JP3760892B2 - Clogging prevention device for continuous pressure dehydrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention is a continuous pressure dehydrator that presses a raw solution such as industrial wastewater sludge, sewage sludge, etc. into an annular filtration chamber, discharges the filtrate from the filter plate while concentrating the impeller and the raw solution, and concentrates and dehydrates it. More particularly, the present invention relates to an improvement in a scraper that is fixed to a blade of an impeller to prevent clogging of a filtration surface of a filter plate.
[0002]
[Prior art]
Conventionally, a filtration chamber is formed by a disc-shaped filter plate and an outer casing, and a rotatable impeller is disposed in the filtration chamber, and the stock solution press-fitted from the center of the filtration chamber is fed by the impeller. Friction resistance generated between the filter plate and the undiluted solution and shear friction resistance force generated between the cake laminated on the filtration surface and the undiluted solution are dehydrated and filtered while scraping the cake on the filtration surface with an impeller An apparatus for reclaiming the surface and taking out the cake from the outlet of the outer casing has been proposed by the applicant of the present invention in, for example, the specification of Japanese Patent Application No. 2000-573906.
[0003]
[Problems to be solved by the invention]
A large number of the above-mentioned conventional continuous pressure dehydrators can perform large-capacity processing in parallel, does not require a large installation space, and does not require consumables such as filter cloth. The conventional scraper fixed to the impeller blades is elastically slid on the filtration surface of the filter plate to eliminate the clogging of the screen. When it is no longer possible to make sliding contact with the board, it is necessary to replace it, which takes time and effort. In addition, the scraper that is in sliding contact with the filter plate may be pushed back by the cake and separated. The present invention provides a scraper that can be adjusted without replacement by sliding the scraper fixed to the blade of the impeller elastically on the filtration surface of the filter plate while taking advantage of the above-described conventional advantages.
[0004]
[Means for Solving the Problems]
The gist of the present invention is that a filter chamber is formed by a disc-shaped filter plate having a pair of filtration surfaces and an annular outer casing, and an impeller is disposed in the filtration chamber, and a side end portion of a blade of the impeller In the filtration device that is rotatable in the vicinity of the filter plate, a scraper is provided along the both ends of the blades of the impeller to increase the thickness from the inside of the filter chamber toward the filter plate. The scraper is sandwiched between the sloped surface of the trapezoidal presser plate and the blades of the impeller.
[0005]
A specific attachment means of the scraper is to fasten the blade of the impeller and the presser plate with an attachment bolt through which a spring is inserted, and elastically slide the sandwiched scraper against the filter plate. Also, the scraper may be provided with a long hole in the width direction of the filtration chamber, and the blade of the impeller and the presser plate may be fastened with a mounting bolt inserted through the long hole of the scraper. It can be adjusted along the long hole. And a series of notch grooves are provided on the contact surface of the filter plate of the scraper, and the notch grooves of the scraper increase the number of scraping of the filter plate. In order to reduce the sliding frictional resistance, a lubricating member is attached to the holding surface of the presser plate of the scraper and the blade of the impeller.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The apparatus according to the present invention is configured as described above, and the cake outlet is closed with a closing plate, and the stock solution is press-fitted from the supply port of the stopped filtration chamber. The filtrate is separated, and a cake layer is gradually formed on the filtration surface of the filter plate. The scraper fixed to the impeller blades rotates while sliding on the filtration surface of the filter plate, scrapes the cake layer that becomes clogged, and regenerates the filtration surface of the filter plate while conveying the cake. Eventually, the stock solution from which the filtrate was separated lost its fluidity, and when the dehydrated cake was filled in the filtration chamber, the cake outlet in the filtration chamber was opened, and the cake rotating with the impeller was gradually removed from the filtration chamber. Discharging and continuous operation becomes possible.
[0007]
Even if the scraper slides on the filter plate and wears, the slant surface of the scraper is pressed by the slant surface of the trapezoidal pressure plate with the reaction force of the compressed spring and the internal pressure of the filter chamber that the rotating impeller receives, The scraper moves so as to press against the filter plate, and the scraper is always slid on the filter plate. As the stock solution in the filtration chamber is concentrated and the internal pressure in the filtration chamber is increased, the degree of wear of the scraper increases. However, the force of the presser plate that presses against the scraper also increases, and the amount of movement of the scraper increases, resulting in wear. Even if it is always pressed against the filtration surface of the filter plate, there is no need to replace the worn scraper.
