JP6874532B2 - Flat screen cleaning device and cleaning method - Google Patents

Description

The present invention relates to a cleaning device and a cleaning method for cleaning a flat screen used for removing dust in water.

The thermal power plant is equipped with a condenser for cooling the steam generated by the boiler and used in the turbine, and seawater is used as the cooling water for the condenser. The intake channel for taking seawater into the condenser has a dust remover that removes dust in the seawater near the intake, and a secondary screen (flat screen) that removes fine dust that could not be removed by the dust remover. An intake pump is provided to send seawater that has passed through the secondary screen to the condenser. The secondary screen is made of, for example, a metal plate provided with a large number of fine holes for passing seawater after removing dust, and is installed so as to block the intake channel.

In recent years, due to the large amount of jellyfish and algae and the large inflow of dust, the dust remover alone cannot properly remove dust, and a large amount of dust adheres to the secondary screen to block the seawater. When the seawater is blocked by the secondary screen, a water level difference occurs between the upstream side and the downstream side of the secondary screen, and the amount of seawater supplied to the condenser decreases, so the vacuum of the condenser decreases. It ends up. In addition, on the downstream side of the secondary screen, a state in which seawater is blocked and the water level drops, and a state in which a large amount of seawater flows over the clogged part of the secondary screen and the water level rises at once occur repeatedly. Therefore, hunting occurs in the motor current of the intake pump. When such a state occurs, the power generation output becomes unstable, so it is necessary to take measures such as limiting the output of the generator and stopping the generator (unit trip), and it becomes impossible to obtain the specified amount of power generation. It ends up.

Therefore, the dust adhering to the secondary screen is removed (cleaned) regularly or according to the adhering condition. The state of adhesion of dust is confirmed, for example, visually or based on the sound of water flow. As described above, when the secondary screen is clogged and the seawater is blocked, a loud noise is generated when a large amount of seawater flows in, so that it can be seen that the secondary screen is clogged. To clean the secondary screen, a worker gets on the boat and enters the intake channel, scrapes off the dust adhering to the secondary screen from the boat with a brush or scraper, collects the dropped dust on the boat, and cleans it from the intake channel. It has been removed. However, this cleaning work is dangerous and requires a lot of work cost and work time.

Although it is not related to the secondary screen of a thermal power plant, a screen that allows cleaning parts (rakes, scrapers, brushes, etc.) to be moved on a flat screen installed in the intake channel to remove dust adhering to the flat screen. The device has been conventionally invented (see, for example, Patent Documents 1 to 4). Such a screen device eliminates the need for an operator to enter the intake channel for cleaning work.

Utility Model Registration No. 3094044 Japanese Unexamined Patent Publication No. 2014-07726 Japanese Unexamined Patent Publication No. 2007-046375 Japanese Unexamined Patent Publication No. 2000-129653

However, the screen device described in Patent Documents 1 to 4 uses a cleaning unit and a dedicated flat screen having a shape that is easy to clean by the cleaning unit, and is an existing screen device installed in the intake channel. It cannot be mounted on a flat screen. Therefore, when the screen device of Patent Documents 1 to 4 is used for the intake channel of the thermal power plant, a large-scale repair work of removing the existing secondary screen and installing a new screen device having a cleaning function is performed. Is required, so it cannot be easily applied.

An object of the present invention is to provide a cleaning device and a cleaning method that can be attached to an existing secondary screen (flat screen) installed in an intake channel in order to solve the above problems.

In order to solve the above problems, the invention according to claim 1 is used for a flat screen installed in the water channel to remove dust mixed in the water flowing through the water channel, and the flat screen is clogged. A cleaning device for cleaning so as not to be present, a mesh screen arranged on the upstream side of the flat screen to remove dust, an elevating means for moving the mesh screen up and down along the surface of the flat screen, and the above. It is characterized by comprising a dust removing means for removing dust adhering to at least an upstream surface of the mesh screen when the mesh screen is raised or lowered and collecting the removed dust.

