JPH0961087A - Removing device for deposit on heat transfer tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide boiler equipment facilitating an operation, enabling easy removal of hard clinker in a short time and having no effect on a base material. SOLUTION: An operating part 29a of a nozzle manipulator having a nozzle 16 fitted at the fore end and being provided also with a high-pressure water supply pipe is provided at an opening part of a manhole, an observation window or the like in a boiler or at a place inside the boiler wherein an operator is movable. By the operation of the nozzle manipulator, the nozzle 16 is brought close to a clinker-shaped substance deposited on a heat transfer tube and a high-speed water jet 31 is jetted toward the clinker-shaped deposit from the nozzle 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preventive maintenance technology for boilers, and more particularly to a technology for removing deposits on the outer surface of heat transfer tubes by using a water jet.

[0002]

2. Description of the Related Art In a coal-fired boiler and a heavy oil-fired boiler,
Ash particles melt at high temperature and adhere to the heat transfer tube. As shown in FIG. 26, a suspension superheater (2
The ash attached to the next superheater 2 grows into a large lump, and becomes the attached hard clinker 3. When the boiler is stopped, a part of the adhered hard clinker 3 is separated from the heat transfer tube due to thermal shock and drops into the furnace hopper 7, but most of the adhered hard clinker 3 remains as it is without being separated or dropped.

It is said that the growth of such adhered hard clinker 3 is due to a combined action of the heat load of the boiler furnace 1, gas temperature, properties of fuel species (melting point of ash), etc., but detailed mechanism is known. Not not.

When the attached hard clinker 3 grows significantly, it becomes a flow resistance of the gas flow in the furnace when the boiler is in operation. Further, the hard clinker 3 becomes a great obstacle to the furnace repair work at the time of regular inspection, and it is very dangerous if it suddenly drops. Therefore, much effort has been expended to remove this adherent hard clinker.

In FIG. 26, 4 is a nose, 5 is a burner, and 6 is a coal feeding pipe.

FIG. 27 schematically shows one processing example of the hard clinker 3. A simple scaffold 9 is attached to the upper part of the nose 4, and a worker 10 operates a water washing gun 11 to spray a water jet toward the attached hard clinker 3.

According to this method, a relatively fragile clinker can be removed, but it is quite difficult to destroy all the hard clinker, and a long washing time is required. Further, the work of constructing the simple scaffold 9 is work at a high place in the boiler furnace,
Workers with special skills are required.

In FIG. 27, 8 is a manhole,
Reference numeral 12 is a water jet flow, 13 is a water supply pipe, 14 is a plunger pump, 15 is a bottom clinker, and 32 is an ash treatment device.

The above washing method has a problem that the hard clinker cannot be easily destroyed.
The reason is that the energy is dispersed in the water jet.

Conventionally, the injection pressure P is 80 kgf / cm.
Water injection was performed at a relatively low pressure of about ² (8 MPa). FIG. 28 schematically illustrates the state of the water jet.

At the center of the water flow ejected from the nozzle 16,
At first, a core-shaped water column 24 is generated, but it is split downstream and the water droplet group 2
It becomes 5. This jet stream becomes a spray stream 27, which spreads considerably before it collides with the adhered hard clinker 3, and the collision energy is dispersed and attenuated.

Therefore, the adhered hard clinker 3 is hardly destroyed by such a conventional water washing method. When the injection pressure P is low and the standoff distance x _S (distance between the nozzle 16 and the adhered hard clinker 3) is too long, it is considered that the jet flow is formed so that the collision energy is attenuated as shown in FIG. 28. . In such a spray flow, the action of the low-speed water droplets colliding on the large surface of the adhered hard clinker 3 only occurs.

In FIG. 28, 17 is high pressure water, 22
Is a central axis and 26 is a water droplet.

The in-furnace ash removal method using a low-speed water jet that diffuses like spray is commercialized as a wall blower shown in FIG. According to the method as shown in the figure, the soft ash on the membrane water wall 28 can be removed, but the hard clinker 3 is considered to be difficult to remove. Reference numeral 30 in the drawing is a nozzle gun.

[0015]

The problems in the prior art will be summarized here, although it will be partially repeated.

As described above, according to the conventional washing method,
Although a jet with a large flow rate is used, (1) the distance between the tip of the nozzle and the clinker to be removed (standoff distance) is too long,
(2) There is a problem that the collision energy of the jet flow is dispersed because the jet pressure of the nozzle is low and the jet velocity is low.

A fragile clinker can be easily removed by such a method, but it is difficult to destroy a so-called hard clinker which is once melted and solidified. Therefore, it takes a lot of time to remove the hard clinker, which sometimes hinders the boiler inspection work.

