JP2002213729A - Opening/closing mechanism of supply valve of injection medium of long retractable soot blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the thermal shock damage of a lance pipe in a long retractable soot blower used for sweeping off the soot of a wall at the rear of the furnace of a coal-heating boiler. SOLUTION: In the long retractable soot blower 60 for removing built-up and deposits for purifying the inside of a furnace by inserting a lance pipe 31 into the furnace 1 of a boiler or the like and then injecting a high-pressure injection medium from the tip nozzle, the opening/closing mechanism of a head valve 52 for supplying the vapor of the injection medium to the lance pipe 31 is opened or closed in two steps of half open and total open, and includes an opening/closing mechanism for including an opening/closing cam 67 for half-opening the head valve 53 and an opening/closing mechanism for including an opening/closing cam 65 for totally opening the head valve 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soot blower for removing soot and the like adhering to a furnace such as a boiler, and more particularly to an opening / closing mechanism for an injection medium supply valve of a long-displacement soot blower using a long lance tube.

[0002]

2. Description of the Related Art Since soot and the like adhere to a furnace wall and the like in a furnace such as a boiler, it is necessary to remove the adhered matter periodically or as necessary and to operate the boiler and the like efficiently and safely. . Generally, a soot blower using a lance tube is used to remove such deposits. This is to blow out a jet medium such as high-pressure steam or air from the nozzle at the tip of the lance tube and spray it onto the deposit surface. The surface is cleaned by mechanically removing the deposits. Particularly in a coal-fired boiler, the front wall and the side wall of the furnace are usually provided with a short slip-type soot blower, but a long lance tube is used for soot removal on the rear wall of the furnace. A equipped long-displacement soot blower is used.

The state of soot removal by a conventional soot blower will be described with reference to FIGS. First, the structure of the boiler will be described. In the figure, a furnace 1 of a coal-fired boiler is surrounded by four walls of a front wall 3, a rear wall 5, and side walls 7 on both sides. A boiler tube 9 is provided along the predetermined arrangement. Then, the coal is burned by a burner 11 installed at a corner portion of the surrounding wall of the furnace 1, and the generated high-temperature combustion gas rises in the furnace 1, passes through a superheater, etc. It flows to the heat exchanger 13 installed behind. Next, a description will be given of the soot blower. In the front wall 3, the side walls 7, 7, a large number of ordinary short-drawing soot blowers 20 are arranged, and the lance tube 21 can be inserted into and removed from the furnace 1 respectively. ing. However, since the heat exchanger 13 is installed behind the rear wall 5, it is not possible to dispose the short-pitch soot blower 20 on the rear wall 5. For this reason, a long-removal soot blower 30 is arranged on the side wall 7 close to the rear wall 5, from which a long lance tube 31 can be inserted into the furnace 1, and the rear wall 5 and the boiler tube on the front surface thereof. 9 and so on.

Next, the structure and function of a conventional long-removal type soot blower 30 will be described with reference to FIG. When the ball screw 33 is rotated by driving means (not shown), the screw box 35 engaged with the screw box 35 is moved in the axial direction, and the gear 37 connected to the screw box 35 and the lance tube 31 are moved in the axial direction. The tube 31 is advanced into the furnace 1 of the boiler. Further, the lance tube 31 can be moved backward by rotating the driving means in the reverse direction. On the other hand, the rotation of the lance tube 31 is achieved by rotating the gear 39 along with the axial movement thereof via the key groove and the key in the axial length of the ball screw 33 and rotating the meshed gear 37, thereby connecting the lance tube 31. The rotated lance tube 31 is rotated around an axis.

[0005] The injection medium is supplied to the lance tube 31 as follows. That is, the screw box 35 moves in the axial direction, and the dog 41 moves from the position 41a to the valve opening / closing cam 43.
Is activated, the head valve 53 is opened via the connecting rod 45, the levers 47 and 49, and the spring 51, and the ejection medium is supplied to the lance pipe 31 through the supply pipe 55. At this time, the tip of the lance tube 31 has reached the point C after passing through the normal ejection position B, and the ejection medium is ejected from the tip nozzle. Subsequently, the lance tube 31 is rotated around the axis while ejecting, and is advanced to move to the end point. When the reversing switch is operated, the reversing operation is started. When the tip of the lance tube 31 is retracted to the point C, the valve opening / closing cam 43 is opened. Operates in the opposite direction to the case of forward movement, closes the head valve 53, continues retreating and returns to the point A, thereby completing one cycle of operation.

