WO2012114985A1 - 遠心脱水方法及び遠心脱水装置 - Google Patents
遠心脱水方法及び遠心脱水装置 Download PDFInfo
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- WO2012114985A1 WO2012114985A1 PCT/JP2012/053754 JP2012053754W WO2012114985A1 WO 2012114985 A1 WO2012114985 A1 WO 2012114985A1 JP 2012053754 W JP2012053754 W JP 2012053754W WO 2012114985 A1 WO2012114985 A1 WO 2012114985A1
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- centrifugal
- bowl
- straight
- cake
- screw conveyor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
- B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B11/00—Feeding, charging, or discharging bowls
- B04B11/08—Skimmers or scrapers for discharging ; Regulating thereof
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04B—CENTRIFUGES
- B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
- B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
- B04B2001/2091—Configuration of solids outlets
Definitions
- the present invention relates to a centrifugal dehydration method and a centrifugal method in which a treatment liquid is separated into solid and liquid by centrifugal force to recover a solid and a separated liquid in various products for sewage treatment, industrial wastewater treatment or chemical / food industry.
- the present invention relates to a dehydrator.
- a decanter type centrifugal dehydration apparatus has been widely used for solid-liquid separation of sludge and the like (hereinafter referred to as a treatment liquid) by centrifugal force.
- the conventional decanter type centrifugal dewatering device has the disadvantage that the centrifugal force is weakened and the water content is increased because the distance (diameter) from the center of rotation is shortened in the bowl cone part.
- Patent Document 1 a straight barrel type centrifugal dewatering device as a solution to the disadvantages of the conventional decanter type centrifugal dewatering device.
- the straight barrel centrifugal dewatering device has a cylindrical shape in which the inner peripheral wall of the bowl extends along the rotation axis thereof, and a discharge path for discharging the precipitated heavy components to the outside of the bowl is provided in the one end wall of the bowl.
- the discharge path bowl opening is provided in the vicinity of the inner peripheral wall of the bowl, and the discharge path serves as a throttle path for limiting the discharge amount.
- the dewatered cake in the compacted state is directly passed through the discharge path by the centrifugal head pressure acting on the dewatered cake according to the thickness of the deposited layer formed by the discharge resistance of the throttle passage and the conveying force of the screw conveyor. It is characterized by being discharged. As a result, only the portion of the dehydrated cake deposit layer in the bowl that is receiving the highest consolidation action is directly discharged, so the moisture content of the dehydrated cake is lowered to an unprecedented level in conventional centrifugal dehydrators. I was able to.
- a polymer flocculant and / or an inorganic flocculant is added to the treatment liquid to form a floc for separation / dehydration. Processing is done.
- the method for adding these flocculants varies depending on the type of dehydrator and the type of treatment liquid.
- a composite tube is used as the inner cylinder.
- a method of supplying a polymer flocculant together with sludge to a sludge supply chamber is generally agglomerated by adding a polymer flocculant to the sludge in an external stirring tank in advance and stirring.
- the so-called two flocs are supplied to the sludge supply chamber of the inner cylinder, and the inorganic flocculant is added from the inner cylinder to the sludge deposit that moves to the small diameter side while dewatering the tapered portion of the inner periphery of the outer cylinder.
- Patent Document 4 A liquid method (Patent Document 4) or a method of reinjecting an inorganic flocculant into separated sludge that has been subjected to solid-liquid separation in a centrifugal dehydrator (Patent Document 5). Etc. have been proposed.
- the proposed straight-cylinder centrifugal dewatering device directly discharges only the part of the in-machine dewatered cake pile that is subjected to the highest consolidation action, so the water content of the dewatered cake is higher than that of the conventional centrifugal dewatering device.
- the wall could rise dramatically from the tip of the inner cylinder of the screw conveyor and extend to the outlet of the discharge path, the dehydrated cake piled up against the front end of the bowl.
- the dehydration effect is further improved by a two-component method in which an inorganic flocculant is added in addition to the polymer flocculant in the same manner as the decanter type centrifugal dehydrator shown in Patent Documents 4 and 5.
- an inorganic flocculant such as polyferric sulfate
- the front end portion of the bowl is a vertical wall, and a deposited layer of dewatered cake is formed at that location.
- the conventional straight barrel centrifugal dehydrator Since the deposited layer is hardened and cannot be discharged, the inside of the machine is blocked and the operation becomes impossible. Therefore, the conventional straight barrel centrifugal dehydrator has a problem that the two-component addition method by the post-addition of the inorganic flocculant cannot be adopted.
- the present invention is intended to solve the above-mentioned problems of the straight-cylinder centrifugal dewatering device, and it is easy to remove moisture from the dewatered cake in the bowl, thereby improving the dewatering effect and increasing the compression efficiency.
- the first object is to provide a centrifugal dehydration method and a straight barrel type centrifugal dehydrator that can reduce the internal load, and a two-component addition method by post-addition of an inorganic flocculant can be adopted to further increase the dehydration effect.
- a straight barrel centrifugal dewatering method of the present invention that solves the above-mentioned problems is a straight barrel bowl that rotates in one direction, and rotates in the same direction with a rotational speed difference coaxially with the bowl in the bowl.
- Centrifugal dehydration using a straight-cylinder centrifugal dehydration device that collects solids and separated liquid by separating the processing liquid into solid and liquid using a straight-cylinder centrifugal dehydration device having a screw conveyor with spiral blades wound around the outer periphery of the rotating drum.
- the centrifugal dewatering device has a cylindrical shape in which an inner peripheral wall of the bowl extends along a rotation axis of the bowl, and an outer peripheral surface of the rotary drum of the screw conveyor is a circle whose upstream side is straight.
- the bowl includes a straight portion having a peripheral surface and a tapered portion having a downstream side inclined in a large diameter direction from the straight portion, and the treatment liquid is supplied to the bowl through a treatment liquid supply chamber formed in the rotary drum.
- the separated liquid is discharged from the separating liquid outlet, and the dewatered cake is separated from the centrifugal head pressure and the screw conveyor.
- the dewatered cake is pushed to the dewatered cake discharge path side by the taper portion toward the dewatered cake discharge path side and gradually moved to the high centrifugal force field and toward the dehydrated cake discharge path side.
- the passing area of the dehydrated cake is gradually reduced to dehydrate.
- the axial length L1 of the straight portion from the processing liquid supply port of the rotating drum to the tapered portion start point, and the axial length L2 of the tapered portion of the rotating drum By setting the ratio L1 / L2 in the range of 1.2 to 5.0, it is desirable that the pushing force from the straight portion increases and the water content can be further reduced.
- An inorganic flocculant addition step of adding an inorganic flocculant to the dewatered cake that is supplied to the annular space around the inner periphery of the bowl and transported by the screw conveyor while being dewatered by centrifugal force is provided from the inside of the rotary drum of the screw conveyor. Therefore, the second object can be achieved.
- the inorganic flocculant supplying step is added to the dehydrated cake between the downstream side of the straight port of the screw conveyor and the upstream end of the tapered portion. This is desirable in order to prevent the dewatered cake from being blocked in the machine at the tapered portion. Further, the addition of the inorganic flocculant is preferably performed by a combination of addition to the surface of the dehydrated cake and the inside of the dehydrated cake in order to further increase the dewatering efficiency.
- a straight barrel centrifugal dewatering apparatus for carrying out the above-described straight barrel centrifugal dewatering method includes a straight barrel type bowl rotating in one direction and a rotational speed difference coaxially with the bowl in the bowl.
- a straight barrel centrifugal dewatering apparatus having a screw conveyor in which a spiral blade is wound around the outer periphery of a rotating drum rotating in a direction
- the inner peripheral wall of the bowl forms a cylindrical shape extending along the rotation axis of the bowl
- the outer peripheral surface of the rotary drum of the screw conveyor is composed of a straight part having a straight circumferential surface on the upstream side, and a tapered part in which the downstream side is inclined in a radial direction from the straight part,
- the taper start portion of the taper portion has an inclination angle in the range of 5 to 30 °.
