JP7090274B2 - Dehydrator - Google Patents

Description

The present invention relates to a dehydrator, and more particularly to a dehydrator provided with a cleaning device using electromagnetic waves.

Conventionally, a dehydrator such as a belt press dehydrator or a screw press dehydrator has been used for dehydrating sludge or the like.

Then, in the dehydrator, in order to prevent the dehydration efficiency from being lowered due to clogging of the filter body such as a filter cloth or a screen, a cleaning device is provided to clean the filter body. Specifically, for example, in Patent Document 1, a cleaning device that irradiates a filter body immersed in water with ultrasonic waves is used to clean the filter body.

Japanese Unexamined Patent Publication No. 61-12299

However, in the dehydrator equipped with the above-mentioned conventional washing device, the amount of water required for washing the filter body is large. Therefore, there has been a demand for a dehydrator equipped with a cleaning device capable of efficiently cleaning the filter body.

Therefore, an object of the present invention is to provide a dehydrator capable of efficiently cleaning the filter body.

An object of the present invention is to solve the above problems advantageously, and the dehydrator of the present invention is a dehydrator including a filter body used for dehydration of an object to be dehydrated and a cleaning device for the filter body. The cleaning device is characterized by having a liquid supply mechanism for supplying a liquid to the filter body and an electromagnetic wave irradiation mechanism for irradiating the filter body to which the liquid is supplied with an electromagnetic wave. As described above, if the liquid supply mechanism and the electromagnetic wave irradiation mechanism are provided and the filter body after supplying the liquid is irradiated with electromagnetic waves, the filter body can be efficiently cleaned.

Then, in the dehydrator of the present invention, the dehydrator has a dehydration section for dehydrating the dehydrated substance using a filter cloth as the filter body, a peeling section for peeling the dehydrated substance from the filter cloth, and the dehydrated product. It is a belt press dehydrator provided with a cleaning unit for cleaning the filter cloth from which the cloth has been peeled off by the cleaning device, and the electromagnetic wave irradiation mechanism winds the filter cloth so as to surround it in a direction intersecting the traveling direction of the filter cloth. It is preferable to have an electromagnetic wave irradiation unit made of a rotated coil. When the dehydrator is a belt press dehydrator using a filter cloth as a filter, if an electromagnetic wave irradiation mechanism having an electromagnetic wave irradiation part composed of a coil wound around the filter cloth is used, the filter body can be used. The cleaning efficiency of the filter can be further improved by reliably irradiating the filter cloth with electromagnetic waves.

Further, in the dehydrator of the present invention, the dehydrator has a dehydrating section for dehydrating the dehydrated substance using a filter cloth as the filter body, a peeling section for peeling the dehydrated substance from the filter cloth, and the dehydrated product. It is a belt press dehydrator provided with a cleaning unit for cleaning the filter cloth from which the stripped cloth has been peeled off by the cleaning device. It is also preferable to have a bent electromagnetic wave irradiation portion. When the dehydrator is a belt press dehydrator that uses a filter cloth as a filter, use an electromagnetic wave irradiation mechanism that has an electromagnetic wave irradiation part that bends the lead wire in a plane, and filters from the side to which the dehydrated material has adhered. By irradiating the cloth with electromagnetic waves, the filter cloth as a filter can be reliably irradiated with electromagnetic waves to further improve the cleaning efficiency of the filter.

According to the dehydrator of the present invention, the filter body can be efficiently washed.

It is explanatory drawing which shows the schematic structure of an example of the dehydration machine which according to this invention. It is a bottom view which shows the schematic structure of an example of an electromagnetic wave irradiation mechanism. It is sectional drawing which shows the schematic structure of an example of a liquid supply mechanism. It is sectional drawing which shows the schematic structure of another example of an electromagnetic wave irradiation mechanism. It is explanatory drawing which shows the schematic structure of the other example of the dehydrator according to this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The dehydrator of the present invention is not particularly limited, and can be used, for example, for dehydrating sludge such as excess sludge generated when sewage or wastewater is biologically treated.

