JP6013205B2 - Concentrator - Google Patents

Description

  The present invention relates to a concentration apparatus that concentrates by gravity filtration while conveying sludge on the upper surface of a filter body.

  Conventionally, as a pre-process of a belt press-type dehydrator that pressurizes and dewaters sludge such as sewage and industrial wastewater between a pair of upper and lower filter cloth belts, the upper surface of the endless belt-like filter body (filter cloth) that moves around A sludge dewatering system provided with a concentration device that performs gravity filtration while being transported is used.

  In this type of sludge dewatering system, in order to improve the dewatering capacity of the belt press-type dewaterer, it is important to improve the sludge concentration performance in the pre-concentration apparatus. Of course, even when the concentration device is used alone or when it is systemized with a device other than the belt press type dehydrator, it is essential to improve the concentration performance.

  In Patent Document 1, the upper surface of one filter cloth belt constituting the belt press type dehydrator is used as a gravity filtration zone (concentration device), and the water-containing sludge conveyed on the filter cloth belt in the middle of the gravity filtration zone. The structure which installed the mixing apparatus for scraping up (sludge) is disclosed. This mixing device is composed of a screw, paddle-shaped scraping rod, scraping plate, etc., and by providing a mixing device, it is said that the sludge can be scraped to make the thickness uniform and its moisture content can be reduced. ing.

Japanese Utility Model Publication No. 62-13296

  By the way, in the structure of patent document 1, the moisture content is reduced by scraping up the sludge conveyed on a filter cloth belt, equalizing the thickness, and destroying the rate-controlling layer formed in a water-containing sludge. For this purpose, the above-mentioned mixing device is provided. In the case of using a screw as the mixing device, the rotation speed (rotation speed) of the screw is set within a range that does not destroy the aggregated particles (floc) of the hydrous sludge.

  However, when the amount of sludge transported by the filter cloth belt increases or decreases, it may be difficult to smoothly wind the entire amount of sludge transported with a screw. In this case, the sludge is not smoothly wound around the screw and passes directly to the downstream side. However, in the configuration described in Patent Document 1, the purpose of installing the screw is simply to scrape the sludge. It is assumed that no serious problem will be caused even if sludge is caught in the sludge.

  On the other hand, if a screw is installed in the middle of the concentrator, the sludge can be well kneaded and consolidated with the drug while moving the sludge in the direction crossing the conveying direction, and the finally obtained dehydrated cake There is an advantage that the concentrated concentration of can be increased. However, when the screw is provided to move and knead the sludge in this way, if the sludge does not smoothly enter the screw and passes downstream as it is, the original purpose of installing the screw is sufficiently achieved. The concentration of the resulting dehydrated cake can also be reduced. In addition, when the amount of sludge transported by the filter cloth belt increases or decreases, the amount of entrainment with the screw changes, and there is a possibility that the drug cannot be uniformly mixed in the sludge.

  The present invention has been made in consideration of the above-described conventional problems, and an object of the present invention is to provide a concentrating device capable of smoothly moving and kneading sludge conveyed on a filter cloth belt with a screw. .

  The concentration device according to the present invention is a concentration device that concentrates by gravity filtration while conveying sludge on the upper surface of the filter body, and extends in a direction intersecting the direction of sludge conveyance by the filter body, and the sludge is rotated by its rotation. A screw that moves in a direction that intersects the conveying direction of the filter body, and a control unit that controls the rotational speed of the screw in accordance with the amount of sludge that is conveyed by the filter body.

  According to such a configuration, by controlling the rotational speed of the screw that moves the sludge in accordance with the amount of sludge transported by the filter, it is possible to prevent the sludge from being caught in the screw. In addition, the amount of sludge scraped by the screw can be made uniform, and the sludge conveyed on the filter can be smoothly moved and kneaded by the screw, so that the concentrated concentration of sludge can be increased.

  A guide plate for guiding the movement of the sludge by the screw may be erected at a position on the downstream side of the screw and in the vicinity of the screw in the sludge conveyance direction by the filter. Then, the sludge can be moved by the screw while being dammed by the guide plate, so that the sludge can be kneaded more uniformly, and further, the concentrated concentration can be further increased by pressing the sludge.

  When a sludge transported on the filter body is provided with a chemical injection device for adding a chemical agent upstream of the screw, the screw sludge is controlled by controlling the rotational speed of the screw according to the amount of sludge transported. The amount of scraping can be made uniform at an optimum amount, and the chemical can be uniformly kneaded in the sludge, so that the concentrated concentration of sludge can be further increased.

  The control unit controls the rotational speed of the screw according to the traveling speed of the filter body. When the traveling speed of the filter body is faster than a reference speed, the rotational speed of the screw is set to the reference speed. It may be faster than the corresponding reference rotational speed.

  A measuring device that measures the thickness of the sludge conveyed on the filter body upstream of the screw, and the control unit controls the rotational speed of the screw according to the detection result of the measuring device. In the case where the thickness of the sludge conveyed on the filter body is higher than the reference thickness, the rotation speed of the screw may be made faster than the reference rotation speed set corresponding to the reference thickness.

  According to the present invention, by controlling the rotational speed of the screw that moves the sludge according to the amount of sludge transported, the amount of sludge scraped by the screw is made uniform, and the sludge transported on the filter body is smoothed by the screw. And can be kneaded to increase the concentration of sludge.

FIG. 1 is a side view showing an overall configuration of a sludge dewatering system including a concentrating device according to an embodiment of the present invention. FIG. 2 is a plan view of the concentrating device shown in FIG. FIG. 3 is a block diagram showing the configuration of the control device of the sludge dewatering system shown in FIG. 1 and its control system. FIG. 4 is an enlarged explanatory view of the periphery of the moving mechanism of the concentrating device shown in FIG. 2, and in FIG. 4A, the rotational speed of the screw appropriately corresponds to the amount of sludge transported by the filter cloth belt. FIG. 4B is an explanatory diagram in a state where the rotational speed of the screw does not appropriately correspond to the amount of sludge transported by the filter cloth belt. FIG. 5 is a side view showing an overall configuration of a sludge dewatering system including a concentration device according to a modification.

  Hereinafter, a preferred embodiment of the concentrating device according to the present invention will be described in detail in connection with a sludge dewatering system equipped with the concentrating device, with reference to the accompanying drawings.

1. Description of Overall Configuration of Sludge Dewatering System FIG. 1 is a side view showing the overall configuration of a sludge dewatering system 10 including a concentrating device 12 according to an embodiment of the present invention, and FIG. 2 is a concentrating device shown in FIG. 12 is a plan view of FIG. A sludge dewatering system 10 shown in FIG. 1 is a sludge treatment facility for discharging sludge (for example, sewage sludge) by gravity with an upper concentration device 12 and then discharging it as a dehydrated cake by dehydrating under pressure with a lower dewatering device 14. is there. The concentrating device 12 can be applied to systems other than the system combined with the dehydrating device 14 as described above, and the concentrating device 12 may be used alone.

