JPH11300400A - Mobile sludge dehydrating car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a lightweight dehydrating machine and to improve the dehydration efficiency by preparing a flocculant liquid in a chemical liquid dissolving tank to be mixed to a sludge, mixing and agitating the flocculant liquid to a sludge in a reaction tank to produce floc, and dehydrating the liquid content in the floc in a screw-type dehydrating machine. SOLUTION: A specified amt. of water and a cationic flocculant is mixed and stirred in a first chemical liquid dissolving tank 22 to prepare a cationic flocculant liquid. A specified amt. of water and an anionic flocculant is mixed and stirred in a second chemical liquid dissolving tank 23 to prepare an anionic flocculant liquid. The cationic flocculant liquid is supplied to a first reaction tank 34 to mix with a sludge. The suspended material,produced in the sludge by the reaction is sent with the sludge to a second reaction tank 35. Then the anionic flocculant is supplied to the second reaction tank 35 to mix with the suspended material. Thus, a large amt. of floc is produced in the sludge. Then the floe is sent to a screw-type dehydrating machine 16 to be dehydrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile sludge dewatering vehicle, and more particularly to a mobile sludge dehydration vehicle which moves between sites by a vehicle.
The present invention relates to a mobile sludge dewatering vehicle that effectively dewaters organic sludge (including oil such as grease traps of industrial waste) and inorganic sludge.

[0002]

2. Description of the Related Art In recent years, the spread of sewerage nationwide has shown that sewerage, which had been limited to large metropolitan areas, has shifted from middle cities to small cities, and to agricultural, mountainous and fishing villages with relatively few households. It is expanding up to. With such small populations, small cities and rural areas require only small-scale facilities to treat sewerage. Small-scale treatment facilities are usually provided with small-scale combined treatment septic tanks for treating night soil and household wastewater together. This combined treatment septic tank is of a batch type. That is, when a predetermined amount of sludge accumulates,
This must be removed and disposed of at a final disposal facility for incineration or burial. In this case, the sludge taken out of the tank is passed through a dehydrator to form a dewatered cake in consideration of the economics of final disposal. The sludge that has become a dewatered cake has a small volume and is lightweight. Further, the water content is small and the flammability is good. As a result, transportation costs and final disposal costs are reduced. Handling becomes easy.

[0003] As a final disposal method of sludge, incineration at a refuse incineration plant and burial at a final disposal site are common. Until recently, sludge was dumped in the ocean. However, in the year 2000, the Act on the Prohibition of Sludge Dumping into the Ocean is enforced. Due to this, dumping into the ocean has been avoided in recent years. By the way, a dehydrator is relatively expensive. Therefore, it is not economically feasible to permanently install it in small-scale sludge treatment facilities in various places. To solve this problem, for example, a sludge dewatering vehicle disclosed in JP-A-58-164843 and a sludge dewatering vehicle disclosed in JP-A-3-275830 are known. These are mobile dewatering equipments in which a dewatering machine is mounted on the bed of a vehicle and travels between small-scale treatment facilities in various places to dewater sludge accumulated in the septic tank at each site.

[0004] The former is a dewatering vehicle equipped with a belt press type dewatering machine that wraps two endless filter cloths between rolls and pressurizes and dewaters sludge. By sandwiching sludge between two endless filter cloths, the water therein is dehydrated under pressure. The latter is a dehydrator equipped with a multiple disc dehydrator. The multi-disc dehydrator is a dehydrator having the following structure. That is, a large number of filter bodies each having a large or small disk fitted on the rotary shaft at a constant pitch are prepared, and these filter bodies are divided into an upper-stage filter body group and a lower-stage filter body group. And it has a structure in which these are assembled to the outer casing of the dehydrator. The upper and lower filter bodies are arranged on the outer casing such that the interval gradually decreases in the sludge discharge direction. When sludge is passed between the upper and lower filter bodies, moisture in the sludge is squeezed out from the gap between the large and small disks of the adjacent filter bodies, and finally becomes a dewatered cake.

[0005]

By the way, as described above, in the case of the former prior art, several heavy rotating shafts are incorporated inside the dehydrator. Therefore, the center of gravity of the vehicle is moving upward as compared to when the vehicle is not mounted. As a result, there is a problem in stability during running of the vehicle. To solve this, shorten the rotating shaft,
It is conceivable to reduce the weight of the dehydrator. However,
In such a case, the filtration width becomes short, and another problem that the dewatering ability is reduced occurs.