- the ratio L1 / L2 is in the range of 1.2 to 5.0 in order to increase the compression efficiency.
- the straight cylinder type centrifugal dehydration apparatus of the present invention has an inorganic flocculant supply path for supplying an inorganic flocculant to the inner peripheral surface of the straight portion of the rotary drum, and the inorganic flocculant is provided in the straight portion.
- the second object is achieved by providing an inorganic flocculant addition orifice that communicates with the supply path and protrudes into the annular space of the bowl through the rotary cylinder. Can be achieved.
- an inorganic flocculant supply path for supplying an inorganic flocculant to the inner peripheral surface of the straight portion of the rotating drum is provided, and the straight portion communicates with the inorganic flocculant supplying path and passes through the rotating drum.
- An inorganic flocculant addition orifice and an inorganic flocculant addition nozzle projecting into the annular space of the bowl are provided.
- the tapered portion has a two-stage structure with different inclination angles, the first-stage inclination angle is a gentle inclination angle, and the subsequent second-stage inclination angle is steeper than the first-stage inclination angle. Therefore, it is desirable to effectively prevent a short path to the discharge side of the high water content dehydrated cake.
- a short path preventing means a boundary portion between the straight portion and the tapered portion and / or a weir having a step surface is formed in the middle of the tapered portion, and the spiral disposed in the tapered portion. It is possible to effectively employ a notch provided in a part of the base portion of the blade on the rotating drum.
- the following special (1) to (4) effective (1)
- the outer peripheral surface of the rotating drum into a tapered shape that is inclined within a range of 5 to 30 ° in the radial direction toward the discharge side of the dewatered cake, the discharged dewatered cake is gradually made into a high centrifugal force field. Since it can be moved, moisture can be easily removed and the moisture content of the dehydrated cake can be reduced.
- the dewatered cake By concentrating the outer peripheral surface of the rotating drum in a radial direction toward the discharge side of the dewatered cake, the dewatered cake in a compacted state at the discharge side end as in a conventional straight-cylinder centrifugal dewatering device
- the dehydrated cake can be easily discharged without accumulating.
- the screw conveyor has a tapered part inclined in the large diameter direction, the volume of the dehydrated cake gradually decreases toward the dehydrated cake discharge side, so that the indentation pressure can be used effectively, and the pressing force increases.
- the moisture content of the dehydrated cake can be reduced and discharged easily. As a result, it is possible to reduce the load pressure, the apparatus load is reduced, and the power consumption can be reduced.
- the taper portion increases the retention capacity of the highly dehydrated cake and can be expected to prevent water leakage to the dehydrated cake side during a negative dam. (4) Since the dewatering cake conveying force and the water head pressure can be effectively used as the pushing pressure, the blockage in the apparatus due to the dewatering cake during operation is greatly reduced.
- the dewatered cake can be easily discharged without the accumulation of the dewatered cake in the compacted state at the discharge side end as in the conventional straight barrel centrifugal dewatering device. Inorganic flocculants could not be added in the machine, which was impossible with a barrel-type centrifugal dehydrator, and a dehydrated cake with a lower water content could be obtained.
- the inorganic flocculant added in the machine to the treatment liquid is effectively mixed with the treatment liquid at the taper portion, and the water content of the dehydrated cake is further reduced.
- the inorganic flocculant is added to the dehydrated cake whose moisture content is decreasing in the machine, the coagulation effect is high and the dehydration effect can be enhanced.
- the dewatering cake conveying force and the water head pressure can be effectively used as the pushing pressure, the blockage in the apparatus due to the dewatering cake during operation is greatly reduced.
- the inorganic flocculant is further added in the straight part and added to the dehydrated cake whose moisture content is decreasing in the machine. Since the inorganic flocculant is not added to the tapered portion where the agglomeration effect is high and the dewatering effect is enhanced and the squeezing force is increased to the maximum, the dewatered cake is effectively prevented from clumping at the tapered portion and can be easily discharged. Furthermore, according to the invention of claim 5 and claim 8, the addition of the inorganic flocculant to the dewatered cake is performed by a combination of the surface of the dewatered cake and the inside of the dewatered cake. Can be mixed.
- the dewatered cake is gradually squeezed and dehydrated by the gentle taper portion of the first stage, and the high moisture content dehydrated cake of the low centrifugal force portion is formed at the bottom of the bowl by the steep portion of the second stage The gentle taper portion is moved to the separation liquid side without moving to the (cake discharge port).
- FIG. 3 is a ZZ cross-sectional view in FIG. 1.
- FIG. 2 is a sectional view taken along line XX in FIG.
- FIG. 2 is a YY sectional view in FIG. 1.
- FIG. 2 is a cross-sectional view taken along the line UU in FIG.
- It is an expanded sectional schematic of the principal section of the principal part of the centrifugal dehydration device concerning other embodiments of the present invention.
- FIG. 10 is an AA arrow view of the spiral wing of FIG. 9.
- FIG. 9 is an enlarged schematic cross-sectional view of a main part front cross-section of a centrifugal dehydration apparatus according to another embodiment in which the embodiment shown in FIG. 8 is added to the embodiment shown in FIG. 7 of the present invention.
- FIG. 10 is an enlarged schematic cross-sectional view of a main-part front cross-section of a centrifugal dehydrator according to another embodiment in which the embodiment shown in FIG. 9 is added to the embodiment shown in FIG. 7 of the present invention.
- the graph which shows the change of the dewatering cake moisture content with respect to the polymer flocculent addition rate in an Example and a comparative example It is a graph which shows the moisture content distribution of the in-machine dewatering cake in Example 2 and Comparative Example 3. It is a graph which shows the relationship between the water content of the dewatering cake in Example 3 and the comparative example 4, and a processing amount. It is a graph which shows the relationship between the dewatering cake moisture content and the centrifugal effect in Example 3 and Comparative Example 4. It is a graph which shows the relationship between the moisture content of the dewatering cake in Example 4 and the comparative example 5, and a processing amount.
- FIG. 1 shows a straight barrel centrifugal dewatering apparatus 1 according to this embodiment
- FIG. 2 is an enlarged schematic view of the main part thereof.
- the straight barrel centrifugal dewatering device 1 of this embodiment includes a straight barrel cylindrical bowl 10, a screw conveyor 20 that is disposed in the bowl and rotates in the same direction with a relative speed difference, the bowl 10, and the screw conveyor 20. Hollow shafts 35 and 40 projecting from both ends, a dehydrated cake discharge chamber 50 provided at the front end of the screw conveyor, and a separation liquid discharge chamber 60 provided at the rear end are provided.
- the bowl 10, the screw conveyor 20 mounted therein, the dewatered cake discharge chamber 50, and the separated liquid discharge chamber 60 are accommodated in the casing 19.
- the bowl 10 has a horizontal cylindrical straight body shape, the bowl front end forms a dehydrated cake discharge chamber wall 11, and the bowl rear end forms a bowl rear end wall 12 in which a separation liquid discharge port 13 is formed.
- the separation liquid discharge port 13 is preferably formed by concentrically separating a large number of small holes in the bowl rear end wall 12, but is not limited thereto and can be appropriately formed.
- Hollow shaft 40 1 of the bowl rear end wall 12 upstream formed to project outwardly from the central portion of rotatably journalled in a bearing 95 provided on the base frame 80, and dehydrated wall discharge chamber wall is bowl front end wall the hollow shaft 40 2 of the downstream formed to project outward side is a bearing rotatably to the bearing portion 90 from the central portion 11.
- Pulley 71 is provided on the outer periphery of the hollow shaft 40 1, the bowl 10 is transmitted to the motor as a drive source (not shown) is driven to rotate.