  The sludge dewatering system 10 is concentrated by the concentrating device 12 including a filtering unit 18 that gravity filters (gravity concentration) sludge on the upper surface 16a of the filter cloth belt (filter body) 16 that travels in an endless track, and the concentrating device 12. A dewatering device 14 that conveys sludge while being sandwiched between a pair of filter cloth belts 20 and 22 and pressurizes and dehydrates, and a control device (control unit) 15 that comprehensively controls the entire system are provided. Immediately before the concentrating device 12, there is provided a flocculation / mixing tank 24 which is transported from the preceding equipment of the sludge dewatering system 10 and mixes the polymer flocculant (first chemical) F1 into the sludge. As the polymer flocculant F1, generally known ones may be used, and examples thereof include an anionic polymer flocculant and a cationic polymer flocculant.

2. Description of the concentration device First, the concentration device 12 will be described.

  As shown in FIGS. 1 and 2, the concentrating device 12 according to the present embodiment includes a filtration unit 18 that gravity filters sludge introduced from the coagulation mixing tank 24 onto the upper surface 16 a of the filter cloth belt 16, and a filtration unit 18. There is provided a pressure unit 28 that depressurizes and dewaters the gravity-filtered sludge by the primary dewatering roller 26 and discharges it to the lower dewatering device 14. A moving mechanism 30 that moves sludge in a direction that intersects (orthogonally in FIG. 2) the conveying direction by the filter cloth belt 16 is provided in the middle of the filtering unit 18.

  The filtration unit 18 is composed of an upper surface (outer peripheral surface) 16a of an endless filter cloth belt 16 that is wound around a plurality of rollers 19a, 19b, 19c, 19d, and 19e and driven to rotate in one direction. The sludge is placed on the upper surface 16a of the filter cloth belt 16 stretched between 19e, so that water contained in the sludge is filtered and separated by gravity.

  The filter belt 16 is constituted by, for example, a long belt-like filter cloth having water permeability, a long belt-like metal screen in which a plurality of fine holes are formed in a mesh shape, and each roller with sufficient tension. It is wound around 19a-19e. The filter cloth belt 16 is driven by a predetermined drive roller (for example, a roller 19a) by a drive source such as a motor (not shown) provided in the upper drive unit 29, which is driven and controlled by the control device 15, so that FIG. The vehicle can travel in the direction of the arrow shown in the figure (counterclockwise in FIG. 1). That is, in FIGS. 1 and 2, the direction from the right side (upstream side) to the left side (downstream side) is the sludge transport direction in the concentrator 12.

  Therefore, the sludge thrown in and placed from the outlet port 24a of the flocculation / mixing tank 24 at the upstream position of the filtration unit 18 is transported downstream by the filter cloth belt 16, while only the moisture passes through the filter cloth belt 16 by gravity. Permeated, filtered and dehydrated, the filtered water (separated liquid, filtrate) is collected by the filtrate receiving trays 32a and 32b (see FIG. 1).

  On the upper surface 16a of the filter cloth belt 16 constituting the filtration unit 18, a plurality of rod bodies 34 (a total of twelve configurations are illustrated before and after the moving mechanism 30 in FIG. 2) are erected. The rod 34 is an obstacle for abutting and dispersing the sludge transported on the filter cloth belt 16 to promote draining of the sludge, and its installation position, number, shape and the like can be appropriately changed. Note that a part of the rod body 34 installed on the upstream side of the screws 40 a and 40 b may be replaced with a roller (not shown) similar to the primary dewatering roller 26. In that case, a slight gap may be provided between the roller and the filter cloth belt 16, and the roller is used not for dehydration but for simple draining. There may be a plurality of the rollers.

  A second chemical injection device (chemical injection device, chemical addition device) for adding an iron-based inorganic flocculant (second chemical) F2 to the sludge to be conveyed on the upstream side of the moving mechanism 30 in the filtration unit 18. 36 is provided. The second chemical injection device 36 includes a chemical tank 36a for storing the inorganic flocculant F2, and a first line 36c and a second line 36d branched from the outlet of the chemical tank 36a by a two-way valve 36b. As the inorganic flocculant F2, generally known ones may be used, and examples thereof include iron-based and aluminum-based ones.

  As shown in FIG. 2, in the present embodiment, the first line 36 a is further branched into two in parallel, and the two first lines 36 c and 36 c are arranged in the width direction of the filter cloth belt 16 at the upstream position of the moving mechanism 30. The addition nozzles 36e are provided in the vicinity of both side portions of the filter cloth belt 16, respectively. As indicated by a one-dot chain line in FIG. 1, the second line 36d is arranged so that the inorganic flocculant F2 can be added to the sludge charged into the flocculation mixing tank 24. The configuration may be the same as that of the addition nozzle 36e of 36c. In the normal operation state of the present embodiment, the two-way valve 36b is controlled to be switched to the first line 36c side under the control of the control device 15.

  On the other hand, the above-described polymer flocculant F1 is added to the sludge immediately before being put into the agglomeration mixing tank 24 by the first chemical injection device (drug addition device) 38 in the normal operation state of the present embodiment. The first chemical injection device 38 includes a chemical tank 38a for storing the polymer flocculant F1, and a first line 38c and a second line 38d branched from the outlet of the chemical tank 38a by a two-way valve 38b.

  As shown in FIG. 1, the first line 38c can add the polymer flocculant F1 to the sludge charged into the flocculation mixing tank 24 at a position downstream of the second line 36d of the second chemical injection device 36. It is arranged. As indicated by a one-dot chain line in FIG. 2, the second line 38 d extends across the width direction of the filter cloth belt 16 at a position upstream of the first line 36 d of the second chemical injection device 36, and the filter cloth belt 16. The addition nozzles 38e are provided in the vicinity of both side portions of each. In the normal operating state of the present embodiment, the two-way valve 38b is controlled to be switched to the first line 38c side under the control of the control device 15.

  During normal operation, the coagulation mixing tank 24 into which the sludge to which the polymer flocculant F1 is added from the first chemical injection device 38 is introduced has a tank 24b in which the sludge is stored, and the sludge in the tank 24b to the motor 24c. And a stirring blade 24d for stirring. The sludge in which the polymer flocculant F1 is sufficiently mixed in the tank 24b by the stirring blade 24d is put into the upper surface 16a of the filter cloth belt 16 from the outlet port 24a.

  Next, the moving mechanism 30 provided in the middle of the filtering unit 18 moves the sludge conveyed on the filter cloth belt 16 in the crossing direction, while reducing the width direction size and simultaneously increasing the sludge height. By doing so, the inorganic flocculant F2 added by the second chemical injection device 36 is sufficiently kneaded. Thereby, the filtration efficiency of the sludge in the concentration apparatus 12 and the dehydration apparatus 14 can be improved, and the sludge concentration can be increased.