[0008]
In addition, in the case of an apparatus having a long hole in the scraper, if it becomes impossible to make sliding contact with the filtration surface of the screen, the inclined surface of the presser plate is pressed against the inclined surface of the scraper by tightening the mounting bolt. When the scraper is adjusted by moving along the blade surface and abutting against the filtration surface of the filter plate, and the scraper wears and cannot slide on the filtration surface of the screen, tighten the mounting bolts. For example, the inclined surface of the presser plate is pressed against the inclined surface of the scraper, the scraper moves along the blade surface, and is brought into contact with the filtration surface of the filter plate to adjust the scraper, which can be adjusted with little effort. . Further, a series of notch grooves provided on the outer peripheral surface of the scraper increases the number of scrapes, and the contact surface of the scraper with the filtration surface of the filter plate is reduced to enable elastic pressing. If a lubricating member is stuck on both side surfaces of the scraper, the lubricity increases and the movement in the direction of the filter plate becomes easy.
[0009]
【Example】
The continuous pressure dehydrator according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of the continuous pressure dehydrator according to the present invention, and reference numeral 1 denotes a pair of discs in which a metal filter medium is stretched. A pair of filter plates 1, 1 is formed by connecting an annular outer casing 2 to the outer peripheral end of the filter plate 1 and an inner ring support cylinder 3 to the inner peripheral end of the filter plate 1. An annular filtration chamber 4 is formed between the two. Support cylinders 5, 5 are connected to the front and rear of the inner ring support cylinder 3, and a drive shaft 6 is inserted into the support cylinder 5. A stock solution supply chamber 7 surrounded by an inner ring support cylinder 3 and a support cylinder 5 is formed between the filtration chamber 4 and the drive shaft 6. An undiluted solution supply path 8 is provided inside the drive shaft 6, and a plurality of supply ports 8 a that communicate with the undiluted solution supply chamber 7 are opened on the peripheral surface of the drive shaft 6.
[0010]
As shown in FIG. 1, an impeller 9 is supported on the drive shaft 6, and the impeller 9 extends from the central portion of the stock solution supply chamber 7 to the filtration chamber 1. The side edge of the impeller 9 is brought close to the filter plate 1, and its tip is brought close to the outer casing 2. FIG. 2 shows an impeller disposed in a filtration chamber. The impeller 9 is moved backward in the rotational direction, and in the embodiment of the present invention, the blade 10 of the impeller 9 is bent into four straight pieces. It is approximated to a curve. A reinforcing plate 11 is fixed to the blade 10 on the rear side in the rotational direction of the impeller 9 along the center line of the blade surface.
[0011]
FIG. 3 is a flowchart of the continuous pressure dehydrator, in which a support cylinder 5 having an annular filtration chamber 4 standing on a frame 13 through a bearing 12 is inserted into the support cylinder 5. The shaft 6 is linked to a driving machine 15 via a driving pulley 14. An undiluted solution supply pipe 17 is connected to one end of the drive shaft 6 via a universal joint 16, and the supply pipe 17 is connected to a sludge tank 19 via a supply pump 18. As shown in FIG. 3, the sludge in the sludge tank 19 is caused to flow into the stock solution supply chamber 7 from the plurality of supply ports 8 a of the drive shaft 6, and the sludge is uniformly pressed into the filtration chamber 4 from the stock solution supply chamber 7. Reference numeral 20 denotes a cleaning pipe provided on the filter plate 1, reference numeral 21 denotes a cover for preventing splashing of cleaning water, and reference numeral 22 denotes a filtrate receiving trough.
[0012]
FIG. 4 is a cross-sectional view of the scraper fixed to the blades of the impeller. Scrapers 23 are disposed at both ends of the blades 10 of the impeller 9 and face the filter plate 1 from the inside of the filtration chamber 4. The thickness has been enlarged. As shown in FIG. 2, the scraper 23 is disposed on the front surface in the rotational direction from the tip of the blade 10 of the impeller 9 to the base end. As shown in FIG. 4, the inclined surfaces 24 a on both sides of the lower surface of the trapezoidal pressing plate 24 are in contact with the inclined surface 23 a of the upper surface of the scraper 23. A mounting bolt 26 through which the spring 25 is inserted is inserted into the through hole 10a of the blade 10 of the impeller 9, and a tip screw portion 26a of the mounting bolt 26 is screwed into a screw hole 24c provided in the holding plate 24. The scraper 23 is always pressed against the filtration surface of the filter plate 1 by the inclined surface 24a of the trapezoidal pressing plate 24 and the blade 9a of the impeller 9 by the spring 25.