The invention according to claim 5 is used for a flat screen installed in the water channel to remove dust mixed in the water flowing through the water channel, and is used for cleaning the flat screen so as not to be clogged. A method of raising and lowering a mesh screen disposed on the upstream side of the flat screen along the surface of the flat screen, and at least upstream of the mesh screen during raising or lowering of the mesh screen. It is characterized by including a removing step of removing dust adhering to the side surface and a collecting step of collecting the removed dust after the mesh screen is stopped.

According to the first and fifth aspects of the invention, the dust in the water is removed by the mesh screen arranged on the upstream side of the existing flat screen. When cleaning to prevent clogging of the flat screen, the elevating means moves the mesh screen up and down along the surface of the flat screen and adheres to at least the upstream surface of the mesh screen while the mesh screen is raised or lowered. Remove the dust by a dust removing means. Then, after the mesh screen is stopped, the removed dust is collected by a dust removing means.

The invention according to claim 2 is the flat screen cleaning device according to claim 1, wherein the mesh screen is guided by a support column provided to support the flat screen. ..

The invention according to claim 3 is the flat screen cleaning device according to claim 1 or 2, wherein the dust removing means removes dust adhering to the mesh screen while the mesh screen is being raised or lowered. It is provided with a dust collecting section for scraping off, a dust receiving section for receiving dust scraped off by the dust dropping section, and a dust collecting section for collecting dust collected in the dust receiving section after the mesh screen is stopped. It is a feature.

The invention according to claim 4 is the flat screen cleaning device according to any one of claims 1 to 3, wherein a measuring means for measuring water levels on the upstream side and the downstream side of the flat screen, and the upstream side. It is characterized by including a control means for operating the elevating means and the dust removing means when the water level difference between the side and the downstream side reaches a predetermined value.

According to the first and fifth aspects of the invention, since the mesh screen is arranged on the upstream side of the flat screen to remove the dust in the water, the dust adheres to the flat screen, that is, the flat screen. It is possible to prevent pollution. In addition, when cleaning to prevent clogging of the flat screen, the mesh screen is moved up and down along the surface of the flat screen by an elevating means, and the surface at least upstream of the mesh screen is raised or lowered while the mesh screen is being raised or lowered. Since the dust adhering to the screen is removed by the dust removing means, it is possible to prevent the flat screen from being clogged even if the operator does not enter the intake channel and work. Further, since the removed dust is collected by the dust removing means after the mesh screen is stopped, it is possible to prevent the dust removed from the mesh screen from being mixed and adhering to the water again.

Further, since the cleaning device of the present invention can be configured by attaching a mesh screen, an elevating means and a dust removing means to an existing flat screen, it can be relatively easily attached to the existing flat screen. It is possible.

According to the invention of claim 2, since the mesh screen is guided by the support provided to support the flat screen, the configuration for guiding the mesh screen can be simplified. It can be relatively easily attached to an existing flat screen.

According to the third aspect of the present invention, the dust adhering to the mesh screen is scraped off by the dust removing portion of the dust removing means while the mesh screen is being raised or lowered, so that the entire area of the mesh screen can be cleaned. It is possible. Further, since the dust scraped off by the dust scraping portion is received by the dust receiving portion, it is possible to prevent the scraped dust from being scattered and contaminating the periphery of the flat screen.

Further, since the dust collected in the dust receiving portion is collected by the dust collecting portion, it is possible to prevent the scraped dust from being mixed in the water again and contaminating the mesh screen and the flat screen.

According to the fourth aspect of the present invention, by comparing the water level difference between the upstream side and the downstream side of the flat screen with a predetermined value, dust adheres to the mesh screen and the water is blocked. It is possible to maintain a stable water intake state even if the periodic inspection of the flat screen by the operator is reduced because the mesh screen can be automatically started to be cleaned by detecting the above.