- the hollow shaft 40 2 of the tip with is connected to the transmission 70, a screw conveyor drive shaft 23 provided rotatably through the interior of the hollow shaft 40 2 is connected to the transmission 70, the hollow shaft 40 2 is transmitted to the scree conveyor drive shaft 23 via the transmission 70, and the screw conveyor 20 is rotationally driven in the same direction as the bowl 10 with a relative speed difference.
- the treatment liquid supply pipe 41 of the double pipe structure outer peripheral portion has a coagulant supply pipe which will be described later, through the processing liquid and coagulant Can be supplied to the inside of the rotary drum 21 of the screw conveyor.
- the screw conveyor 20 disposed in the bowl has a spiral blade 22 wound around the outer periphery of a rotating drum 21 having a hollow inside, and in the same direction with the required speed difference from the bowl 10 by the driving device as described above. It is designed to rotate.
- the outer surface of the rotating drum 21 is formed of a cylindrical straight portion 24 and a tapered portion 25. As shown in FIG.
- the straight portion 24 extends from the upstream end portion of the rotating drum and further extends from the dehydrated cake supply port 27 toward the downstream side of the rotating drum to a position of a distance L1, and the tapered portion 25 Inclined toward the inner peripheral wall of the bowl at an inclination angle ⁇ to the inlet of the discharge passage of the dewatered cake 14 toward the downstream side of the dewatering cake 14 and formed in the range of the axial distance L2.
- the tapered portion 25 has a taper structure in which a conventional rotating drum having a straight structure is inclined toward a dehydrated cake discharge side so that the pressing force increases as the dehydrated cake is conveyed in the dehydrated cake discharge direction. The water content of the dewatered cake discharged is reduced and formed.
- the taper angle of the taper portion of the rotating drum is set to a steep slope of 30 ° or more, a conveyance failure occurs and a carry-over in which the dehydrated cake flows out from the separated liquid side occurs, and the load on the conveyance cannot be increased. No improvement in moisture content was observed.
- the taper angle ⁇ is preferably less than 30 °, particularly 10 to 15 °.
- the taper angle refers to the angle of the taper start portion of the taper portion.
- the taper portion is formed in multiple stages, and the taper angle is set to an inclination angle that exceeds the above range on the downstream side.
- L1 / L2 1.2 to 1.5.
- L1 / L2 1.2 to 1.5.
- L1 / L2 ⁇ 1.2 the pushing force from the straight line portion is weakened and the dehydration rate is reduced.
- L1 / L2> 5 or more the axial length of the apparatus becomes longer than necessary. This is not preferable in reducing the size of the apparatus.
- L2 is too short, the taper angle becomes large, and as described above, poor conveyance occurs and the effect of lowering the moisture content of the dehydrated cake is small.
- a reverse taper surface 28 that is inclined inward from the position is formed.
- a throttle passage 52 serving as a discharge path for the dewatered cake is formed between the two.
- the member that forms the reverse tapered surface 28 is formed of a disk member that is a separate member from the rotating drum 21, but may be formed integrally with the rotating drum 21. By forming it as a separate member from the rotary drum, there is an advantage that the shape and cross-sectional area of the throttle passage can be adjusted according to the properties of the processing liquid.
- the bowl side throttle passage member 18 is attached so as to be opposed to the reverse tapered surface 28 on the rotating drum side.
- the bowl side throttle passage member 18 is also formed separately from the bowl in this embodiment, but may be formed integrally with the bowl.
- the rotary drum side throttle passage member 28 and the bowl side throttle passage member 18 form a dewatered cake discharge path 52 that is a conical annular passage having a cross-sectional area gradually decreasing toward the downstream side.
- the inlet 53 of the dewatering cake discharge path 52 that is, the opening of the bowl of the discharge path is provided in contact with the inner peripheral surface 15 of the bowl 10, while the outlet of the dewatering cake discharge path serving as a discharge port to the outside of the bowl.
- 54 has a height in the radial direction. Therefore, the dehydrated cake that can enter the discharge path 52 from the inlet 53 is limited to only the lowermost portion of the deposited layer.
- the outlet 54 is supplied to such an extent that the processing liquid does not overflow the outlet 54 in the initial stage of operation, and determines the initial height of the liquid level in the bowl.
- the separation liquid discharge port 13 determines the liquid level of the annular space 17 during operation, and when the position of the separation liquid discharge port 13 is lower than the outlet 54, the operation is performed in a “lower overflow” state, which is high. Sometimes the operation is in the “upper overflow” state. In the case of the operation in the upper overflow state, the treatment liquid is prevented from flowing out from the dehydrated cake discharge path 52 by the dehydrated cake accumulated in the vicinity of the inlet 53 of the dehydrated cake discharge path. In the most extreme case, the separation liquid can be discharged from the axial center, so that the separation liquid does not overflow from the outlet 54 of the dehydrated cake.
- a processing liquid supply chamber 26 is provided in the rotary drum 21, and a plurality of supply ports 27 are formed on the peripheral wall thereof to communicate with the annular space 17 between the bowl 10 and the rotary drum 21.
- a treatment liquid supply pipe 41 inserted through the hollow shaft 40 of the bowl 10 is provided in the supply chamber 26 so as to open.
- the inner pipe 100 serves as a processing liquid passage, and the processing liquid supply pipe having a double structure has an outer side.
- the surrounding outer tube 101 is divided into three supply paths, a polymer flocculant supply path 101a, an inorganic flocculant supply path 101b, and a washing water supply path 101c, and supply ports 102a, 102b, and 102c are provided at upstream ends thereof. Each supply pipe can be connected.
- the polymer flocculant supply path 101a extends along the inner tube 100 as it is, and is opened in the processing liquid supply chamber 26.
- the polymer flocculant supply path 101a is supplied from the periphery of the processing liquid into the supply chamber and is stirred and mixed with the processing liquid.
- the inorganic flocculant supply path 101b is opened on the upstream side where the processing liquid supply pipe 41 reaches the processing liquid supply chamber 26 and is defined along the inner peripheral surface of the rotary drum 21 as shown in FIG.
- the surface and the inside of the dewatered cake to be centrifugally dehydrated in the bowl as described later are opened in communication with the radial flow path 104 leading to the axial flow path (four in the illustrated embodiment) 105 of the inorganic flocculant. It is comprised so that an inorganic flocculant may be added to.
- the processing liquid supply chamber 26 is partitioned from the upstream side inside the rotary drum 21, and the inner section of the straight portion on the downstream side is an inorganic flocculant addition region 107, and the tapered portion is Is configured not to reach the inorganic flocculant.
- the inorganic flocculant efficiently mixes with the treatment liquid and effectively enhances the flocculation effect to contribute to the improvement of the dehydration rate. In order to enable good discharge without obstruction, the following measures were taken.
- a plurality of orifices 108 communicating with the axial flow path 105 of the inorganic flocculant and the body wall project into the bowl from the body wall of the rotating body 21 of the straight portion up to A nozzle 109 is provided, and an inorganic flocculant is post-added to the surface of the dewatered cake 14 during the dehydration process in the centrifugal field through the orifice 108 of the rotating drum wall, and is added to the inside of the dehydrated cake 14 by the nozzle 109 to thereby add an inorganic material.
- the flocculant is uniformly and effectively added to the dehydrated cake.
- the post-addition position of the inorganic flocculant is preferably a section of 1 to 2 pitches of the spiral blade 22 of the screw conveyor from the treatment liquid supply port 27 toward the cake discharge side. It is desirable to provide it.
- the addition of the inorganic flocculant is not limited to the case where only the addition from the inner peripheral surface of the rotary drum to the surface of the dewatered cake or the inside by the nozzle is performed. It can be seen that the addition effect is improved by combining these, and in this embodiment, the orifice and the nozzle are arranged at the above positions.