  The moving mechanism (screw conveyor) 30 is open toward the entire upstream surface of the upper surface 16a of the filter cloth belt 16 and can receive sludge, and intersects the conveying direction by the filter cloth belt 16 (orthogonal in FIG. 2). A pair of screws 40a, 40b for moving sludge in the direction to be moved, and a pair of guide plates 42a, 42b which are disposed close to the downstream side of the screws 40a, 40b and are erected on both ends in the width direction of the filter cloth belt 16, respectively. Is provided. In the moving mechanism 30, a gap between the guide plates 42 a and 42 b (substantially the same as the gap between the screws 40 a and 40 b) and a passage (sludge passage 43) for discharging sludge downstream from the moving mechanism 30. It has become.

  The screws 40 a and 40 b extend in a direction orthogonal to the sludge transport direction by the filter cloth belt 16, a screw shaft 44 extending across the filter cloth belt 16 in the width direction, and outer peripheral surfaces on both sides except for the vicinity of the center of the screw shaft 44. And screw blades 41a and 41b provided in a spiral shape.

  The screw shaft 44 is rotationally driven by a drive source such as a motor (not shown) provided in the screw drive unit 31 that is driven and controlled by the control device 15, and corresponds to the traveling speed of the filter cloth belt 16 under the control of the control device 15. Rotation speed (number of rotations) is set and controlled In this way, by controlling the traveling operation of the filter cloth belt 16 and the rotational speed of the screw shaft 44 under the control of the control device 15, the amount and speed of sludge transported by the filter cloth belt 16 and the screw shaft are controlled. The relationship between the rotational speed of 44, that is, the sludge moving speed and scraping speed by the screws 40a and 40b can be easily set and controlled.

  The screw blades 41a and 41b constituting the screws 40a and 40b are respectively provided on the outer peripheral surface of the screw shaft 44 at positions close to both sides in the width direction of the filter cloth belt 16, and the tip ends of the screw blades 41a and 41b are guide plates 42a and 42b. It faces through a gap of the same degree as the gap between them. The direction of the spiral of each screw blade 41a, 41b is a contrast shape (reverse direction) at the center line of the filter cloth belt 16, and the direction of sludge movement by each screw 40a, 40b is set in the opposite direction. Yes. For this reason, each screw 40a, 40b moves sludge from the outer side toward the inner side (center) in the width direction of the filter cloth belt 16, and at the center part where the tips are separated from each other via the gap, both outer sides The sludge moved from the above is pressed against each other to be compacted, and the inorganic flocculant F2 is sufficiently kneaded in the sludge. Each screw 40a, 40b is good also as a structure using each screw shaft instead of the structure using the common screw shaft 44. FIG.

  In the case of the present embodiment, the sludge that has been conveyed on the center side in the width direction of the filter cloth belt 16 to the central portion of the screw shaft 44, that is, the outer peripheral surface of the screw shaft 44 exposed between the screws 40a and 40b, and a pair of A plurality of paddles 45 for smoothly discharging the sludge consolidated in the center by the screws 40a, 40b to the downstream side are provided. The paddle 45 is, for example, an impeller provided in pairs on the outer peripheral surface of the screw shaft 44 along the circumferential direction.

  The guide plates 42a and 42b are provided on the downstream side of the screws 40a and 40b and at a position close to the screws 40a and 40b. It has a bottom portion 47 that covers the lower half of the screws 40a and 40b by curving and projecting toward the upstream side. A pair of passage plates 48a and 48b extending downstream along the sludge transport direction by the filter cloth belt 16 are provided at the center ends of the guide plates 42a and 42b, respectively. The gap between the guide plates 42a and 42b is located on the front side in the direction of sludge movement by the screws 40a and 40b, and this gap forms a sludge passage 43 for discharging the sludge downstream. Yes.

  The wall portion 46 is a plate-like member set to a height approximately equal to the height of the screws 40a and 40b, and the height can be changed as appropriate. As shown in FIG. 1, the bottom portion 47 is a plate-like member that protrudes from the lower end of the wall portion 46 toward the upstream side in the transport direction to a position that is substantially the center of the screws 40 a and 40 b. The standing angle and the like can be changed as appropriate. For the wall portion 46 and the bottom portion 47 constituting the guide plates 42a and 42b, a screen or the like in which many fine holes are formed may be used.

  The passage plates 48a and 48b are erected so as to face each other with a gap having the same width as the gap formed between the screw blades 41a and 41b and between the guide plates 42a and 42b. The passage plates 48a and 48b are wall members that form a passage for smoothly discharging sludge, which is compacted near the center of the filter cloth belt 16 by the screws 40a and 40b, to the downstream side. Set to a height of about. In practice, the sludge consolidated in the center by the screws 40a and 40b is moved downstream from the sludge passage 43 formed between the pair of guide plates 42a and 42b (wall portion 46) by the traveling of the filter cloth belt 16. The passage plates 48a and 48b can be omitted. However, if the passage plates 48a and 48b are provided, the sludge that has been consolidated in the center and increased in height can be more smoothly conveyed to the downstream side. Can do.

  On the upstream side just before the moving mechanism 30, for example, at a position between the moving mechanism 30 and the rod 34 just before the moving mechanism 30, the filter cloth belt 16 constituting the filtering unit 18 is placed on the filter cloth belt 16. A measuring device 37 for measuring the thickness (height) of the sludge before being conveyed and being caught in the moving mechanism 30 is installed.

  The measuring device 37 is, for example, an optical sensor including a light emitting unit 37a and a light receiving unit 37b provided on both sides of the filter cloth belt 16, respectively. By providing the issuing unit 37a and the light receiving unit 37b in a plurality of stages (three stages in FIG. 1) in the height direction, the measuring device 37 can set the thickness of the sludge conveyed on the filter cloth belt 16 in three stages, for example. It can be detected. Based on the measurement result of the measuring device 37, the control device 15 can calculate and estimate the amount of sludge transported by the filter cloth belt 16, that is, the amount of sludge thrown into the moving mechanism 30. As the measuring device 37, a distance sensor or the like that linearly measures sludge conveyed on the filter cloth belt 16 from above may be used.

  The pressurizing unit 28 constitutes a pre-stage dehydrating unit (primary dehydrating unit) of the dehydrating device 14 disposed below the concentrating device 12, and an outer peripheral surface thereof is pressed against the filter cloth belt 16. A primary dewatering roller 26 is provided.