[0013]
Even when the scraper 23 slides on the filter plate 1 and wears, the inclined surface 23a of the scraper 23 is trapezoidally pressed by the reaction force of the compressed spring 25 and the internal pressure of the filter chamber 4 received by the rotating impeller 9. 24, the scraper 23 moves so as to press against the filter plate 1, and the scraper 23 is always slid on the filter plate 1. Then, the stock solution in the filtration chamber 4 is concentrated, and the higher the internal pressure in the filtration chamber 4 is, the greater the degree of wear of the scraper 23 is. However, the force of the presser plate 24 pressed against the scraper 23 also increases, and the movement of the scraper 23 The amount also increases.
[0014]
As shown in FIG. 4, a series of notch grooves 27 are provided on the contact surface of the filter plate 1 of the scraper 23, and the tip of the scraper 23 is divided by the notch grooves 27 to increase the number of scrapes. To prevent clogging of the filtration surface of the filter plate 1. The contact surface of the scraper 23 with respect to the filtration surface of the filtration plate 1 can be made small and elastically pressed. Although the number of grooves of the notch groove 27 is two in the drawing, it can be appropriately changed depending on the size of the filter plate 1. Further, if a lubricating member 28 such as Teflon or ultrahigh molecular weight polyethylene is attached to both side surfaces of the scraper 23, sliding friction is reduced and the scraper 23 is easily moved. Reference numeral 29 is a washer for preventing the spring 25 from being removed, and reference numeral 30 is a contamination prevention cover disposed around the spring 25.
[0015]
FIG. 5 shows another embodiment of the scraper fixed to the blade of the impeller. The scraper 31 is provided with a long hole 31b in the width direction of the filtration chamber 4, and is provided at both ends of the blade 10 of the impeller 9. The mounting bolts 32, 32 inserted into the through holes 10 a, 10 a are inserted into the long holes 31 b, 31 b of the scraper, respectively, and screw holes 33 c, 33 c provided on both sides of the trapezoidal holding plate 33 are attached to the mounting bolts 32. The tip screw portion 32a is screwed. The scraper 31 is sandwiched between the inclined surface 33 a of the trapezoidal holding plate 33 and the blade 10 of the impeller 9, and the inclined surface 33 a of the holding plate 33 is reduced in the direction of the filtering plate 1. Since the inclined surface 31a expanded in the direction is tightened, the scraper 31 can be brought into sliding contact with the filtration surface of the filter plate 1 elastically.
[0016]
When the scraper 31 is worn and cannot be brought into sliding contact with the filter plate 1, if the mounting bolt 32 screwed to the press plate 33 is tightened, the press plate 33 is pulled and the scraper 31 slides in the direction of the filter plate 1. Then, it comes into sliding contact with the filter plate 1 again. It is not necessary to replace the scraper 31, and the scraper 31 can be adjusted with a little effort. Reference numeral 34 denotes a series of notch grooves provided on the contact surface of the filter plate 1 of the scraper 31. The contact surface of the scraper 31 with respect to the filter surface of the filter plate 1 can be made small and elastically pressed. . Reference numeral 35 denotes a lubricating member such as Teflon or ultrahigh molecular weight polyethylene attached to both side surfaces of the scraper 23. Reference numeral 36 denotes a washer provided between the blade 10 and the head of the mounting bolt 32.