There is also a problem in the latter case of the prior art provided with a multi-disc dehydrator. That is, in ordinary dewatering, the dewatering property of sludge is emphasized, and the rotation speed of each filter is set to a very low speed. As a result, there is a problem that the dehydration time becomes longer. Therefore, it is conceivable to simply increase the rotation speed of the filter. However, the multi-disc dehydrator has an upper and lower filter group in which the distance between each other becomes narrower toward the downstream side. As a result, even if the rotation speed of the filter is increased, the dehydration speed does not basically increase so much. And if you forcibly increase the rotation speed,
There was also a risk of damage to the device, such as overloading the filter body downstream of the dehydrator, causing warpage of the rotating shaft. On the other hand, many filter bodies incorporated in the outer casing are arranged with a slight gap therebetween. For this reason, even at the time of normal dehydration, sludge was easily caught in a narrow gap between large and small discs facing each other in a staggered manner in the relationship between adjacent filter bodies. As a result, clogging of sludge is likely to occur, and in order to avoid this, the time for cleaning the dehydrator has been long. Therefore, there is a problem that the dewatering efficiency per unit time is further reduced.

[0007]

An object of the present invention is to provide a mobile sludge dewatering vehicle capable of simultaneously reducing the weight of a dewatering machine, improving the dewatering efficiency, shortening the dewatering time, and eliminating sludge clogging during dewatering. Its purpose is to provide. Another object of the present invention is to provide a mobile sludge dewatering vehicle capable of improving the dewatering properties of flocs and compactly mounting a dewatering facility on a vehicle bed.

[0008]

According to the first aspect of the present invention, there is provided a chemical solution dissolving tank for producing an agglomerated liquid which is stirred and mixed into sludge, and a flocculant produced in the chemical solution dissolving tank is formed in the sludge. A mobile sludge dewatering vehicle equipped with a reaction tank that mixes and agitates to generate floc, which is an agglomerate of sludge, and a screw type dehydrator that dewaters the liquid contained in the floc, and these are mounted on the bed of a vehicle It is. What is sludge?
It refers to various types of organic sludge and inorganic sludge. Specific examples of the organic sludge include, for example, sewage sludge (small-scale sewage sludge, etc.), sanitation center sludge (excess, digestion, mixing, septic tank sludge, etc.), agricultural / fishing village collection fall water (excess, first settling, mixed sludge, etc.), Fishery processing sludge (pressurized floating scum, surplus sludge, etc.), meat processing sludge (pressurized floating scum, surplus sludge, etc.), food and beverage industry sludge (pressurized floating scum, surplus sludge, etc.), chemical industry sludge ( Pressurized flotation scum, surplus sludge, etc.), livestock sludge, industrial waste sludge, and the like. Further, specific examples of the inorganic sludge include, for example, earth and sand settled in a dam. In particular, since the screw-type dehydrator is employed in this manner, highly viscous sludge such as sludge having a high concentration of biochemical oxygen demand (BOD) can be satisfactorily dewatered.

The main components of the flocculant are, for example, a cationic polymer flocculant (hereinafter referred to as a cationic flocculant), an anionic polymer flocculant (hereinafter referred to as an anionic flocculant), a nonionic polymer flocculant ( Hereinafter, referred to as a nonionic coagulant). These coagulants are used according to the type and concentration of sludge to be treated. That is, it is dissolved in a predetermined amount of water in the chemical solution tank. The shape and size of the chemical solution tank are not limited. Usually, when producing a flocculant in this chemical solution dissolving tank, a stirrer for stirring and mixing the flocculant with water is used. Further, for example, the number of chemical solution tanks mounted on one dehydration vehicle is not limited. Tanks for a plurality of types of flocculants may be mounted respectively. Furthermore, a tank for coagulation liquid of the same type may be provided with not only a tank for actually producing coagulation liquid but also a chemical storage tank for storing the completed coagulation liquid. If this chemical storage tank is used, a flocculant to be used next is produced in the chemical dissolution tank while floc is being generated in the reaction tank, and the produced flocculant is stored in the chemical storage tank. You can keep it. That is, flocs can be generated in the reaction tank at all times without waiting for the preparation of the coagulation liquid.