  The sludge that has been filtered and concentrated by the filtration unit 18 and sufficiently mixed with the inorganic flocculant F2 by the moving mechanism 30 and increased in height by compaction is separated between the primary dewatering roller 26 and the filter cloth belt 16 by the pressurization unit 28. After the pressure dehydration between the two, it is discharged / dropped from the outlet of the pressurizing unit 28 (the outlet of the concentrating device 12), and put into the dehydrating device 14 in the next step. The pressurizing unit 28 crushes the sludge that has been consolidated by the moving mechanism 30 and gathered in the center, and sends it to the dehydrating device 14 in a state where it has been expanded again in the width direction of the filter cloth belt 16. It also has a function of increasing the dewatering area of the sludge to be added and improving the dewatering efficiency here.

  As shown in FIG. 1, an inclined plate 49 is disposed between the pressurizing unit 28 and the dehydrating device 14 below the pressurizing unit 28. The inclined plate 49 is a guide for smoothly guiding the sludge discharged / dropped from the concentrating device 12 onto the filter cloth belt 22 serving as a loading position of the dehydrating device 14.

3. Description of Dehydration Device Next, the dehydration device 14 will be described.

  As shown in FIG. 1, the dehydrating device 14 includes a dehydrating unit 50 that depressurizes and dewaters the sludge introduced from the outlet of the concentrating device 12 through the inclined plate 49 while being transported between the pair of filter cloth belts 20 and 22. The pressing part 52 further pressurizes and squeezes the sludge dehydrated by the dehydrating part 50, and has substantially the same configuration as a general belt press type dehydrator.

  The lower filter cloth belt 20 is configured by, for example, a long band-shaped filter cloth having water permeability, a long band-shaped metal screen in which a plurality of fine holes are formed in a mesh shape, and the like. The filter cloth belt 20 is wound around a plurality of rollers 21a, 21b, 21c, 21d, 21e, 21f, 21g, 21h, 21i, 21j, 21k, 21l, 21m, and 21n with sufficient tension. The filter cloth belt 20 is driven by a predetermined driving roller (for example, a roller 21a) rotated by a driving source such as a motor (not shown) provided in the lower driving unit 33 that is driven and controlled by the control device 15, so that FIG. The vehicle can travel in the direction of the arrow shown in the figure (clockwise in FIG. 1).

  In a similar manner, the upper filter cloth belt 22 is constituted by, for example, a long belt-like filter cloth having water permeability, a long belt-like metal screen in which a plurality of fine holes are formed in a mesh shape, and the like. The The filter cloth belt 22 is wound around a plurality of rollers 21o, 21b, 21c, 21d, 21e, 21f, 21g, 21h, 21i, 21j, 21p, 21q with sufficient tension. The filter cloth belt 22 is driven by a predetermined drive roller (for example, a roller 21o) rotated by a drive source such as a motor (not shown) provided in the lower drive unit 33 that is driven and controlled by the control device 15. The vehicle can travel in the direction of the arrow shown in the figure (counterclockwise in FIG. 1).

  A portion where the outer peripheral surfaces (surfaces) of the lower filter cloth belt 20 and the upper filter cloth belt 22 between the rollers 21b to 21i are in contact (or close) while meandering up and down constitutes the dewatering unit 50. During this time, the sludge is sufficiently pressurized and dehydrated. Moreover, the part which contact | abutted (or adjoined) the outer peripheral surface (surface) of the lower filter cloth belt 20 and the upper filter cloth belt 22 between the rollers 21j and 21p comprises the pressing part 52. The sludge is further pressurized and pressed between the rollers 21j and 21p serving as pressing rollers, and is discharged to the outside as a dehydrated cake having a desired moisture content.

  In the vicinity of the inlet of the dewatering device 14, the height of the sludge dropped and introduced from the outlet of the concentrating device 12 onto the filter cloth belt 20 is made uniform to some extent, and a dewatering section formed between the filter cloth belts 20 and 22. A leveling plate 51 is provided for smooth introduction into the 50 inlets 50a. The leveling plate 51 is a plate member that is disposed slightly upstream on the downstream side of the sludge dropping position from the concentrating device 12 onto the filter cloth belt 20, and that is gradually inclined downward toward the inlet 50a and presses the sludge downward. You may form with the leaf | plate spring member urged | biased to the direction.

  At the outlet of the dewatering device 14, a discharge tray 54 is installed in an inclined posture with the rear end lowered so as to be close to the filter cloth belt 20 running on the outer peripheral surface of the roller 21 j. The dehydrated cake is discharged while sliding on the discharge tray 54. Above the discharge tray 54, a scraper (scraping plate) 56 is installed in an inclined posture with the rear end raised so as to be close to the filter cloth belt 22 running on the outer peripheral surface of the roller 21p. The sludge that is not discharged to the discharge tray 54 from between the rollers 21j and 21p but remains attached to the upper filter cloth belt 22 is scraped off by the scriber 56 and discharged to the discharge tray 54. The sludge that remains attached to the lower filter cloth belt 20 is scraped off by the discharge tray 54 and slides down on the discharge tray 54 as it is.

  In such a dewatering device 14, the sludge introduced from the concentrating device 12 onto the filter cloth belt 20 is drawn between the filter cloth belts 20 and 22 constituting the dewatering unit 50 from the inlet 50 a and is sandwiched and pressurized. In the state, it is conveyed downstream. During this time, only moisture passes through the filter cloth belt 20 by the pressure applied by the two filter cloth belts 20 and 22, and is filtered and dehydrated. Further, after being squeezed by the squeezing unit 52, it is discharged onto the discharge tray 54 as a dehydrated cake. The water filtered by the dewatering unit 50 and the pressing unit 52 passes through the filter cloth belt 20 and falls, and is collected by the filtrate receiving tray 58.

  As shown in FIG. 1, in the sludge dewatering system 10 according to the present embodiment, the filter cloth belt 16 of the concentrating device 12 and the filter cloth belts 20 and 22 of the dewatering device 14 are different from the systems generally used conventionally. It is set as the structure which makes each run by an independent endless track. For this reason, the upper drive unit 29 and the lower drive unit 34 are appropriately driven and controlled under the control of the control device 15, so that the traveling speed of the filter cloth belt 16 of the former concentration device 12 and the filter cloth of the subsequent dehydration device 14 are controlled. The running speed of the belts 20 and 22 can be easily controlled to a different speed. In this case, it is preferable to set and control the traveling speeds of the filter cloth belts 20 and 22 of the dehydrator 14 to be lower than the traveling speed of the filter cloth belt 16 of the concentrating device 12. That is, in the sludge dewatering system 10, since the moving mechanism 30 is mounted on the concentrating device 12, the dewatering rate is significantly increased as compared with the conventional concentrating device, and as a result, the sludge that is input to the dewatering device 14. The amount of cake (the amount of cake) can be significantly reduced, and even if the traveling speed of the filter cloth belts 20 and 22 in the dehydrating device 14 is slowed down, it is possible to sufficiently dehydrate the total amount of sludge to be charged. It has become. Then, by slowing the traveling speed of the filter cloth belts 20 and 22 in the dehydrator 14, the time required to pass between the filter cloth belts 20 and 22 during the dehydration can be lengthened, and the dehydrator 14 has a compact configuration. However, high dewatering performance can be obtained.