[0006]

The corner of the surrounding wall of the furnace 1 of the boiler has an oblique shape as shown in FIG.
In addition, since the boiler tube 9 is disposed, when the injection medium is started to be injected from the point B using the conventional long-removal type soot blower as described above, the erosion occurs in the boiler tube 9 in the corner portion. May occur. Therefore, in order to prevent this erosion, the injection medium is started to be injected from the point C. However, for this reason, while the tip of the lance tube 31 enters the furnace 1 and reaches the point C from the point B,
For example, it is heated by a high temperature combustion gas of about 1300 ° C.
In some cases, the tip of the lance tube was damaged by thermal shock due to rapid cooling to ℃. Therefore, according to the present invention, when using a long slip type soot blower to blow down soot on the rear wall of a boiler furnace, the injection medium supply of the long slip type soot blower that does not generate a large thermal shock at the tip of the lance tube is provided. It is intended to provide a valve opening / closing mechanism.

[0007]

According to the present invention, a lance tube is inserted into a furnace such as a boiler, and a high-pressure injection medium is injected from a nozzle at a tip of the lance tube. In a long-removal type soot blower that removes deposits and deposits and cleans the inside of the furnace, the opening and closing mechanism of a supply valve that supplies an injection medium to the lance tube is opened and closed in two stages, half open and full open. Be composed. The mechanism for fully opening the supply valve is configured as a second-stage opening / closing cam mechanism including a dog that moves together with the lance tube and an opening / closing cam connected to the supply valve via a link mechanism. The mechanism for half-opening the supply valve may be configured as a mechanical mechanism or an electrical mechanism including a switch for detecting an intermediate position of the dog. In the latter case, an automatic opening and closing bypass valve having half the flow rate of the supply valve is installed in parallel with the supply valve,
It is opened and closed by a detection signal from the switch. A play mechanism or a displacement absorbing mechanism using a long hole is provided between the first-stage opening / closing cam mechanism having a mechanical configuration for half-opening the supply valve and the second-stage opening / closing cam mechanism.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same members are denoted by the same reference numerals throughout the drawings including the drawings related to the prior art. First, referring to FIG. 1, the soot blower 60 includes a lance tube 31 supported so as to be able to move forward and backward, and a ball screw 33 is rotatably attached to a casing 61. A ball screw 33 connected to a driving means (not shown) is engaged with a screw box 35. Then, when the ball screw 33 is rotated by the driving means, the screw box 35 straddling the supply pipe 55 moves in the axial direction, that is, moves forward and backward. Since the gear 37 and the lance tube 31 are rotatably connected to the screw box 35, the gear 37 and the lance tube 31 move in the axial direction as the screw box 33 moves in the axial direction, and the lance tube 31 moves. 31 is advanced into the furnace 1 of the boiler or retracted from the furnace 1 of the boiler. A gear 39 provided on the ball screw 33 so as to be movable in the axial direction is engaged with the gear 37, and when the ball screw 33 rotates, the gear 3
The lance tube 31 is rotated around the axis through the meshing of 7, 39. That is, the lance tube 31 moves forward or backward while rotating around the axis.

Further, as shown in FIG.
The opening / closing cams 65 and 67 are connected to the head valve 53 via levers 47 and 49, respectively. Between the lever 49 and the main body of the head valve 53,
A spring 51 is provided. The state of connection between the connecting rod 63 and the second-stage full-open / close cam 65 will be described with reference to FIG.
1 and the base end of the link member 71 is fixed to the rotation shaft 69. Further, the tip of the link member 71 and the connecting rod 63
And the front end connection fitting 63 a is linked via a rotating shaft 73. That is, when the distal end fitting 63a of the connecting rod 63 moves as shown by the arrow, the opening / closing cam 65 pivots as shown by a two-dot chain line via the link member 71 and the rotating shaft 69. Further, the first-stage half-opening opening / closing cam 67 is provided as shown in FIG. That is, the base end of the opening / closing cam 67 is attached to the rotating shaft 75 attached to the casing 61, and the other end of the link member 77, one end of which is connected to the rotating shaft 75, is turned around the tip of the auxiliary connecting rod 79. It is connected via a driving shaft 81.
The base end (not shown) of the auxiliary connecting rod 79 is connected to the connecting rod 63 via a long hole as described later.

The connecting rod 63, the auxiliary connecting rod 79, the opening / closing cam 6
The overall relationship, such as 5, 67, is shown in the plan view of FIG. A shaft 87 at one end of a sub-connecting rod 79 is slidably connected to a long hole 85 of a holder 83 fixed to the center of the connecting rod 63. As described above, the link member 77 rotatably connects the rotating shafts 75 and 81 to each other, and the link member 71 rotatably connects the rotating shafts 69 and 73 to each other. The rotating shaft 69 and the rotating shaft 75 are rotatably attached to the casing 61 on the fixed side via a support member or a bearing member.

