JPH0775646B2 - Dehydrator - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to an improvement of a dehydration treatment apparatus that removes water from a sludge slurry containing a solid mass dredged in a dredging work such as a harbor to separate solid and liquid.

[Prior art]

As a dehydration treatment device for solid-liquid separation from slurry containing dredged solid mass, solid mass and water are separated by the difference in centrifugal force generated by conventionally rotating sludge sludge matter at high speed. The centrifuge, the settling device that separates the solid mass and the water by separating the solid mass downward due to the difference in specific gravity, and the solid mass is attached to the surface of the filter cloth or strainer. There is such a filtering device. However, it is difficult to keep the centrifugal force constant in the solid / liquid separation by the above-mentioned centrifugal separator, and in the filtering apparatus, the filter medium must be frequently replaced, which causes a problem that the dehydration treatment efficiency is poor. there were. Therefore, in view of such problems, the applicant has installed a filtering member on the surface of the rotating drum, and a doctor blade is slidably contacted with the surface of the rotating drum, and a suction tube having a suction port opening inside the rotating drum. Is connected to the negative pressure forming means, and the lower half of this rotating drum is immersed in sludge-like sludge substance to adhere to the surface of the filtering member, and the dehydrated solid mass is scraped off with a doctor blade. A dehydration treatment device having such a structure was previously proposed (Japanese Patent Publication No. 61-46164, etc.).

[Problems to be Solved by the Invention]

In the dewatering apparatus having the above structure according to the above proposal, the diameter of the rotating drum is formed to be large in order to increase the adsorption area of the filtering member and enhance the dewatering ability. The volume of the negative pressure action space is also large. As a result, when the negative pressure of the negative pressure forming means acts on the negative pressure acting space in the rotary drum, a so-called “rise time” until the negative pressure acting space becomes a predetermined negative pressure takes a long time. was there. Therefore, in order to reduce the "rise time", it is conceivable that the negative pressure forming means has a large capacity, but in such a case not only the entire apparatus becomes large, but also the initial cost and running cost are high. There is also the problem of being completed. The present invention has been proposed in view of the above problems, and even in a large-diameter rotary drum having a large adsorption area of a filtering member, the negative pressure in the negative pressure acting space is increased without increasing the capacity of the negative pressure forming means. The purpose is to be able to shorten the "rise time".

[Means for Solving the Problems]

In order to achieve the above object, the dehydration treatment apparatus according to the present invention is configured such that a drum having a filter member formed on a peripheral surface thereof is rotatable in a state that a part of the drum is immersed in sludge in a sludge tank, A doctor tube that slides a doctor blade on the inside of the rotary drum, creates a negative pressure by injecting a high-pressure fluid into the suction pipe with the suction port opening inside the rotary drum, and takes out the generated negative pressure. It is characterized in that it is connected to a negative pressure forming means composed of a pump, and is provided with a space reducing means for reducing a negative pressure acting space inside the rotary drum, and a suction port is opened in a peripheral surface portion of the space reducing means. Is. Another feature is that the space reducing means is formed of a cylindrical member whose peripheral surface is located in the vicinity of the filtering member. The suction port is opened at the lower end portion of the space reducing means close to the inner peripheral surface of the rotary drum. It is also a feature.

[Advantageous Effects] A high pressure fluid is injected into the pipe to generate a negative pressure, and the negative pressure is generated by the negative pressure forming means composed of a jet pump configured to take out the generated negative pressure. Through the suction port to act on the negative pressure acting space. At this time, even if the rotating drum has a large diameter, since the space reducing means is provided inside the rotating drum, the negative pressure working space formed inside the rotating drum is narrowed accordingly. Therefore, the negative pressure acting from the suction port immediately raises the negative pressure in the negative pressure acting space. Similarly, when the rotating drum is rotated by the driving means,
The part of the sludge tank that is immersed in the sludge adsorbs the sludge, and only the water content of the adsorbed sludge is sucked into the negative pressure action space, while the sludge adsorbed on the filter member reaches the doctor blade. It is dehydrated enough. Thus, the dehydrated sludge is scraped off from the filter member by the doctor blade.

