JPH0448806Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a solid-liquid separator, and more particularly to a solid-liquid separator called a filter cloth traveling type filtration machine or a filter cloth traveling type dehydrator.

[Conventional technology]

Solid-liquid separation is performed efficiently in so-called filter-cloth traveling type dehydrators and filters, which separate solid components by supplying solid-liquid to the surface of an endless filter cloth that can travel in one direction and rotate freely. For this reason, a vacuum suction tank is provided on the back side of the filter cloth and opposite the solid-liquid supply section to suck the liquid component in the solid-liquid supplied onto the filter cloth and promote its passage. . Since such a vacuum suction tank is maintained at a fairly high vacuum, such as 500 mm or more in the water column, the filter cloth is sucked and flexes significantly. Therefore, for example,
In the device described in Publication No. 83862, a large number of filter cloth guide rolls are arranged side by side at the vacuum suction port of the vacuum suction tank, which has a constant width in the running direction of the filter cloth, and the filter cloth is guided by the guide rolls. This is to prevent bending.

However, simply arranging a large number of the above-mentioned guide rolls cannot prevent bowing of the filter cloth.
This bowing is a phenomenon in which the center of the filter cloth lags behind the running direction in an arched manner.Especially at the vacuum suction port, a large load is applied to the center of the filter cloth due to suction from the vacuum suction tank. As the filter cloth is pulled toward the downstream side, its central portion lags behind. When a large bowing occurs, the weft (weft) of the filter cloth base material assumes the bowing shape, and the filter width becomes relatively narrow. In addition, the central part of the filter cloth is stretched out compared to both sides in the width direction.
It becomes difficult to obtain stable running of the filter cloth.

In order to solve the above-mentioned problem, the present applicant has previously proposed a method in which a large number of filter cloth guide rolls 2 are formed in the vacuum suction port 1 in a V-shape with respect to the running direction, as schematically shown in FIG. 6, for example. They are arranged side by side so that the filter cloth 3 is guided so as to prevent the filter cloth 3 from bending, and at the same time, force is applied in the left and right outward directions in the width direction, so that the center part of the filter cloth 3 is aligned with respect to the running direction. A structure has been proposed that prevents the bowing phenomenon, which causes a bowing delay.

[Problem that the invention attempts to solve]

However, the following problems remain in the conventional device as described above.

In other words, in order to increase the effectiveness of preventing Boeing,
When the angle θ of the V-shaped arrangement shown in Fig. 6 is increased, the force that pushes the guide roll toward the center (the reaction force) increases in proportion to the force that pulls the filter cloth outward. This increases the force for rotating the guide roll, that is, the filter cloth tension, and this filter cloth tension actually promotes bowing. Furthermore, if the force that pushes the guide rolls toward the center increases, there is a risk that friction will occur between the ends of the guide rolls and the support frame between the guide rolls, which will wear out the ends of the guide rolls themselves and The ends of the rolls now form a knife edge, and by increasing the angle θ of the V-shaped arrangement, the portion 4 between the guide rolls on both sides of the V-shaped arrangement opens wide, and the filter cloth During this time, the filter cloth tends to fall down, and the abrasion of the contact position of the filter cloth with the guide roll becomes severe, causing the filter cloth to wear out. In severe cases, the filter cloth may be torn. Therefore, there is naturally a limit to the angle θ of the V-shaped arrangement of the filter cloth guide rolls, and there is also a limit to the effect of preventing bowing of the filter cloth by the V-shaped arrangement. If bowing cannot be properly prevented, stable running of the filter cloth cannot be achieved.

The present invention is intended to solve the above conventional problems, and aims to prevent bowing of the filter cloth without accelerating wear of the filter cloth, and to ensure stable running of the filter cloth.

[Means for solving problems]

The solid-liquid separator of the present invention that meets this purpose includes: an endless filter cloth that runs in one direction on a fixed trajectory and is provided so as to be able to rotate freely; and a guide roll that guides the filter cloth.
In the solid-liquid separation device, the solid-liquid separation device includes a solid-liquid supply section provided on the front side of the filter cloth, and a reduced pressure suction tank provided on the back side of the filter cloth and facing the solid-liquid supply section. A guide roll located on the downstream side of the reduced pressure suction tank with respect to the running direction of the cloth is configured as a roll whose longitudinal center portion has a larger diameter than both side portions.

The guide roll is, for example, a trapezoidal roll whose diameter is gradually reduced in a straight line toward the end of the roll on both sides in the longitudinal direction of the roll, or a crowning roll whose diameter is gradually reduced in a curved manner.