4). Next, the control device 15 and the control system using the control device 15 will be described.

  FIG. 3 is a block diagram showing the configuration of the control device 12 of the sludge dewatering system 10 shown in FIG. 1 and its control system. As shown in FIG. 3, the control device 15 includes a drive control unit 60, a screw control unit 62, a measuring instrument control unit 64, and a medicine injection device control unit 66, and a predetermined unit stored in the storage unit 68. The controller performs overall control of the dewatered sludge system 10 while controlling the operation of the concentrating device 12 and the dewatering device 14 based on the control program.

  As shown in FIGS. 1 to 3, the drive control unit 60 controls the operation of the upper drive unit 29 and the lower drive unit 33. Information such as the traveling speed of the filter cloth belts 16, 20, and 22 is fed back to the drive control unit 60 via the upper drive unit 29 and the lower drive unit 33. Based on the feedback information and information such as screw rotation speed and sludge thickness (sludge height) from the screw controller 62 and the measuring instrument controller 64, the drive controller 60 filters the belts 16, 20,. 22 travel control is performed.

  The screw control unit 62 controls the operation of the screw drive unit 31. Information such as the rotational speed of the screws 40 a and 40 b (screw shaft 44) constituting the moving mechanism 30 is fed back to the screw control unit 62 via the screw driving unit 31. The screw control unit 62 controls the rotation of the screws 40a and 40b based on the fed back information and information such as the traveling speed and sludge thickness of the filter cloth belt 16 from the drive control unit 60 and the measuring device control unit 64. Do.

  The detection result by the measuring instrument 37 is sent to the measuring instrument control unit 64. Thereby, the control apparatus 15 is based on the sludge thickness information detected by the measuring device 37 and the sludge conveyance amount assumed from the sludge thickness information stored in the storage unit 68 in advance. An optimum rotation speed can be calculated and acquired, and this rotation speed can be transmitted to the screw control unit 62.

  The chemical injection device control unit 66 controls the operation of the first chemical injection device 38 and the second chemical injection device 36. Based on information such as the traveling speed of the filter cloth belt 16 sent from the drive control unit 60 and information such as the thickness of the sludge sent from the measuring device control unit 64, the chemical injection device control unit 66 is a first medicine for sludge. The addition amounts of the polymer flocculant F1 and the inorganic flocculant F2 from the pouring device 38 and the second chemical pouring device 36 are controlled, and the two-way valves 36b and 38b are switched and controlled based on the input settings to the control device 15. To do.

5. Next, the operation / control method and the operational effect of the sludge dewatering system 10 configured as described above will be described.

  First, sludge, which is a processing target to be concentrated and dehydrated by the sludge dewatering system 10, is predetermined by the first line 38 c of the first chemical injection device 38 under the control of the chemical injection device control unit 66 constituting the control device 15. The polymer flocculant F1 is added and introduced into the flocculation mixing tank 24. The sludge introduced into the tank 24b of the agglomeration mixing tank 24 is sufficiently stirred and mixed by the stirring blade 24d to form a floc, and from the outlet port 24a to the upstream side of the upper surface 16a of the filter cloth belt 16, that is, the inlet of the concentrating device 12. It is thrown into.

  The sludge thrown into the concentrating device 12 is conveyed through the filtration unit 18 by the traveling filter cloth belt 16 and gravity filtered (gravity dehydration) while receiving a draining promoting action by the rod body 34 on the way. During this time, as shown in FIGS. 2 and 4 (A), the second chemical injection device 36 is controlled under the control of the chemical injection device control unit 66 for the sludge conveyed on both sides in the width direction of the filter cloth belt 16. The sludge reaches the moving mechanism 30 while a predetermined inorganic flocculant F2 is dropped from the addition nozzle 36e.

  As shown in FIG. 4 (A), in the moving mechanism 30, sludge that has been transported on both sides in the width direction of the filter cloth belt 16 and in which the inorganic flocculant F2 has been added in the form of a continuous belt in the transport direction is each screw 40a. , 40b, it is guided by the guide plates 42a, 42b and moves while being pushed toward the center. At this time, the inorganic flocculant F2 is attached to each lump of small sludge that is moved while being cut at regular intervals by the rotating screw blades 41a and 41b.

  The sludge moved by the screws 40a and 40b with the inorganic flocculant F2 is mixed with the sludge that has been transported through the central portion (center portion) of the filter cloth belt 16. At the same time, sludges are crushed and consolidated in the center of the filter cloth belt 16 by the pressing force of the screws 40a and 40b. As a result, the sludge is passed through the sludge passage 43 from the passage plates 48a and 48b to the downstream side while the rotational force of the paddle 45 is applied while the width direction dimension is reduced and the height (bulk) is increased. During this time, gravity filtration by the filter cloth belt 16 is continued and concentrated to a desired concentration. In addition, since the filter cloth belt 16 is running at the front and rear positions of the screws 40a and 40b, even if the paddle 45 is omitted, the sludge compacted by the screws 40a and 40b is used as the opening between the guide plates 42a and 42b. Of course, it is possible to discharge smoothly from the sludge passage 43 to the downstream side.

  In the concentration process by the concentration device 12, for example, as shown in FIGS. 1 and 2, the filter cloth belt 16 spreads to the width W1 in the width direction of the filter cloth belt 16 at the inlet side of the filtration unit 18 and is introduced at a height h1. When the sludge is discharged from the moving mechanism 30, the sludge is reduced to a width W2 that is narrower than the width W1. It is in a consolidated state. For this reason, the concentration concentration of sludge increases significantly compared with the case where it receives only normal gravity filtration with a general concentration apparatus. Further, since the sludge height is increased on the downstream side from the moving mechanism 30, the gravity filtration efficiency is further improved by its own weight, and the inorganic flocculant F2 is sufficiently kneaded by the screws 40a and 40b. Therefore, even the sludge that has been sufficiently dehydrated and concentrated up to the moving mechanism 30 can further promote concentration by gravity filtration. Further, when the sludge is moved to the central portion by the screws 40a and 40b, the sludge is compressed while being moved by the rotational force of the guide plates 42a and 42b and the screw blades 41a and 41b, so that the concentration of the sludge is further increased. It will be. At this time, the moisture of the sludge compressed by the screws 40 a and 40 b flows from the wall portion 46 through the bottom portion 47 and is filtered by the filter cloth belt 16.