Further, since the heat transfer tube is wetted by a large amount of cleaning water for a long time, general corrosion (so-called "red rust") occurs.
There is also a case where the above-mentioned form) occurs. If the hard clinker cannot be removed sufficiently, there is a danger that the clinker will fall, and the safety of the inspection work inside the furnace cannot be said to be perfect.

On the other hand, in such a washing work, a simple scaffold is assembled on the nose part of the boiler, but assembling the scaffold and washing the scaffold from the scaffold work at high places, and even if sufficient safety measures are taken, the working environment is good. It is hard to say that. Further, since the washing work is performed in a narrow space, it is hot and there is a problem that it is performed in an environment where dust and water drops are scattered.

It is an object of the present invention to provide a heat transfer tube deposit removing device which is easy to operate, can easily remove a hard clinker in a short time, and has no effect on a base material.

[0021]

In order to achieve the above object, the present invention has a nozzle attached to the tip of a manhole in a boiler, an opening such as an observation window, or a position where an operator can move inside the boiler. An operation part of the nozzle manipulator with a high-pressure water supply pipe is provided, and by operating the nozzle manipulator, the nozzle is brought close to the clinker-like substance adhering to the heat transfer pipe, and the high-pressure water is directed from the nozzle to the clinker-like adhering substance. It is characterized by the fact that it is made to jet.

The base portion of the manipulator is an operating portion, and the manipulator is capable of expanding, contracting, bending and rotating.

The injection conditions are as follows. In each case,
The collision energy of the jet flow ejected from the nozzle with respect to the clinker is increased as compared with the above-mentioned conventional technique. (1) Standoff distance x _S : 50 to 400 mm, more preferably 70 to 250 mm (2) Injection pressure P: 250 to 1500 kgf / cm
² (25 to 150 MPa), more preferably 300 to 6
00 kgf / cm ² (30-60 MPa) (3) Traverse speed Vt of nozzle: 5-40 mm / s
ec, more preferably 8 to 15 mm / sec.

At the time of high-pressure water jetting, a dummy jet is jetted at the nozzle portion in order to cancel the reaction force acting on the nozzle. As a result, the nozzle can be prevented from swinging and the standoff distance can be stably maintained under a predetermined condition.

The nozzle is provided with a light for illuminating the clinker in a dark furnace and a small camera for recognizing the attachment of the clinker. By doing this, it is possible to confirm the falling of the clinker and the naked heat transfer tube after the construction using high-pressure water. The image from the camera is the position where the manipulator is operated, and the operator confirms it on the CRT to recognize the mother tube and the clinker. As soon as a clinker is found by traversing the nozzle, high-pressure water is jetted from the nozzle to destroy the clinker.

The nozzle manipulator is provided with a remotely operable clamp member to clamp the heat transfer tube at the time of jetting the water jet to prevent the nozzle manipulator and the heat transfer tube group from swinging.

The clinker adhering to the heat transfer tube group has a relatively fragile portion and a portion having a considerably high strength, and these are layered and mixed to form a lump. In order to remove these efficiently, the low-speed water jet and the high-speed water jet are switched and injected. The slow water jet impinges on the fragile part, while the high velocity water jet impinges on the hard clinker.

The strength state of the clinker can be easily identified from the image of the TV camera installed near the nozzle manipulator. The fragile clinker has the appearance that the surface layer is "chunky". The high-strength hard clinker has a smooth surface, probably due to the solidification of what is once melted, and the color is dark and there are many foam marks.

Since the nozzle is preferably as compact as possible, it has a double pipe structure, and a high-speed water jet is jetted from the central cylindrical portion, and a low-speed water jet is jetted from the outer peripheral annular opening. Switching between low-speed and high-speed water jets is performed by operating the switching valve.

In the above low-speed water jet, an injection pressure of less than 200 kgf / cm ² (20 MPa) is suitable,
The high-speed water jet requires an injection pressure of 200 kgf / cm ² (20 MPa) or more.

These conditions are derived from an experiment of destroying a large number of clinker under a wide range of injection conditions. A low-speed water jet and a high-speed water jet can be jetted at the same time, and a high-speed water jet is jetted into the low-speed water jet. Due to the large velocity difference, the central high-speed water jet develops severe cavitation. The clinker can also be removed by utilizing the impact action of this cavitation.

[0032]

According to the present invention, the effects of destroying and removing the hard clinker are produced by the following actions.

The nozzle is brought close to the clinker to the optimum position. Furthermore, the injection pressure of the nozzle is set to an appropriate condition.
By doing so, the form of the jet flow colliding with the clinker is in an optimum state for applying a hydraulic impact to the clinker.

That is, the water jet ejected from the nozzle at a predetermined injection pressure is intermittently split, and the split water column repeatedly collides with the hard clinker like a "bullet" to destroy the hard clinker.