It is a front view (A) of the water intake and a secondary screen to which the cleaning device of this invention is attached, the sectional view (B) seen from the side surface side, and the sectional view of the secondary screen seen from the upper surface side. It is a front view which shows the structure of the cleaning apparatus which concerns on Embodiment 1. FIG. FIG. 5 is a cross-sectional view of the cleaning device shown in FIG. 1 as viewed from the side surface side. It is sectional drawing which shows the state which the mesh screen is raised by the cleaning apparatus shown in FIG. It is a side view of the guide unit which guides a mesh screen by the cleaning device shown in FIG. FIG. 5 is a cross-sectional view of the guide unit shown in FIG. 5 as viewed from the upper surface side. It is sectional drawing of the guide rail which guides a mesh screen by the cleaning device shown in FIG. FIG. 5 is a cross-sectional view of the traversing unit of the cleaning device shown in FIG. 1 as viewed from the front side. It is a block diagram which shows the electrical structure of the cleaning apparatus shown in FIG. It is a flowchart which shows the procedure which starts the cleaning of a mesh screen automatically by the cleaning apparatus shown in FIG. It is a flowchart which shows the procedure of cleaning a mesh screen by the cleaning apparatus shown in FIG. It is a front view which shows the structure of the collecting apparatus which concerns on Embodiment 2. FIG. It is a side view which shows the structure of the mesh screen which can clean a secondary screen.

Hereinafter, the present invention will be described based on the illustrated embodiment.

(Embodiment 1)
FIG. 1 shows an intake channel C of a thermal power plant in which the cleaning device of the present invention is installed, and FIG. 1A is a front view of a secondary screen (flat screen) S installed in the intake channel C. , FIG. 3B shows a cross section of the secondary screen S as viewed from the side surface side. The intake channel C is, for example, a water channel for guiding seawater W from an intake (not shown) provided in a harbor to a condenser (not shown), and is provided underground. In the intake channel C, a dust remover (not shown) for removing dust in the seawater W near the intake, a secondary screen S for removing fine dust that could not be removed by the dust remover, and a secondary screen S are provided. An intake pump (not shown) is provided to send the passed seawater W to the condenser.

The secondary screen S is made of, for example, a metal plate provided with a large number of fine holes for passing the seawater W from which dust has been removed, and the upper part of the secondary screen S is the water intake direction T of the seawater W when viewed from the side surface side. It is arranged so that it can be tilted to the side. At the position where the secondary screen S of the intake channel C is installed, a floor F used as a work place for installing, inspecting, and replacing the secondary screen S is provided.

Since the intake channel C has a large width of, for example, about 2 m and a height of about 2 m, the secondary screen S is divided into two in the width direction so as to lean against the floor F at the center of the intake channel C in the width direction. The side side is supported by the support column P installed in the above direction. As shown in FIG. 1C, which is a cross-sectional view of the support column P viewed from above, H-shaped steel having an H-shaped cross section is used for the support column P, for example. The cross-sectional shape of the support column P includes a pair of short sides P1 arranged in parallel and a long side P2 arranged so as to be orthogonal to the short side P1 and connecting the short sides P1. The measuring side of the secondary screen S is supported by being inserted into a pair of grooves P3 composed of a short side P1 and a long side P2.

1 to 11 show an embodiment of the present invention, FIG. 2 is a front view showing a cleaning device 1 installed on the existing secondary screen S described above, and FIG. 3 is a cleaning device. 1 is a cross-sectional view seen from the side surface side, and FIG. 4 is a cross-sectional view showing the cleaning device 1 being cleaned as seen from the side surface side. In FIG. 2, the secondary screen S is not shown in order to prevent the drawings from becoming complicated.

The cleaning device 1 includes a mesh screen 2 arranged on the upstream side of the secondary screen S to remove dust, and an elevating mechanism (elevating means) 3 for moving the mesh screen 2 up and down along the surface of the secondary screen S. The mesh screen 2 is provided with an upstream dust removing device 4 and a downstream dust removing device 5 for removing dust adhering to the mesh screen 2 and collecting the removed dust when the mesh screen 2 is raised or lowered.