- the flocculant is added at the taper part where the squeezing force increases, the dehydrated cake will be hardened and it will be difficult to press with a screw, so the inorganic flocculant is not added at the taper part, and the inorganic flocculant is added only at the straight part. It was decided to add.
- the processing liquid to be dehydrated enters the processing liquid supply chamber 26 from the processing liquid supply pipe 41 and is supplied into the annular space 17 from the supply port 27, and the centrifugal force of rotation of the bowl 10 and the screw conveyor 20 is used. It is conveyed toward the front end by the spiral blade 22 while being separated into solid and liquid. The separated liquid, which is the separated liquid, is discharged out of the apparatus from the separated liquid discharge port 13 on the rear end wall. On the other hand, the dehydrated cake is scraped toward the front end of the bowl 10 by the spiral blades 22 and further subjected to separation action by centrifugal force, so that the separation of the remaining liquid proceeds, and the separated liquid is separated into the separated liquid discharge port 13. More discharged.
- the dewatered cake is gradually moved to the high centrifugal force field and dewatered toward the dewatered cake discharge path side. Since the passage area of the cake gradually decreased, the discharge resistance and the volume reduction force increased, and the moisture content of the dehydrated cake could be further reduced. More specifically, since the volume of the dewatered cake in the tapered portion is gradually reduced, the compression efficiency is improved and the indentation pressure can be used effectively. As a result, the load pressure can be reduced and the power consumption can be reduced.
- the dehydrated separation liquid can be easily moved from the dewatering cake discharge side to the separation liquid discharge side of the rotating drum, and only the dehydration cake having a low water content can be discharged without mixing the separation liquid into the dewatering cake. It was. Furthermore, the high dewatering cake holding capacity is increased, and the effect of preventing water leakage to the solid side when overflowing upward can be expected. Furthermore, since the dewatered cake conveying force and the hydraulic pressure can be effectively used as the pushing pressure, the blockage in the apparatus during operation is greatly reduced.
- the taper angle is less than 30 ° and 10 ° or more, and the ratio L1 / L1 between the distance L1 from the dewatered cake supply port to the straight portion and the distance L2 between the taper portions.
- L2 1.2 times or more, the moisture content is reduced by 2% or more (that is, the dewatering rate is improved) compared to the conventional straight barrel centrifugal dewatering device, and the polymer flocculant and the straight portion in the machine
- a water content reduction of 2% or more was obtained.
- the high-moisture dehydration cake on the inner radius side moves through the tapered portion, and the bottom of the bowl is reduced. It was found that there are some dehydrated cake species in which it is difficult to lower the moisture content of the cake because it is discharged after being mixed with the moisture content dehydrated cake. For example, in the case of mixed raw sludge, the dehydration of solids can be sufficiently dewatered to the limit value, but the separation liquid that reaches the tapered surface adheres to the surface of the solids and is discharged in that state, resulting in a dehydration rate as a result.
- FIG. 7 shows another embodiment of the present invention in which the occurrence of a short path is prevented.
- the same reference numerals are given to the same parts as those in the above embodiment, and only different main parts will be described.
- the taper part 25 By making the taper part 25 into a two-stage structure in this way, the dewatered cake is squeezed by the first stage of the gentle taper part 25a.
- the high-water-content dehydrated cake having an inner radius moves to the separating liquid side through the gently tapered portion 25 without moving to the cake discharge port at the bottom of the bowl by the steep tapered portion 25b in the second stage.
- the moisture content of the external dewatered cake discharged from the discharge path can be reduced by about 3 to 4% compared to the conventional straight body type.
- FIG. 8 shows still another embodiment of the present invention in which the occurrence of a short path is prevented.
- the occurrence of a short path is prevented by providing a weir 29 composed of a ring or the like having a height of about 10 mm at the inlet of the tapered portion 25 (the shape change point of the outer peripheral surface of the rotating drum).
- a weir 29 composed of a ring or the like having a height of about 10 mm at the inlet of the tapered portion 25 (the shape change point of the outer peripheral surface of the rotating drum).
- the weir is not limited to the case of the present embodiment, and can be formed in the middle of the tapered portion.
- FIG. 9 shows still another embodiment of the present invention in which the occurrence of a short path is prevented.
- a notch 30 is provided in a part as shown schematically in FIG. 10 on the surface of the tapered portion of the tapered portion 25 of the rotating drum 21 and the connecting portion of the spiral blade 22.
- the spiral blade 22 prevents the high water content dehydrated cake from moving up by pushing up the tapered portion 25.
- FIGS. 7 to 10 can effectively prevent a short pass of a dehydrated cake having a high water content. However, by having these means in combination, the short pass can be more effectively prevented. Can be prevented.
- FIG. 11 is obtained by adding the short path preventing means of the embodiment shown in FIG. 8 to the embodiment shown in FIG. 7, and the same reference numerals are given to the same portions as in the above-described embodiment, and the detailed description is omitted.
- FIG. 12 is the same as the embodiment shown in FIG. 7 except that the short path prevention means of the embodiment shown in FIG. 9 is added. To do.
- Example 1 Treatment liquid: Digested sludge Inorganic flocculant: Polyferric sulfate
- Polymer flocculant Amphoteric polymer flocculant
- Addition method As shown in Table 1, the addition rate of polymer flocculant is 0.92-1.80 DS% It is changed between the two and supplied to the processing liquid supply chamber and stirred and mixed with the processing liquid, and a constant amount (addition amount 19.0 L / h) of polyferric sulfate is always added from the orifice and the nozzle. The change in the moisture content of the cake was examined. As a result, the result of the diagram a shown in Table 1 and the graph of FIG. 13 was obtained.
- the cake water content high polymer flocculant addition rate of 0.92 DS% is about 73.4%, 1.55% is about 71.6%, 1.80% is 71.1%. It was confirmed that the water content was extremely low and the dehydration effect was extremely high.
- Comparative Example 1 Only the polymer flocculant in Example 1 was added to the same treatment liquid as in Example 1, and changes in the addition rate and the moisture content of the cake were examined. The result is shown as a diagram c in FIG. 13 together with Example 1. Comparative Example 2 As shown in Table 1, the same amphoteric polymer flocculant and polyferric sulfate were added in advance to the treatment solution similar to the examples as in the conventional two-component method (the treatment solution was previously stirred). The inorganic flocculant was fixed in the same amount as in Example 1 and the addition rate of the polymer flocculant was changed in the same manner as in Example 1. As a result, it is shown as a diagram b in Table 1 and FIG.
- Example 1 As is clear from the results of Example 1 and Comparative Examples 1 and 2, it can be seen that the moisture content of the cake in Example 1 is lower than the substantially same addition rate of the polymer flocculant.
- Comparative Example 2 in which the inorganic flocculant is added in advance, the water content of the example is about 2 to 3% even if the inorganic flocculant and the polymer flocculant are added in substantially the same amount as in Example 1. The result of lowering was obtained.
- the comparative example 1 which adds only a polymer flocculent, the result in which the Example fell about 6% or more was obtained.
- the apparatus and the chemical addition method of the present embodiment have a special dehydration effect as compared with the prior art. Further, in any of the examples and comparative examples, the dewatered cake can be discharged without causing a poor discharge of the dehydrated cake, and the centrifugal dewatering device of the present embodiment has an excellent centrifugal dewatering function. It was confirmed that
- the pre-addition of the flocculant was performed, and the in-flight dehydration rate distribution state was examined for each.
- a comparative example 3 a conventional straight barrel centrifugal dewatering device was used, and a similar verification test of the mixed raw sludge dewatering treatment was performed to examine the in-machine dewatering rate distribution state.
- the distribution of the in-machine dewatering rate is measured by stopping the operation at the time of steady operation of the centrifugal dewatering equipment, completely stopping it, then disassembling the equipment and depositing it between the screws in the axial cross section of the screw conveyor. This was performed by measuring the moisture content of the cake at three points on the outer peripheral side, the middle, and the inner peripheral side for each screw pitch. The result is shown in FIG.