According to the injection conditions in the present invention, the hard clinker is easily broken and separated from the heat transfer tube. Since no heat is applied, the clinker completely separates from the heat transfer tube.

With the standoff distance x _S , the injection pressure P and the nozzle traverse speed Vt set in the present invention, the heat transfer tube is not damaged at all. Further, since the injection pressure P is not increased unnecessarily and the water injection amount is not increased, the swinging of the suspended heat transfer tube group does not cause any problem.

Furthermore, since a dummy jet is used in the nozzle, the reaction force in the nozzle is small, and even if the nozzle is provided at the tip of the cantilever arm, there is no vibration of the nozzle during ejection. Further, the displacement of the nozzle is small, and the hard clinker can be reliably destroyed and removed under the set conditions.

Further, by using the low speed water jet together, the fragile clinker can be removed, and the hard clinker can be destroyed and removed by the high speed water jet.

By doing so, it becomes possible to eliminate waste such as removing the fragile clinker with an excessively high-pressure water jet, or colliding the hard clinker with the low-speed water jet and injecting it for a long time without destroying it. The water used as can be used effectively.

Furthermore, since the nozzle manipulator clamps the heat transfer tube group, the heat transfer tube group sways less even during water jet injection, and the nozzle manipulator sway can be suppressed.

Therefore, the optimum standoff distance between the nozzle and the clinker to be removed can be set. Immediately after jetting from the nozzle, a columnar core portion is generated in the water jet, and the core portion is divided into water droplets, which are dispersed in the jet stream spreading downstream.

The tip of the column-shaped core portion vibrates intermittently, but if the region of the tip of the vibrating column-shaped core portion is used to collide with the clinker, the clinker can be destroyed quite effectively.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a top view of an in-furnace deposit removal device using a high-speed water jet according to the first embodiment, and FIG. 2 is a side view of the deposit removal device.

The adhered hard clinker 3 is firmly fixed to the suspension superheater (secondary superheater) 2 near the top of the boiler furnace. The nozzle 16 is fixed to the tip of a nozzle manipulator 29 that is remotely operated by the worker 10.
The nozzle manipulator 29 can be expanded / contracted (a), rotated (b), and rotated (c), and the nozzle 16 can be easily brought close to the attached hard clinker 3.

The nozzle manipulator 29 is bent at the rotary joint 29c, and the direction determining support jig 2 is used.
It is fixed in a bent state by 9d. Nozzle 1
6 approaches the adhered hard clinker 3 so that the optimum standoff distance is obtained.

The high pressure water 17 is supplied to the nozzle manipulator 29.
It is guided to the nozzle 16 from a base portion of the nozzle through a high-pressure water supply pipe (not shown in the drawing) that is provided in the nozzle manipulator 29.

The operator 10 operates the nozzle manipulator 29.
The extended portion 29b is pulled out by operating the operating portion 29a of (1) to bring the nozzle 16 close to the attached hard clinker 3. As will be described later, the nozzle 16 is equipped with a small camera with a built-in light so that the clinker can be identified even in a dark furnace.
The worker 10 confirms the heat transfer tube and the adhered hard clinker 3 on the basis of the screen displayed on the TV, and as soon as he or she finds the adhered hard clinker 3, the high-pressure water (high-speed water jet 3
1) is sprayed to destroy the adhered hard clinker 3.

In FIG. 3, a high-speed water jet is jetted from a nozzle,
This is a schematic drawing of a situation in which this collides with a hard clinker.

In this embodiment, the right angle collision nozzle 16a whose tip is divided into a T shape is used. Nozzle manipulator 2
9 is positioned parallel to the adhered hard clinker 3, the high-speed water jet 3 ejected from the right-angle collision nozzle 16a.
1 collides with the adhered hard clinker 3 at a right angle and destroys the clinker 3. A dummy jet 33 is ejected from the other of the T-shaped right-angle collision nozzles 16a.

This is to cancel the reaction force generated in the nozzle 16 by jetting high-pressure water. Due to this dummy jet, the oscillation of the nozzle 16 is eliminated, and the stand-off distance x _S between the nozzle and the clinker is equal to
It is kept stable during the injection period of 7.

If this dummy jet can be made to collide with the adhered hard clinker 3 of the hanging superheater (secondary superheater) 2 at the opposing portion, the clinker removal efficiency is improved.

FIG. 4 is basically the same as the example of FIG. 3, but the high-speed water jet 31 from the Y-shaped inclined nozzle 16b is used.
Are obliquely collided with the adhered hard clinker 3. Even in this case, the dummy jet 33 for canceling the reaction force is jetted from the other branched jet hole,
Prevents the nozzle from rocking.

