JP2015020115A - Slurry feeding system and slurry feeding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a slurry feeding system capable of molding even such slurry as with unstable water content or characteristics into a sheet-like or string-like shape and securely feeding the slurry, and a slurry feeding method.SOLUTION: A slurry feeding system is a system for feeding slurry 11 after a primary dehydration treatment to a secondary dehydrator 40. The slurry feeding system includes: a feed port 31 configured to feed the slurry 11 to the secondary dehydrator 40; and a water addition device 24 to slurry, arranged on an upstream of the feed port 31.

Description

  The present invention relates to a system and method for supplying slurry such as sludge produced from wastewater treatment facilities and the like and a hydrous intermediate produced in a production process of industrial products to a dehydrator.

  Slurry dehydration is widely performed when reducing sludge generated from a wastewater treatment plant, or when separating and recovering useful materials from intermediate products during production of various industrial products. In addition, in order to obtain a lower water content by highly dehydrating the slurry, the slurry is first dehydrated by mechanical dehydration such as centrifugation or filter press, and then further heated and dried, or by electroosmotic dehydration. In some cases, secondary dehydration treatment may be performed. In such secondary dehydration treatment, the slurry is generally supplied in the form of a sheet or string in order to improve the dehydration efficiency.

  For example, in the electroosmotic dehydration method, it is desirable that the slurry is formed into a thin and uniform layer when a direct current voltage is applied with the slurry sandwiched between an anode and a cathode. This is because if the slurry layer is too thick, the electrical resistance increases and the power consumption increases. In addition, even when the slurry has a non-uniform thickness and voids, the voids do not conduct electricity, so the electrical resistance increases and power consumption increases.

  Examples of dryers that heat and dehydrate the slurry include a drum dryer that dries the slurry on the surface of the heated drum by circulating steam, and a belt dryer that passes hot air while the slurry is conveyed by a conveyor belt. . In any case, in order to facilitate diffusion of moisture in the slurry to the surface, the slurry is preferably supplied in the form of a sheet or string.

  In this regard, in Patent Document 1, in a sludge dewatering apparatus equipped with an electroosmotic dehydrator as a secondary dehydrator, the sludge is cut out while stirring with a screw, and a sheet having a predetermined thickness is formed by a pair of parallel rollers disposed below. It has been proposed to be molded into a shape and supplied to an electroosmotic dehydrator. Patent Document 2 describes that dehydrated sludge is supplied to a multi-stage band dryer (belt dryer) through a forming nozzle having a rectangular section having a width of about 2 m at maximum and a thickness of about 10 mm. ing.

Japanese Patent No. 4651045 Japanese Patent No. 5176033

  However, when the slurry is supplied in the form of a sheet or string, various supply problems may occur due to non-uniformity of the fluidity of the slurry and fluctuation over time. . The present inventors have found that there is still room for improvement in order to stably supply the slurry to the dehydrator even by the methods described in Patent Documents 1 and 2.

  That is, in the method of Patent Document 1, the sludge that has not entered between the parallel rollers rolls on the rollers to form a dump, which inhibits the entry of newly supplied sludge, and the sludge lump is greatly increased in a snowball style. It could happen. This is because if there is a part where the water content is low and the fluidity is impaired, the sludge is not smoothly sandwiched between the parallel rollers, or when the sludge is put on the rollers, a lump larger than the roller interval is formed. This happens due to the formation.

  When such a situation occurs, it is necessary to stop the operation of the dehydrator and allow the worker to break down the dumpling sludge and push it between the rollers. Or the problem that the uniformity of the sheet sludge supplied to a dehydrator is spoiled even if it does not stop operation.

  In the method of Patent Document 2, the sludge does not flow out uniformly from the entire width of the slit nozzle, and the distribution of the sludge amount in the width direction may be non-uniform.

  The present invention has been made in consideration of the above points, and a slurry supply system capable of stably forming a sheet or string into a sheet or string even if the water content and properties are not stable. And to provide a method.

  In response to the above problem, in the present invention, when the fluidity of the slurry to be supplied is lowered, the problem in supply is prevented by adding water to the slurry.

  A slurry supply system of the present invention is a system for supplying a slurry subjected to primary dehydration treatment to a secondary dehydrator, and a supply port for supplying slurry to the secondary dehydrator, and upstream of the supply port And an apparatus for adding water to the slurry.