- the graph of FIG. 14 shows the in-machine dewatering rate distribution of Examples 2-1 to 2-3 and Comparative Example 3 measured as described above, and shows the average value of three points for each pitch.
- the moisture content in the machine decreases almost linearly toward the discharge side end as shown in the figure, and the moisture content of the discharge side end is It decreased to about 80.3%.
- the moisture content in the machine in the examples all decreased toward the taper starting point with a high decline gradient compared to the comparative example, and the decline in moisture content at the taper portion slightly decreased, but the moisture content was discharged. Continues to decline.
- Example 2-1 in which L1 / L2 1.5 / 1 showed the most decrease in water content, and decreased to 78.0%, which was about 7% lower than the conventional straight barrel centrifugal dehydrator.
- Example 2-1 can secure a more sufficient indentation pressure than Examples 2-2 and 2-3, and is more effective in reducing the water content. It was confirmed.
- the “supply section” indicates a position corresponding to the supply port 27 in the straight body centrifugal dewatering apparatus of the embodiment shown in FIG. 1, and the “discharge section” is a discharge path of the dehydrated cake. A position corresponding to the entrance 53 is shown.
- Example 3 Comparative Example 4
- the influence of the centrifugal effect when the mixed raw sludge was dehydrated as the treatment liquid was examined in the same manner as in Example 2.
- the result is shown in FIG.
- FIG. 15 shows the water content of the dehydrated cake obtained when the centrifugal effect of Example 3-1 and Comparative Example 4 is both 2000 G and 2 m 3 / h is processed at a recovery rate of 98% or more.
- -2 shows the relationship between the dehydrated cake moisture content and the treatment amount when treated at 2-5 m 3 / h based on the centrifugal effect of 2500 G
- FIG. 16 shows the relationship between the centrifugal effect and the moisture content of the dehydrated cake. ing.
- FIG. 15 also shows the results of Example 5 described later.
- the water content of the dewatered cake was 69.0% with a centrifugal effect of 2000 G.
- Example 3-1 was able to reduce the water content by about 2% compared to Comparative Example 4, and the effectiveness of the present invention was confirmed.
- Example 3-2 shows the relationship between the amount of treatment and the moisture content of the dehydrated cake when the centrifugal effect is 2500G, but the moisture content of the dehydrated cake is increased in correlation with the increase in the amount of treatment, Since this tendency is also expected for the centrifugal effect 2000G, conversely, if the apparatus of Example 2-1 is dehydrated at the same water content of 71.8% as the apparatus of Comparative Example 2, the graph of FIG.
- the processing of 5 m 3 / h is possible in the apparatus of the example, and the processing amount of 2 to 2.5 times that of the comparative example 4 is expected in the example 3-1.
- the centrifugal effect is reduced by about 1 ⁇ 2 at the equivalent water content, and the apparatus load can be reduced correspondingly.
- the embodiment can be reduced in size and capacity as compared with the comparative example, and the cost can be greatly reduced and the power can be saved as compared with the comparative example.
- the dehydrated cake concentration (TS) of the anaerobic digested sludge which is the treatment solution used for the verification test, was 1.82%, and the organic matter concentration (VTS) was 73.8%.
- the moisture content of the dehydrated cake increases as the treatment amount increases under the same centrifugal effect.
- the example has a higher moisture content than the comparative example.
- a decrease was observed.
- Example 4-1 having a taper angle of 10 ° a decrease of about 2.0 to 2.7% was recognized as compared with the comparative example, and a remarkable effect was recognized.
- the taper angle of a rotating drum has the tendency for a dehydration cake moisture content fall to the smaller one of an Example.
- Example 5 As shown in FIG. 7, in order to confirm the effect when the taper portion of the rotary cylinder is a two-stage taper, a straight cylinder type centrifugal dewatering apparatus having a first-stage taper angle of 10 ° and a second-stage taper angle of 30 °. And the relationship between the throughput and the water content of the dehydrated cake was examined. As a result, the results shown in Table 2 and FIG. 15 were obtained.