The shape and size of the reaction tank are not limited. The reaction tank is preferably provided with a stirrer for stirring and promoting the reaction between the flocculated liquid and the sludge.
Then, for the floc generation of sludge, a two-stage reaction, that is, first suspending sludge in advance with a cationic coagulation liquid,
Next, it is preferable to adopt a reaction type in which floc is generated from this suspension in full-scale with an anionic flocculant because a relatively large amount of floc can be generated from sludge. In the screw dehydrator, for example, a screw having a shaft whose diameter gradually increases toward the downstream side is arranged in a mesh cylinder. By rotating the screw, the water in the sludge is filtered off from the mesh of the cylinder while gradually moving the sludge supplied into the cylinder to the downstream. The type of the screw dehydrator used and the number of used dehydrators are not limited. Vehicles here include trucks,
Trains and the like. However, a space for mounting various types of dewatering equipment must be provided on the loading platform or its equivalent. Note that a track is preferable in terms of the movement range. In particular, a car less than a 5-ton car that can be driven with a normal license is preferable.

[0011] The invention according to claim 2 is that the floc discharge part provided in the reaction tank and the floc supply part provided in the screw type dehydrator are moved into the supply part by natural flow of the flocs. An unloading conveyor connected to the inclined supply pipe for supplying the sludge dewatered cake discharged from the dewatering device is disposed in an internal space of a gantry supporting the screw dewatering device. 2. The mobile sludge dewatering vehicle according to 1. The discharge part of the floc of the reaction tank is not limited as long as it is provided at a position where the floc can be discharged from the tank. For example, a discharge pipe that is provided at the upper part of the tank and discharges the overflowed floc may be used. If the supply unit of the screw dehydrator can receive the floc that has naturally flowed down from the reaction tank, it may be temporarily stored in a floc supply tank, or may be supplied directly into the dehydration unit. The height position of the inclined supply pipe at the end on the screw type dehydrator side is slightly lower than the height position at the end on the reaction tank side. The inclination angle is not limited,
For example, several degrees to 60 degrees are preferable. The greater the angle of inclination, the greater the drop impact of the flocs flowing into the supply section of the screw type dehydrator, and the more easily the flocs are broken. As a result, dehydration by the screw dehydrator is reduced. Examples of the unloading conveyor here include a belt conveyor, a roller conveyor, and a bucket conveyor. There is no limitation on the type. Also, the number of conveyors used is not limited. For example, only one long conveyor may be used. Further, a plurality of short conveyors may be connected and used.

[0012]

According to the present invention, a flocculant is prepared by mixing a flocculant and water in a chemical solution tank. It is put into a reaction tank, where it is mixed with sludge. as a result,
Flock is generated from sludge. Thereafter, the flocs are sent to a screw dehydrator to be dehydrated. In this way, the sludge from which the contained water is removed is a dewatered cake having a relatively small volume. Since a screw type dehydrator is used as the dehydrator, the dehydrator becomes lighter in weight than, for example, a conventional belt press type or multi-disc type dehydrator. For this reason, the dehydration equipment can be mounted on a vehicle having a smaller total weight. In addition, the screw type dehydrator has better dehydration efficiency than these conventional dehydrators. The time required for dehydration is also relatively short. Moreover, unlike the multi-disc type, the filter does not have a filter body in which large and small discs that are easily clogged are mounted on the rotating shaft, so that clogging of the dewatering unit hardly occurs.
Even if clogged, the dewatering machine has a simple structure in which a screw is rotatably inserted into the cylinder, so it is easy to clean.

[0013] In particular, according to the second aspect of the present invention, the floc generated in the reaction tank is supplied from the discharge part thereof to the supply part of the screw dehydrator by gravity flow through an inclined supply pipe. Thereby, the drop impact of the floc is reduced as compared with, for example, the case where the floc is dropped vertically into the supply section of the screw type dehydrator. This allows
Flock lump is hard to break. As a result, dehydration by the screw dehydrator is enhanced. In addition, an unloading conveyor for unloading the dehydrated cake is provided in the internal space of the mount of the screw dehydrator. Therefore, after dehydration, the dewatered cake discharged from the screw type dehydrator,
It is dropped into the conveyor immediately below, and then carried out in the direction of the length of the dehydrator. In this way, because the conveyor for unloading was placed inside the gantry of the screw dehydrator,
The dewatering equipment can be mounted compactly on the bed of the vehicle.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a mobile sludge dewatering vehicle according to one embodiment of the present invention. FIG. 2 is a plan view of a mobile sludge dewatering vehicle according to one embodiment of the present invention. FIG.
1 is a rear view of a mobile sludge dewatering vehicle according to one embodiment of the present invention. FIG. 4 is a sectional view taken along line S4-S4 of FIG. FIG. 5 is an enlarged front view of the chemical solution preparation unit. FIG. 6 is an enlarged plan view of the chemical solution preparation unit. FIG. 7 is an enlarged side view of the chemical solution preparation unit.