  Here, “upstream” is based on the slurry flow. The fact that the water supply device is provided upstream of the supply port means that the slurry that has passed through the water supply device reaches the supply port thereafter. With this configuration, when the fluidity of the slurry is lowered, it is possible to add water to the slurry to increase the fluidity, and to prevent supply problems.

  In one aspect of the slurry supply system, the slurry is sludge. The sludge generated in a wastewater treatment facility, a waste treatment facility or the like has a particularly large effect obtained by the slurry supply system of the present invention because the moisture content and properties are likely to vary among various slurries.

  Preferably, the slurry supply system further includes a pumping pump, and the slurry is pumped by the pumping pump. According to this configuration, by applying pressure to the slurry and discharging it from the supply port, the discharge amount of the slurry is less affected by viscosity and fluidity.

  Preferably, the slurry supply system further includes slurry fluidity detecting means. Thereby, the fluctuation | variation of the fluidity | liquidity of a slurry can be monitored, and water addition can be performed when fluidity | liquidity falls.

  Preferably, the slurry supply system having a pressure feed pump has a pressure gauge for measuring the slurry supply pressure as the fluidity detecting means of the slurry. Thereby, the fluctuation | variation of fluidity | liquidity can be detected more simply. The pressure gauge can be provided between the pressure pump and the supply port.

  The slurry supply system may supply a slurry formed into a sheet shape to a drum dryer or an electroosmotic dehydrator that functions as a secondary dehydrator. In these dehydrators, since the dewatering efficiency is greatly improved by supplying the slurry in a thin and uniform sheet, the effect of the slurry supply system of the present invention is particularly great.

  The slurry supply system is a system for supplying slurry to a drum dryer or an electroosmotic dehydrator that functions as a secondary dehydrator, and a plurality of the supply ports are provided at intervals in the width direction. Good. Here, the “width direction” refers to the width direction of the slurry supplied to the secondary dehydrator. Thereby, the distribution in the width direction of the slurry supply amount can be made more uniform.

  The slurry supply method of the present invention is a method of supplying the slurry discharged from the primary dehydrator to the secondary dehydrator, the step of pumping the slurry with a pump, and the slurry from the supply port to the secondary dehydrator A step of supplying, a step of detecting the supply pressure of the slurry, and a step of adding water to the slurry when the supply pressure exceeds a predetermined magnitude.

  By this method, even when the fluidity of the slurry is lowered, it can be added to the slurry to improve the fluidity, thereby preventing supply problems.

  According to the slurry supply system or the slurry supply method of the present invention, even a slurry whose water content and properties are not stable can be formed into a more uniform sheet or string and stably supplied to the dehydrator. it can.

It is a figure which shows the whole structure of 1st Embodiment. It is a figure which shows the whole structure of 2nd Embodiment. It is a figure which shows the sludge supply machine of 2nd Embodiment. It is a figure which shows the whole structure of 3rd Embodiment. It is a figure which shows the sludge supply machine of 3rd Embodiment. It is a figure which shows the result of a sludge supply experiment. It is a figure explaining the condition where the moisture content of the sludge stored by the hopper becomes non-uniform | heterogenous.

  A first embodiment of the present invention will be described with reference to FIG. In the first embodiment, sludge generated from a wastewater treatment facility or the like as slurry is supplied to an electroosmotic dehydrator.

  First, the overall configuration of this embodiment and the flow of sludge will be described. FIG. 1 shows a sludge conveyance system 20, a sludge feeder 30 and an electroosmotic dehydrator 40.

  As the sludge 11 to be treated in the present embodiment, sludge produced from various wastewater treatment facilities and waste treatment facilities and subjected to primary dehydration treatment can be used. The method and frequency | count of a primary dehydration process are not specifically limited, As long as the fluidity | liquidity of sludge is not lost, it can process 1 time or more by various methods. When the sludge is biologically treated sludge, its moisture content is typically 97-99%. The moisture content of the sludge which processed this by primary dehydration processes, for example, mechanical dehydration methods, such as centrifugation and a filter press, is about 82 to 86% typically.

  In FIG. 1, a sludge conveyance system 20 includes a hopper 21, a hydration device 24 and a kneader 23 below the hopper 21, a pump 22 for pumping sludge below the kneader 23, a conveyance pipe 26, a pump A pressure gauge 25 is provided at the outlet from 22. The sludge 11 is temporarily stored in the hopper 21, kneaded by the kneader 23, and pumped by the pump 22 to the sludge feeder 30 through the transfer pipe 26.