- the treatment liquid (sludge type) is mixed raw sludge as in Example 3-1 and Comparative Example 4. As is apparent from the above table, the water content of Example 5 was reduced by about 1% compared to Example 3-1 having a single-stage taper by using a two-stage taper.
- the straight barrel centrifugal dehydrator of the present invention can be used for sewage treatment, industrial wastewater treatment, dehydration treatment of various products for the chemical and food industries, and the like.
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Abstract
Description
以上のように、従来のデカンタ型遠心脱水機の脱水ケーキ含水率は、小型機で例えば消化汚泥の場合で、実機で最大で75%で程度しか低下させることができなかった。
本発明の上記直胴型遠心脱水装置において、前記回転胴の処理液供給口から前記テーパー部開始点までのストレート部の軸方向長さL1と、前記回転胴のテーパー部の軸方向長さL2との比L1/L2が1.2~5.0の範囲であることが、圧搾効率を高める上で望ましい。
また、前記回転胴のストレート部の内周面に無機凝集剤を供給する無機凝集剤供給経路を有し、且つ前記ストレート部には、前記無機凝集剤供給経路と連通し前記回転胴を貫通して無機凝集剤添加用のオリフィスとボウルの環状空間内に突出する無機凝集剤添加用ノズルが設けられている。
(1)回転胴の外周面を脱水ケーキの排出側に向かって径大方向に5~30゜の範囲内で傾斜したテーパー形状とすることにより、排出される脱水ケーキを徐々に高遠心力場に移動させることができるので、水分の抜けが容易となり、脱水ケーキの含水率低下が図れる。
(2)回転胴の外周面を脱水ケーキの排出側に向かって径大方向にテーパー形状とすることにより、従来の直胴型遠心脱水装置のような排出側端部での圧密状態の脱水ケーキが堆積することがなく脱水ケーキの排出が容易となる。
(3)スクリューコンベアが径大方向に傾斜したテーパー部を有するため、脱水ケーキ排出側に向かって脱水ケーキの体積が徐々に減少することにより押し込み圧を有効に使用でき、圧搾力が増大して脱水ケーキ含水率を低下させ且つ容易に排出することができる。その結果、負荷圧を軽減することが可能となり、装置負荷が減少して消費電力の低減を図ることができる。
(3)テーパー部により高脱水ケーキ保持容量が増え、ネガティブダム時の脱水ケーキ側への漏水防止効果が期待できる。
(4)脱水ケーキ搬送力と水頭圧を押し込み圧として有効に利用できることから運転中の脱水ケーキによる装置内閉塞が大幅に軽減される。
(5)前記テーパー部を有することにより、従来の直胴型遠心脱水装置のような排出側端部での圧密状態の脱水ケーキが堆積することがなく脱水ケーキの排出が容易となり、従来の直胴型遠心脱水装置では不可能であった無機凝集剤の機内添加が可能となり、より低含水率の脱水ケーキを得ることが可能となった。
(6)処理液に機内添加された無機凝集剤はテーパー部で処理液との混合が有効に行なわれ、脱水ケーキ含水率をさらに低下させる。
(7)無機凝集剤は、機内で含水率が低下しつつある脱水ケーキに添加されるので、凝集効果が高く脱水効果を高めることができる。
(8)脱水ケーキ搬送力と水頭圧を押し込み圧として有効に利用できることから運転中の脱水ケーキによる装置内閉塞が大幅に軽減される。
さらに、請求項5及び請求項8の発明によれば、無機凝集剤の脱水ケーキへの添加は、脱水ケーキ表面と脱水ケーキ内部への組み合わせにより行なうので、無機凝集剤が脱水ケーキと効率よく均一に混合することができる。
請求項9の発明によれば、1段目の緩やかなテーパー部で脱水ケーキが徐々に圧搾されて脱水され、2段目の急勾配部により低遠心力部の高含水率脱水ケーキはボウル底部(ケーキ排出口)に移動することなく緩やかなテーパー部を分離液側に移動する。この場合、1段目のテーパー部でショートパスがあっても、2段目のテーパー部で押し戻されてしまうので、ケーキ含水率は、従来の直胴型と比較して約3~4%の水分低下が得られる。
請求項10の発明によれば、テーパー部の入口及び又テーパー部の途中に段差を形成して堰を設けることによって、高含水率脱水ケーキがテーパー部にショートパスすることを有効に防止することができる。
請求項11の発明によれば、螺旋翼に切り欠けを設けることによって、高含水率脱水ケーキが螺旋翼によってテーパー部へ押し上げられて移動することを防止でき、高含水率脱水ケーキの排出側へのショートパスを有効に阻止することができる。
11 脱水ケーキ排出室壁 12 ボウル後端壁
13 分離液排出口 14 脱水ケーキ
15 周壁内面 17 環状空間
18 ボウル側絞り通路部材 19 ケーシング
20 スクリューコンベア 21 回転胴
22 螺旋翼 23 回転軸
24 ストレート部 25 テーパー部
26 供給室 27 供給口
28 逆テーパー面 29 堰
30 切り欠き 35 下流側の中空軸
401 上流側の中空軸 402 下流側の中空軸
41 処理液供給管 50 脱水ケーキ排出室
52 脱水ケーキ排出経路 53 入口
54 出口 60 分離液排出室
70 駆動装置 80 ベースフレーム
90、95 軸受部
100 内管 101 外管
101a 高分子凝集剤供給路 101b 無機凝集剤供給路
101c 洗浄水供給路 102a~102c 供給口
104 半径方向流路 105 軸方向流路
108 オリフィス 109 ノズル
図1は、本実施形態に係る直胴型遠心脱水装置1を示し、図2はその要部の拡大概略図である。本実施形態の直胴型遠心脱水装置1は、直胴円筒型のボウル10と該ボウル内に配置され相対速度差を有して同方向に回転するスクリューコンベア20、ボウル10及びスクリューコンベア20の両端部に突出形成された中空軸35、40、スクリューコンベアの前端に設けられた脱水ケーキ排出室50、後端部に設けられた分離液排出室60を備えている。そして、ボウル10、その内部に装着されたスクリューコンベア20、脱水ケーキ排出室50、分離液排出室60がケーシング19内に収納されている。
ボウル後端壁12の中央部から外側に突出形成された上流側の中空軸401がベースフレーム80に設けられた軸受95に回転自在に軸受され、且つボウル前端壁である脱水壁排出室壁11の中央部から外側に突出形成された下流側の中空軸402が軸受部90に回転可能に軸受されている。中空軸401の外周にプーリ71が設けられ、図示しない駆動源としてのモータに伝動されボウル10が回転駆動される。中空軸402の先端部は変速装置70に連結されていると共に、中空軸402の内部を貫通して回転自在に設けられたスクリューコンベア駆動軸23が変速装置70に連結され、中空軸402の回転力は変速装置70を介してスクリーコンベア駆動軸23に伝達され、スクリューコンベア20がボウル10と同方向に相対速度差を持って回転駆動される。
そして、上流側の中空軸401の中心部を貫通して、外周部が後述する凝集剤供給管となっている二重管構造の処理液供給管41が貫通して、処理液と凝集剤をスクリューコンベアの回転胴21の内部まで供給できるようになっている。
回転胴21内には、処理液の供給室26が設けられ、その周壁には、ボウル10と回転胴21との間の環状空間17に通ずる複数個の供給口27が開設されているとともに、ボウル10の中空軸40より挿通された処理液の供給管41が供給室26に開口して設けられている。二重構造になっている処理液供給管は、図1におけるZ-Z断面、X-X断面を図3、4に示すように、内管100が処理液通路となっており、その外側を囲む外管101は、高分子凝集剤供給路101a、無機凝集剤供給路101b、洗浄水供給路101cの3つに供給路に区画され、その上流端でそれぞれ供給口102a、102b、102cが設けられ、それぞれの供給配管を接続できるようになっている。
すなわち、テーパー部先端に向けて高含水率脱水ケーキのショートパスが生じる。したがって、この高含水率脱水ケーキのショートパスを封じることによって、さらに脱水率を高めることが期待できる。ショートパスを防止する方法について、さらに研究した結果、以下に示すような方法が有効であることが確認された。
本実施形態では、回転胴21のテーパー部25を2段構造にしたことに特徴を有する。即ち、1段目は緩やかなテーパー部25a(傾斜角α1=5~15゜)とし、2段目は1段目よりも急勾配なテーパー部25b(傾斜角α2=20~60゜)としたものである。テーパー部25をこのように2段構造にすることによって、1段目の緩やかなテーパー部25aで脱水ケーキが圧搾される。そして、2段目の急勾配のテーパー部25bにより内半径の高含水率脱水ケーキは、ボウル底部のケーキ排出口に移動することなく緩やかなテーパー部25を分離液側に移動する。その結果、排出路から排出された機外脱水ケーキの含水率を、従来の直胴型と比較して約3~4%低下させ得ることが確認できた。
本実施形態では、テーパー部25の入口(回転胴外周面の形状変換点)に高さ10mm程度のリング等で構成した堰29を設けることによってショートパスの発生を防止したものである。このようにテーパー部25の入口に段差を形成して堰29を設けることによって、高含水率脱水ケーキがテーパー部にショートパスすることを有効に防止することができた。なお、堰は本実施形態の場合に限らず、テーパー部の途中に形成することも可能である。