【Example】

An embodiment of a dehydration processing apparatus according to the present invention will be described below with reference to the drawings. <Example 1> As shown in Fig. 1 and Fig. 2, the dehydration treatment apparatus 1 according to this example has a precoat layer (filter member) 2 formed on the periphery thereof and is configured to be rotatable by a driving means 3. Rotating drum 4
A sludge tank 6 disposed below the rotating drum 4 for storing sludge 5, a space reducing means 7 provided inside the rotating drum 4, an inner peripheral surface 2a of the precoat layer 2 and a space reducing means 7. The negative pressure acting space 8 formed between them is provided with a suction device 9 for exerting a negative pressure, and a doctor blade 11 for scraping off the solid mass 10 adsorbed by the precoat layer 2 and dehydrated. The precoat layer 2 has a wire mesh (strainer) 12 stretched on the outer peripheral surface of the rotary drum 4, and the surface of the wire mesh 12 is diatomaceous earth.
13 is formed in a relatively thick layer, and the lower part of the precoat layer 2 is immersed in the sludge 5 stored in the sludge layer 6. The drive means 3 of the rotary drum 4 includes a chain wheel 15 fixed to one drum pivot shaft 14 and the chain wheel 15
Is connected to a drive chain wheel 18 attached to the output shaft of the electric motor 16 by a chain 19. Although the electric motor 16 is used here as a drive source, a drive source such as a hydraulic / pneumatic motor or an internal combustion engine can be used, and the electric motor for rotation can be a shaft instead of a chain, It is also possible to directly drive the drum pivot shaft 14. The space reducing means 7 is configured such that a cylindrical member 20 formed in a cylindrical shape is mounted inside the rotary drum 4 and the centers of the plate members 21 on both sides are fixed to the drum support shaft 17 so as not to rotate. The peripheral wall 20a of the tubular member 20 is located near the inner peripheral surface 12a of the wire net 12. When the peripheral wall 20a portion of the tubular member 20 is positioned near the inner peripheral surface 12a of the wire net 12 in this way, the negative pressure acting space 8 formed in the rotary drum 4 is formed to be narrow. The suction device 9 is attached to the lower surface of the peripheral wall 20a of the tubular member 20.
The end of a branch pipe 22a branched from the suction pipe 22 constituting the above is opened downward as a suction port 23. The suction device 9 is, as shown in FIG.
25 is sucked up by the pump 26 and jetted from the jet nozzle 27 toward the protection pipe 28, and the negative pressure formed in the discharge pipe 27 when the jet water flow is jetted from the protection pipe 28 to the discharge pipe 29 is a negative pressure supply port. This jet pump MJP is formed by forming a jet pump (negative pressure forming means) MJP formed so as to be taken out from 30.
The negative pressure supply port 30 is connected to the suction port 32 by a suction pipe 22. Next, the operation of the dehydration processing apparatus 1 configured as above will be described. First, on the surface of the wire net 12 of the rotary drum 4, for example, Japanese Patent Laid-Open No. 1-
The diatomaceous earth 2 is preliminarily adsorbed in a thick layered manner by the method described in Japanese Patent No. 249115 to form the precoat layer 2. Next, operate the jet pump MJP to apply a negative pressure from the negative pressure supply port 30 to the suction pipe 2
It acts on the negative pressure acting space 8 via 2 and the suction port 23. Then, since the negative pressure acting space 8 is narrowed by the space reducing means 7, the negative pressure in the negative pressure acting space 8 immediately increases. When the negative pressure in the negative pressure action space 8 becomes high, the sludge 5 is adsorbed by the negative pressure in the precoat layer 2 portion immersed in the sludge 5 in the sludge tank 6, and only the moisture passes through the precoat layer 2. It is sucked into the load acting space and then sucked from the suction port 23 through the suction pipe 22 to the jet pump MJP. Here, as shown in FIG. 2, when the position of the liquid level L of the sludge 5 in the sludge tank 6 is set higher than the water absorption position of the suction port 23, the water head between the liquid level L and the water absorption position of the suction port 23 Due to the difference H, the water content in the sludge 5 easily passes through the precoat layer 2, and the negative pressure for suction can be reduced accordingly. When the water head difference H is to be increased, the sludge tank 6 is increased in height as shown by the imaginary line, and the rotary drum 4
If you position so that almost the whole is buried, the head difference H
Can be formed large. Thus, the solid mass 10 adsorbed on the surface of the precoat layer 2 by the negative pressure of the negative pressure acting space 8 is sufficiently dehydrated while reaching the doctor blade 11, and is scraped off from the surface of the precoat layer 2 by the doctor blade 11. Of. Incidentally, the water content of the solid mass dehydrated by the dehydration processing apparatus 1 having the above structure and scraped off by the doctor blade 11 is about 20%.
The good result that it was dehydrated up to was obtained. <Embodiment 2> As shown in FIG. 3, in the dehydration treatment apparatus 1 according to this embodiment, the space reducing means 7 is spread over both side plates 4a and 4a of the rotary drum 4 so that both ends of the cylindrical member 20 are directly airtight. It is designed to be joined to. In this case, the pivot structure of the rotary drum 4 can be simplified as compared with the first embodiment. Further, since the cylindrical member 20 rotates together with the rotary drum 4, the suction pipe 22 formed on the peripheral wall 20a of the cylindrical member 20 and the suction port 23 at the tip thereof also rotate. When the suction port 23 rotates together with the rotary drum 4 and is located in the upper part of the rotary drum 4 as shown in the phantom diagram, air is sucked, but when the lower water absorption position is reached again, the interior of the rotary drum 4 is stopped. It comes to suck the water sucked in. Other configurations and operations are similar to those of the first embodiment. <Embodiment 3> As shown in FIG. 4, in the dehydration treatment apparatus 1 according to this embodiment, the space reducing means 7 is formed by the hollow cylindrical member 20 in the rotary drum 4 in Embodiments 1 and 2 above. However, in this example, this is formed of a solid columnar member 30 of synthetic resin or the like, and the suction pipe 22 is formed of a through hole in the wall 30a thereof. It is needless to say that a plurality of suction pipes 22 can be provided as shown by the imaginary line in FIG. Although the precoat layer 2 is formed of diatomaceous earth 13 in each of the above-mentioned embodiments, the solid mass in the sludge to be dehydrated is, for example, fibrous or has aeration and water permeability. If present, this solid mass can be adsorbed on the wire net 12 to form the precoat layer 2, or the precoat layer 2 itself can be omitted. Further, although the wire net 12 is stretched in each of the above-mentioned embodiments, it goes without saying that the wire net 12 can be made of punching metal or a sintered alloy. Further, in each of the above embodiments, the negative pressure forming means is a jet pump.
Although it is configured with an MJP, it goes without saying that this can be a negative pressure forming device using a plunger pump or an ejector.

