JP5886096B2 - Automatic backwash strainer - Google Patents

Description

  The present invention relates to an automatic backwash strainer. In particular, the present invention relates to a structure of a rotation detection mechanism that detects the rotation of a backwash arm shaft in an automatic backwash strainer that can backwash a filtration screen disposed inside a strainer that removes dust from a liquid such as seawater.

  In a thermal power plant or the like, liquefied natural gas (LNG) may be used as a fuel for operating a boiler. In this case, seawater is pumped and LNG is vaporized using seawater temperature. By the way, since seawater contains foreign matter, dust, and the like, the seawater is circulated through a strainer having a cylindrical filtration screen inside to remove dust and the like.

  The strainer as described above includes, for example, a mechanism that automatically removes dust and the like captured by the filtration screen by causing the treated water to flow backward into the strainer. And what is called an automatic backwashing type strainer which backwashes a filtration screen is disclosed (for example, refer patent document 1).

  The automatic backwash strainer according to Patent Document 1 includes a backwash arm shaft that is disposed at the center of the filtration screen and rotates the backwash arm. In addition, the automatic backwash strainer according to Patent Document 1 includes a rotary drive device that rotates the backwash arm shaft at the top.

  The automatic backwashing strainer according to Patent Document 1 drives the rotary drive device to rotate the backwashing arm, and backwashes the filtration screen by causing the treated water to flow back through the filtration screen. And the dust supplemented with the filtration screen falls, and dust is discharged | emitted with the treated water from the drain pipe provided in the bottom part outside.

JP 2001-162114 A

  An automatic backwash strainer as disclosed in Patent Document 1 includes a shear pin (shear pin) between a motor and a backwash arm shaft, for example. And if an obstruction bites into the filter screen, the shear pin breaks, limiting the overload of the rotary drive device and preventing the power transmission path from being damaged.

  In addition, an automatic backwash strainer as disclosed in Patent Document 1 is, for example, a striker composed of a “mushroom-shaped” plate cam whose rotation center is fixed to a backwash arm shaft, and is disposed opposite to the striker. A rotation detection mechanism composed of a roller plunger type limit switch is provided. Then, the limit switch is operated while the striker makes one rotation, thereby monitoring the normal operation of the filtration screen.

  When the filter screen is operated repeatedly, the time required for the roller provided on the limit switch to roll to the contour of the striker increases, so that the contour of the striker wears out and the limit switch may not operate. In this case, the monitoring device determines that the shear pin has been cut and generates an alarm. Then, when the shear pin is pulled out and it is confirmed that the shear pin is not broken, it is determined that the wear of the outline of the striker is the cause. And it was repaired so that a limit switch might operate normally by exchanging a worn striker with a new striker for the backwash arm shaft.

  However, in order to replace the striker for the backwash arm shaft, it was necessary to disassemble the upper part of the strainer and pull out the backwash arm shaft, and it took time to adjust the limit switch to operate. There was a problem. There is a need for a rotation detection mechanism that can easily adjust the position of the limit switch even if the striker has worn out. The above can be said to be the subject of the present invention.

  The present invention has been made in view of such a problem, and is provided with an automatic rotation detection mechanism that can easily adjust the position of the limit switch even when the contour of the striker that detects the rotation of the backwash arm shaft is worn. An object is to provide a backwash strainer.

  The present inventor considers that the position adjustment with the limit switch is facilitated by providing a detachable curved adjustment plate on the wear part of the striker, and based on this, a new automatic backwash strainer as described below is provided. It came to invent.

  (1) An automatic backwash strainer according to the present invention is an automatic backwash strainer capable of backwashing a cylindrical filter screen disposed inside a strainer body that removes dust from a liquid. A backwash arm shaft that is disposed in the center and is rotatable, a backwash arm that extends in a centrifugal direction from the backwash arm shaft, and has a tip that rotates to face the inner wall of the filtration screen, and the backwash arm shaft A striker composed of a plate cam having a bulging end portion whose center of rotation is bulged and a part of the contour bulges, and a limiter having a roller plunger disposed opposite to the striker and driven by the bulging end portion of the striker A switch, and the striker has a curved adjustment plate that is detachably fixed to the bulging end and can come into contact with the contour of the bulging end.