  The sludge supply machine 30 has a sludge supply port 31. The sludge pumped by the pump 22 is discharged from the sludge supply port 31 and supplied to the electroosmotic dehydrator 40. If the sludge fluidity becomes poor due to some cause, an increase in pump discharge pressure can be detected by the pressure gauge 25, so that the water content of the sludge 11 can be increased by operating the water adding device 24.

  The electroosmotic dehydrator 40 includes an anode-side pressure rotary drum 42, an endless belt 43 wound around a plurality of rollers 45, and a portion of the belt 43 that overlaps the belt 43. And an endless filter 44. A region where the rotary drum 42, the filter 44, and the belt 43 face each other constitutes a dewatering unit 46. The sludge 11 is squeezed by the rotary drum 42 and the belt 43 and dehydrated by electroosmosis. Is done. The thickness of the sludge sheet supplied to the dewatering unit is 5 to 30 mm.

  Next, details of each part will be described.

  In the sludge transport system 20 of FIG. 1, once the sludge 11 is temporarily stored in the hopper 21, several advantages can be obtained. The advantage is that it can absorb the difference in the processing capacity of the former stage equipment and the latter stage electroosmosis dehydrator where sludge is generated by adjusting the operation time, and can be used as a buffer in case of any equipment trouble. However, when the sludge 11 is stored in the hopper 21, drying proceeds on the surface that comes into contact with air, and moisture in the sludge flows downward, so that the moisture content of the sludge tends to be uneven depending on the position in the hopper 21. Furthermore, if new sludge is sent from there to the previous stage, layers with different moisture contents will be stacked one above the other. When this state is schematically shown in FIG. 7, a portion 11 a having a low moisture content and a portion 11 b having a high moisture content are formed in the hopper 21. In such a state, even if the sludge is stirred and cut out, it becomes difficult to make the sludge properties uniform. Moreover, since sludges having different moisture contents are sequentially pumped, the moisture content of the sludge sent to the sludge feeder varies over time.

  The kind of the kneader 23 is not particularly limited, and a known one such as a rotating paddle or screw can be used. Further, sludge may be kneaded by a static mixer downstream of the pump 22. The type of the pump 22 is not limited, but it is always possible to continue to send a certain secured volume first, and it is suitable for transporting substances with high viscosity and low fluidity. A uniaxial pump such as a registered trademark) can be suitably used.

  The pressure gauge 25 can be provided between the pump 22 and the sludge supply port 31 of the sludge supply machine 30. For example, it can be provided in the middle of the pump outlet, the pipe 26 of the sludge conveyance system, immediately before the sludge supply port 31, and the like. Although the value measured differs depending on the location where the pressure gauge is provided, it is not always necessary to know the pressure value at a specific location for the purpose of this embodiment. Regardless of where the pressure gauge is installed, it is possible to grasp the relationship between pressure measurement values and supply problems for individual devices by recording pressure measurements and supply problems for a while. .

  In this embodiment, the pump discharge pressure, that is, the slurry supply pressure is measured by the pressure gauge 25 as a means for indirectly detecting the fluidity of sludge, but other means may be used. For example, the sludge discharged from the sludge supply port 31 may be observed visually without providing any fluidity detecting means, a weight sensor such as a weighing conveyor equipped with a load cell, a flow sensor such as an electromagnetic flow meter, an image A monitor or the like may be used as the slurry fluidity detection means.

  The water adding device 24 can be provided upstream of the sludge supply port 31. For example, it can be provided in the middle of the kneader 23 at the lower part of the hopper, the pipe 26 of the sludge conveyance system, immediately before the sludge supply port 31, and the like. The water used for hydration does not necessarily need to be fresh water, and any water that does not adversely affect the sludge properties, such as sewage used for cleaning equipment to which sludge has adhered, may be used.

  The form of the sludge supply port 31 is not particularly limited. For example, the sludge supply port 31 may be a nozzle or a hole provided in the pipe wall of the header pipe. Various shapes such as a circular shape, an oval shape, a rectangular shape, and a slit shape can be adopted as the shape of the discharge cross section of the supply port 31. Moreover, the number of the sludge supply ports 31 may be one or plural. The size of the sludge supply port 31 can be appropriately designed in consideration of the discharge pressure, the capacity of the subsequent dehydrator, and the like.