Further, the cleaning device 1 includes an upstream water level sensor (measuring means) 6A and a downstream water level sensor (measuring means) 6B for measuring the water level of seawater W, an elevating mechanism 3 and an upstream side based on the water level measurement result. A control device (control means) 7 (see FIG. 8) for controlling the dust removing device 4 and the downstream dust removing device 5 is provided.

The mesh screen 2 is, for example, a metal plate provided with a large number of fine holes for passing the seawater W from which dust has been removed. The holes of the mesh screen 2 are made to have the same size as the secondary screen S or smaller than the secondary screen S in order to prevent dust from adhering to the secondary screen S.

The mesh screen 2 is guided by a guide unit 8 attached to the downstream surface of the lower center and a pair of guide rails 9 installed on both side surfaces C1 of the intake channel C. As a result, the mesh screen 2 is moved up and down between the dust removing position where the dust is removed facing the secondary screen S and the cleaning position where the mesh screen 2 is raised to remove the attached dust.

The guide unit 8 moves along the support column P together with the two-character screen S to guide the mesh screen 2. As shown in the side view shown in FIG. 5 and the cross-sectional view seen from the upper side shown in FIG. 6, the guide unit 8 is rotatably mounted in the main body portion 81 attached to the mesh screen 2 and in the main body portion 81. It is composed of three guide rollers. The main body 81 has a substantially U-shape including a front portion 81a attached to the mesh screen 2 and a pair of side surface portions 81b vertically raised from the front portion 81a. The three guide rollers include a long roller 82 whose both ends are supported by the side surface portion 81b, and two short rollers 83 which are cantileveredly supported by the side surface portion 81b. The two short rollers 83 are arranged coaxially when viewed from the side surface. As a result, the three guide rollers 82 and 83 are arranged parallel to the front surface portion 81a, that is, parallel to each other.

The guide unit 8 is arranged so as to sandwich the support column P between the side surface portions 81b, the long roller 82 abuts on the outside of one short side P1 of the support column P, and the two short rollers 83 sandwich the long side P2. In this way, it comes into contact with the inside of the short side P1. As a result, the guide unit 8 is movable along the support column P, so that the mesh screen 2 attached to the guide unit 8 is also movable along the support column P. Since the thickness of the secondary screen S is thinner than the width of the groove P3 of the support column P, if the secondary screen S is shifted in the groove P3, a gap into which the short roller 83 can be inserted can be obtained.

The guide rail 9 extends upward from the bottom surface side of the intake channel C so as to face the measuring side of the mesh screen 2. The guide rail 9 is made of a steel material (grooved steel, channel steel) having a U-shaped cross section, as shown in the cross-sectional view seen from the upper side shown in FIG. 7, for example, and the U-shaped groove is formed. The measuring side of the mesh screen 2 is inserted and supported inside. In FIGS. 3 and 4, the guide rail 9 is not shown in order to prevent the drawings from becoming complicated.

The elevating mechanism 3 includes a pair of wire drums 31, two wires 32, four rollers 33, and an elevating motor 34 for driving the wire drums 31, which are installed on the floor F. ing. The wire drum 31 is rotatably supported by rotating shafts arranged along the width direction of the mesh screen 2, and wires 32 are wound around the outer periphery of the wire drum 31. An elevating motor 34 is connected to the rotating shaft. The wire 32 is guided by a roller 33, and its ends are fixed to both side surfaces of the guide unit 8. As a result, when the elevating motor 34 rotates in the first direction for winding up the wire 32, the mesh screen 2 is moved (raised) upward, and when the elevating motor 34 rotates in the second direction for feeding out the wire 32, the mesh screen 2 Moves (descends) downward.

Further, the elevating mechanism 3 includes an elevating position sensor 35 that detects whether the mesh screen 2 is in the dust removal position or the cleaning position in order to control the stop position and the moving direction of the mesh screen 2. .. For the elevating position sensor 35, for example, an optical sensor, a magnetic sensor, a limit switch, or the like is used.