  (2) The adjustment plate is preferably made of a steel plate.

  (3) It is preferable that the adjusting plate is screwed to the bulging end portion.

  (4) It is preferable that a cylindrical cam box that surrounds the striker has an inspection hole on the outer periphery that allows the adjustment plate to be easily attached to the striker.

  The automatic backwash strainer according to the present invention can be easily adjusted in position with the limit switch by replacing the adjustment plate attached to the bulging end of the striker with a new adjustment plate.

It is a longitudinal cross-sectional view which shows the structure of the automatic backwashing type strainer by one Embodiment of this invention. It is a longitudinal cross-sectional view which shows the structure of the rotational drive apparatus with which the automatic backwashing type strainer by the said embodiment is equipped, and is the elements on larger scale of FIG. It is the perspective view which looked at the coupling part of the rotary drive device with which the automatic backwashing type strainer by the above-mentioned embodiment was seen from the upper part. It is the perspective view which looked at the rotary drive device with which the automatic backwashing type strainer by the said embodiment was seen from diagonally upward. It is the perspective view which looked at the striker with which the automatic backwashing type strainer by the said embodiment was seen from diagonally upward. It is the perspective view which looked at the striker with which the automatic backwashing type strainer by the said embodiment was equipped from the side, and is the state figure by which the striker was accommodated in the cam box. It is the perspective view which looked at the striker with which the automatic backwashing type strainer by the said embodiment was provided from diagonally upward, and is the state figure which arranged the limit switch facing. It is the perspective view which looked at the striker with which the automatic backwashing type strainer by the said embodiment was equipped from the side, and is the state figure which attached the adjustment board to the striker. It is the perspective view which looked at the striker with which the automatic backwashing type strainer by the said embodiment was equipped from the side, and is a state figure in which the striker is rotating.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[Configuration of automatic backwash strainer]
First, the configuration of an automatic backwash strainer according to an embodiment of the present invention will be described. FIG. 1 is a longitudinal sectional view showing a configuration of an automatic backwash strainer according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a configuration of a rotary drive device provided in the automatic backwash strainer according to the embodiment, and is a partially enlarged view of FIG.

(overall structure)
Referring to FIG. 1, an automatic backwash strainer (hereinafter abbreviated as strainer) 10 according to an embodiment of the present invention includes a cylindrical main body 1 and a cylindrical filter screen 2. The main body 1 is a cylindrical container having a hollow inside, and the top is sealed with a top cover 11. The main body 1 is provided with an inflow pipe 1a on one end side of the outer periphery thereof. Moreover, the main body 1 is provided with an outflow pipe 1b on the other end side of the outer periphery thereof.

  Referring to FIG. 1, the inflow pipe 1a is connected to a water intake pipe (not shown) for taking seawater or the like. Then, seawater or the like can flow into the main body 1. The filtration screen 2 is disposed at the center of the main body 1. The filtration screen 2 has a water conduit 21 connected to the lower part thereof. The water guide pipe 21 connects the outflow pipe 1b. The water guide pipe 21 and the outflow pipe 1b are supported inside the main body 1 by the support member 12. Moreover, the inside of the main body 1 is partitioned into a filtration chamber 11a and a treated water chamber 11b.

  Referring to FIG. 1, a liquid such as seawater that flows in from the inflow pipe 1 a is filtered by the filtration screen 2 and flows out from the outflow pipe 1 b via the water conduit 21. And the filtered clean seawater is utilized in order to vaporize LNG, for example.

  Referring to FIG. 1 or FIG. 2, a backwash arm shaft 22 is disposed at the center of the filtration screen 2. In addition, a rotation driving device 3 for rotating the backwash arm shaft 22 is disposed on the upper portion (top cover 11) of the main body 1.

  Referring to FIG. 1, the strainer 10 includes a hollow backwash arm 23. The base end of the backwash arm 23 is fixed to the backwash arm shaft 22 and extends from the backwash arm shaft 22 in the centrifugal direction. The tip of the backwash arm shaft 22 is close to the inner wall of the filtration screen 2. And the front-end | tip part of the backwash arm shaft 22 can rotate facing the inner wall of the filtration screen 2. As shown in FIG.