5 and 6 show examples of nozzle structures.
The nozzle 16 in FIG. 5 has a conical diameter contraction portion (squeezing portion), and the high-pressure water 17 is slowly decompressed and accelerated.
The nozzle 16 is suitable for suppressing the spread of the high-speed water jet as much as possible and narrowing the high-speed water jet 31 into a beam shape.

A circular counterbore 21 is provided at the outlet of the ejection hole 20 in order to prevent non-circular erosion due to the action of the high-speed water jet 31. When the outlet of the ejection hole 20 erodes into a non-circular shape, the shape of the high-speed water jet 31 is broken and split, and there is a problem that the force of penetrating far away becomes insufficient. 2 in the figure
2 is a central axis.

The nozzle 16 shown in FIG. 6 has a bell-shaped diameter contraction portion (throttle portion) 23, and the jet flow is disturbed at the expense of a slight spread of the jet flow as compared with the jet flow from the nozzle 16 shown in FIG. Promote. This type has a large ejection hole 20 and is suitable for a nozzle having a relatively large capacity.

FIG. 7 shows a state in which the small camera 34 with a built-in light source is attached to the nozzle 16. A small camera 34 with a built-in light source is fixed to the nozzle 16 and a fiber cable 35 is attached.
Is also fixed to the nozzle manipulator 29 by a band (fixing device) 36. With this light source, the clinker 3 in the dark furnace is projected and the position of the nozzle 16 is determined. The high-pressure water 17 is guided to the nozzle 16 through the high-pressure water supply passage 18 in the nozzle manipulator 29.

In this embodiment, an example in which the small camera 34 with a built-in light source is fixed to the nozzle 16 is shown. However, the illuminator and the camera (for example, the light source described above) are provided in an opening different from the nozzle manipulator 29 or the portion where the nozzle manipulator 29 is inserted. It is also possible to install a built-in small camera 34).

FIG. 8 schematically shows the mechanism of destroying the clinker by the collision of the high-speed water jet.
The core-shaped water column 24 ejected from the nozzle 16 is a high-speed water jet 31.
Although it extends inward, it splits at a position on the downstream side, and the water column releases the water mass 25 in which the water column has split. The position of this division fluctuates intermittently. The water mass 25 discharged at high speed intermittently collides with the attached hard clinker 3 like a bullet and destroys it.

By utilizing the region of the jet flow in which such a phenomenon occurs, the adhered hard clinker 3 can be destroyed extremely efficiently. Therefore, the standoff distance x _S
Selection of is important. Further, since the split position of the core water column 24 also depends on the injection pressure P, the standoff distance x _S
The combination of and the injection pressure P is very important.

FIG. 9 summarizes the selection ranges of important operating conditions of the standoff distance x _S , the injection pressure P and the traverse speed Vt of the nozzle.

The standoff distance x _S is 50 <x _S <45
0 mm, more preferably 70 <x _S <190 mm.

If x _S is too short, the core water column 2 in FIG.
The unchanging continuous portion in 4 will collide, that is, a force like a "static press" will be applied even at high pressure, so that the clinker will be less likely to be destroyed. If x _S is too long, the jet flow is dispersed in the water droplet group as shown in FIG. 16, and the breaking energy is diffused.

The injection pressure P is 200 <P <900 kgf /
cm ² , more preferably 300 <P <550 kgf /
Select from the range of cm ² , but if P is raised excessively, the suspended heat transfer tube group may vibrate, a large reaction force may be generated in the nozzle, and the base material of the heat transfer tube may be damaged by erosion. Therefore, the upper limit of P is naturally decided.

If the traverse speed Vt of the nozzle is too high, the clinker cannot be destroyed. Therefore, Vt is 0 <Vt <4
5 mm / sec, more preferably 4 <Vt <22 mm
Determine from the range of / sec.

FIG. 10 compares the time required for removing the clinker. Time t to represent as a relative value
Was made dimensionless by dividing by the clinker removal time t ^* in the prior art. Therefore, the construction time in the prior art is t / t ^* = 1.

When practicing the present invention, t / t ^* = 0.
12, it was confirmed from this result that the working time according to the present invention was significantly reduced, which is the result that the clinker can be efficiently destroyed / removed by the high-speed water jet.

FIG. 11 shows a comparison of the residual clinker amount M which is not completely removed after the clinker removal process, and is expressed dimensionlessly based on the residual clinker amount M ^* in the prior art. In the prior art, M / M ^* = 1, but when the present invention is embodied, it is possible to greatly reduce it to M / M ^* = 0.02. Almost nothing is left behind.

FIG. 12 summarizes the amount of erosion (erosion) Δm when the high-speed water jet directly collides with the metal surface of the heat transfer tube as a change with time.