FIG. 1 shows a schematic configuration of an example of the dehydrator of the present invention. The dehydrator 100 shown in FIG. 1 uses sludge S as a dehydrated substance supplied from a coagulation-mixing tank 30 having a coagulant addition mechanism (not shown) for adding a coagulant such as a polymer flocculant as a filter body. This is a belt press dehydrator that obtains a dehydrated cake DC by dehydrating using the filter cloths 11, 12, and 21. The dehydrator 100 includes a belt press dehydration section 10 that dehydrates sludge S using a belt press, and a preliminary dehydration section 20 that is arbitrarily provided on the front stage side of the belt press dehydration section 10 when viewed in the flow direction of sludge S. have.

The pre-dewatering section 20 is located on the side opposite to the sludge S side with the filter cloth 21 sandwiched between the endless filter cloth 21, a plurality of rollers 22 (four in the illustrated example) for driving and / or supporting the filter cloth 21. A tray 23 for collecting water separated from sludge S carried on the filter cloth 21, a scraping screw 24 for scraping sludge S, and dehydration for dehydrating sludge S scraped by the scraping screw 24. It is equipped with a roller 25. Further, the pre-dewatering unit 20 has a coagulant addition mechanism (not shown) that adds a coagulant such as an inorganic coagulant to the sludge S between the position where the sludge S is supplied from the coagulation mixing tank 30 and the scraping screw 24. ) Further.
At least one of the plurality of rollers 22 is a drive roller. Further, the water collected in the tray 23 can be treated by any treatment method.

Then, in the pre-dewatering unit 20, the sludge S supplied from the coagulation-mixing tank 30 is concentrated by gravity concentration, then a coagulant such as an inorganic coagulant is added, and then the sludge S is scraped by the scraping screw 24. Then, after the sludge S is dehydrated by the dehydration roller 25, it falls downward from the left end in the illustrated example and is supplied to the belt press dehydration section 10 provided under the preliminary dehydration section 20.

The belt press dehydration section 10 includes an endless lower cloth 11 to which sludge S is supplied from the preliminary dehydration section 20, an upper cloth 12 that sandwiches the sludge S together with the lower cloth 11 to dehydrate the sludge S, a lower cloth 11 and an upper cloth. A plurality of rollers (11 in the illustrated example) that drive and / or support the filter cloth 12, and sludge S that is provided on the side opposite to the sludge S side with the lower cloth 11 sandwiched between them and is conveyed on the lower cloth 11. It is equipped with a tray 16 for collecting water separated from the cloth.
At least one of the plurality of rollers 15 that drives and / or supports the lower cloth 11 is a drive roller, and at least one of the plurality of rollers 15 that drives and / or supports the lower cloth 12 is. It is a drive roller. Further, the water collected in the tray 16 can be treated by any treatment method.

Then, in the belt press dehydration section 10, the sludge S supplied from the preliminary dehydration section 20 onto the lower cloth 11 is sandwiched between the lower cloth 11 and the lower cloth 12 and dehydrated. Then, the dehydrated cake DC (dehydrated product) obtained by dehydrating the sludge S is peeled off from the lower cloth 11 at the right end in the illustrated example and falls. That is, in the belt press dehydration section 10, the portion where the sludge S is sandwiched between the lower cloth 11 and the upper filter cloth 12 becomes the dehydration section for dehydrating the sludge S using the filter cloths 11 and 12, and the lower cloth 11 and the upper filter cloth. In the illustrated example, the portion on the right end side after being separated from the filter cloth is the peeling portion for peeling the dehydrated cake DC from the filter cloth. As will be described in detail later, in the belt press dehydration section 10, the dehydration section also functions as a dirt stripping mechanism for stripping dirt from the filter cloth as a filter.

Further, the belt press dehydration section 10 serves as a cleaning device for cleaning the lower cloth 11 and the upper cloth 12 to the liquid supply mechanism for supplying the liquid to the filter and the filter cloths 11 and 12 to which the liquid is supplied from the liquid supply mechanism. It has an electromagnetic wave irradiation mechanism that irradiates electromagnetic waves. Specifically, the belt press dehydration section 10 is provided with a cleaning device having a liquid supply mechanism and an electromagnetic wave irradiation mechanism on the downstream side of the peeling section when viewed in the traveling direction of the filter cloths 11 and 12 indicated by the arrows in FIG. ing.