  The sludge consolidated by the moving mechanism 30 is transported further downstream and introduced into the pressurizing unit 28 while receiving drainage promoting action by the rod 34 on the downstream side. The sludge introduced into the pressure unit 28 is sandwiched and pressurized between the primary dewatering roller 26 and the filter cloth belt 16 so that the sludge spreads from the width W2 to the width W3 and becomes a height h3 lower than the height h2. It is dehydrated under pressure, discharged and dropped, and slid on the inclined plate 49 and put into the dehydrator 14. In this way, the sludge once consolidated by the moving mechanism 30 is again flattened by the pressurizing unit 28, so that the dewatering area of the sludge in the dewatering device 14 which is a subsequent process is expanded and the dewatering efficiency is improved. Can do.

  The sludge dropped and introduced to the inlet side of the dewatering device 14 is leveled by the leveling plate 51 while being transported by the traveling filter cloth belt 22, and is first introduced from the inlet 50a into the dewatering unit 50. In the dewatering unit 50, the sludge is nipped and pressurized between a pair of upper and lower filter cloth belts 20, 22 that meander and is transported while being efficiently dehydrated, and then introduced into the pressing unit 52. In the squeezing section 52, the sludge is sandwiched between the pair of filter cloth belts 20 and 22, and is strongly pressed and squeezed between the rollers 21j and 21p serving as squeezing rollers to form a dehydrated cake having a desired moisture content, and discharged. The paper is discharged from the tray 54 to the outside of the system.

  During the operation of the sludge dewatering system 10 as described above, the concentrating device 12 controls the rotation speed of the screws 40a and 40b according to the amount of sludge transported by the filter cloth belt 16 under the control of the control device 15, thereby Then, the amount of sludge (cake amount, cake thickness) scraped off by the screw blades 41a, 41b is made constant at an optimal amount, and control is performed to maintain the mixing degree (uniformity) of the inorganic flocculant F2 in the screws 40a, 40b. .

  For example, in the case of the present embodiment, the storage unit 68 of the control device 15 stores a standard amount of sludge (reference sludge) to be introduced into the screw 40a (40b) by the filter cloth belt 16 per unit time or per rotation of the screw. Amount) and a standard rotation speed (reference rotation speed) of the screw 40a (40b) corresponding to the reference sludge amount are preset and stored. And in the concentration apparatus 12, when the conveyance amount of the sludge by the filter cloth belt 16 becomes larger than the reference | standard sludge amount, the rotational speed of the screw 40a (40b) is made quick. In addition, when the amount of sludge transported by the filter cloth belt 16 becomes smaller than the reference sludge amount, it is also effective to reduce the rotational speed of the screw 40a (40b). Then, as shown in FIG. 4A, it is possible to prevent the sludge from being poorly wound into the screw 40a (40b), and the amount of sludge scraped by the screw 40a (40b) is made uniform with the optimum amount (small amount). Therefore, the sludge and the inorganic flocculant F2 can be uniformly and sufficiently mixed with the screw 40a (40b).

  In addition, even if the rotational speed of the screw 40a (40b) is not slowed down when the amount of sludge transported by the filter cloth belt 16 becomes smaller than the reference sludge amount, the sludge is poorly caught in the screw 40a (40b). In addition, since the amount of sludge scraped by the screw 40a (40b) is made uniform with a small amount, there is no practical problem. However, when the sludge transport amount is smaller than the reference sludge amount, if the control of slowing the rotation speed of the screw 40a (40b) is performed, the sludge scraping amount with the screw 40a (40b) is always kept constant. Thus, the concentration concentration in the concentration device 12 can be stabilized.

  On the other hand, the rotation speed of the screw 40a (40b) is controlled based on the amount of sludge transported. For example, when the amount of sludge transported by the filter cloth belt 16 becomes larger than the reference sludge amount, the rotation of the screw 40a (40b) is performed. The speed shall remain at the reference rotational speed. Then, as shown in FIG. 4 (B), the amount of sludge scraped by the screw 40a (40b) becomes large and non-uniform, so that the sludge and the inorganic flocculant F2 are uniformly distributed by the screw 40a (40b). And it can be difficult to mix well. In addition, the amount of sludge scraped by the screw 40a (40b) cannot catch up with the transport amount, and there is a possibility of causing sludge entrainment failure.

  Here, in this embodiment, two types of detection methods are exemplified as a method for detecting the amount of sludge transported by the filter cloth belt 16.

  As a first detection method, the traveling speed of the filter cloth belt 16 detected by the drive control unit 60 and the upper drive unit 29 is used. That is, when the traveling speed of the filter cloth belt 16 is higher than the standard traveling speed (reference speed), the amount of sludge transported is large, and when the traveling speed of the filter cloth belt 16 is slower than the reference speed, the sludge transporting is performed. It can be assumed that the amount is small. When this detection method is applied, the control device 15 controls the rotational speed of the screw 40a (40b) according to the traveling speed of the filter cloth belt 16 under the control of the drive control unit 60 and the screw control unit 62. Specifically, when the traveling speed of the filter cloth belt 16 is faster than the reference speed, the rotational speed of the screw 40a (40b) is made faster than the reference rotational speed set corresponding to the reference speed. If necessary, when the traveling speed of the filter cloth belt 16 is slower than the reference speed, the rotational speed of the screw 40a (40b) may be slower than the reference rotational speed.

  In other words, for example, if the traveling speed of the filter cloth belt 16 is made slower than the reference speed and the rotational speed of the screw 40a (40b) is made faster than the reference rotational speed, as shown in FIG. The amount of sludge scraped by 40a (40b) can be easily made uniform with the optimum amount. In other words, when the traveling speed of the filter cloth belt 16 is set for the control device 15, the screw 40a (40b) automatically operates at a rotational speed at which sludge can be scraped off at an optimum amount according to the traveling speed. Such operation parameters may be stored in the storage unit 68, and this control can be achieved by a configuration in which the filter cloth belt 16 and the screw shaft 44 are linked by a gear mechanism (not shown). . In this case, for example, if the reference sludge amount supplied from the filter cloth belt 16 to the screw 40a (40b) is 100, the rotation of the screw 40a (40b) may be controlled at a speed at which 100 or more sludge amount can be moved. .

  As the second detection method, the sludge thickness on the filter cloth belt 16 detected by the measuring device 37 and the measuring device control unit 64 is used. That is, according to the detection result of the measuring instrument 37, when the thickness of the sludge thrown into the screw 40a (40b) is higher than the standard thickness (reference thickness), the amount of sludge transported is large, and the sludge thickness is larger than the reference thickness. If it is low, it can be estimated that the amount of sludge transported is small. When this detection method is applied, the control device 15 rotates the screw 40a (40b) according to the thickness of the sludge conveyed on the filter cloth belt 16 under the control of the measuring instrument control unit 64 and the screw control unit 62. Control the speed. Specifically, when the thickness of the sludge is higher (thick) than the reference thickness, the rotation speed of the screw 40a (40b) is made higher than the reference rotation speed set corresponding to the reference thickness. When the thickness of the sludge is lower (thin) than the reference thickness, the rotational speed of the screw 40a (40b) may be slower than the reference rotational speed.