Next, the operation of the valve opening / closing mechanism for the injection medium supply valve, ie, the head valve 53, of the long-removal type soot blower constructed as described above will be described with reference to FIGS. First, a ball screw 33 (FIG. 1) is driven by driving means (not shown).
To rotate. When the screw box 35 engaged with the ball screw 33 is rotated to the right (in the figure) in the axial direction with the rotation of the ball screw 33, the dog 41 fixed to the screw box 35
As shown in FIG. 5 (a), the first opening / closing cam 6 is moved rightward.
Approach 7. In this state, the head valve 53
Is in a fully closed state, and the injection medium is not supplied to the lance tube 31. Next, when the dog 41 further moves as shown in FIG. 5B, the dog 41 engages with the forked portion of the
It is turned around five times to shift to the position of reference numeral 67a. In this case, the connecting rod 63 is moved rightward by the link motion of the rotating shaft 75, the link member 77, the rotating shaft 81, the auxiliary connecting rod 79, the shaft 87, and the holder 83. However, since there is the long hole 85, the movement of the dog 41 is transmitted in half. The halved movement of the connecting rod 63 is transmitted to the head valve 53 by the link movement of the connection fitting 63b, the levers 47 and 49, and the spring 51, and the head valve 53 is opened halfway. In this state, the first-stage opening / closing cam 67 has rotated to the position 67a, and the second-stage opening / closing cam 65 has rotated to the position 65a.

As shown in FIG. 5 (c), when the dog 41 further moves, it approaches and engages with the opening / closing cam 65, and moves it from the position 65a to the position 65b with the rotation shaft 69 as the axis. Rotate. The movement of the opening / closing cam 65 is determined by the rotation shaft 69, the link member 71, the rotation shaft 73, and the connection fitting 6.
It is transmitted to the connecting rod 63 via the link motion of 3a, and is moved rightward. The movement of the connecting rod 63 is further transmitted to the head valve 53 via the connection fitting 63b, the levers 47 and 49, and the spring 51, and the head valve 53 is fully opened.
In this state, the first-stage opening / closing cam 67 stops at the position 67a, and the second-stage opening / closing cam 65 has rotated to the position 65b. Also, even if the connecting rod 63 moves,
Since the holder 85 is provided with the elongated hole 85, the connecting rod 7
9 is in a stopped state.

Subsequently, the lance tube 31 is sprayed while being fully opened.
When the end of the lance tube 31 is retracted to the point C, the valve opening / closing cam 65 is actuated in the opposite direction to the case where the head valve is moved forward. When the valve 53 is opened halfway, and further retracted to the point B, the head valve 53 is closed. When the valve 53 continues to retract and returns to the point A, the operation of one cycle is completed. Thus, the tip of the lance tube 3 is pointed at points A and B in FIG.
5 (a) and 5 (b) in FIG.
(C) As shown in the figure, when the valve opening and closing mechanism is operated, at point B, the head valve 53 is opened halfway to supply cooling steam, and at point C, the head valve 53 is fully opened to supply a predetermined amount of injection steam. be able to.

Next, another embodiment of the present invention will be described with reference to FIG. A description will be given focusing on the changed part from the conventional one shown in FIG. In other words, in this embodiment, the head is provided such that cooling steam can be supplied to the tip of the lance tube at point B (the position where the lance tube 31 is inserted into the furnace 1) with respect to the valve opening / closing mechanism of the prior art. Bypass piping 91 of valve 53
And an automatic opening / closing bypass valve 93 were added and installed.
Other configurations are the same as those of the related art. In FIG.
A position sensor 95 provided at an intermediate portion of the movement path of the dog 41 detects that the dog 41 has moved rightward in the drawing together with the lance tube 31 and the tip of the lance tube 31 has reached point B. A detection signal when the dog 41 moves and passes through the position sensor 41 is sent to the automatic opening / closing bypass valve 93. The automatic opening / closing bypass valve 93 is connected to the injection medium supply pipe 57.
The discharge side is connected to the main body of the head valve 53, so that the ejection medium can be supplied to the lance tube 31.