More specifically, the belt press dehydration unit 10 is a cleaning device for cleaning the lower cloth 11, and is a liquid supply mechanism that supplies a liquid such as water to the surface side of the lower cloth 11 in contact with the sludge S in the illustrated example. A 13A and an electromagnetic wave generator 14A for irradiating the lower cloth 11 with an electromagnetic wave provided on the downstream side (left end side in the illustrated example) of the position where the liquid supply mechanism 13A supplies the liquid to the lower cloth 11 are provided. There is. Further, the belt press dehydration unit 10 serves as a cleaning device for cleaning the lower cloth 12 with a liquid supply mechanism 13B that supplies a liquid such as water to the surface side of the lower cloth 12 in contact with the sludge S in the illustrated example. The liquid supply mechanism 13B is provided on the downstream side (left end side in the illustrated example) of the position where the liquid is supplied to the upper cloth 12, and is provided with an electromagnetic wave generator 14B for irradiating the upper cloth 12 with an electromagnetic wave. There is. Then, in the belt press dehydration section 10, the dirt adhering to the filter cloths 11 and 12 irradiated with the electromagnetic wave after the supply of the liquid is dehydrated when the sludge S is next sandwiched between the filter cloths 11 and 12 and dehydrated. It adheres to and integrates with sludge and is peeled off from the filter cloth. That is, in the belt press dehydration section 10, dirt is peeled off from the portion provided with the liquid supply mechanism 13A and the electromagnetic wave generator 14A, the portion provided with the liquid supply mechanism 13B and the electromagnetic wave generator 14B, and the filter cloth. The dehydrated portion as a stain peeling mechanism serves as a cleaning portion for cleaning the filter cloths 11 and 12 with a cleaning device.

In the dehydrator 100 of this example, the electromagnetic wave generator 14A has a configuration as shown in the bottom view of FIG. That is, the electromagnetic wave generator 14A includes an electromagnetic wave irradiation unit 14a in which a conducting wire is bent in a plane, and an alternating current generator 14b for passing an alternating current through the electromagnetic wave irradiation unit 14a. Further, the electromagnetic wave irradiation unit 14a of the electromagnetic wave generator 14A is arranged on the side of the lower cloth 11 to which the sludge S has adhered. Further, the electromagnetic wave irradiation unit 14a has a portion in which the direction in which the alternating current flows differs by 180 °. As described above, if the electromagnetic wave generator 14A having the electromagnetic wave irradiation unit 14a formed by bending the lead wire in the plane is used, the electromagnetic wave can be reliably irradiated to the lower cloth 11 and the cleaning efficiency of the lower cloth 11 can be further improved. can. In particular, if the electromagnetic wave irradiation unit 14a having a portion where the alternating current flows in different directions by 180 ° is used, the electromagnetic wave can be efficiently irradiated to the lower cloth 11 and the cleaning efficiency of the lower cloth 11 can be further improved.
Since the electromagnetic wave generator 14B used for cleaning the lower cloth 12 has the same configuration as the electromagnetic wave generator 14A used for cleaning the lower cloth 11, detailed description thereof will be omitted below.

Further, in the dehydrator 100 of this example, the liquid supply mechanism 13A has a configuration as shown in FIG. 3 as a cross-sectional view taken along the traveling direction of the lower cloth 11. That is, the liquid supply mechanism 13A includes a pipe 13b having an injection hole (not shown) for injecting water W as a liquid into the lower cloth 11 and a liquid box 13a for collecting the liquid injected into the lower cloth 11. ing.
Since the liquid supply mechanism 13B used for cleaning the lower cloth 12 has the same configuration as the liquid supply mechanism 13A used for cleaning the lower cloth 11, detailed description thereof will be omitted below.

Since the dehydrator 100 includes liquid supply mechanisms 13A and 13B and electromagnetic wave generators 14A and 14B, the liquid (water W) is supplied to the filter cloths 11 and 12 after the dewatered cake DC is peeled off. By irradiating with electromagnetic waves, the filters 11 and 12 as a filter can be efficiently washed with a small amount of liquid.
The reason why the cleaning efficiency can be improved by supplying the liquid to the filter cloths 11 and 12 and irradiating the filter cloth with the electromagnetic wave is not clear, but by irradiating the filter cloth with the electromagnetic wave after supplying the liquid, the cleaning efficiency can be improved. Since the dirt adhering to the filter cloth as a filter can be floated and easily peeled off, the dirt adhering to the filter cloth is dehydrated when the sludge S is sandwiched and dehydrated next time. It is presumed that this is because it adheres to and integrates with sludge and is easily peeled off from the filter cloth.