At first, there is almost no increase in Δm, but from a certain time, Δm starts to increase rapidly, and finally Δm
The increase of will reach the ceiling. The start time of erosion (erosion) becomes a problem, but this time is sufficiently longer than the time for injecting a high-speed water jet to the clinker when embodying the present invention. Therefore, it can be judged that the heat transfer tube is not damaged by embodying the present invention. From the above, the reliability of the clinker removal and construction method according to the present invention was confirmed.

The embodiments described thus far relate to a method of operating a nozzle manipulator from a peep window in front of a can.

In the present invention, it is possible to install a simple scaffold on the upper part of the nose of the boiler in the same manner as in the prior art, and allow the operator to operate the nozzle manipulator there.

FIG. 13 schematically shows the operation from above such a simple scaffolding on the upper part of the nose. The simple scaffold 9 is assembled on the upper part of the nose 4, and the operator operates the nozzle manipulator 29 on it. The basic structure and function of the nozzle manipulator are the same as those described in FIGS. 1 and 2.

A high-speed water jet is jetted from the nozzle 16 provided at the tip of the nozzle manipulator 29 and collided with the hard clinker 3 attached to the bend portion of the hanging superheater (secondary superheater) 2 to cause the attached hard clinker 3 To remove.

FIG. 14 shows an embodiment in which a clinker destruction / removal device by a water jet is applied to a large boiler.

The hard clinker 102 to be removed is attached to the suspended heat transfer tube 101 near the top of the boiler furnace 107. The operator 114 inserts and operates the manipulator rod 105 from the access hole to operate the nozzle 103.
Close to the hard clinker 102.

As will be described later, a clamp device extends from the manipulator rod 105 so as to grasp the suspended heat transfer tube group. A water jet 104 is jetted from the nozzle 103, which collides with the hard clinker 102 and destroys it, forming fragments 144, and the hopper water 145 at the bottom of the furnace.
Fall inside.

The water used as the water jet 104 is the water tank 1.
09 is pumped up and pressurized by the high-pressure water feed pump 108, and is sent to the manipulator rod 105 and the nozzle 103 through the switching valve 110 as high-pressure water 113 through the high-pressure hose 116.

The switching valve 110 adjusts the pressure and flow rate of the high pressure water to be supplied to the nozzle 103.
When switching high-pressure water or low-pressure water from the nozzle 103 and injecting it, the switching valve 110 is operated.
In FIG. 14, 111 is a pumping flow, 112 is a returning flow, and 115 is an access hole.

FIG. 15 is a sectional view showing a structural example of the nozzle. The basic configuration of the nozzle 103 is that the high-speed water jet nozzle 10 is provided in the nozzle 103 that feeds and jets low-pressure water 117.
3'is arranged. The low-pressure water 117 is the low-pressure water supply channel 1
It is guided through 22, is decompressed and accelerated by the diameter contraction portion (restriction portion) 121, and is ejected from the low-speed water jet injection hole 118. An enlarged portion 119 is provided at the outlet of the low-speed water jet injection hole 118.

The high-pressure water 113 is the high-speed water jet nozzle 10
3'is passed through the high-speed water jet ejection hole 120 and is injected into the low-speed water jet ejection hole 118 as a high-speed water jet.

In the nozzle according to this embodiment, both the low speed water jet and the high speed water jet are jetted to the outside through the enlarged portion 119. When the jet flow is ejected inside the enlarged portion 119, an unstable vortex flow is generated and the jet flow is somewhat open.

The basic structure of the nozzle shown in FIG. 16 is that the low-pressure water uses the flow path of the nozzle body, and the high-pressure water jet nozzle 103 ′ to which the high-pressure water is supplied is arranged therein. Same as the embodiment.

However, the outlet of the high-speed water jet outlet 120 is
It is aligned with the outlet of the low-speed water jet outlet 118 in the nozzle 103. Compared with the nozzle shown in FIG. 15, this type of nozzle is characterized in that the jet becomes a beam shape and is less likely to spread in both the high-speed water jet and the low-speed water jet.

FIG. 17 shows an embodiment in which a clamp system is adopted in order to prevent the nozzles and the suspended heat transfer tube group from swinging at the time of jet injection.

From the manipulator rod 105, in addition to the tubular body portion for supplying high-pressure water to the nozzle 103, a tubular body portion having a clamp device 138 attached at its tip is extended.
The clamp device 138 is configured to grasp a plurality of heat transfer tubes of the suspended heat transfer tube group 101 together.

With the suspended heat transfer tube group 101 supported in this manner, a water jet is jetted from the nozzle 103 to collide with the hard clinker 102. Since the nozzle 103 is also supported by the hanging heat transfer tube group 101 by the clamp device 138, the nozzle 103 does not swing. Therefore, the standoff distance x _S between the nozzle 103 and the hard clinker 102 is kept substantially constant. The standoff distance x _S is 100 to 300 mm,
It is a proper condition that can destroy and remove most of the hard clinker 102.