[Effect]

In such a device, the guide roll is
Since the diameter of the center portion in the longitudinal direction of the roll is larger than that of both side portions, the endless filter cloth guided by the guide roll is pulled more strongly at the center portion in the width direction than on both side portions. Since this guide roll is located downstream of the vacuum suction tank,
The center portion in the width direction of the filter cloth, which tends to lag behind in the vacuum suction tank, is effectively pulled by the large diameter portion at the center of the guide roll, preventing the lag and effectively preventing bowing. To prevent this occurrence of boeing,
Since this is achieved simply by the shape of the guide roll, there is no need for forcible expansion of the filter cloth by the filter cloth guide roll in the reduced pressure suction tank section as described above, and there is no need for forceful expansion of the filter cloth by the filter cloth guide roll itself or its arrangement. It also does not cause wear of the filter cloth.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 to 3 show a solid-liquid separator according to a first embodiment of the present invention, in which the present invention is applied to a filter cloth traveling type dehydrator.

In FIG. 1, 11 is an endless filter cloth, and as shown in FIG. 3, rubber belts 11a with holes are sewn on both sides. This endless filter cloth 11 is tensioned between a drive roll 12 and three guide rolls 13, 14, 15.
4, 15, the rollers 16, 17, 18, the transfer drum 19, etc., travel and rotate in the direction of arrow A on a fixed trajectory regulated by the rollers 16, 17, 18, transfer drum 19, and the like. The above filter cloth 11
is stretched toward the guide rolls 13 to 14 so as to have a slight upward angle with respect to the horizontal plane. This angle is preferably in the range of 5 to 20 degrees so that the liquid depth in the solid liquid supply tank 23 can be made as shallow as possible and the contact area between the solid liquid 20 and the filter cloth 11 can be increased.

The above-mentioned filter cloth is as described in Japanese Patent Application Laid-Open No. 115720/1983. In other words, at least the weft yarns arranged in the width direction of the filter cloth have a single yarn diameter of 0.1~
Using a textile base material using 10 μm synthetic fiber thread,
The base material is mainly made of weft threads that are raised in the longitudinal direction (travelling and circumferential direction) to form a raised filter layer of ultrafine fibers with a thickness of 0.1 to 10 μm on the surface. Further, a knitted raised filter cloth as described in JP-A-58-207917 may also be used. In such a filter cloth, the naps lie uniformly in the longitudinal direction, but when in use, the naps are stretched in such a way that they face in the opposite direction to the traveling and circumferential direction of the filter cloth 11.

On the surface side of the filter cloth 11 and the guide roll 1
Between 3 and 14 is a solid-liquid supply tank (solid-liquid supply section) 2.
3 is installed. However, in the present invention, the so-called solid-liquid supply part does not necessarily need to be configured as a tank, and may be a pipe or gutter that can directly discharge the solid-liquid.

On the back side of the filter cloth 11, an air intake means 2 is provided via an air intake pipe 24 at a position facing the solid-liquid supply tank 23.
A vacuum suction tank 21 that is connected to 5 and is capable of maintaining the back side in a reduced pressure state of 500 mm or more in the water column.
is installed. This reduced pressure suction tank 21 is equipped with a discharge pipe 36 for liquid components. In addition, a plurality of filter cloth guide rolls 27 are arranged in the reduced pressure suction port 26 facing the back surface of the filter cloth 11 in the running and circumferential direction of the filter cloth 11 . This filter cloth guide roll 27
The roll may be a roll with a smooth surface, but it may be a cylindrical roll with many holes, so-called a perforated roll, or a cylindrical roll or a solid roll with circumferential grooves or spiral grooves cut on the surface. It is preferable to use so-called grooved rolls because the actual opening area of the vacuum suction ports 26 does not decrease significantly even if they are arranged closely, and a large degree of vacuum can be obtained with a small amount of power.

FIG. 4 shows the vacuum suction port 26, which widens toward the traveling and circumferential direction of the filter cloth (in the direction of the arrow). A construction frame 28, which similarly widens toward the end, is detachably attached to the reduced pressure suction port 26. Therefore, in this embodiment, the construction frame 28 effectively forms the vacuum suction port 26.

In this embodiment, as shown in FIG. 4, the filter cloth guide rolls 27 are supported by the construction frame 28 in three groups in the width direction of the filter cloth. The two outermost filter cloth guide rolls 27 in the row are both oriented slightly outward in the filter cloth traveling direction, forming a V-shape in the filter cloth traveling and circumferential direction. There is. This so-called V-shaped arrangement of the filter cloth guide rolls is not necessarily required. However, the V-shaped arrangement is preferable because it allows the filter cloth to be spread out in the width direction. The angle θ of the V-shaped arrangement is preferably 0.5 to 2 degrees.