  The material and structure of the rotary drum 42, belt 43, and filter 44 of the electroosmotic dehydrator 40 are not particularly limited, and known ones can be used. The sludge 11 supplied to the electroosmotic dehydrator 40 is adjusted in shape and thickness by the pressing roll 48 and enters the dehydrating unit 46.

  In this embodiment, when the pump pressure rises, such as when the sludge 11 having a low water content is approaching the sludge supply port 31, the above configuration allows water to be added to the sludge 11. As a result, it is possible to prevent the supply port 31 from being blocked and clogging at the pressing roll 48 after the supply and discharge. Moreover, even if it does not reach this obstacle, it can suppress that the uniformity of a sheet | seat is impaired by including the part where sludge is poor in fluidity | liquidity. For example, the sludge can be discharged more uniformly from the entire width of the slit-like nozzle.

  Sludge whose moisture content has decreased due to primary dehydration may change its fluidity greatly due to slight changes in moisture content. However, according to the system or method of the present embodiment, sludge whose moisture content and properties are not stable. Even if it exists, it can be stably supplied to the secondary dehydrator.

  Next, a second embodiment of the present invention will be described based on FIG. 2 and FIG. In the second embodiment, sludge generated from a wastewater treatment facility or the like as slurry is supplied to an electroosmotic dehydrator. The second embodiment is different from the first embodiment in that the supply ports 31 of the sludge supply machine 30 are a plurality of nozzles 31 provided at intervals in the width direction.

  FIG. 2 shows the sludge transport system 20, the sludge feeder 30 and the electroosmotic dehydrator 40. In FIG. 2, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG. The sludge supply machine 30 has a plurality of sludge supply ports 31. The sludge pumped by the pump 22 is discharged from the plurality of sludge supply ports 31 in a string shape such as a string shape or a ribbon shape, and supplied to the electroosmotic dehydrator 40. The sludge 11 from the sludge feeder 30 is discharged to the receiving portion 46, and is then sandwiched between the downstream pressing roll 41, the filter 44, and the belt 43 to be formed into a sheet shape, and then the rotary drum 42, the filter 44, and the belt 43. Enters the opposite dewatering section 46.

  Next, the detail of the sludge supply machine 30 and the electroosmosis dehydrator 40 of 2nd Embodiment is demonstrated.

  FIG. 3 shows the configuration of the sludge feeder 30 together with a part of the electroosmotic dehydrator 40. In FIG. 3, the sludge supply machine 30 includes a header pipe 32 to which the sludge pumped by the pump 22 arrives, and a plurality of sludge supply ports branched from the header pipe 32 and provided at intervals in the width direction. Nozzle 31. The nozzle 31 of FIG. 3 is a straight tube, and a pipe 35 branched from the header tube 32 is connected in the middle of the straight tube. Each nozzle 31 includes a discharge amount adjusting valve 33 and a lid 34 that can be opened and closed at the rear end.

  In FIG. 3, the shape of the nozzle 31 is not particularly limited. Various shapes such as a circular shape, an oval shape, a rectangular shape, and a slit shape can be adopted as the shape of the discharge section of the nozzle 31. Preferably, the aspect ratio of the discharge cross section is close to 1. This is because the amount of sludge discharged from each nozzle 31 does not vary depending on the position in the width direction. Since the supply port 31 is a nozzle, an appropriate discharge resistance is generated when the sludge passes through the nozzle 31, the discharge amount is less affected by the sludge fluidity, and the discharge amount from the plurality of nozzles 31 is balanced. Is less likely to fluctuate.

  The size of the nozzle 31 is not particularly limited, but it is preferable that the thickness of the discharged sludge is sufficiently smaller than the diameter of the pressing roll 41. Specifically, the uppermost surface of the discharged sludge is the rotation center of the pressing roll 41. It is preferable that it is in a lower position. More specifically, when the thickness of the discharged sludge is h, the radius of the pressing roll 41 is R, and the gap between the pressing roll 41 and the filter 44 is C, the relationship of h <R + C is established. preferable. This is because it is possible to suppress the discharge of a sludge lump that does not easily enter between the sheet forming means, that is, between the filter 44 and the pressing roll 41. In the present embodiment, since the pressure is applied to the sludge, the sludge can be discharged without any problem even if the opening of the nozzle 31 is small.