FIG. 18 is a diagram showing a high pressure water supply system.
In this embodiment, a three-way switching valve 131 is provided near the operator who operates the nozzle manipulator.
This is because the operator himself / herself switches the low pressure water / high pressure water while observing the appearance of the clinker.

The water in the water storage tank 128 is drawn up by the high-pressure pump 127, guided to the nozzle 103 through the water supply pipe 129 and the three-way switching valve 131, and jetted as the water jet 126. Excessive discharge amount from the high-pressure pump 127 is returned to the water storage tank 128 through the return line 130 by the three-way switching valve 131.

In this embodiment, by operating the three-way switching valve 131, the high pressure water and the low pressure water in the nozzle 103 can be directly switched. Therefore, the three-way switching valve 13
Since the feed line from 1 to the nozzle 103 is two parallel feed lines (a high-pressure water line and a low-pressure water line), the switching valve 131 can substantially switch between four directions.

FIG. 19 is a diagram schematically showing the attachment state of clinker ash (ash) to the heat transfer tube 101a.
Since the temperature of the surface of the heat transfer tube 101a through which the steam flow flows has not risen so much, the ash is not melted first and the heat transfer tube 101a is not melted.
To the surface, i.e. the metal surface. The resulting clinker 102 'is fragile. The surface of the fragile clinker 102 ′ is separated from the steam, so that the temperature rises, the attached clinker melts, and when it cools, the clinker 102 ′ becomes a glassy state while changing to a blackish color, so that it becomes the hard clinker 102.

After that, depending on the melting point of the ash of the coal type used, it becomes a hard clinker 102 and adheres (when using a coal having a low melting point), or a fragile clinker 102 '.
(When using high melting point coal).

In this way, the hard clinker 102 and the fragile clinker 102 'are roughly layered and fixed to the heat transfer tube 101a as a large lump.

In this embodiment, a high-speed water jet is used for breaking the hard clinker 102, and a low-speed water jet is used for removing the fragile clinker 102 '.

In FIG. 20, the low-speed water jet 125 is used for the nozzle 10.
3 is a schematic drawing of the appearance of jetting from 3. A small circulating vortex 124 is generated between the inner wall surface of the outlet expansion portion 119 and the interface of the low-speed water jet 125. The action of this vortex 124 gives rise to turbulence at the interface of the low-speed water jet 125, and this turbulence affects the intensity of jet splitting.

In FIG. 21, the low-speed water jet 125 collides with the fragile clinker 139, destroys them, and the heat transfer tube 101a
It is a schematic drawing of the aspect of removal from the. The low-speed water jet 125 ejected from the nozzle 103 is a columnar jet 141.
, Which split into water droplet groups 106 and collide with the fragile clinker 139 at high speed.

Due to the collision of the water droplet groups 106, the fragile clinker 139 receives a large number of impact forces, and the fragile clinker 139 collapses and easily separates from the heat transfer tube 101a. The separated clinker becomes fragments 140 and scatters and falls to the furnace bottom of the boiler. 142 in the figure is a water droplet that has been divided.

In FIG. 22, the high-speed water jet 123 is directed to the nozzle 10
It is a drawing of the state that spouted from 3. Nozzle 103
The high-speed water jet nozzle 103 ′ installed inside the nozzle ejects the high-speed water jet 123, and does not come into contact with the low-speed water jet ejection hole 118, but ejects through the enlarged portion 119.

As in the case of the low-speed water jet 125, the circulating swirl 12 around the high-speed water jet 123 in the outlet expansion part 119.
4 results. Turbulence occurs in the high-speed water jet 123 due to the action of the vortex 124, which affects important behavior such as vibration and splitting of the columnar jet described later.

On the other hand, the mechanism of collision of the high-speed water jet 123 is basically different from that of the low-speed water jet 125.
It is suitable for breaking the hard clinker 102.

FIG. 23 is a schematic drawing showing how the hard clinker 102 is destroyed by the collision of the high-speed water jet 123. In this high-speed water jet 123, the columnar jet 141 generated immediately after the jet from the nozzle 103 extends longer than in the case of the low-speed water jet 125. Then, the columnar jet flow 141 vibrates (α), and the columnar water mass 143 that has been divided into a bullet shape collides with the hard clinker 102 at an ultrahigh speed.

Since this shocking behavior is repeated intermittently, the hard clinker 102 is destroyed and the heat transfer tube 101a
To fall into the boiler bottom of the boiler.
The size of the debris 144 of the hard clinker 102 is relatively larger than the debris 140 of the fragile clinker 139.