From the viewpoint of further improving the cleaning efficiency of the filters 11 and 12, as an AC current generator that passes an AC current to the electromagnetic wave irradiation unit in the electromagnetic wave generator, a square wave AC current whose frequency changes with time is used. It is preferable to use an AC current generator to generate an AC current, and a single frequency AC current or an AC current generator to generate two or more single frequency AC currents having different frequencies from each other. It is more preferable to use an AC current generator that generates AC currents of two or more single frequencies having different frequencies from each other. Specifically, the alternating current generator is not particularly limited, and for example, the devices described in JP-A-2011-255345 and JP-A-2013-167160, and "Water Watcher" manufactured by Cyrise Co., Ltd. ] Etc. can be used.

Although the dehydrator of the present invention has been described above using an example, the dehydrator of the present invention is not limited to the above-described configuration.
Specifically, the electromagnetic wave generator may have a configuration as shown in FIG. 4, for example. The electromagnetic wave generator 14A showing a cross section along the width direction of the lower cloth 11 in FIG. 4 surrounds the lower cloth 11 in a direction intersecting the traveling direction of the lower cloth 11 (in the illustrated example, the width direction of the lower cloth 11). It has an electromagnetic wave irradiation unit 14a made of a wound coil. Specifically, the electromagnetic wave generator 14A shown in FIG. 4 is formed by inserting a lead wire into a U-shaped tube 14c arranged so as to sandwich the lower cloth 11 and winding the lead wire so as to surround the lower cloth 11. A coil (electromagnetic wave irradiation unit 14a) and an alternating current generator 14b for passing an alternating current through the electromagnetic wave irradiation unit 14a are provided. As described above, if the electromagnetic wave generator 14A having the electromagnetic wave irradiation unit 14a composed of the coil wound around the lower cloth 11 is used, the lower cloth 11 is surely irradiated with the electromagnetic wave and the lower cloth 11 is washed. The efficiency can be further improved.

Further, the liquid may be supplied to the filter cloth by immersing the filter cloth in a water tank or the like for storing the liquid.

Further, in the above example, the case where the dirt adhering to the filter cloth is attached to and integrated with the sludge to be dehydrated to be peeled off from the filter cloth is shown, but the dirt is contaminated from the filter body irradiated with electromagnetic waves after the liquid is supplied. The dirt peeling mechanism for peeling the cloth can have any configuration. Specifically, the dirt removing mechanism may be, for example, a cleaning liquid injection device that removes dirt from the filter body by injecting the cleaning liquid onto the filter body after supplying the liquid and irradiating with electromagnetic waves. ..

Further, the supply of the liquid and the irradiation of the filter body with electromagnetic waves may be performed from the side opposite to the surface side to which the dehydrated cake DC as a dehydrated product is in contact.

Further, in the above example, the case where the dehydrator is a belt press dehydrator is shown, but the dehydrator of the present invention may be another type of dehydrator. Specifically, the dehydrator of the present invention may be, for example, a screw press dehydrator as shown in FIG. 5 with a cross section in a direction orthogonal to the axis. The dehydrator 200 shown in FIG. 5 includes a screw 210 and a cylindrical screen 220 surrounding the screw 210. The dehydrator 200 also includes a liquid supply mechanism 230 and an electromagnetic wave generator 240 that are movable along the outer circumference of the screen 220. The liquid supply mechanism 230 and the electromagnetic wave generator 240 have the same configurations as the liquid supply mechanism 13A and the electromagnetic wave generator 14A of the above example, except that they can move along the outer periphery of the screen 220, respectively. , The explanation is omitted. Then, in the dehydrator 200, the liquid can be ejected from the liquid supply mechanism 230 to the screen 220 as a filter body, and the screen 220 can be irradiated with electromagnetic waves from the electromagnetic wave generator 240. Therefore, the screen 220 as a filter body can be efficiently cleaned.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)
Using a belt press dehydrator (filter cloth width: 1 m) having the configuration shown in FIG. 1, digested sludge is sprayed with water and irradiated with electromagnetic waves to the filter cloth from which the dewatered product (dehydrated cake) has been peeled off. Was dehydrated.
For dehydration, digestive sludge concentration: 2%, treatment amount: 3 m ³ / hour, polymer flocculant addition rate: 1.7%, polyferric sulfate addition rate: 20%, operation time: 7 hours / day. , Number of driving days: The condition was 4 days.
Then, the water content of the dehydrated cake and the peelability of the dehydrated cake were evaluated. The results are shown in Table 1.