In FIG. 1 to FIG. 4, reference numeral 10 denotes a mobile sludge dewatering vehicle according to an embodiment of the present invention. The mobile sludge dewatering vehicle 10 is a four-ton truck (vehicle) 11 that can be operated with a normal automobile license. The bed 12 is equipped with sludge dewatering equipment. This dewatering facility is covered with a pan-shaped gull wing hood 13 that can open the side surface of the carrier 12 even in a relatively small parking lot. The dehydration equipment includes a chemical liquid producing section 14 for producing a flocculated liquid to be stirred and mixed into sludge, a reaction section for stirring and mixing the flocculated liquid produced in the chemical liquid producing section 14 and the sludge to be treated to generate flocs. 15, a screw type dehydrator 16 for dewatering the floc discharged from the reaction unit 15, a belt conveyor (conveyance conveyor) 17 for discharging the dewatered cake obtained by the dehydration process to the outside, and sludge (raw water). A slurry pump 18 for pumping to the reaction section 15;
Pump 19 for cleaning the inside of the chamber with a jet water stream
, A generator 20 and a control panel 21 containing a control unit for controlling the entire apparatus. Hereinafter, these configurations will be described in detail.

As shown in FIG. 5 to FIG.
Is mounted on the driver's seat side end of the carrier 12. The chemical solution producing section 14 mainly includes an upper chemical solution dissolving section 14A for producing an aggregate liquid and a lower chemical liquid storage section 14B for storing the produced aggregate liquid. The chemical solution dissolving portion 14A and the chemical solution storage portion 14B are vertically divided by a partition plate 14a extending in the horizontal direction. The inside of the chemical solution dissolving part 14A is provided with a partition plate 14 extending in the vertical direction.
b separates into two rooms. One room is a first chemical solution dissolving tank 22 for dissolving the cationic coagulant,
The other room is a second chemical solution dissolution tank 23 for dissolving the anionic coagulant. Both dissolving tanks 22 and 23 have open upper surfaces. In addition, both melting tanks 22 and 2
3, a small stirrer 25 is attached via a fixing jig 24 to the upper end of the partition plate 14b. In addition, 25a is a stirring blade. Furthermore, at the upper end of the corner on the back side of both melting tanks 22 and 23,
A pair of injection nozzles 26 for flowing a cationic or anionic coagulant along the tank back surface to the liquid level into the tank are provided. The coagulant outlet formed at the lower end of each injection nozzle 26 is directed toward the inner surface of the tank side plate by bending the lower part of the nozzle. A concave portion 14c having a U-shape in plan view is bent at the center of the side plate on the front side of the chemical solution dissolving portion 14A.

The chemical storage section 14B mainly includes a first chemical storage tank 27 disposed directly below the first chemical liquid dissolving tank 22, and a second chemical liquid storage tank 27 disposed directly below the second chemical liquid dissolution tank 23. And a chemical storage tank 28. The storage tanks 27 and 28 are partitioned by a partition plate 14d extending in the vertical direction. At the bottoms of both storage tanks 27 and 28, discharge ports 27a and 28a and drains 27b and 28b for the coagulated liquid are provided with a slight step. Further, the partition plates 14a constituting the upper plates of both storage tanks 27, 28 are provided with opening / closing lids 27c, 28c that slide in the horizontal direction at portions exposed by the formation of the recesses 14c. Open / close lid 27c
Is a lid that opens and closes an air flow opening formed in the upper part of the first chemical liquid storage tank 27. Also, the other opening / closing lid 28c
Is a lid that opens and closes an air circulation port formed in the upper part of the second chemical liquid storage tank 28.

On the other hand, each opening / closing lid 27c of the partition plate 14a,
A discharge pipe 27d for dropping the cationic coagulant of the first chemical solution tank 22 into the first chemical solution storage tank 27 and a second chemical solution tank 23
And a discharge pipe 28d for dropping the anionic coagulant into the second chemical liquid storage tank 28 located immediately below. In the middle of both discharge pipes 27d and 28d,
Valves 27e and 28e are provided. Therefore,
The coagulant of each system is stored in the storage tank 2
7 and 28, when the operator opens and closes the lid 27c,
The cover 28c is opened, the hands are reached into the storage tanks 27, 28 from the respective air circulation ports opened thereby, and the valves 27e, 28e of the discharge pipes 27d, 28d are opened. Thereby, the coagulated liquid of each system produced in the dissolution tanks 22 and 23 is dropped into the storage tanks 27 and 28.