Up to this point, the specific examples in which the low-speed water jet and the high-speed water jet are switched and used have been described, but it is also possible to jet both water jets simultaneously by using the same nozzle.
In the case of simultaneously injecting in this way, instead of the system as shown in FIG. 18, two pumps are used to guide two independent water supply lines to the same nozzle.

FIG. 24 is a view showing a state in which the high pressure water 113 and the low pressure water 117 are simultaneously jetted from the nozzle 103 shown in FIG. The low-pressure water 117 is the low-speed water jet ejection hole 1
It is injected through 18. The high-pressure water 113 is jetted as a submerged high-speed water jet from the high-speed water jet nozzle 103 ′ in the low-speed water jet jet hole 118. The high-pressure water 113 injected into the low-speed water jet 125 becomes a water jet accompanied by active cavitation.

Therefore, the simultaneous injection of low and high speed water jets destroys and removes the clinker not only by the force of the water jets colliding but also by the action of the impact pressure generated when the cavitation bubbles collapse.

FIG. 25 is a view showing an example in which the simultaneous low-pressure water / high-pressure water injection method shown in FIG. 24 is applied to the removal of the burner-attached clinker 135 attached around the burner 133. The jet flow 137 shown in FIG. 25 is jetted from the nozzle 103 to collide with the burner-attached clinker 135. Clinker 135
Breaks into lumps and becomes fragments 136 that fall to the bottom of the boiler.

A burner-attached clinker called "Eyebrow" causes a collision of flames when it grows to a large extent, which may make the combustion state unstable. Further, if the clinker is attached to the upper burner, there is a risk of falling, which may hinder the inspection work of the lower burner. The burner-attached clinker can be efficiently removed by using the heat transfer tube deposit removal device according to each embodiment of the present invention.

[0107]

The effects of the present invention can be summarized as follows.

(1) The hard clinker firmly adhered to the heat transfer tube can be easily and completely destroyed and removed in a short time.

(2) Since there is no clinker left unremoved and removed, there is no fear of dropping and the inspection work inside the furnace can be completed.

(3) Due to the effect of (2), the regular inspection process can be shortened.

(4) The number of workers directly involved in clinker removal can be reduced, and the work becomes economical.

(5) The work environment for removing the clinker is improved.

(6) Although high pressure water is used, the amount of water to be jetted can be reduced because a nozzle having a small ejection hole diameter is used.

(7) Since the reaction force generated due to the high-pressure water jet is well canceled, the nozzle position is surely set.

(8) The high-speed water jet ejected from the nozzle is
It is possible to surely make a collision toward the clinker.

(9) The clinker can be removed immediately after the boiler is stopped, that is, without waiting for the boiler furnace to cool.

(10) If the water jet gun is operated directly from the inspection window without entering the furnace, it is not necessary to work at a high place to assemble a scaffold in the furnace.

[Brief description of drawings]

FIG. 1 is a top view showing an example of an apparatus for removing substances adhering to a furnace using a high-speed water jet according to the present invention.

FIG. 2 is a side view of the attached substance removing device.

FIG. 3 is a schematic diagram showing a state in which a high-speed water jet is jetted from a nozzle of the attached substance removing device and collided with a hard clinker.

FIG. 4 is a schematic diagram showing another example of a state in which a high-speed water jet is jetted from a nozzle and collides with a hard clinker.

FIG. 5 is a cross-sectional view showing an example of a nozzle.

FIG. 6 is a cross-sectional view showing another example of a nozzle.

FIG. 7 is a configuration diagram of a nozzle with a small camera.

FIG. 8 is a schematic diagram showing a phenomenon of water jet.

FIG. 9 is a chart showing a selection range of operating conditions according to the present invention.

FIG. 10 is an explanatory diagram comparing the time required for removing clinker according to the present invention.

FIG. 11 is an explanatory diagram comparing the amount of residual clinker that has not been completely removed after the clinker removal construction according to the present invention.

FIG. 12 is an explanatory diagram showing the amount of erosion when the high-speed water jet directly collides with the metal surface of the heat transfer tube according to the present invention as a change with time.

FIG. 13 is a diagram showing how the apparatus for removing deposits in a furnace using a high-speed water jet according to the present invention is operated from above a simple scaffold.

FIG. 14 is a view showing how the apparatus for removing deposits in a furnace using a high-speed water jet according to the present invention is operated.

FIG. 15 is a cross-sectional view showing an example of a nozzle of the deposit removing device.

FIG. 16 is a cross-sectional view showing another example of a nozzle.

FIG. 17 is a perspective view showing an example in which a clamp system is adopted in the apparatus for removing deposits in a furnace using a high-speed water jet according to the present invention.

FIG. 18 is a diagram of a high pressure water feed system in the deposit removing device.

FIG. 19 is a schematic diagram showing a state in which ash is attached to the heat transfer tube.