本実施形態の遠心脱水装置では、回転胴21のテーパー部25の螺旋翼22のテーパー部表面と螺旋翼22の接続部に、図10に模式的に示すように一部に切り欠き30を設けることによって、螺旋翼22によって高含水率脱水ケーキがテーパー部25を押し上げて移動することを防止したものである。それにより、テーパー領域の内周側脱水ケーキを搬送させないようにし、高含水率脱水ケーキの排出側へのショートパスを有効に阻止することができる。
図11は、図7に示す実施形態に図8に示す実施形態のショートパス防止手段を付加したものであり、前記実施形態と同様な箇所に同一符号を付して詳細な説明は省略する。図12は、同様に図7に示す実施形態に図9に示す実施形態のショートパス防止手段を付加したものであり、前記実施形態と同様な箇所に同一符号を付して詳細な説明は省略する。
実施例1:
処理液:消化汚泥
無機凝集剤:ポリ硫酸第二鉄
高分子凝集剤:両性高分子凝集剤
添加方法:表1に示すように、高分子凝集剤を添加率0.92~1.80DS%の間で変化させて処理液供給室に供給して処理液と攪拌混合させ、ポリ硫酸第二鉄を前記オリフィス及びノズルから常に一定量(添加量19.0L/h)添加して、そのときのケーキ含水率の変化を調べた。その結果、表1及び図13のグラフに示す線図aの結果が得られた。該結果から本実施例では、ケーキ含水率高分子凝集剤添加率0.92DS%で約73.4%で、1.55%で約71.6%、1.80%で71.1%というきわめて低い含水率になり、脱水効果が極めて高いことが確認された。
実施例1と同様な処理液に対して、実施例1おける高分子凝集剤のみを添加して、その添加率とケーキ含水率の変化を調べた。その結果を実施例1と共に図13に線図cとして示す。
比較例2
実施例と同様な処理液に対して、表1に示すように、同様な両性高分子凝集剤とポリ硫酸第二鉄とを従来の2液法と同様に、前添加(処理液に予め攪拌槽又は配管を通して、遠心脱水前の処理液に攪拌混合)して、無機凝集剤は実施例1と同様に一定量とし、高分子凝集剤の添加率実施例1と同様に変化させた。その結果、実施例1と共に表1および図13に線図bとして示す。
以上の実施例から、本実施形態の装置および薬剤添加方法が従来技術と比較して格別な脱水効果があることが確認された。また、実施例及び比較例の何れの場合も脱水ケーキの排出不良を起こすことなく、高脱水率の場合も良好に排出することができ、本実施形態の遠心脱水装置が遠心脱水機能に優れていることが確認された。
[実施例2および比較例3]
実施例2-1~2-3として図1に示す実施形態の遠心脱水装置において、α=10゜、L1/L2=1.5/1(実施例2-1)、L1/L2=1.2/1(実施例2-2)、L1/L2=1/1(実施例2-3)である試験機をそれぞれ製作して、当該装置により処理液として混合生汚泥の脱水処理を高分子凝集剤の前添加のみで行い、それぞれについて機内脱水率分布状態を調べた。
また比較例3として従来の直胴型遠心脱水装置を使用して、同様な混合生汚泥の脱水処理の実証試験を同様に行って機内脱水率分布状態を調べた。
機内脱水率の分布状態の測定は、それぞれ遠心脱水装置の定常運転時に運転を非常停止させて完全停止後、装置を分解してスクリューコンベアの軸方向断面におけるスクリュー間に堆積している機内堆積ケーキを採取して、それぞれのスクリューピッチ毎の外周側・真中及び内周側の3点におけるケーキ含水率を測定することによって行った。その結果を図14に示す。
実施例2-1で採用した遠心脱水装置において、実施例2の場合と同様に処理液として混合生汚泥の脱水処理を行った場合の遠心効果の影響を調べた。その結果を図15に示す。図15は、実施例3-1および比較例4の遠心効果を共に2000Gのもとで2m3/hの処理を回収率98%以上で行った場合の脱水ケーキの含水率と、実施例3-2では2500Gの遠心効果の基で2~5m3/hを処理した場合の脱水ケーキ含水率と処理量との関係を示し、図16は、遠心効果と脱水ケーキ含水率との関係を示している。なお、図15、図16の各グラフには、そのときの回収率も併せて表示してある。また、図15には、後述する実施例5の結果も併せて表示してある。
実施例3-1の装置で混合生汚泥を処理量2m3/hを処理した場合の脱水ケーキの含水率は遠心効果2000Gで69.0%であった。これに対して、比較例1の装置で同じく混合生汚泥を処理量2m3/hを遠心効果2000Gで処理した場合の脱水ケーキの含水率71.8%であった(実施例3-1、比較例4)。
即ち、実施例3-1が比較例4よりも約2%含水率を低下させることができ、本発明の有効性が確認できた。そして、実施例3-2は、遠心効果2500Gで行った場合の処理量と脱水ケーキ含水率の関係を示しているが、処理量の増大により脱水ケーキ含水率は相関的に増大しており、この傾向は遠心効果2000Gの場合も見込まれるので、逆に実施例2-1の装置で比較例2の装置と同じ含水率71.8%の含水率で脱水処理をするとしたら、図15のグラフに示すように、実施例の装置では5m3/hの処理が可能となることを示し、実施例3-1では比較例4の2~2.5倍の処理量が見込まれる。また、図16のグラフに示すように、同等含水率では1/2程度の遠心効果の低下が認められ、その分装置負荷の低減が可能となる。これらのことから、実施例は、比較例と比較して小型大容量化が可能であり、比較例と比較して大幅なコストの低減および省電力化が可能である。
実施例2-1と同様な装置(L1/L2=1.5/1)において、テーパー角度を10゜(実施例4-1)、30゜(実施例4-2)、40゜(実施例4-3)に変更した装置を試作して、処理液として嫌気性消化汚泥の脱水処理を行った。実証試験に供した処理液である嫌気性消化汚泥の脱水ケーキ濃度(TS)は1.82%、有機物濃度(VTS)は73.8%であった。実証試験は、遠心効果2500G、回収率99%以上の基で行い、処理量をそれぞれ2.0~5.0m3/hに1.0m3/hづつ増やして4段階で行った。そのときの脱水ケーキの含水率は、それぞれ図17に示すとおりであった。
Claims (11)
- 一方向に回転する直胴型のボウルと、該ボウル内で該ボウルと同軸に回転速度差を有して同方向に回転する回転胴の外周に螺旋翼を巻装してなるスクリューコンベアを有する直胴型遠心脱水装置により、処理液を固液分離して固形物及び分離液の回収を行なう直胴型遠心脱水装置による遠心脱水方法において、
前記直胴型遠心脱水装置は、前記ボウルの内周壁が前記ボウルの回転軸に沿って延在する円筒形を形成し、且つ前記スクリューコンベアの前記回転胴の外周面が、上流側がストレートな円周面からなるストレート部と、下流側が前記ストレート部から径大方向に傾斜したテーパー部とから構成され、
前記処理液は、前記回転胴の内部に形成された処理液供給室を介して前記ボウルと前記スクリューコンベアとの間の環状空間に供給され、前記ボウル及び前記スクリューコンベアの回転の遠心力で固液分離されながら分離液は分離液排口より排出され、脱水ケーキは遠心水頭圧と前記スクリューコンベアの搬送力とにより脱水ケーキ排出経路へ押出してなり、
前記脱水ケーキは、前記脱水ケーキ排出経路側に向けて前記テーパー部によって、徐々に高遠心力場に移動させ、かつ脱水ケーキ排出路側に向かって脱水ケーキの通過面積を漸減させて脱水することを特徴とする直胴型遠心脱水装置による遠心脱水方法。 - 前記回転胴の処理液供給口から前記テーパー部開始点までのストレート部の軸方向長さL1と、前記回転胴のテーパー部の軸方向長さL2との比L1/L2が1.2~5.0の範囲であることを特徴とする請求項1に記載の遠心脱水方法。
- 前記処理液供給室に処理液と高分子凝集剤を供給する処理液供給工程、前記処理液供給室から前記高分子凝集剤が添加された処理液が回転胴に形成された供給口を介してボウル内周の環状空間に供給され、遠心力により脱水されながら前記スクリューコンベヤにより搬送される前記脱水ケーキに、前記スクリューコンベアの回転胴内方より無機凝集剤を添加する無機凝集剤添加工程を備えている請求項1又は2に記載の直胴型遠心脱水装置による遠心脱水方法。
- 前記無機凝集剤の供給工程は、前記スクリューコンベアのストレート部の前記供給口から下流側と前記テーパー部上流端との間で、前記脱水ケーキに添加することを特徴とする請求項3に記載の遠心脱水方法。
- 前記無機凝集剤の添加は、脱水ケーキ表面と脱水ケーキ内部への添加の組合せにより行なう請求項4に記載の遠心脱水方法。
- 一方向に回転する直胴型のボウルと、該ボウル内で該ボウルと同軸に回転速度差を有して同方向に回転する回転胴の外周に螺旋翼を巻装してなるスクリューコンベアを有する直胴型遠心脱水装置において、
前記ボウルの内周壁が前記ボウルの回転軸に沿って延在する円筒形を形成し、且つ前記スクリューコンベアの前記回転胴の外周面が、前記上流側がストレートな円周面からなるストレート部と、前記下流側が前記ストレート部から径大方向に傾斜したテーパー部とから構成され、前記テ―パー部のテーパー開始部の傾斜角が5乃至30゜の範囲内であることを特徴とする直胴型遠心脱水装置。 - 前記回転胴の処理液供給口から前記テーパー部開始点までのストレート部の軸方向長さL1と、前記回転胴のテーパー部の軸方向長さL2との比L1/L2が1.2~5.0の範囲であることを特徴とする請求項6に記載の直胴型遠心脱水装置。
- 前記回転胴のストレート部の内周面に無機凝集剤を供給する無機凝集剤供給経路を有し、且つ前記ストレート部には、前記無機凝集剤供給経路と連通し前記回転胴を貫通して無機凝集剤添加用のオリフィスとボウルの環状空間内に突出する無機凝集剤添加用ノズルが設けられている請求項6又は7に記載の直胴型遠心脱水装置。
- 前記テーパー部が、傾斜角の異なる2段構造をなし、1段目の傾斜角が緩やかな傾斜角で、それに続く2段目が前記1段目の傾斜角より大きい急勾配の傾斜角となっていることを特徴とする請求項6又は7に記載の直胴型遠心脱水装置。
- 前記ストレート部と前記テーパー部との境界部及び/又はテーパー部の途中に段差面となっている堰が形成されていることを特徴とする請求項6又は7に記載の遠心脱水装置。
- 前記テーパー部に配置された前記螺旋翼の回転胴への付け根部の一部に切り欠けを設けてなることを特徴とする請求項6又は7に記載の遠心脱水装置。
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CN103657880B (zh) * | 2013-12-18 | 2016-08-31 | 山东博润工业技术股份有限公司 | 分体式筛网沉降离心机螺旋输送器 |