In FIGS. 5 to 7, reference numeral 29 denotes a handrail, reference numeral 30 denotes a pair of mounting plates on which the injection nozzles 26 are mounted, and a pair of mounting plates 31 are mounted on the upper ends of the melting tanks 22 and 23. Attached to the mounting plate 30 of
This is a liquid level sensor that detects the height of the liquid level of the cationic coagulation liquid that has been put into the first chemical liquid dissolution tank 22. 32 is
The liquid level sensor is attached to the other attachment plate 30 and detects the level of the liquid level of the anionic coagulation liquid supplied to the second chemical liquid dissolution tank 23.

Next, the sludge reaction section 15 will be described in detail with reference to FIGS. FIG. 8 is an enlarged front view of the reaction section. As shown in FIG. 1 and FIG.
Reference numeral 5 is disposed on one side in the vehicle width direction, close to the chemical solution preparation unit 14 on the loading platform 12. As shown in FIG. 8, the reaction unit 15 is mainly mounted on a gantry 33 and is configured to form a first reaction tank 34 for stirring and reacting sludge and a cationic coagulant with a cationic coagulant. It comprises a second reaction tank 35 for stirring and reacting the suspension obtained by the reaction with the anionic coagulation liquid. The two reaction tanks 34 and 35 are defined by a partition plate 36 extending in the vertical direction. In the lower part of the partition plate 36,
A relatively large circulation port 36a for moving the suspension generated in the first reaction tank 34 into the second reaction tank 35 is formed.

The upper portions of the two reaction tanks 34 and 35 are open. Here, a small stirrer 39 is mounted via a pair of parallel frames 37. Each stirrer 39 has a drive motor 3
The stirring blade 39a is accommodated in each of the reaction tanks 34 and 35 with the height of the stirring blade 39a kept low. A discharge pipe (discharge unit) 40 for discharging generated flocs to the outside by overflow is connected to one side plate of the upper end of the second reaction tank 35. Liquid level sensors 50 and 51 are provided in the first and second reaction tanks 34 and 35, similarly to the dissolution tanks 22 and 23. A drain 41 extending across the two reaction tanks 34 and 35 is provided vertically at a joint between the bottom plates of the two reaction tanks 34 and 35. A valve 42 is provided in the middle of the drain 41.

Next, a washing tank 43 for storing washing water supplied to the washing pump 19 is accommodated in the space between the columns of the gantry 33. As the cleaning pump 19, an Ebara MMLF type barrel motor pump (manufactured by Ebara Corporation) capable of jetting cleaning water at a high speed (250 liter / m) is employed. In addition, in the space between the columns, a first metering pump 44 for pumping the cationic coagulation liquid stored in the first storage tank 27 to the first reaction tank 34, and a second storage tank 28 A second metering pump 45 for pumping the anionic coagulation liquid stored in the second reaction tank 35 to the second reaction tank 35 is also housed. In FIG. 8, reference numeral 46 denotes a liquid level sensor in the cleaning tank 43;
Reference numeral 7 denotes a ball tap, reference numeral 48 denotes a discharge port for the cleaning liquid, and reference numeral 49 denotes a level gauge.

Next, the screw type dehydrator 16 will be described in detail with reference to FIGS. FIG. 9 is an explanatory diagram of a screw type dehydrator. As shown in FIGS. 1 to 4, the screw type dehydrator 16 is a main component of a dewatering unit that dewaters sludge (flock), and extends in the vehicle length direction from the center to the rear of the bed 12. Here, the solution S whose sludge treatment amount is (40-60 kg · ds / h)
X-3 (manufactured by Sekisui Environment Co., Ltd.) is employed. The screw type dehydrator 16 is mounted on a gantry 52 having a relatively low height. The gantry 52
The belt conveyor 17 extending in the same direction as the screw dehydrator 16 is accommodated in the space between the columns.