  The number of nozzles 31 can be determined according to the size of the equipment, the width of the sludge supplied to the electroosmosis dewatering unit, the viscosity of the sludge, etc., but is 2 or more because it is provided at intervals. It is preferably 3 or more. By providing a plurality of supply ports 31, sludge can be discharged to a preset position in the width direction, and the distribution of the sludge amount in the width direction can be made more uniform. According to the experiments by the inventors, good results were obtained by using three nozzles with a width of 500 mm and five nozzles with a width of 2000 mm.

  The interval between the nozzles 31 is not particularly limited, but it is preferable that the sludge discharged from each nozzle 31 is large enough to form an independent line. Even when the opening has a slit shape that is long in the width direction, the interval between the adjacent nozzles 31 is preferably larger than the short side or the short diameter of the opening.

  Each nozzle 31 is preferably provided with a discharge amount adjusting valve 33. Thereby, the distribution in the width direction of the amount of sludge supplied to the electroosmosis dehydration unit can be adjusted more closely. As the discharge amount adjusting valve, a known valve valve, needle valve, globe valve or the like can be used.

  In FIG. 3, an openable / closable lid 34 is provided at the rear end of the straight tubular nozzle 31. Accordingly, the lid 34 can be closed during operation, and the lid 34 can be opened during cleaning to easily clean the inside of the nozzle 31.

  The sludge 11 is discharged in a plurality of streaks from the sludge supply device 30 onto the filter 44 supported on the belt 43 by the receiving portion 46 of the electroosmotic dehydrator 40. Preferably, the sludge 11 is discharged near the pressing roll 41. If a nozzle is used as the supply port 31, sludge can be discharged closer to the pressing roll, which is also preferable in this respect.

  Downstream of the sludge receiving portion 47, the belt 43, the filter 44, and a pressure adjusting roll 41 that is disposed above the filter 44 with a space therebetween are entered, and are formed and stretched into a sheet shape. The

  The distance between the pressing roll 41 and the lower filter 44 and belt 43 can be adjusted. In the case where there are a plurality of press rolls 41, it is preferable to gradually narrow the interval in the sludge moving direction because the sludge enters smoothly and the sludge thickness can be determined at the position of the last press roll. .

  Preferably, at least one of the pressing rolls 41 has a driving device different from the belt 43 and the filter 44 so that the rotation speed can be controlled. By making the circumferential speed of the pressing roll 41 slightly larger than the linear speed of the filter 44, the sludge 11 can be sandwiched more strongly and smoothly.

  As described above, the sludge 11 pumped by the pump 22 is divided in the width direction and discharged from the nozzles 31, whereby the distribution of the sludge supply amount in the width direction can be made more uniform. As a result, the sludge can be supplied to the dehydrating unit 46 of the electroosmotic dehydrator 40 in a more uniform sheet form. And when pump discharge pressure rises, it is the same as that of a 1st embodiment that it can be added to sludge 11 and the problem on sludge supply can be prevented.

  Next, a third embodiment of the present invention will be described based on FIG. 4 and FIG. In the third embodiment, sludge generated from a wastewater treatment facility or the like as slurry is supplied to a drum dryer. The third embodiment is different from the second embodiment in that the dehydrator is a drum dryer.

  FIG. 4 shows the sludge conveyance system 20, the sludge feeder 30 and the drum dryer 50. In FIG. 4, the same components as those in the second embodiment are denoted by the same reference numerals as those in FIG. The sludge supply machine 30 has a plurality of sludge supply ports 31. The sludge pumped by the pump 22 is discharged from the sludge supply port 31 in a string shape such as a string shape or a ribbon shape and supplied to the drum dryer 50. The sludge 11 is heated in contact with the surface of the high temperature drum 52 and dried.

  FIG. 5 shows a portion where the sludge 11 is supplied to the drum dryer 50. The sludge 11 is discharged from the nozzle 31 onto the drum 52 in a plurality of streaks. Next, the sludge 11 is spread in the form of a sheet on the surface of the drum 52 by two pressing rolls 58a and 58b provided at an interval above the drum 52. In the drum dryer, it is not always necessary to form the sludge into a sheet shape, but the dewatering efficiency is improved when the sludge contacts the drum in a wider area. The roll 59 is disposed at a position opposite to the direction in which the sludge travels in order to prevent the sludge 11 that has not smoothly entered the holding roll 58a from spilling out.