FIG. 20 is a schematic view showing a state where a low-speed water jet jets from a nozzle.

FIG. 21 is a schematic diagram showing how a low-speed water jet collides with and breaks a fragile clinker.

FIG. 22 is a schematic diagram showing a state in which a high-speed water jet flow is jetted from a nozzle.

FIG. 23 is a schematic diagram showing how a high-speed water jet collides with and breaks a hard clinker.

FIG. 24 is a schematic diagram showing a state where high-pressure water and low-pressure water are simultaneously jetted from the nozzle of FIG.

FIG. 25 is a schematic diagram showing how the clinker is removed by the water injection shown in FIG. 24.

FIG. 26 is a schematic view showing a state in which ash is attached to the superheater.

FIG. 27 is a schematic view showing a state of conventional ash removal.

FIG. 28 is a schematic diagram showing a state of conventional water injection.

FIG. 29 is a schematic view of a conventional ash removing apparatus.

[Explanation of symbols]

 1 Boiler Furnace 2 Suspended Superheater 3 Adherent Hard Clinker 4 Nose 5 Burner 6 Coal Transfer Pipe 7 Furnace Bottom Hopper 8 Manhole 9 Simple Scaffold 10 Worker 16 Nozzle 17 High Pressure Water 18 High Pressure Water Supply Channel 29 Manipulator 31 High Speed Water Jet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koujiro Yamada, No. 36 Takara-cho, Kure City, Hiroshima Prefecture, Babkotuku Hitachi, Ltd., Kure Research Institute, Ltd. (72) Yumei Matsumoto, No. 6-9, Takara-cho, Kure City, Hiroshima, Hitachi Inside Kure Factory (72) Inventor Miyako Imon 6-9 Takara-cho, Kure City, Hiroshima Babkotsk Hitachi Inside Kure Factory

Claims (11)

[Claims] 1. An operation part of a nozzle manipulator equipped with a high-pressure water supply pipe with a nozzle attached to a tip of a nozzle at an opening such as a manhole or an observation window in a boiler or a place where an operator can move inside the boiler. By providing the nozzle manipulator, the nozzle is brought close to the clinker-like substance adhering to the heat transfer tube, and high-pressure water is sprayed from the nozzle toward the clinker-like adhering material. Kimono removal device. 2. The standoff distance x _S between the nozzle and the clinker-like deposit according to claim 1, 50 <x _S <400 mm, the injection pressure at the nozzle or the discharge pressure P of the pump is 250 <P <1500 kgf / cm. ² (25 <P <15
0 Mpa) A heat transfer tube deposit removing device characterized in that the moving speed Vt of the nozzle is regulated within a range of 5 <Vt <40 mm / sec. 3. The stand-off distance x _S between the nozzle and the clinker-like deposit according to claim 1, 70 <x _S <250 mm, the injection pressure at the nozzle or the discharge pressure P of the pump is 300 <P <600 kgf / cm. ² (30 <P <60M
pa) A heat transfer tube deposit removing device characterized in that the moving speed Vt of the nozzle is regulated within a range of 8 <Vt <15 mm / sec. 4. The heat transfer tube deposit removing device according to claim 1, wherein the nozzle manipulator is configured to be expandable / contractible, bendable, and rotatable. 5. The heat transfer tube deposit removing device according to claim 1, wherein the nozzle is provided with a dummy jet port for jetting a dummy jet. 6. The heat transfer tube deposit removing device according to claim 1, wherein an illuminator and a camera are installed in an opening different from the opening where the nozzle, the nozzle manipulator, or the nozzle manipulator is inserted. 7. The heat transfer tube deposit removing device according to claim 1, wherein the nozzle manipulator is provided with a clamp member that can be remotely operated, and the heat transfer tube is clamped by the clamp member during water injection. 8. The structure according to claim 1, wherein the nozzle has a structure capable of separately ejecting into a low-speed water jet and a high-speed water jet,
A heat transfer tube deposit removing device characterized in that a low-speed water jet and a high-speed water jet are jetted independently by switching the jetting pressure. 9. The heat transfer tube deposit removal according to claim 8, wherein the nozzle has a double tube structure, and a high-speed water jet is injected from the central tube and a low-speed water jet is injected from an outer peripheral side annular opening. apparatus. 10. The method of claim 8 or the ninth aspect, the injection pressure of less than 200 kgf / cm ² low-speed water jet (20 MPa), a high-speed water jet 200kgf / cm ^{2 (2}
An apparatus for removing deposits on a heat transfer tube, characterized in that it is sprayed from a nozzle with a spray pressure of 0 MPa or more. 11. The transmission according to claim 8, wherein a high speed water jet is simultaneously injected into the low speed water jet to create a high speed water jet with cavitation in the low speed water jet. Heat pipe deposit removal device.