As shown in FIG. 1, FIG. 2 and FIG. 9, the screw type dehydrator 16 mainly comprises a horizontally long outer casing 53 having a rectangular cross section, and a cylindrical filtering structure housed in the outer casing 53. (Barrel) 54 which is
Screw 70 which is housed in
And a floc supply tank (supply unit) 55 provided on one end of the outer casing 53 for storing flocs, and provided below the barrel 54 to receive the filtrate and drain it from a drain 56a. And a drive unit 57 having a drive motor 57a. As shown in FIG. 9, the barrel 54 is formed by connecting a large number of wedge wires 54a having an inverted triangular cross section (see an enlarged view of a part of FIG. 9) 54a at an extremely short pitch in an annular manner. , A plurality of filtration structures connected along the axis of the barrel 54. Each wedge wire 54a is
The blade is a blade whose width gradually narrows outward in the radial direction of the barrel 54. Therefore, the adjacent wedge wire 54a
The gap between them widens outward. As a result, clogging during the dewatering of floc is unlikely to occur. Moreover, the filtration speed is higher than that of the above-mentioned conventional dehydrator. In addition, the processing amount is large, and the recovery rate of the dewatered cake is high.

The screw 70 has a shaft 71 whose diameter gradually increases as it proceeds downstream. This shaft 71
The spiral blade 72 is provided around the outer peripheral surface of the spiral blade 72. Spiral blade 7
The upstream part of 2 has a relatively long helical pitch. The floc supply tank 55 is a closed tank and is arranged at a position close to the side of the reaction unit 15. The floc supply tank 55 and the discharge pipe 40 of the second reaction tank 35 are connected via an inclined supply pipe 58 that allows the flocs to flow naturally into the floc supply tank 55 (see FIG. 4). A liquid level sensor 59 for detecting the liquid level of sludge containing flocs is attached to the floc supply tank 55.

The drive section 57 has a chain type power transmission system 60 in which a chain is hung between sprockets housed in a casing. The drive motor 57a is mounted on one side of the gantry 52. The torque of the drive motor 57a is transmitted to the screw 70 via the speed reducer 61 and the chain type power transmission system 60. As a result, the flock in the flock supply tank 55 is gradually cut out by the spiral blade 72. Thereafter, the flock passes through a flock transfer path 73 which is a space between the shaft body 71 whose diameter gradually increases and the barrel 54 having the same diameter over the entire length. At this time, the floc is gradually dehydrated.

That is, the floc transfer passage 73 is a passage whose passage area gradually decreases as it proceeds downstream. By passing here, the floc is gradually compressed from the inside and outside directions, and the moisture in the floc is removed from the barrel 54.
From the very narrow slit between the wedge wires 54a. At the downstream end of the barrel 54, a plurality of dewatering rings 74 for applying a brake to the flock and increasing the internal pressure of the flock transfer path 73 are provided. By these dewatering rings 74, the moisture in the flocks is filtered well. Thereafter, the sufficiently dewatered dewatered cake is discharged from the discharge port at the end of the dewatering ring 74. The dewatering power of the screw dewatering machine 16 can be adjusted by changing the number of dewatering rings 74 used. Further, the discharged dewatered cake falls on the belt conveyor 17 and passes directly below the screw type dewatering machine 16 to the loading platform 1.
2 is taken out.

If the barrel 54 is clogged during dehydration, the cleaning water in the cleaning tank 43 is sprayed at high speed onto the outer peripheral surface of the barrel 54 by using the cleaning pump 19. This washing may be performed at regular intervals by a timer control while the dewatering equipment is operating. In this mobile sludge dewatering vehicle 10, when viewed in plan,
A scaffold 75 is provided so as to surround the flock supply tank 55. On this scaffold 75, handrails 76 are provided at important points. Since the scaffold 75 is provided, for example, when an operator checks the inside of the dissolution tanks 22 and 23 and the reaction tanks 34 and 35 and cleans them, it is relatively easy and safe to work. it can.

Next, the operation of the mobile sludge dewatering vehicle 10 according to this embodiment will be described. FIG. 10 is a flow sheet showing a use state of the mobile sludge dewatering vehicle. As shown in FIGS. 1 and 2, when the mobile sludge dewatering vehicle 10 arrives at the site,
The gull wing hood 13 is moved to open the side surface of the carrier 12 to expose the dewatering equipment. At this time, as shown in FIG. 10, outside the vehicle, for example, sludge (raw water) in a small-sized combined treatment septic tank (not shown) is removed using a slurry pump 80.
It is sucked into the sludge treatment standby tank 81. In addition, the other end of the sludge suction pipe 82 having one end connected to the slurry pump 18 is inserted into the sludge treatment standby tank 81. Further, air for bubbling sludge is supplied into the sludge treatment standby tank 81.