(Comparative Example 1)
The digested sludge was dehydrated in the same manner as in Example 1 except that the irradiation with electromagnetic waves was not performed.
Then, the water content of the dehydrated cake and the peelability of the dehydrated cake were evaluated. The results are shown in Table 1.

＜剥離性の評価基準＞
「◎」：ろ布に付着物が残らず脱水ケーキの剥離性が非常に良い。
「○」：ろ布に時々付着物が残る。

<Evaluation criteria for peelability>
"◎": No deposits remain on the filter cloth, and the dewatering cake has very good peelability.
"○": Occasionally deposits remain on the filter cloth.

From Table 1, it can be seen that in Example 1 irradiated with electromagnetic waves, the water content of the dehydrated cake is lowered and the peelability of the dehydrated cake is improved as compared with Comparative Example 1 not irradiated with electromagnetic waves.

According to the dehydrator of the present invention, the filter body can be efficiently washed.

10 Belt press dehydration part 11 Lowering cloth 12 Lowering cloth 13A, 13B Liquid supply mechanism 13a Liquid box 13b Piping 14A, 14B Electromagnetic wave generator 14a Electromagnetic wave irradiation part 14b AC current generator 14c U-shaped tube 15 Roller 16 Tray 20 Preliminary dehydration part 21 Filter cloth 22 Roller 23 Tray 24 Scraping screw 25 Dewatering roller 30 Coagulation mixing tank 100,200 Dewatering machine 210 Screw 220 Screen 230 Liquid supply mechanism 240 Electromagnetic wave generator S Sludge DC Dewatering cake W Water

Claims (3)

A dehydrator provided with a filter body used for dehydrating the object to be dehydrated and a cleaning device for the filter body.
The cleaning device has a liquid supply mechanism for supplying a liquid to the filter body and an electromagnetic wave irradiation mechanism for irradiating the filter body to which the liquid is supplied with electromagnetic waves.
The dehydrated product is sludge.
The electromagnetic wave irradiation mechanism includes an electromagnetic wave irradiation unit and an alternating current generator that allows an alternating current to flow through the electromagnetic wave irradiation unit, and the electromagnetic wave irradiation unit is a coil formed by winding a conductor wire or a wire bent in a plane . It is an electromagnetic wave irradiation part
The dehydrator has a dehydration section in which the dehydrated object is sandwiched between an endless lower cloth and an endless lower cloth as a filter to dehydrate, a peeling section for peeling the dehydrated substance from the lower cloth, and the dehydrated product. It is provided with a lower cloth from which the dehydrated material has been peeled off and a cleaning unit for washing the upper filter cloth with the cleaning device, and the dirt adhering to the lower cloth and the upper filter cloth from which the dehydrated product has been peeled off is supplied with the liquid by the cleaning device. A dehydrator, which is a belt press dehydrator that adheres to and integrates with the dehydrated object that is dehydrated when the dehydrated object is sandwiched between the dehydrated portions and is separated from the filter cloth after irradiation with electromagnetic waves. The dehydrator according to claim 1, wherein the electromagnetic wave irradiation mechanism has an electromagnetic wave irradiation unit including a coil wound around the filter cloth in a direction intersecting the traveling direction of the lower cloth and the upper filter cloth. The dehydrator according to claim 1, wherein the electromagnetic wave irradiation mechanism has an electromagnetic wave irradiation portion in which a lead wire is bent in a plane on the side of the lower cloth and the upper cloth to which the dehydrated material is attached.

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