  Also in the third embodiment, when the pump discharge pressure rises, it can be added to the sludge 11 to prevent the problem of sludge supply as in the first and second embodiments.

  Next, a sludge supply experiment performed by the present inventors for confirming the relationship between the moisture content of sludge and supply trouble will be described.

  The supply experiment was performed using the equipment of the third embodiment shown in FIGS. 4 and 5. In the experiment, sludge obtained by dewatering sludge generated at a human waste treatment plant to a water content of about 82 to 86% by a centrifugal separation method was used. The drum dryer 50 includes a drum 52 having a diameter of 1000 mm and a width of 2000 mm, and two pressing rolls 58 a and 58 b provided above the drum 52 with a space therebetween. The sludge 11 pumped by a pump (not shown) was discharged from the nozzle 31 to the front of the pressing roll 58a. Nozzles 31 having an inner diameter of about 25 mm and a length of 200 mm were branched from the header tube 32 and provided in the width direction. A pressure gauge (not shown) was provided at the outlet of the pump to measure the pump discharge pressure. The sludge 11 shrinks in volume as it dries, but has a thickness of about 20 to 30 mm at the positions of the press rolls 58a and 58b.

  FIG. 6 shows the results of five experiments. Each experiment was run for about 6 hours on different days. The horizontal axis in the figure indicates the operation time from the start of the experiment, and the vertical axis indicates the pump discharge pressure at that time. The moisture content of sludge in each experiment varied in the range of 81.8% to 86.2%. In an experiment on May 12, when the moisture content was relatively high at 86.2%, the discharge pressure was stable at about 0.2 MPa or less. On the other hand, in the experiments on April 11, 13, 14, and 19 in which the moisture content was 85% or less, the discharge pressure was almost doubled to 0.4 MPa or more, and increased to 0.5 MPa at the maximum. In the experiment on April 13, the discharge pressure rapidly increased from 0.3 MPa in the initial operation to 0.4 MPa or more. Among the five experiments, in the experiments on April 11, 14, and 19, sludge clogging occurred at the position of the presser roll 58b.

  As a result of this experiment, the pump discharge pressure increased greatly and supply failure occurred when the moisture content of the sludge decreased by only 1 to 2 points from the middle of the 80% range. However, the moisture content of the sludge often varies when it is supplied from the previous equipment as in this experiment, and even if a primary dehydrator is installed in the previous stage, the moisture content (%) of the sludge is It is difficult to control within the range of 1 to 2 points. Further, as described above, the moisture content of the sludge changes during storage in the hopper 21.

  Therefore, the effect of the present invention is clear also from the result of this experiment. In the present invention, when the fluidity becomes poor while directly or indirectly monitoring the supply amount of sludge, supply failure can be prevented by adding water to the supplied sludge. For example, in the case shown in FIG. When the pump discharge pressure exceeds 0.3 MPa, water is added.

  In addition, adding water to sludge scheduled for dehydration is accompanied by energy loss. However, if the increase in water content (%) by only 1 to 2 points can prevent sludge supply problems to the subsequent electroosmosis dehydrator and decrease in efficiency of the electroosmosis dehydrator as a whole, It may lead to improvement of sludge treatment efficiency. In this regard, for example, the loss when the water content of the sludge is added by 2.2 points from the average of 84.0% of the experiment on April 14 to the average of 86.2% of the experiment on May 12 is as follows. Estimated. Assuming that the volume of sludge pumped and the mass of water removed by the electroosmosis dehydrator are constant, the sludge is 84% to 86.2% compared to the case where the sludge is dehydrated from 84% to 68%. As a result, the treatment capacity was reduced by 15%, and the water content of the sludge after dehydration was increased by 4 points from 68% to 72%. Sludge having a moisture content of about 70% originally has no fluidity, and such a change in moisture content does not cause a problem in operating the sludge transporting equipment after dehydration. On the other hand, the merit of adding water is that the possibility of clogging at the supply port and the pressing roll, the accompanying stoppage of the apparatus, cleaning work, increased burden on workers, risk of accidents, and the like can be reduced.

  The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the technical idea.