The upstream dust removing device 4 includes a brush (dust removing section) 41, a dust receiving section 42, and a collecting device (dust collecting section) 43. The brush 41 is provided on the downstream side surface (rear surface) of the traversing unit 43d constituting the collecting device 43, and abuts on the upstream side surface (front surface) of the rising mesh screen 2 to scrape off the adhering dust. .. The brush 41 is provided over the width direction of the mesh screen 2. The brush 41 is, for example, a metal brush.

The dust receiving portion 42 is made of a gutter-shaped metal plate and is attached to the lower part of the front surface of the mesh screen 2. The dust receiving portion 42 receives (accommodates) the dust scraped off from the mesh screen 2 by the brush 41. The dust receiving portion 42 moves up and down together with the movement of the mesh screen 2.

The collecting device 43 includes a suction nozzle 43a, a suction hose 43b, an upstream suction device 43c, and a traversing unit 43d that moves the suction nozzle 43a across the width direction of the mesh screen 2.

The suction nozzle 43a is a nozzle for sucking dust accumulated in the dust receiving portion 42, and is arranged on the upstream side and above the mesh screen 2. When the mesh screen 2 moves to the cleaning position at the upper end, the suction nozzle 43a enters the dust receiving portion 42 that has risen together and sucks the dust accumulated in the dust receiving portion 42. The suction hose 43b is a hose for sucking dust through the suction nozzle 43a, and has a length and flexibility capable of following the movement of the suction nozzle 43a.

The upstream suction device 43c is, for example, a device such as a vacuum cleaner, and sucks dust through a suction hose 43b and a suction nozzle 43a. The upstream suction device 43c is installed outside the intake channel C, for example, so that dust accumulated in the suction device 43C can be treated without entering the intake channel C.

The traversing unit 43d is installed over the width direction of the intake channel C, and reciprocates the suction nozzle 43a in the lateral direction (horizontal direction) along the width direction of the mesh screen 2. As shown in FIG. 8, for example, the traversing unit 43d includes a case 431d having a brush 41 on the back side, sprockets 432d arranged at both ends in the case 431d, and a chain 433d hung on the sprockets 432d. A bracket 434d attached to the chain 433d to hold the suction nozzle 43a, and an upstream transverse motor 43e for driving the sprocket 432d are provided.

Then, when the sprocket 432d is rotated by the upstream traversing motor 43e, the chain 433d hung on the sprocket 432d travels, and the bracket 434d attached to the chain 433d moves the suction nozzle 43a along the width direction of the mesh screen 2. Let me. Further, the traversing unit 43d is provided with an upstream traversing position sensor 43f that detects the moving position of the suction nozzle 43a. For the upstream traverse position sensor 43f, for example, a limit switch, an optical sensor, a magnetic sensor, or the like is used. As the drive mechanism of the traversing unit 43d, a ball screw or the like may be used in addition to the sprocket and the chain.

Like the upstream dust removing device 4, the downstream dust removing device 5 includes a brush (dust removing section) 51, a dust receiving section 52, and a collecting device (dust collecting section) 53. The difference from the upstream dust remover 4 is that the brush 51 is provided on the front side of the traverse unit 53d in order to remove dust adhering to the downstream surface (back surface) of the mesh screen 2. A point where the receiving portion 52 is fixed on the floor F, and the like. That is, the brushes 41 and 51 for removing dust from the mesh screen 2 are arranged so as to sandwich both sides of the mesh screen 2.

The collecting device 53 includes a suction nozzle 53a, a suction hose 53b, a downstream suction device 53c, and a traversing unit 53d, similarly to the collecting device 43 of the upstream dust removing device 4. The traversing unit 53d includes a case, a sprocket, a chain, a bracket, a downstream traversing motor 53e, and a downstream traversing position sensor 53f (see FIG. 9), similarly to the traversing unit 43d of the upstream dust removing device 4.