  In other words, for example, the amount of sludge input to the filter cloth belt 16 is suppressed, the thickness of the sludge conveyed on the filter cloth belt 16 is made lower than the reference thickness, and the rotational speed of the screw 40a (40b) is made higher than the reference rotational speed. If it is made faster, as shown in FIG. 4 (A), the amount of sludge scraped off by the screw 40a (40b) can be easily made uniform with the optimum amount.

  The rotational speed of the screw 40a (40b) is based on the increase / decrease width of the sludge transport amount from the reference sludge amount, and table data or mathematical formulas set and stored in the storage unit 68 in advance so as to correspond to the increase / decrease width. For example, the calculation may be performed by the screw controller 62 and the setting may be changed as appropriate. The reference sludge amount, reference rotation speed, reference speed, and reference thickness are optimal based on the experimental results, etc., depending on the specifications of the actual device / system to which the present invention is applied and the properties of the sludge to be treated. What is necessary is just to set suitably as a parameter.

  As described above, the concentrating device 12 according to the present embodiment extends in a direction intersecting the sludge transport direction by the filter cloth belt 16 that is a filter, and the sludge crosses the transport direction by the filter cloth belt 16 by the rotation. A screw 40a (40b) that moves in the direction, and a control device 15 that controls the rotational speed of the screw 40a (40b) according to the amount of sludge transported by the filter cloth belt 16.

  Therefore, in the concentrator 12, by controlling the rotational speed of the screw 40a (40b) according to the amount of sludge transported, sludge entrainment failure or the like in the screw 40a (40b) can be prevented. Moreover, the amount of sludge scraped by the screw 40a (40b) is made uniform at an optimum amount, and the sludge conveyed on the filter cloth belt 16 can be smoothly moved and kneaded by the screw 40a (40b). The concentration concentration of sludge in the apparatus 12 can be increased, and the sludge dewatering performance in the sludge dewatering system 10 can be improved.

  In this case, the concentration device 12 includes a second chemical injection device 36 that adds the inorganic flocculant F2 upstream of the screw 40a (40b) to the sludge conveyed on the filter cloth belt 16. For this reason, as described above, by controlling the rotational speed of the screw 40a (40b) according to the amount of sludge transported, the amount of sludge scraped by the screw 40a (40b) is made uniform with an optimum amount, and inorganic coagulation is performed. The agent F2 can be uniformly kneaded, and the concentrated concentration of sludge can be further increased. In particular, even when using an iron-based inorganic flocculant F2 in which the appropriate amount added to the sludge is set to a small amount, the small amount of the inorganic flocculant F2 can be easily and sufficiently mixed into the sludge. Can do.

  In the concentrating device 12, the movement of the sludge by the screw 40a (40b) is guided to the position downstream of the screw 40a (40b) and in the vicinity of the screw 40a (40b) in the sludge conveying direction by the filter cloth belt 16. The guide plates 42a and 42b are erected. Accordingly, the sludge can be moved by the screws 40a and 40b while being dammed by the guide plates 42a and 42b, so that the sludge can be kneaded more uniformly, and further, the concentrated concentration can be further increased by pressing the sludge. be able to.

  The guide plates 42a and 42b are moved by the screw screws 40a and 40b to the front side in the sludge movement direction by the screws 40a and 40b, that is, from the screws 40a and 40b toward the center of the filter cloth belt 16 in FIG. It has the sludge channel | path 43 used as the opening which lets the made sludge pass downstream. Then, the moving mechanism 30 moves the sludge to which the inorganic flocculant F2 has been added with the screw screws 40a and 40b and discharges it from the sludge passage 43 to the downstream side, whereby the sludge width direction on the filter cloth belt 16 is reached. At the same time as reducing the size, the inorganic flocculant F2 is kneaded into the sludge. Therefore, the moving mechanism 30 can knead the inorganic flocculant F2 while increasing the height of the sludge, and can be smoothly discharged from the sludge passage 43 to the downstream side, while further increasing the concentration concentration of the sludge, It is possible to prevent the moving mechanism 30 from obstructing the smooth conveyance of the sludge on the filter cloth belt 16. Further, the guide plates 42 a and 42 b can prevent the sludge that receives the conveying force of the filter cloth belt 16 during the movement by the moving mechanism 30 from flowing out downstream without being moved by the moving mechanism 30.

  In addition, the sludge dewatering system 10 including the concentrating device 12 as described above includes a dehydrating device 14 that pressurizes and dehydrates sludge discharged from the concentrating device 12, and the concentrating device 12 includes a first chemical (for example, a high-pressure dehydrator). A filtration unit 18 that gravity-filters the sludge to which the molecular flocculant F1) is added; a second chemical injection device 36 that adds a second drug (for example, the inorganic flocculant F2) to the sludge conveyed through the filtration unit 18; A moving mechanism 30 is provided for moving the sludge to which the second chemical is added in a direction crossing the conveying direction by the filter cloth belt 16.

  Therefore, in the sludge dewatering system 10, the first chemical is added in the concentration device 12, and the second chemical is added to the sludge concentrated to some extent by gravity filtration in the filtration unit 18, and then filtered by the moving mechanism 30. By moving the sludge in a direction crossing the conveying direction of the cloth belt 16, the sludge can be sufficiently mixed with the second chemical and further consolidated during the movement, and the sludge is concentrated and dehydrated by the concentrating device 12. The rate can be improved and the concentrated concentration can be increased. Further, after adding and concentrating the first medicine, the second medicine injection device 36 for adding the second medicine and the moving mechanism 30 for kneading the second medicine are provided in the concentration device 12, and the subsequent stage Provided with a dewatering device 14 for dewatering sludge under pressure, while reducing the amount of the polymer flocculant F1 and inorganic flocculant F2, the water content of the sludge is greatly reduced with a compact structure, It is possible to further increase the concentration concentration of the. At this time, in the sludge dewatering system 10, the traveling speed of the filter cloth belts 20, 22 of the subsequent dewatering device 14 is set and controlled slower than the traveling speed of the filter cloth belt 16 of the preceding concentration device 12. The sludge dewatering performance can be improved.

  Further, the concentrating device 12 is disposed on the downstream side of the moving mechanism 30, and the width direction dimension is reduced by the moving mechanism 30 to pressurize and dehydrate sludge sent from the sludge passage 43 and at the same time, the sludge width direction dimension is increased. After that, a pressurizing unit 28 for discharging to the dehydrating device 14 is provided. Thereby, since two chemicals are added and the sludge consolidated by the moving mechanism 30 can be flattened again by the pressure unit 28 and then sent to the dehydrator 14, the sludge introduced into the dehydrator 14 can be removed. The dewatering area is expanded, and the dewatering efficiency there is further improved.

