 1 and the lance pipe 2 remain in the overlapping portion. A drain discharge pipe 6 is provided in the feed pipe 1 in order to discharge the drain D. The drain discharge pipe tip 6a penetrates the feed pipe 1 as shown in FIG. 2, and is below the lower region of the lance pipe 2, more specifically, the portion where the feed pipe 1 and the lance pipe 2 overlap. It communicates with the side area. Further, the base end 6b of the drain discharge pipe passes through the base end portion of the feed pipe 1 and communicates with the outside of the feed pipe 1 as shown in FIG.

  In this way, at the intermediate stop position in FIG. 1B, the drain discharge pipe 6 whose tip 6a communicates with the lower region of the lance pipe 2 and whose base end 6b communicates outside the feed pipe 1 is placed in the feed pipe 1. By providing the low-pressure steam to the feed pipe 1 at this intermediate stop position, the drain that does not discharge from the nozzle 2a at the tip of the lance pipe is accumulated in the portion where the feed pipe 1 and the lance pipe 2 overlap. Due to the internal pressure, the drain discharge pipe 6 is discharged from the drain discharge pipe 6 to the outside of the feed pipe 1 through the drain discharge pipe 6 through the drain discharge pipe 6 as indicated by an arrow in FIG. Other drainage is discharged from the nozzle 2a at the tip of the lance pipe. Therefore, in the soot blower of the present invention, the drain accumulated in each pipe can be surely discharged, and the occurrence of the drain attack and the damage to the heat transfer tube of the boiler due to the drain attack can be prevented.

  In the present invention, it is preferable that the tip 6a of the drain discharge pipe is provided so as to communicate with the lower region of the base end portion of the lance pipe 2 at the intermediate stop position as shown in FIG. As a result, the drain accumulated in the part where the feed pipe 1 and the lance pipe 2 overlap can be more reliably discharged via the drain discharge pipe 6.

  Further, for example, the determination of whether or not the drain accumulated in the portion where the feed pipe 1 and the lance pipe 2 overlap is completely measured by measuring the temperature of the portion of the lance pipe 1 at the position 6a of the drain discharge pipe. This can be done depending on whether the saturated steam temperature has been reached or not. Therefore, in the present invention, the drain discharge is continued at the intermediate stop position in FIG. 1B until the temperature of the portion of the lance pipe 1 at the position 6a of the drain discharge pipe reaches the saturated steam temperature. The lance pipe 2 can be advanced as shown in FIG. 1C to inject steam from the nozzle 2a. Accordingly, it is possible to reliably prevent the drain from being ejected from the nozzle 2a at the blow position, and it is possible to prevent the occurrence of the drain attack.

  Instead of measuring the temperature of the portion of the lance pipe 1 at the tip 6a position of the drain discharge pipe and judging whether or not the drain is completely discharged, the drain is discharged from the base end 6b portion of the drain discharge pipe. You may make it confirm directly whether it is done. The adjustment can be made so that the supply of the low-pressure steam at the intermediate stop position in FIG. 1B is time-controlled by setting a timer, and the drain discharge at the intermediate stop position is terminated when a predetermined time has elapsed.

It is explanatory drawing which shows a structure and operation | movement of the soot blower of this invention. It is AA sectional drawing of FIG.1 (b). It is explanatory drawing which shows the basic composition and operation | movement of the conventional long pulling type | mold soot blower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feed pipe 2 Lance pipe 2a Nozzle 3 Seal member 4 Inlet valve 5 Main steam line 6 Drain discharge pipe 6a Drain discharge pipe tip 6b Drain discharge pipe base B Boiler B1 Boiler outer wall D Drain

Claims (3)

It has a double pipe structure in which the lance pipe can be inserted and removed outside the feed pipe. Steam supplied to the feed pipe is introduced into the lance pipe, and steam is blown from the nozzle at the tip of the lance pipe to the heat transfer pipe of the boiler. In soot blowers that remove fly ash adhering to heat tubes,
A drain discharge pipe is provided in the feed pipe, and the tip of the drain pipe is positioned near the boiler outer wall in the boiler for the warm-up of the soot blower and the drain discharge in the soot blower (hereinafter referred to as this state). position communicating with the lower region of the lance pipe called.) in the "intermediate stop position", the base end is communicated with the outside the feed pipe,
Due to the internal pressure of the steam supplied to the feed pipe at the intermediate stop position, the drain accumulated in the lower region of the lance pipe is passed from the distal end of the drain discharge pipe to the boiler through the drain discharge pipe. A soot blower that discharges outside . The soot blower according to claim 1, wherein a distal end of the drain discharge pipe communicates with a lower region of a proximal end portion of the lance pipe at the intermediate stop position . It has a double pipe structure in which the lance pipe can be inserted and removed outside the feed pipe. Steam supplied to the feed pipe is introduced into the lance pipe, and steam is blown from the nozzle at the tip of the lance pipe to the heat transfer pipe of the boiler. A soot blower that removes fly ash adhering to the heat pipe, and a drain discharge pipe is provided in the feed pipe. In the operation method of the soot blower in which the base end communicates with the lower region of the lance pipe in the state of being positioned in the vicinity of the boiler outer wall (hereinafter, this position is referred to as “intermediate stop position”)
  Steam is supplied to the feed pipe at the intermediate stop position, and the drain accumulated in the lower region of the lance pipe is caused by the internal pressure of the steam from the tip of the drain discharge pipe through the drain discharge pipe. An operation method of a soot blower characterized by discharging from the base end to the outside of the boiler.

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