  Referring to FIG. 1, when the rotation drive device 3 is driven to rotate the backwash arm 23 and the treated water flows backward from the treated water chamber 11 b toward the filtration chamber 11 a, the outer periphery of the filtration screen 2 is supplemented. Can remove dust. That is, the filtration screen 2 can be backwashed. And the removed dust is discharged | emitted with a treated water outside from the backwash water discharge pipe 1c provided in the outer periphery of the main body 1, and the drain pipe 1d provided in the bottom part of the main body 1. FIG.

(Structure of rotation drive device)
Next, the configuration of the rotary drive device 3 provided in the strainer 10 according to the embodiment will be described. FIG. 3 is a perspective view of the coupling portion of the rotary drive device provided in the automatic backwash strainer according to the embodiment as viewed from above. FIG. 4 is a perspective view of the rotary drive device provided in the automatic backwash strainer according to the embodiment as viewed obliquely from above.

  FIG. 5 is a perspective view of the striker provided in the automatic backwash strainer according to the embodiment as viewed obliquely from above. FIG. 6 is a perspective view of the striker provided in the automatic backwash strainer according to the embodiment as viewed from the side, and is a state diagram in which the striker is accommodated in the cam box. FIG. 7 is a perspective view of the striker provided in the automatic backwash strainer according to the embodiment as viewed obliquely from above, and is a state diagram in which limit switches are arranged to face each other.

  Referring to FIG. 2 or FIG. 3 and FIG. 4, the rotary drive device 3 includes a motor 3m, a gear reducer 3g, a disk-like lower coupling 3dc, and a disk-like upper coupling 3uc. The motor 3m connects the gear reducer 3g. The gear reducer 3g can decelerate and output the rotational speed of the motor 3m.

  Referring to FIG. 2, the gear reducer 3g is fixed to the cam box 3cb. Further, the backwash arm shaft 22 passes through the gear reducer 3g. A backwash arm shaft 22 passes coaxially through the output shaft 3sh of the gear reducer 3g. A lower coupling 3dc is coupled to the output shaft 3sh through a key. An upper coupling 3uc is coupled to the end of the backwash arm shaft 22 via a key. The upper coupling 3uc is covered with a cover 3cp (see FIG. 2).

  Referring to FIG. 2, FIG. 3 and FIG. 4, the lower coupling 3dc and the upper coupling 3uc are connected with a shear pin 3sp interposed therebetween. Referring to FIG. 2, when the motor 3m is driven, the backwashing arm passes through the power transmission path of the gear reducer 3g → the output shaft 3sh → the lower coupling 3dc → the shear pin 3sp → the upper coupling 3uc → the backwashing arm shaft 22. 23 can be rotated (see FIG. 1).

  On the other hand, referring to FIG. 1 or FIG. 2, when an obstacle is caught in the backwash arm 23, the shear pin 3sp is broken, and it becomes difficult to transmit power from the lower coupling 3dc to the upper coupling 3uc. And while restricting the overload of the rotation drive device 3, damage to the power transmission path mentioned above can be prevented.

  Referring to FIG. 2 or FIG. 5 to FIG. 7, a striker 3st is fixed to the backwash arm shaft 22. The striker 3st is accommodated in the cam box 3cb. The striker 3st is composed of a “mushroom-like” plate cam having a bulging end portion 3bu with a part of the contour bulging (see FIG. 7).

  Referring to FIG. 2 or FIG. 5 to FIG. 7, a limit switch 3sw disposed to face the striker 3st is attached to the cam box 3cb. The limit switch 3sw protrudes from the roller plunger 3rp. When the striker 3st is rotated, the roller 3r at the tip end portion of the roller plunger 3rp is pushed by the bulging end portion 3bu, and the internal switch of the limit switch 3sw is operated to detect the rotation of the striker 3st. When the bulging end portion 3bu passes the roller 3r, the roller plunger 3rp returns to the original state and stands by.

  5 to 7, the striker 3st includes a curved adjustment plate 3ap that is detachably fixed to the bulging end portion 3bu. The adjustment plate 3ap is curved so as to be in contact with the contour of the bulging end portion 3bu. Then, the adjustment plate 3ap is attached to the bulging end 3bu, and the roller 3r at the tip of the roller plunger 3rp can roll.