  In the above-described concentrating device 12, a configuration in which only one set of the moving mechanism 30 provided with the screws 40a and 40b is installed in the sludge conveyance direction by the filter cloth belt 16 is illustrated. For example, as illustrated in FIG. You may comprise as the concentration apparatus 12a which added another moving mechanism 30a to the downstream of 30.

  The moving mechanism (screw conveyor) 30a has the same configuration as the moving mechanism 30, and a pair of screws 40a and 40b that move sludge in a direction that intersects (orthogonally in this embodiment) the conveying direction by the filter cloth belt 16, A pair of guide plates 42a, 42b and passage plates 48a, 48b, which are disposed close to the downstream side of the screws 40a, 40b and are erected on both ends in the width direction of the filter cloth belt 16, respectively. By appropriately installing a rod 34 between the moving mechanism 30 installed on the upstream side and the moving mechanism 30a installed on the downstream side in the direction of sludge conveyance by the filter cloth belt 16, the upstream side Sludge once consolidated by the moving mechanism 30 can be introduced into the moving mechanism 30a on the downstream side in a state of being dispersed in the width direction, and further compaction and dehydration are possible. Of course, the rod 34 between the moving mechanisms 30 and 30a may be replaced with a roller (not shown).

  The screw shafts 44 of the screws 40a and 40b constituting the moving mechanism 30a are also rotationally driven by a drive source such as a motor (not shown) provided in the screw driving unit 31 as in the case of the moving mechanism 30, and are controlled by the control device 15. Below, it is set and controlled at a predetermined rotational speed (number of rotations).

  In such a concentrator 12a, the screws 40a, 40b of the moving mechanism 30a have different rotational speeds, preferably from the screws 40a, 40b of the moving mechanism 30 installed upstream in the sludge transport direction by the filter cloth belt 16. It is rotationally driven at a lower rotational speed than that of the upstream moving mechanism 30. That is, the sludge conveyed by the filter cloth belt 16 has a higher concentration in the downstream moving mechanism 30a than in the upstream moving mechanism 30, that is, its moisture content is low, and thus the volume is reduced. Therefore, in the downstream moving mechanism 30a, the dewatering effect during rotation can be improved by turning the screws 40a and 40b more slowly than the upstream one, and the movement of sludge is not delayed by the moving mechanism 30a. .

  5 illustrates the configuration in which the moving mechanism 30a is provided on the downstream side of the moving mechanism 30, the moving mechanism 30a may be provided on the upstream side of the moving mechanism 30, and in this case, for example, the upstream side A movement mechanism 30a may be installed between the addition nozzle 36e on the downstream side of the addition nozzle 36e and the inorganic flocculant F2 may be sufficiently kneaded by the movement mechanisms 30 and 30a. 5 illustrates the configuration in which the screws 40a and 40b are provided in two sets of the moving mechanisms 30 and 30a in the sludge conveyance direction, but the screws 40a and 40b may be installed in three or more sets in the sludge conveyance direction. In this case, for example, at least two arbitrary sets may be set so that the rotational speeds of the upstream screw 40a, 40b and the downstream screw 40a, 40b are different, and more preferably, among the plurality of screws 40a, 40b. The rotational speed of the most downstream screws 40a, 40b may be made slower than the rotational speed of the most upstream screws 40a, 40b, and further, the rotational speed of the screws 40a, 40b is stepped from the upstream side toward the downstream side. You may make it slow.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be freely changed without departing from the gist of the present invention.

  For example, FIG. 2 illustrates a configuration in which the screws 40a and 40b and the guide plates 42a and 42b constituting the moving mechanism 30 are installed in a direction perpendicular to the sludge transport direction by the filter cloth belt 16, but these screws 40a and 40b are illustrated. And the guide plates 42a and 42b are good also as the attitude | position inclined with respect to the conveyance direction of sludge. Of course, the moving mechanism 30 may be configured by a single screw extending in the width direction of the filter cloth belt 16.

DESCRIPTION OF SYMBOLS 10 Sludge dehydration system 12, 12a Concentrator 14 Dehydrator 15 Controller 16, 20, 22 Filter cloth belt 18 Filtration part 24 Coagulation mixing tank 28 Pressurization part 29 Upper drive part 30, 30a Movement mechanism 31 Screw drive part 33 Lower drive Part 36 Second chemical injection device 37 Measuring instrument 38 First chemical injection device 40a, 40b Screw 42a, 42b Guide plate 43 Sludge passage 44 Screw shaft 50 Dehydration part 52 Squeezing part 60 Drive control part 62 Screw control part 64 Measuring instrument control part 66 Chemical Injection Device Control Unit 68 Storage Unit

Claims (7)

It is a concentration device that concentrates by gravity filtration while conveying sludge on the upper surface of the filter body,
A screw that extends in a direction that intersects the conveying direction of the sludge by the filter body, and moves the sludge in a direction that intersects the conveying direction by the filter body by its rotation;
A control unit for controlling the rotational speed of the screw according to the amount of sludge transported by the filter,
Equipped with a,
A measuring device for measuring the thickness of the sludge conveyed on the filter body on the upstream side of the screw;
When the thickness of the sludge conveyed on the filter body measured by the measuring device is higher than a reference thickness, the control unit sets the rotation speed of the screw corresponding to the reference thickness. Concentrator characterized by making it faster. The concentrator according to claim 1, wherein
A concentrating apparatus, wherein a guide plate for guiding the movement of sludge by the screw is erected at a position on the downstream side of the screw in the sludge conveying direction by the filter body and in the vicinity of the screw. The concentration apparatus according to claim 1 or 2,
A concentrating device comprising a chemical injection device for adding chemicals upstream of the screw to the sludge conveyed on the filter body. In the concentration apparatus of any one of Claims 1-3,
The said control part controls the rotational speed of the said screw according to the travel speed of the said filter body, The concentration apparatus characterized by the above-mentioned. The concentrating device according to claim 4, wherein
When the traveling speed of the filter body is faster than a reference speed, the control unit makes the rotation speed of the screw faster than a reference rotation speed set corresponding to the reference speed. It is a concentration device that concentrates by gravity filtration while conveying sludge on the upper surface of the filter body,
A screw that extends in a direction that intersects the conveying direction of the sludge by the filter body, and moves the sludge in a direction that intersects the conveying direction by the filter body by its rotation;
A control unit for controlling the rotational speed of the screw according to the amount of sludge transported by the filter,
With
A concentrating device, wherein a plurality of the screws are installed in the sludge transport direction by the filter, and the rotational speeds of the upstream screw and the downstream screw differ in the transport direction. The concentrator according to claim 6 , wherein
The concentrating device characterized in that, among the plurality of screws, the rotational speed of the most downstream screw is made slower than the rotational speed of the most upstream screw.

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