Next, the chemical liquid preparation section 14 prepares a cationic flocculant and an anionic flocculant suitable for sludge treatment. Prior to this production, the water quality of sludge is inspected. This is for performing a chemical solution treatment adapted to the on-site sludge. The two coagulation liquids are prepared based on the sludge data at the time of the water quality inspection. Specifically, a predetermined amount of water and a cationic coagulant are stirred and mixed in the first chemical solution dissolving tank 22. Further, in the second chemical solution dissolution tank 23,
A predetermined amount of water and an anionic coagulant are mixed with stirring. A small stirrer 25 is used for each stirring. The thus prepared cation-based and anion-based flocculants are dropped into first and second storage tanks 27 and 28 immediately below the respective dissolution tanks 22 and 23. As shown in FIG. 7, this dropping operation is performed by firstly
7c and 28c are opened to open the air circulation port. Thereafter, the two storage tanks 2 are opened from the open / close lids 27c and 28c.
This is achieved by reaching hands 7, 28 and opening valves 27e, 28e. The open / close lids 27c and 28c remain open until the respective coagulation liquid is completely dropped. This allows the internal air in the storage tanks 27 and 28 to be exhausted without being forcedly exhausted by an expensive vacuum device or the like.
It is possible to prevent inconveniences such as poor dropping of each coagulating liquid and deformation of the tank due to an increase in the internal pressure of the sealed tank due to dropping of the chemical solution.

Next, a method of generating flocs from sludge by the reaction section 15 will be described. As shown in FIG. 10, the sludge supplied from the sludge treatment standby tank 81 to the first reaction tank 34 via the slurry pump 18 is supplied from the first storage tank 27 by the first metering pump 44 here. The resultant mixture is stirred and mixed with a predetermined amount of the cationic coagulation liquid. A stirrer 39 is used for this stirring and mixing. This mixing produces a suspension in the sludge. The suspended matter, together with the sludge flowing in the tank, flows through the distribution port 36 below the partition plate 36.
a, and moves to the second reaction tank 35. Note that a small amount of the suspension moves to the second reaction tank 35 over the partition plate 36 whose height from the liquid level is relatively low. A predetermined amount of the anionic coagulant in the second storage tank 28 is supplied into the second reaction tank 35 via the second metering pump 45. Then, the stirrer 39
, The suspension and the anionic coagulation liquid are stirred and mixed. As a result, a large amount of floc is generated in the sludge. The floc generated in this way is discharged
Is supplied to the floc supply tank 55 through the inclined supply pipe 58 by natural flow. Thus, for example, the drop impact is smaller than when the flock is vertically dropped into the flock supply tank 55. Therefore, the flock when it reaches the flock supply tank 55 is not relatively collapsed. Therefore, the dehydration by the screw type dehydrator 16 is enhanced.

Thereafter, a dehydration process is performed by the screw type dehydrator 16. That is, as shown in FIG. 9, the floc passes through the floc transfer path 73 in which the passage area gradually decreases as it proceeds downstream, so that the moisture in the floc is filtered from the slit between the wedge wires 54 a of the barrel 54. Taken. At this time, a brake is applied to the flock passing through the flock transfer path 73 by the dewatering ring 74 at the downstream end of the barrel 54. Therefore, the moisture of the floc is filtered well. Thus, the dewatering ring 74
The dewatered cake that has been sufficiently dehydrated is discharged from the discharge port of. Then, the dewatered cake is discharged to the outside of the truck 11 by the belt conveyor 17. In addition, various tanks 22, 23, 34, 35, 43,
The liquid stored in 55 is supplied to the corresponding liquid level sensor 31,
The height is always detected by 32, 46, 50, 51, 59. The control unit in the control panel 21 controls the overall operation of the dewatering facility based on the detection signals sent from these sensors.

In particular, as shown in FIG.
When the control unit 9 detects that the flocs in the floc supply tank 55 are full, a command is issued from the control unit, and each operation in the preparation process of the cation-based and anion-based flocculants and each operation in the floc generation process are performed. Work is suspended. The operation is restarted when the dehydration process by the screw type dehydrator 16 proceeds and the liquid level in the floc supply tank 55 drops to a predetermined height. Also, during dehydration, the barrel 54
When clogging occurs, cleaning water in the cleaning tank 43 is sprayed at high speed onto the outer peripheral surface of the barrel 54 by the cleaning pump 19 for cleaning. Since the cleaning pump 19 is a high-output pump, foreign matters clogged in the slits between the wedge wires 54a can be satisfactorily blown off for cleaning. In FIG. 10, reference numeral 83 denotes a valve. 84
Is an electromagnetic valve.