[0017]
【The invention's effect】
The clogging prevention device of the continuous pressure dehydrator according to the present invention is configured as described above, and the scraper sandwiched between the impeller blades and the press plate can be always slid on the filtration surface of the filter plate. That is, the conventional scraper needs to be replaced when it can no longer be slidably contacted with the outer cylinder screen due to wear. In the present invention, the thickness of the filter blade is reduced at both ends of the impeller blades. A scraper that is enlarged from the inside to the filter plate side is arranged, and the inclined surface of the scraper sandwiched between the press plate and the impeller blades is pressed by the inclined surface of the trapezoidal press plate to the filter plate. Can be pressed. As the stock solution in the filtration chamber is concentrated and the internal pressure in the filtration chamber is increased, the degree of wear of the scraper increases. However, the force of the presser plate that presses against the scraper also increases, and the amount of movement of the scraper increases, resulting in wear. Even if it is always pressed against the filtration surface of the filter plate, there is no need to replace the worn scraper.
[0018]
If the blades of the impeller sandwiching the scraper and the presser plate are fastened with mounting bolts that are inserted through the spring, the worn scraper is removed from the filter plate by the reaction force of the compressed spring and the internal pressure of the filtration chamber that the rotating impeller receives. And can always be slidably contacted with the filtration surface of the filtration plate. The scraper may be provided with a long hole in the width direction of the filtration chamber, and the impeller blade and the press plate may be fastened with a mounting bolt inserted through the long hole of the scraper. The inclined surface is pressed against the inclined surface of the scraper, and the worn scraper moves along the blade surface and comes into contact with the filtration surface of the filter plate, so that adjustment can be made with little effort. A series of notch grooves is provided on the contact surface of the filter plate of the scraper, and the series of notch grooves provided on the outer peripheral surface of the scraper increases the number of scrapes, and the filter surface of the scraper filter plate The contact surface can be made smaller and elastically pressed. Further, if a lubricating member is attached to the holding surface of the presser plate of the scraper and the blades of the impeller, the sliding friction resistance is reduced. If a lubricating member is stuck on both side surfaces of the scraper, the lubricity increases and the movement in the direction of the filter plate becomes easy.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a continuous pressure dehydrator according to the present invention.
FIG. 2 is a side view of an impeller disposed in the filtration chamber.
FIG. 3 is a flowchart of the continuous pressure dehydrator. FIG. 4 is a longitudinal sectional view of the scraper fixed to the impeller blades.
FIG. 5 is a longitudinal sectional view of a scraper according to another embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Filtration plate 2 Outer casing 4 Filtration chamber 9 Impeller 10 Blade 23, 31 Scraper 24, 33 Presser plate 24a, 33a Inclined surface 25 Spring 26, 32 Mounting bolt 27, 34 Notch groove 28, 35 Lubrication member 31b Long hole

Claims (5)

A disk-shaped filter plate (1, 1) having a pair of filter surfaces and an annular outer casing (2) form a filter chamber (4), and an impeller (9) is disposed in the filter chamber (4). In the filtration device in which the side end portion of the blade (10) of the impeller (9) is placed close to the filter plate (1) to be rotatable, both end portions of the blade (10) of the impeller (9) A scraper (23, 31) whose thickness is enlarged from the inside of the filtration chamber (4) to the direction of the filtration plate (1) is provided along with the trapezoidal presser plate (24, 33). An apparatus for preventing clogging of a continuous pressure dehydrator, wherein a scraper (23, 31) is sandwiched between an inclined surface (24a, 33a) and a blade (10) of an impeller (9). The blade (10) of the impeller (9) and the presser plate (24) are fastened with a mounting bolt (26) inserted through a spring (25), and the sandwiched scraper (23) is elastically filtered (1) The clogging prevention device for a continuous pressure dehydrator according to claim 1, wherein the device is slidably contacted with the continuous pressure dehydrator. The scraper (31) is provided with a long hole (31b) in the width direction of the filtration chamber (4), and the blade (9) of the impeller (9) is attached by a mounting bolt (32) inserted into the long hole (31b) of the scraper (31). 10. The continuous pressure dehydrator according to claim 1, wherein the scraper (31) is slidably brought into sliding contact with the filtration surface of the filter plate (1) by fastening the press plate (33). Anti-clogging device. 4. The continuous process according to claim 1, wherein a notch groove (27, 34...) Is provided on the contact surface of the filter plate (1) of the scraper (23, 31). Clogging prevention device for pressure dehydrators. Lubricating members (28, 35) are attached to the clamping surfaces of the presser plates (24, 33) of the scraper (23, 31) and the blades (10) of the impeller (9). 5. The clogging prevention device for a continuous pressure dehydrator according to any one of 4 above.

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