Referring again to FIG. 1, the guide roll 1
A transfer drum 19 and pressure rolls 16, 17, and 18 are disposed opposite to each other between the transfer drum 19 and the drive roll 12 with the filter cloth 11 in between. In addition, the transfer drum 19
A wedge-shaped scraper 22 made of a relatively soft material such as rubber or synthetic resin is brought into contact with the surface. Furthermore, the above scraper 2
A shooter 29 for discharging cake is installed directly below the roll 2 and at a higher position than the drive roll 12. This shooter 29 is made of a plate made of metal or synthetic resin, and is inclined at an angle of 30 to 60 degrees with respect to the horizontal plane, and is away from the surface of the transfer drum 19.
They are installed at a distance of 0.5 to 20 mm.

Draining rolls 30a and 30b that contact the filter cloth 11 are installed between the guide rolls 15 and 13. A filter cloth cleaning nozzle 31 is provided on the front side of the filter cloth between the drain roll and the guide roll 15, and a filter cloth cleaning nozzle 32 is provided on the back side of the filter cloth between the drain roll and the guide roll 13. ing.

A combing device 35 is installed above the guide roll 13 to abut against the filter cloth 11 and align the direction of the nap.

In the filter cloth running type dehydrator having the above configuration, the guide roll 14 located downstream of the vacuum suction tank 21 with respect to the filter cloth running direction is configured as a roll as shown in FIG. 2.

As shown in FIG. 2, the guide roll 14 is a trapezoidal roll whose diameter D at the center in the roll longitudinal direction is larger than the diameter d at both sides, and in this embodiment, the diameter changes linearly between them. is formed. This roll shape may be a so-called crowning roll in which the diameter changing portion changes smoothly into a curved shape. Further, the roll ring portion 33 and the roll surface forming member 34 may be made of the same material or different materials, but from the viewpoint of suppressing bowing, which will be described later, it is preferable that the friction coefficient of the large diameter portion is the same as that of the small diameter portion. It is better to be larger than that of the department. In addition, the dimensional relationship in the roll shape shown in Fig. 2 may be determined depending on the size of bowing that is to occur in the filter cloth.
The preferred ranges are as follows.

0.3≦/L≦0.95 0.9≦d/D≦0.99 To explain the operation of the embodiment device having the above configuration, the device is driven by the drive roll 12,
A solid liquid 20 containing a solid component and a liquid component is supplied from a solid liquid supply tank 23 onto the filter cloth 11 traveling and circulating in the direction of the arrow. The liquid component in the supplied solid-liquid passes through the filter cloth 11 by gravity and by the reduced pressure suction action provided by the reduced pressure suction tank 21.
collected within 1. At this time, the filter cloth 11 is subjected to a large force due to suction, but the action of the filter cloth guide roll 27 and the guide roll 4 prevents the occurrence of bowing as will be described later, and the filter cloth 11 runs stably.

The liquid components collected in the vacuum suction tank 21 are discharged to the outside of the dehydrator via the discharge pipe 36. On the other hand, the components that have not passed through the filter cloth 11 are transferred to the transfer drum 19 and the press roll 1 as the filter cloth 11 travels and rotates.
6, 17, 18 and the drive roll 12, and is squeezed to squeeze out the liquid component, forming a so-called cake. The cake is then transferred from the filter cloth 11 to the surface of the transfer drum 19, scraped off by the scraper 22, and discharged to the outside of the dehydrator. Since the scraped cake is guided by the shutter 29, it will not fall or adhere to the filter cloth 11.

The filter cloth 11 then reaches the position of the filter cloth cleaning nozzle 31, and is washed from its surface side by the cleaning water jetted from the filter cloth cleaning nozzle 31.

The filter cloth 11 is then cleaned from the back side by a filter cloth cleaning nozzle 32 after the liquid components from the cleaning are removed by drain rolls 30a and 30b.
After the so-called clogging substances taken in therein are removed and the direction of the fluff is aligned by the combing device 35, it reaches the position of the solid-liquid supply tank 23 again.
It is then subjected to dehydration.

The drain rolls 30a and 30b also prevent the washing water jetted from the filter cloth cleaning nozzle 32 from flowing back toward the filter cloth cleaning nozzle 31.