As described above, since the screw type dehydrator 16 is employed as the dehydrator, the weight is reduced as compared with, for example, a conventional belt press type or multi-disc type dehydrator. As a result, the dewatering equipment can be mounted on a truck having a smaller total weight. Further, since the screw type is used, the dewatering efficiency is higher than that of the conventional device, and the time required for dewatering can be relatively shortened. further,
For example, clogging of the dewatering section is less likely to occur than in a conventional multi-disc dehydrator. In addition, even if the clogging is performed, the dehydrator has a simple structure in which the screw 70 is stored in the barrel 54, so that the dewatering machine can be easily cleaned.
From the above, the mobile sludge dewatering vehicle 10 of this embodiment is
Is a mobile dewatering equipment that can simultaneously satisfy the requirements of reducing the weight of the dehydrator, improving the dewatering efficiency, shortening the dewatering time, and eliminating sludge clogging during dewatering. Since the storage tanks 27 and 28 are disposed immediately below the melting tanks 22 and 23, and the belt conveyor 17 is disposed in the gantry 52 of the screw type dehydrator 16, the loading platform 1 of the truck 11 is provided.
2, the dewatering equipment can be mounted compactly.

[0035]

According to the present invention, a screw type dehydrator is used as a dehydrator for sludge, so that the dehydrator can be reduced in weight, the dehydration efficiency can be improved, the dehydration time can be shortened, and sludge clogging during dehydration can be prevented. And can be satisfied at the same time.

In particular, according to the second aspect of the present invention, since the discharge part of the floc of the reaction tank and the supply part of the floc of the screw dehydrator are connected by the inclined supply pipe, the dewatering property of the floc is improved. Can be enhanced. In addition, since the unloading conveyor is arranged in the internal space of the mount of the screw type dehydrator, the dehydration equipment can be compactly mounted on the cargo bed of the vehicle.

[Brief description of the drawings]

FIG. 1 is a side view of a mobile sludge dewatering vehicle according to one embodiment of the present invention.

FIG. 2 is a plan view of a mobile sludge dewatering vehicle according to one embodiment of the present invention.

FIG. 3 is a rear view of the mobile sludge dewatering vehicle according to one embodiment of the present invention.

FIG. 4 is a sectional view taken along line S4-S4 of FIG.

FIG. 5 is an enlarged front view of a chemical preparation unit.

FIG. 6 is an enlarged plan view of a chemical preparation unit.

FIG. 7 is an enlarged side view of a chemical solution preparation unit.

FIG. 8 is an enlarged front view of a reaction section.

FIG. 9 is an explanatory view of a screw type dehydrator.

FIG. 10 is a flow sheet showing a use state of the mobile sludge dewatering vehicle.

[Explanation of symbols]

 Reference Signs List 10 movable sludge dewatering vehicle, 11 truck (vehicle), 12 carrier, 16 screw dehydrator, 17 belt conveyor (conveyance conveyor), 22 first chemical liquid dissolving tank, 23 second chemical liquid dissolving tank, 27 first Liquid storage tank, 28 second liquid storage tank, 34 first reaction tank, 35 second reaction tank, 40 discharge pipe (discharge unit), 52 gantry, 55 flock supply tank, 58 inclined supply pipe (supply unit) ).

Claims (2)

[Claims] 1. A chemical solution dissolving tank for producing an agglomerated liquid which is stirred and mixed into sludge; and a floc, which is an aggregate of sludge, is mixed with the agglomerated liquid produced in the chemical solution dissolving tank into the sludge. A mobile sludge dewatering vehicle equipped with a reaction tank to be generated and a screw dehydrator for dewatering the liquid contained in the floc, and these are mounted on the bed of the vehicle. 2. A floc discharge section provided in the reaction tank and a floc supply section provided in the screw dehydrator are connected by an inclined supply pipe that supplies the floc into the supply section by natural flow. The mobile sludge according to claim 1, further comprising an unloading conveyor for unloading the dewatered cake of the sludge discharged from the dehydrator out of the vehicle, in an internal space of the gantry supporting the screw type dehydrator. Dehydration car.