The upstream side water level sensor 6A and the downstream side water level sensor 6B are, for example, ultrasonic sensors, and are installed on the upstream side and the downstream side of the secondary screen S toward the lower side (seawater W). The upstream water level sensor 6A and the downstream water level sensor 6B transmit ultrasonic waves toward the water surface of the seawater W, receive the reflected ultrasonic waves, and measure the water level based on the time from transmission to reception.

FIG. 9 is a block diagram showing an electrical configuration of the cleaning device 1. The control device 7 is, for example, a computer, and includes a CPU, a storage unit in which the control program is stored, a memory in which the control program is read from the storage unit, and the like. The control device 7 includes an elevating motor 34, an elevating position sensor 35, an upstream suction device 43c, an upstream traverse motor 43e, an upstream traverse position sensor 43f, and a downstream suction device 53c via its input / output interface. The downstream traversing motor 53e and the downstream traversing position sensor 53f are connected to the upstream water level sensor 6A and the downstream water level sensor 6B, and these are appropriately controlled according to a control program.

Next, the operation of the above-described embodiment will be described with reference to the flowcharts of FIGS. 10 and 11. In the normal cleaning device 1, as shown in FIGS. 2 and 3, the mesh screen 2 is arranged on the upstream side of the secondary screen S to remove dust mixed in the seawater W. The control device 7 measures the water levels on the upstream side and the downstream side of the secondary screen S by the upstream side water level sensor 6A and the downstream side water level sensor 6B (step S1). The water level may be measured at predetermined time intervals (every few hours, every few days), or may be constantly measured while the generator is in operation.

The control device 7 calculates the difference (water level difference) between the water level measured by the upstream water level sensor 6A and the water level measured by the downstream water level sensor 6B, and compares it with a preset threshold value (predetermined value). (Step S2). It is preferable to measure the water level difference that occurs when the mesh screen 2 is clogged in advance and set this threshold value based on the measurement result.

When the calculated water level difference reaches the threshold value (water level difference ≥ threshold value), the control device 7 starts the cleaning process of the mesh screen 2 (step S3). Since the dust in the seawater W is removed by the secondary screen S during the cleaning of the mesh screen 2, the supply of the seawater W to the condenser can be continued.

In the cleaning process, the control device 7 rotates the elevating motor 34 in the first direction, winds up the wire 32, and raises the mesh screen 2 (step S4, cleaning step). The mesh screen 2 is guided by the guide unit 8 and the guide rail 9 and rises along the support column P. The control device 7 detects the moving position of the mesh screen 2 by the elevating position sensor 35, and stops the elevating motor 34 when the cleaning position at the upper end is reached.

During the ascent of the mesh screen 2, the brush 41 is in sliding contact with the surface on the upstream side of the mesh screen 2, and the brush 51 is in sliding contact with the surface on the downstream side to scrape off the adhering dust (removal step). The scraped dust is received by the dust receiving portions 42 and 52.

When the mesh screen 2 stops at the cleaning position, the suction nozzle 43a enters the dust receiving portion 42 that has risen together with the mesh screen 2. The control device 7 operates the upstream suction device 43c, the upstream transverse motor 43e, and the upstream transverse position sensor 43f to reciprocate the suction nozzle 43a in the width direction of the mesh screen 2 and collects the suction nozzle 43a in the dust receiving portion 42. The dust is sucked and collected (step S5, collection step). After the reciprocating movement of the suction nozzle 43a is completed, the control device 7 stops the operations of the upstream suction device 43c, the upstream transverse motor 43e, and the upstream transverse position sensor 43f.

Next, the control device 7 rotates the elevating motor 34 in the second direction, feeds out the wire 32, and lowers the mesh screen 2 (step S6, elevating step). The mesh screen 2 is guided by the guide unit 8 and the guide rail 9 and descends along the support column P. The control device 7 detects the moving position of the mesh screen 2 by the elevating position sensor 35, and stops the elevating motor 34 when the dust removal position at the lower end is reached.