【The invention's effect】

As described above, the dewatering treatment apparatus according to the present invention has the space reducing means provided inside the rotary drum, whereby the negative pressure acting space is a narrow space, and the negative pressure forming means composed of the jet pump is negative. When the pressure is supplied to this narrow negative working space, the negative pressure in the negative working space immediately increases. As a result, the negative pressure acting space can be made small even with a rotating drum having a large diameter in order to increase the adsorption area of the filtering member and enhance the dehydration capacity, and the "rise time" of negative pressure can be greatly shortened. Of. Further, since the negative pressure working space can be formed small even with a large-diameter rotary drum, the negative pressure forming means does not have to have a large capacity, the overall size of the device is not increased, and the initial cost and the running cost are also reduced. There is an advantage that it can be reduced compared to the one. Moreover, in the case where the space reducing means is formed by the cylindrical member whose peripheral surface is located in the vicinity of the filtering member, the space in which the negative pressure acts can be reduced as much as possible, so that the above effect is made more remarkable. There is an advantage that can be done. Furthermore, if the suction port is opened at the lower end of the space reducing means close to the inner surface of the rotating drum, not only can the water sucked into the rotating drum be sucked, but also the sludge liquid in the filtration tank can be sucked. The head difference between the surface position and the suction port can be increased, and if the head difference is increased, sludge can be filtered in the filtration tank even with a weak suction force, and the burden on the negative pressure forming means can be reduced and the size can be reduced. There is also an advantage that you can.

[Brief description of drawings]

The drawings show an embodiment of the present invention, and FIG.
2 is a front view of a rotary drum portion of the dehydration processing apparatus according to the first embodiment, in which a portion is cut away, FIG. 2 is a vertical cross-sectional side view schematically showing the dehydration processing apparatus according to the first embodiment, and FIG. FIG. 4 is a partially cutaway front view of the rotary drum portion, and FIG. 4 is a vertical cross-sectional side view showing the outline of the dehydration treatment apparatus according to the third embodiment. 1 ... Dewatering device, 2 ... Filtering member (precoat layer), 4 ... Rotating drum, 5 ... Sludge, 6 ... Sludge layer,
7 ... Space reducing means, 8 ... Negative pressure acting space, 11 ... Doctor blade, 22 ... Suction tube, 23 ... Suction port, MJP ...
... Negative pressure forming means (jet pump).

Claims (3)

[Claims] 1. A drum having a filter member formed on its peripheral surface is configured to be rotatable while a part of the drum is immersed in sludge in a sludge tank.
A doctor blade is brought into sliding contact with the surface of the rotary drum, and a suction pipe having a suction port opening inside the rotary drum is made to inject high-pressure fluid into the pipe to generate a negative pressure, and the generated negative pressure is taken out. And a space reducing means for reducing the negative pressure working space inside the rotary drum, and the suction port is opened to the peripheral surface portion of the space reducing means. A dehydration treatment device. 2. The dehydration treatment apparatus according to claim 1, wherein the space reducing means is formed of a cylindrical member whose peripheral surface is located near the filtering member. 3. The dehydration treatment apparatus according to claim 1, wherein the suction port is opened at the lower end portion of the space reducing means adjacent to the inner peripheral surface of the rotary drum.