The operation of the valve opening / closing mechanism of the long-removal type soot blower constructed as shown in FIG.
When the dog 41 moves in the axial direction and the dog 41 passes through the position sensor 95, a detection signal from the position sensor 95 is sent to the automatic opening / closing bypass valve 93. In this state, the tip of the lance pipe 31 has reached the point B, and when the automatic opening / closing bypass valve 93 of the bypass pipe 91 is opened by the detection signal, the cooling steam (injection medium) flows through the main body of the head valve 53. After passing, it is sent to the lance tube 31. The lance tube 31 advances while rotating from the point B to the point C while the cooling steam is being supplied, and reaches the point C. At this time, the dog 41 has advanced to the position of 41a. Is activated, the head valve 53 is fully opened via the connecting rod 45, levers 47 and 49, and spring 51. Subsequently, when the lance tube 31 is rotated and moved forward to the end point while injecting a predetermined amount of the vapor of the injection medium, the reversing switch is operated and the retreat operation is started, and the tip of the lance tube 31 is retracted to the point C,
The valve opening / closing cam 43 operates in the opposite direction to the case of the forward movement to close the head valve 53. When only the cooling steam is supplied from the automatic opening / closing bypass valve 93, the dog 41 retreats to the point B, the dog 41 passes through the position sensor 95, and the automatic opening / closing bypass valve 93
Is closed, and further retreats and returns to the point A, the operation of one cycle ends.

[0016]

As described above, according to the present invention, the two opening / closing cams are arranged so that the head valve for supplying the vapor of the injection medium to the lance tube can be opened and closed in two stages of half opening and full opening. The cooling steam is supplied by the opening / closing cam of the stage,
The stage opening / closing cams can be fully opened to supply injected steam, reducing thermal shock to the lance tube tip when inserted into the furnace (during exit), improving the durability of the lance tube be able to.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged side view showing part II of FIG. 1 in an enlarged manner.

FIG. 3 is a partially enlarged side view showing part III of FIG. 1 in an enlarged manner.

FIG. 4 is a plan view showing a main part of the embodiment of FIG. 1 as a whole;

FIG. 5 is an operation explanatory view of the embodiment.

FIG. 6 is a side view including a system diagram showing another embodiment of the present invention.

FIG. 7 is a conceptual diagram showing a use state of a conventional device.

8 is a plan sectional view taken along line IIX-IIX in FIG.

FIG. 9 is a partially enlarged plan view showing a portion IX of FIG. 8;

FIG. 10 is a side view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace 7 Side wall 9 Boiler tube 31 Lance tube 35 Screw box 37, 39 Gear 41 Dog 47, 49 Lever 51 Spring 53 Head valve 63 Connecting rod 65, 67 Opening / closing cam 79 Secondary connecting rod 83 Holder 85 Long hole

Claims (5)

[Claims] 1. A lance tube is inserted into a furnace such as a boiler,
In a long-displacement type soot blower that removes deposits and deposits and cleans the furnace by injecting a high-pressure injection medium from a nozzle at the tip of the lance pipe, supplying the steam of the injection medium to the lance pipe The opening and closing mechanism of the valve is opened and closed in two stages of half opening and full opening, and comprises a first stage opening and closing cam mechanism for half opening the supply valve and a second stage opening and closing cam mechanism for fully opening the supply valve. The opening / closing mechanism of the injection medium supply valve of the long-displacement soot blower. 2. The second opening / closing cam mechanism is mounted on a second stage rotating shaft that is supported by a fixed casing.
A second stage opening / closing cam and a second shaft connected to a rotating shaft of the opening / closing cam.
2. The opening / closing mechanism for an injection medium supply valve of a long soot blower according to claim 1, wherein the supply valve is opened and closed via a link member at a stage and a connecting rod at a second stage. 3. The first-stage opening / closing cam mechanism is mounted on a first-stage rotating shaft that is supported by a fixed-side casing.
A stage opening / closing cam, and a first shaft connected to a rotating shaft of the opening / closing cam.
The first-stage link member and the first-stage connecting rod, and the supply valve side of the first-stage connecting rod is connected to the second-stage connecting rod via a shaft to open and close the supply valve. 3. The opening / closing mechanism for an injection medium supply valve of a long-removal type soot blower according to claim 1. 4. A long hole which is slidable is provided at a connecting portion between the supply valve side of the first-stage connecting rod and the second-stage connecting rod. Injection medium supply valve opening and closing mechanism of differential soot blower. 5. A lance tube is inserted into a furnace such as a boiler,
In a long-removal type soot blower that removes deposits and deposits by injecting a high-pressure injection medium from a nozzle at the tip of the lance tube and cleans the inside of the furnace, the leading end of the lance tube was inserted into the furnace. A position sensor for detecting a position, an automatic opening / closing bypass valve that is opened / closed based on a detection signal from the position sensor, and the automatic opening / closing bypass valve arranged in the middle of the pipe line to connect the supply pipe of the ejection medium to the valve body. And an opening / closing mechanism for an injection medium supply valve of a long-removal type soot blower.