Even during the descent of the mesh screen 2, the brush 41 is in sliding contact with the surface on the upstream side of the mesh screen 2, and the brush 51 is in sliding contact with the surface on the downstream side to scrape off the adhering dust (removal step). The scraped dust is received by the dust receiving portions 42 and 52.

When the mesh screen 2 stops at the dust removal position, the control device 7 operates the downstream suction device 53c, the downstream transverse motor 53e, and the downstream transverse position sensor 53f to reciprocate the suction nozzle 53a in the width direction of the mesh screen 2. Then, the dust collected in the dust receiving portion 52 is sucked and collected (step S7, collection step). After the reciprocating movement of the suction nozzle 53a is completed, the control device 7 stops the operations of the downstream suction device 53c, the downstream transverse motor 53e, and the downstream transverse position sensor 53f.

As described above, according to the present embodiment, the mesh screen 2 is arranged on the upstream side of the secondary screen S to remove the dust in the water, so that the dust adheres to the secondary screen S is prevented, that is, It is possible to prevent contamination of the secondary screen S. When cleaning the mesh screen 2 in order to prevent clogging of the secondary screen S, the elevating mechanism 3 moves the mesh screen 2 up and down along the surface of the secondary screen S to raise and lower the mesh screen 2. Since the dust adhering to the upstream and downstream surfaces of the mesh screen 2 is removed by the upstream dust removing device 4 and the downstream dust removing device 5, the operator does not have to enter the intake channel C to work. It is possible to prevent the secondary screen S from being clogged. Further, since the dust removed by the upstream dust removing device 4 and the downstream dust removing device 5 is collected after the mesh screen 2 is stopped, it is possible to prevent the dust removed from the mesh screen 2 from being mixed and adhering to the water again. It is possible.

Further, since the cleaning device 1 can be configured by attaching the mesh screen 2, the elevating mechanism 3, the upstream dust removing device 4 and the downstream dust removing device 5 to the existing secondary screen S, the existing 2 The next screen S does not require major repairs and can be attached relatively easily.

Further, since the mesh screen 2 is guided by the support column P provided to support the secondary screen S, the configuration for guiding the mesh screen 2 can be simplified, and the existing secondary screen 2 can be simplified. It can be attached to the screen S relatively easily.

Further, since the dust adhering to the mesh screen 2 is scraped off by the brushes 41 and 51 while the mesh screen 2 is raised and lowered, it is possible to scrape off the dust adhering to the entire area of the mesh screen 2. Further, since the dust scraped off by the brushes 41 and 51 is received by the dust receiving portions 42 and 52, it is possible to prevent the scraped dust from being scattered and soiling the periphery of the secondary screen S. is there. Further, the dust collected in the dust receiving portions 42 and 52 is collected by the suction nozzles 43a and 53a, the suction hoses 43b and 53b, the suction devices 43c and 53c, and the traversing units 43d and 53d. Can be prevented from being mixed in water again and the mesh screen 2 and the secondary screen S from being soiled.

Further, by comparing the water level difference between the upstream side and the downstream side of the secondary screen S with the threshold value, the state where the mesh screen 2 is clogged is detected, and the cleaning of the mesh screen 2 is automatically started. Therefore, it is possible to maintain a stable power generation state by suppressing the output limitation of the generator and the occurrence of unit trips.

(Embodiment 2)
FIG. 12 shows a collecting device (garbage collecting unit) 43Q for collecting dust by the cleaning device according to this embodiment. This embodiment is different from the first embodiment in that the suction nozzle is fixed at a predetermined position, and the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in the figure, the traversing unit 43d is provided with a broom portion 43g that moves in the direction of the arrow on the dust receiving portion 42 and sweeps the dust collected in the dust receiving portion 42 to the bottom of the suction nozzle 43a. The suction nozzle 43a sucks the dust collected by the broom portion 43g at the fixed position.