  For example, although the case where the sludge produced from a wastewater treatment facility etc. is processed as a slurry was demonstrated in the said embodiment, the slurry made into the object of this invention is not limited to this. The present invention can also be used for the treatment of sludge generated in various processes such as a human waste treatment plant, a sewage treatment plant, a paper mill, and a smelting plant in the mining industry even when sludge is targeted. Furthermore, the present invention is intended for slurries other than sludge, separation / extraction of useful components in the food manufacturing field, filtration / squeezing to recover soy sauce, etc., separation / collection of polymer particles in the polymer manufacturing field, etc. It can be used in the manufacturing process. In some industrial fields, words such as “preliminary dehydration / main dehydration” may be used instead of “primary dehydration / secondary dehydration”. Even in such a case, when the water content and properties are not stable in the step of supplying the slurry after dehydration to the next dehydrator and the same problem as in the case of sludge occurs, the supply system or method of the present invention Can be used. The relationship between the water content of the slurry and the fluidity depends on the type of slurry and the like, but the water content of the slurry subjected to the primary dehydration treatment is generally 80 to 90%. A supply system or method can be suitably used.

  Moreover, although the example using a pressure pump such as a single-shaft pump has been described in the above embodiment, the sludge may be pneumatically fed by applying air pressure to the hopper instead. Moreover, although the example which discharges the sludge to which pressure was applied from the supply port was shown as said sludge supply machine in the said embodiment, you may make it sludge fall to a secondary dehydrator through a supply port by dead weight. .

  Further, in the electroosmotic dehydrator of the above embodiment, referring to FIG. 1, a belt 44 and a separate filter 44 are used. Therefore, the sludge 11 is discharged onto the belt 43 through the filter 44 superimposed on the belt 43. However, the filter may be omitted when a belt having functions of both a belt and a filter is used. For example, Japanese Patent Application Laid-Open No. 2011-177692 discloses an electroosmotic dehydrator that omits the filter cloth.

  Moreover, although the example which uses the drum-type thing which uses a drum and a belt as an electroosmotic dehydrator was shown in the said embodiment, you may use a flat bed type electroosmotic dehydrator instead. The flat bed type electroosmotic dehydrator places a sludge layer on the flat part of the conveyor belt, pushes down the flat anode and performs electroosmotic dehydration, and with the anode raised, the conveyor belt is the length of the anode plate. Is moved by the amount of.

11, 11a, 11b Sludge 20 Sludge transport system 21 Hopper 22 Pump 23 Kneading machine 24 Water heater 25 Pressure gauge 26 Transport piping 30 Sludge supply machine 31 Nozzle (sludge supply port)
32 Header pipe 33 Discharge amount adjustment valve 34 Lid 35 Piping 40 Electroosmotic dehydrator 41 Press roll (sheet forming roll)
42 Rotating drum 43 Endless belt 44 Endless filter 45 Roller 46 Dewatering part 47 Sludge receiving part 48 Pressing roll 50 Drum dryer 52 Drum 58a, 58b Holding roll 59 Sludge spill prevention roll

Claims (8)

A system for supplying a slurry subjected to primary dehydration treatment to a secondary dehydrator,
A supply port for supplying slurry to the secondary dehydrator;
An apparatus for adding water to the slurry disposed upstream of the supply port;
A slurry supply system. The slurry supply system according to claim 1, wherein the slurry is sludge. A pressure pump,
The slurry is pumped by the pump.
The slurry supply system according to claim 1 or 2. The slurry supply system according to any one of claims 1 to 3, further comprising slurry fluidity detection means. The slurry supply system according to claim 4, wherein the fluidity detection means of the slurry is a pressure gauge that measures a slurry supply pressure. The secondary dehydrator is selected from the group consisting of a drum dryer and an electroosmotic dehydrator;
The supply port supplies slurry formed into a sheet shape,
The slurry supply system according to any one of claims 1 to 5. The secondary dehydrator is selected from the group consisting of a drum dryer and an electroosmotic dehydrator;
A plurality of the supply ports are provided at intervals in the width direction,
The slurry supply system according to any one of claims 1 to 5. A method of supplying slurry discharged from a primary dehydrator to a secondary dehydrator,
Pumping the slurry with a pump;
Supplying the slurry from the supply port to the secondary dehydrator;
Detecting the supply pressure of the slurry;
Adding water to the slurry when the supply pressure exceeds a predetermined magnitude;
A slurry supply method comprising:

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