As described above, the filter cloth 11 is subjected to a large force due to suction in the reduced pressure suction tank 21, and the bowing phenomenon in which the center portion of the filter cloth 11 in the width direction is delayed is likely to occur. However, since the guide roll 14 immediately downstream thereof is configured as a trapezoidal roll as shown in FIG. is prevented. Since the guide roll 14 has the above-mentioned effect, the angle θ of the V-shaped arrangement of the filter cloth guide rolls 27 does not need to be so large, and bowing can be suppressed even without the V-shaped arrangement.
Therefore, a large force is not applied to the filter cloth guide roll 27 in the filter cloth width direction, and a large gap does not occur between the ends of the filter cloth guide roll 27.

Next, a second embodiment of the present invention is shown in FIG.

In this embodiment, the present invention is applied to a filter cloth traveling type filter. In this device, an endless filter cloth 41 similar to that shown in FIG. It is separated into concentrated components. The filter cloth 41 is guided along a guide roll 42, a drive roll 43, a guide roll 44, a draining roll 45, and a pin-equipped guide roll 46. 47 is a solid liquid supply tank, 48 is a vacuum suction tank, and 49 is a filter cloth guide roll. The guide roll 42 on the downstream side of the solid-liquid supply tank 47 is formed into a trapezoidal roll or a crowning roll similar to that shown in FIG.

Even in such a filter cloth traveling type filter, the first
As in the embodiment, due to the surface shape of the guide roll 42, the center portion of the filter cloth 41 in the width direction is pulled more strongly than the both sides, so that bowing is appropriately prevented. Other operations are similar to those in the first embodiment.

The device of the invention can be used in a variety of applications. For example, it can be used to separate solid components from lake or river water. Also,
Sludge, scum, flocs, and wash water generated during sewage treatment, such as suspended sludge such as surplus sludge generated from activated sludge treatment equipment, and so-called fixed sludge discharged from biofilm treatment equipment. It can be used for filtering, concentrating, and dehydrating sludge, etc. Specifically, for example, sludge generated from water and sewage treatment, excess sludge generated from septic tanks, sludge generated from human waste treatment tanks, scum generated from pressure flotation operations, and flocs generated from industrial wastewater treatment. It can be used for solid-liquid separation of backwash water for various filters such as flocculation and sedimentation flocs and sand filters. Furthermore, it can be used for solid-liquid separation in various manufacturing industries, such as paper pulp manufacturing, food manufacturing, sake brewing, and miso brewing, and for the recovery of valuables in chemical processes.

[Effect of idea]

As explained above, when using the solid-liquid separator of the present invention, the guide roll on the downstream side of the vacuum suction tank has a trapezoidal shape or a crowning roll.
Since the central part in the width direction of the filter cloth can be pulled more strongly than the both sides, it is possible to appropriately prevent bowing from occurring in the filter cloth, and the filter cloth can run stably. .

Further, since the above-mentioned bowing can be prevented simply by changing the shape of the guide roll, there is no need to put too much effort into arranging the filter cloth guide roll in the vacuum suction tank, and the abrasion of the filter cloth caused by these can be eliminated.

[Brief explanation of the drawing]

1 is a schematic side view of a solid-liquid separator according to a first embodiment of the present invention, FIG. 2 is an enlarged sectional view of a guide roll of the device of FIG. 1, and FIG. 3 is a filter of the device of FIG. 1. FIG. 4 is a plan view of the vacuum suction port of the device shown in FIG. 1, FIG. 5 is a schematic side view of the solid-liquid separation device according to the second embodiment of the present invention, and FIG. It is a top view of the reduced pressure suction tank part in the conventional device for explanation. 11, 41... Filter cloth, 12, 43... Drive roll, 13, 14, 15, 42, 44, 46... Guide roll, 16, 17, 18... Press roll,
19...Transfer drum, 20...Solid liquid, 21,48
...Reduced pressure suction tank, 22...Scraper, 23,
47...Solid-liquid supply tank, 24...Intake pipe, 25...
Intake means, 26... Decompression suction port, 27, 49...
Filter cloth guide roll, 28...Erection frame, 29...Shooter, 30a, 30b, 45...Drainer roll, 31, 32...Filter cloth cleaning nozzle, 33...Roll ring portion, 34...Roll surface forming member , 35...
...combing machine, 36...discharge pipe.

Claims (1)

[Scope of utility model registration request] An endless filter cloth that runs in one direction on a constant trajectory and is freely rotatable, a guide roll that guides the filter cloth, and a solid liquid supply section that is provided on the surface side of the filter cloth.
A solid-liquid separator comprising: a vacuum suction tank provided on the back side of the filter cloth and facing the solid-liquid supply section; 1. A solid-liquid separator characterized in that the positioned guide roll is configured as a roll having a diameter larger at the center portion in the longitudinal direction than at both side portions.