JP6278307B2 (ja) * | 2014-01-14 | 2018-02-14 | 三菱重工環境・化学エンジニアリング株式会社 | 遠心脱水装置 |
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JP6420861B2 (ja) * | 2017-03-23 | 2018-11-07 | 株式会社広島メタル&マシナリー | 遠心脱水機 |
US10682585B2 (en) * | 2017-07-12 | 2020-06-16 | James William Masten, JR. | High-efficiency sludge dehydrator using an adaptive mechanical vapor re-compression process |
CN108187928B (zh) * | 2017-12-28 | 2021-04-09 | 攀枝花钢城集团有限公司 | 工业用水杂质分离设备出料装置 |
CN108176521A (zh) * | 2018-02-07 | 2018-06-19 | 广州市昊力工具有限公司 | 淤泥脱水装置及具有淤泥脱水装置的清淤干泥船 |
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CN109678307A (zh) * | 2019-02-21 | 2019-04-26 | 阮文渊 | 一种三段式加热不粘锅含油污泥热解装置 |
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Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE859429C (de) * | 1950-12-19 | 1952-12-15 | Trenntechnik G M B H | Siebschleuder |
JPS4986951A (ja) * | 1972-09-06 | 1974-08-20 | ||
JPS579346U (ja) * | 1980-06-17 | 1982-01-18 | ||
JPS6213551U (ja) * | 1985-07-12 | 1987-01-27 | ||
DE3622655A1 (de) * | 1986-07-05 | 1988-01-14 | Krauss Maffei Ag | Dekantierzentrifuge |
JPH041346B2 (ja) * | 1985-08-13 | 1992-01-10 | Fuji Xerox Co Ltd | |
JPH0641000B2 (ja) | 1985-05-08 | 1994-06-01 | 石川島播磨重工業株式会社 | 汚泥の脱水装置 |
JPH06190302A (ja) * | 1992-04-06 | 1994-07-12 | Alfa Laval Separation Inc | ビーチ部において途切れたフライトを有するデカンタ型遠心分離機 |
JPH0957153A (ja) * | 1995-08-21 | 1997-03-04 | Tsukishima Kikai Co Ltd | 遠心濃縮機 |
JPH0957152A (ja) * | 1995-08-21 | 1997-03-04 | Tsukishima Kikai Co Ltd | 遠心濃縮機 |
JP2000237630A (ja) * | 1999-02-19 | 2000-09-05 | Kubota Corp | 遠心脱水装置 |
JP2000254549A (ja) | 1999-03-08 | 2000-09-19 | Nishihara Environ Sanit Res Corp | 薬品注入手段を備えた遠心分離機 |
JP2002153772A (ja) * | 2000-11-22 | 2002-05-28 | Kubota Corp | 遠心分離装置 |
JP2006192403A (ja) | 2005-01-17 | 2006-07-27 | Tokyo Electric Power Environmental Engineering Co Inc | 脱水汚泥の含水率の低下方法 |
JP4153138B2 (ja) | 2000-02-10 | 2008-09-17 | 株式会社クボタ | 遠心分離装置 |
JP2010264417A (ja) | 2009-05-18 | 2010-11-25 | Nishihara Environment Technology Inc | 遠心分離装置 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2831575A (en) * | 1954-12-16 | 1958-04-22 | Raibl Societa Miniraria Del Pr | Centrifugal classifier for finely granulated solid substances in suspension |
US3228594A (en) * | 1965-02-05 | 1966-01-11 | Clifford L Amero | Centrifugal separator |
JPH0716630B2 (ja) * | 1985-05-09 | 1995-03-01 | 石川島播磨重工業株式会社 | スクリユ−デカンタ型遠心分離機 |
GB9225067D0 (en) * | 1992-12-01 | 1993-01-20 | Broadbent & Sons Ltd Thomas | Decanting-type centrifuges |
-
2011
- 2011-10-21 JP JP2011232090A patent/JP5191565B2/ja active Active
-
2012
- 2012-02-17 EP EP12749994.5A patent/EP2679312B1/en not_active Not-in-force
- 2012-02-17 KR KR1020137025261A patent/KR101557711B1/ko active IP Right Grant
- 2012-02-17 RU RU2013143296/05A patent/RU2013143296A/ru not_active Application Discontinuation
- 2012-02-17 WO PCT/JP2012/053754 patent/WO2012114985A1/ja active Application Filing
- 2012-02-17 US US14/001,410 patent/US9364837B2/en not_active Expired - Fee Related
- 2012-02-17 CN CN2012800100460A patent/CN103415348A/zh active Pending
- 2012-02-23 TW TW101105991A patent/TWI542552B/zh active
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE859429C (de) * | 1950-12-19 | 1952-12-15 | Trenntechnik G M B H | Siebschleuder |
JPS4986951A (ja) * | 1972-09-06 | 1974-08-20 | ||
JPS579346U (ja) * | 1980-06-17 | 1982-01-18 | ||
JPH0641000B2 (ja) | 1985-05-08 | 1994-06-01 | 石川島播磨重工業株式会社 | 汚泥の脱水装置 |
JPS6213551U (ja) * | 1985-07-12 | 1987-01-27 | ||
JPH041346B2 (ja) * | 1985-08-13 | 1992-01-10 | Fuji Xerox Co Ltd | |
DE3622655A1 (de) * | 1986-07-05 | 1988-01-14 | Krauss Maffei Ag | Dekantierzentrifuge |
JPH06190302A (ja) * | 1992-04-06 | 1994-07-12 | Alfa Laval Separation Inc | ビーチ部において途切れたフライトを有するデカンタ型遠心分離機 |
JPH0957153A (ja) * | 1995-08-21 | 1997-03-04 | Tsukishima Kikai Co Ltd | 遠心濃縮機 |
JPH0957152A (ja) * | 1995-08-21 | 1997-03-04 | Tsukishima Kikai Co Ltd | 遠心濃縮機 |
JP2000237630A (ja) * | 1999-02-19 | 2000-09-05 | Kubota Corp | 遠心脱水装置 |
JP2000254549A (ja) | 1999-03-08 | 2000-09-19 | Nishihara Environ Sanit Res Corp | 薬品注入手段を備えた遠心分離機 |
JP4153138B2 (ja) | 2000-02-10 | 2008-09-17 | 株式会社クボタ | 遠心分離装置 |
JP2002153772A (ja) * | 2000-11-22 | 2002-05-28 | Kubota Corp | 遠心分離装置 |
JP2006192403A (ja) | 2005-01-17 | 2006-07-27 | Tokyo Electric Power Environmental Engineering Co Inc | 脱水汚泥の含水率の低下方法 |
JP2010264417A (ja) | 2009-05-18 | 2010-11-25 | Nishihara Environment Technology Inc | 遠心分離装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2679312A4 * |
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