According to the present embodiment, since the suction nozzle 43a is fixed, it is possible to consider the handling so that the suction hose 43b can move together with the suction nozzle 43a as in the first embodiment, or to consider the handling of the suction hose 43b. Since it is not necessary to secure a moving space, it can be more easily attached to the existing secondary screen S.

Although the embodiment of the present invention has been described above, the specific configuration is not limited to the above-described embodiment, and even if there is a design change or the like within a range that does not deviate from the gist of the present invention. Included in the invention. For example, in the first embodiment, the upstream side dust remover 4 and the downstream side dust remover 5 are provided, but since dust mainly adheres to the upstream side surface, the downstream side dust remover 5 is omitted and the upstream side dust remover. Only 4 may be provided. Further, although the mesh screen 2 is automatically cleaned based on the water level difference, the operator may manually start the cleaning based on the visual inspection and the observation of the water intake sound as in the conventional case. .. Further, although an example of application to a cooling intake channel of a thermal power plant has been described, it can also be applied to a flat screen of other intake channels such as a hydroelectric power plant.

Further, in the first and second embodiments, only the mesh screen 2 is cleaned. However, as shown in FIG. 13, for example, a brush 21 is provided on the downstream surface (back surface) of the mesh screen 2. When the mesh screen 2 moves up and down, the brush 21 may be used to scrape off the dust adhering to the upstream surface of the secondary screen S. According to this, when the mesh screen 2 is cleaned, the secondary screen S can be cleaned together, so that it is possible to more effectively prevent the secondary screen S from becoming dirty.

1 Cleaning device 2 Mesh screen 3 Lifting mechanism (lifting means)
4 Upstream dust remover (dust remover)
41 Brush (dust remover)
42 Garbage receiving unit 43 Collection device (garbage collection unit)
5 Downstream dust remover (dust remover)
51 Brush (dust remover)
52 Garbage receiving unit 53 Collection device (garbage collection unit)
6A Upstream water level sensor 6B Downstream water level sensor 7 Control device (control means)
8 Guide unit 9 Guide rail C Intake channel S Secondary screen P Strut

Claims (5)

A cleaning device used for a flat screen installed in the water channel to remove dust mixed in the water flowing through the water channel, and is a cleaning device for cleaning the flat screen so as not to be clogged, and is an upstream side of the flat screen. A mesh screen that is arranged in the mesh screen to remove dust, an elevating means that moves the mesh screen up and down along the surface of the flat screen, and at least an upstream side of the mesh screen when the mesh screen is raised or lowered. A flat screen cleaning device comprising a dust removing means for removing dust adhering to the surface of the screen and collecting the removed dust. The flat screen cleaning device according to claim 1, wherein the mesh screen is guided by a support column provided to support the flat screen. The dust removing means includes a dust removing portion that scrapes off dust adhering to the mesh screen while the mesh screen is being raised or lowered, a dust receiving portion that receives the dust scraped off by the dust removing portion, and the dust receiving portion. The flat screen cleaning device according to claim 1 or 2, further comprising a dust collecting unit for collecting dust collected in the dust receiving unit after the mesh screen is stopped. A measuring means for measuring the water levels on the upstream side and the downstream side of the flat screen, and a control means for operating the elevating means and the dust removing means when the water level difference between the upstream side and the downstream side reaches a predetermined value. The flat screen cleaning device according to any one of claims 1 to 3, wherein the flat screen cleaning device is provided. A cleaning method used for a flat screen installed in the water channel to remove dust mixed in the water flowing through the water channel so that the flat screen is not clogged, and is an upstream side of the flat screen. An elevating step in which the mesh screen arranged in the above is moved up and down along the surface of the flat screen, and removal of dust adhering to at least the upstream surface of the mesh screen while the mesh screen is being raised or lowered. A method for cleaning a flat screen, comprising: a step and a collecting step of collecting the removed dust after the mesh screen is stopped.

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