  Referring to FIG. 7, adjustment plate 3ap is preferably made of a steel plate, and can reduce wear caused by rolling of roller 3r. The adjustment plate 3ap is provided with a screw hole (so-called fool hole) 32h in a region where the roller 3r does not roll, the bulging end portion 3bu is provided with a screw hole 31h, and the adjustment plate 3ap is swelled with the screw 4. It is preferable to screw to the protruding end 3bu. It is also possible to post-process the screw hole 31h in the existing striker 3st.

  Referring to FIG. 6, it is preferable to open an inspection hole 3k on the outer periphery of the cylindrical cam box 3cb surrounding the striker 3st so that the adjustment plate 3ap can be easily attached to the striker 3st. Becomes easier.

[Operation of automatic backwash strainer]
Next, the operation and effect of the strainer 10 will be described while explaining the operation of the rotary drive device 3 provided in the strainer 10 according to the embodiment. FIG. 8 is a perspective view of the striker provided in the automatic backwash strainer according to the embodiment as viewed from the side, and is a state diagram in which an adjustment plate is attached to the striker. FIG. 9 is a perspective view of the striker provided in the automatic backwash strainer according to the embodiment as viewed from the side, and is a state diagram showing that the striker is rotating.

  Referring to FIG. 1 or FIG. 2, while driving the motor 3m and rotating the backwash arm shaft 22, that is, while the striker 3st is rotating (see FIGS. 7 to 9), When the limit switch 3sw does not operate, the monitoring device (not shown) determines that the shear pin 3sp has been disconnected, and generates an alarm. More specifically, the motor 3m is driven and an alarm is generated when the limit switch 3sw does not operate for 3 minutes.

  Referring to FIG. 1 or FIG. 2, when an alarm is generated, when shear pin 3sp is pulled out and it is confirmed that shear pin 3sp is not broken, it is determined that the wear of the contour of striker 3st is the cause. . Then, as shown in FIG. 6, when the wear of the adjustment plate 3ap is confirmed from the inspection hole 3k provided in the cam box 3cb, it is replaced with a new adjustment plate 3ap (see FIG. 7 or FIG. 8).

  Next, as shown in FIGS. 8 and 9, the striker 3st is rotated to confirm the operation of the limit switch 3sw. Then, after confirming the normal operation of the limit switch 3sw, a series of repair work is finished.

  As described above, in the strainer 10 according to the embodiment, when the adjustment plate 3ap attached to the bulging end portion 3bu of the striker 3st is worn, the position adjustment with the limit switch 3sw can be performed by replacing the adjustment plate 3ap with a new adjustment plate 3ap. It became easy. The strainer 10 according to the embodiment can be greatly improved as compared with the position adjustment with the conventional limit switch.

  The striker using the adjusting plate according to the present invention is expected not only to be applied to an automatic backwash strainer but also to any rotation detection mechanism.

DESCRIPTION OF SYMBOLS 1 Main body 2 Filtration screen 3ap Adjustment plate 3bu Expansion end part 3rp Roller plunger 3st Striker 3sw Limit switch 10 Strainer (automatic backwash type strainer)
22 Backwash arm shaft 23 Backwash arm

Claims (4)

An automatic backwash strainer capable of backwashing a cylindrical filter screen disposed inside the strainer body for removing dust from the liquid,
A rotatable backwash arm shaft disposed in the center of the filtration screen and rotatable;
A backwash arm that extends in a centrifugal direction from the backwash arm shaft and whose tip rotates against the inner wall of the filtration screen;
A striker consisting of a plate cam having a bulging end with a center of rotation fixed to the backwash arm shaft and a part of the contour bulging;
A limit switch disposed opposite to the striker and having a roller plunger driven by the bulging end of the striker,
The striker is an automatic backwash strainer having a curved adjustment plate that is detachably fixed to the bulging end and can come into contact with the contour of the bulging end.   The automatic backwash strainer according to claim 1, wherein the adjustment plate is made of a steel plate.   The automatic backwash strainer according to claim 1 or 2, wherein the adjustment plate is screwed to the bulging end.   The automatic backwash strainer according to any one of claims 1 to 3, wherein an inspection hole for easily mounting the adjustment plate on the striker is formed in a cylindrical cam box surrounding the striker.

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