JP4644873B2 - Vertical screw press - Google Patents

Description

  The present invention relates to a vertical screw press used when dewatering sludge generated mainly during dredging work in a dam lake, harbor or river, tunnel excavation work or the like.

  A mixture of water, clay, silt, etc. (hereinafter referred to as “sludge”) generated during dredging work, tunnel excavation work, etc. in dam lakes / harbors / rivers is agglomerated sludge after being agitated and mixed with a coagulant in a coagulation reactor. (Floc), and this agglomerated sludge is supplied into the filter cylinder of the screw press as the object to be compressed, and is dehydrated by being depressurized while being conveyed through the filter cylinder by the rotation of the screw disposed in the filter cylinder. It becomes.

  The screw press includes a horizontal type in which the filter cylinder is elongated in the horizontal direction and a vertical type in which the filter cylinder is elongated in the vertical direction. In urban areas, such as mountainous areas where dam lake dredging works and tunnel excavation works, it is often difficult to secure a large installation space for screw presses. A press is preferably used.

The vertical screw press includes a filter cylinder whose longitudinal direction is the longitudinal direction, a screw rotatably disposed in the filter cylinder, and a cover cylinder that provides a gap in the horizontal direction and covers the periphery of the filter cylinder. The aggregated sludge supplied into the filter cylinder is pressed and dehydrated while being conveyed upward by a screw, and the separated water is discharged from the filter cylinder into the gap. And this discharged | emitted water | moisture content (henceforth a filtrate) is discharged | emitted outside via the drain pipe provided in the downward direction of the cover cylinder. For example, in the vertical screw press disclosed in Patent Documents 1 and 2, a drain port is formed in a bottom plate provided at the lower end of the gap, and a substantially L-shaped drain pipe connected to the drain port is provided. Is provided.
Japanese Patent Laying-Open No. 2005-74384 (paragraph 0020, FIG. 1) JP 2006-26708 A (paragraph 0017, FIGS. 3 and 4)

  However, fine particles obtained by finely agglomerating sludge together with the filtrate are also discharged from the filter tube into the gap with the cover tube. In the vertical screw press disclosed in Patent Documents 1 and 2, the fine particles are accumulated in a substantially L-shaped drain pipe, and further, the fine particles that have not flowed into the drain pipe are deposited on the bottom plate. accumulate. When the accumulation of fine particles proceeds, there is a possibility that drainage may become impossible, and there is a problem that it becomes necessary to disassemble and clean the drain pipe and the cover tube.

  In view of the above circumstances, an object of the present invention is to provide a vertical screw press that eliminates the need for disassembling and cleaning a drain pipe and a cover tube in order to eliminate the possibility of drainage being impossible.

  The present invention includes a filter cylinder having a longitudinal direction as a longitudinal axis, a screw rotatably disposed in the filter cylinder, and a cover cylinder that provides a gap in the horizontal direction and covers the periphery of the filter cylinder, A vertical screw press in which the object to be squeezed supplied into the filter cylinder is squeezed and dehydrated while being conveyed upward by the screw, and the separated water is discharged from the filter cylinder into the gap, wherein the lower end of the gap A plurality of openings are formed in the bottom plate provided in the upper and lower direction over the entire surface, and the water discharged into the gap falls, and the water collection provided below the openings and the openings. It is characterized by being accumulated in a filtrate treatment tank provided below the catchment basin through a culvert.

  According to the present invention, the filtrate discharged into the gap between the filter cylinder and the cover cylinder falls and accumulates in the filtered water tank through the opening of the bottom plate provided at the lower end of the gap and the water collecting tank. Is done. A plurality of openings in the bottom plate are formed over the entire bottom plate. Therefore, most of the fine particles contained in the filtrate are deposited and precipitated in the filtrate treatment tank. A part of the fine particles is deposited on the upper surface of the portion where the opening of the bottom plate is not formed. Since the bottom plate is formed with a plurality of openings over the entire surface, the opening of the bottom plate is formed. The area of the non-existing portion becomes small, the drainage becomes impossible, and fine particles are not deposited on the bottom plate to such an extent that the operation of the vertical screw press is adversely affected. Accordingly, it is possible to eliminate the possibility that drainage becomes impossible by taking out the fine particles precipitated in the filtration water tank, aggregating them, and supplying them again into the filter cylinder. Unlike the vertical screw press disclosed in Patent Documents 1 and 2, it is not necessary to disassemble and clean the drain pipe and the cover tube in order to remove fine particles accumulated on the drain pipe and the bottom plate.

  A vertical screw press 1 according to an embodiment of the present invention will be described. 1 and 2, the vertical screw press 1 includes a filter tube 2 having a longitudinal direction as a longitudinal direction, a screw 3 rotatably disposed in the filter tube 2, and a gap S in a horizontal direction. And a cover cylinder 4 that covers the periphery of the filter cylinder 2, and squeezed and dewatered while conveying the object to be squeezed such as agglomerated sludge supplied into the filter cylinder 2 upward with the screw 3, and separated water. (Hereinafter referred to as the filtrate) is discharged from the filter tube 2 into the gap S.

The vertical screw press 1 has a frame 5 made of a vertical column and a beam or the like that is provided between the vertical columns. The frame body 5 is an exoskeleton of a rectangular columnar vertical screw press 1 whose longitudinal direction is the longitudinal direction, and is erected on a cradle 6. At the lower part of the frame body 5, a bottom plate 7 is provided horizontally between the beams facing each other. The bottom plate 7 is provided with a cylindrical filter tube 2 formed from a metal plate having a large number of holes through which a filtrate such as punching metal can be discharged. A receiving port 8 is provided at the lower part of the filter tube 2, and the object to be squeezed supplied from the supply pipe 9 is introduced into the filter tube 2 through the receiving port 8. A reinforcing frame is provided on the outer peripheral surface of the filter tube 2. The cover cylinder 4 is composed of a transparent shield plate 10 such as an acrylic plate attached so that its lower end is in contact with the bottom plate 7 between the vertical columns constituting the frame body 5. In this way, the bottom plate 7 is provided at the lower end of the gap S.

  The screw 3 is rotatably inserted into the filter tube 2. The screw 3 includes a tapered screw shaft 3a that gradually increases in diameter from the lower end side to the upper end side of the filter tube 2, and a helical screw blade 3b that is fixed to the outer peripheral surface of the screw shaft 3a. The screw 3 rotates when the screw shaft 3 a is rotationally driven by a motor M provided above the filter cylinder 2.

  When the screw 3 is rotated, the object to be squeezed introduced from the receiving port 8 is conveyed upward from below the filter tube 2 by a feeding action by the screw blade 3b. Since the space between the filter tube 2 and the screw shaft 3a is gradually narrowed upward, the object to be squeezed is squeezed while being conveyed toward the discharge chamber 11 at the upper end of the filter tube 2. The discharge chamber 11 is connected to the upper end of the filter tube 2. The dewatered pressed product becomes a dehydrated cake C, which is pushed out from the discharge port 12 to the discharge chamber 11 and discharged to the outside through the discharge chute 13. Further, a baffle plate 15 is provided above the discharge port 12 in a state of being urged toward the discharge port 12 via the air cylinder 14, and the dewatered cake C is pushed up while the baffle plate 15 is pushed up. More discharged. The moisture of the object to be squeezed is squeezed out through the filter cylinder 2 when the object to be squeezed is conveyed and squeezed upward in the filter cylinder 2, and falls in the gap S as filtrate. In the filtrate, there are some fine particles of the object to be squeezed that have passed through the fine mesh of the filter tube 2.

  Further, a water spray pipe 16 is disposed around the outer surface of the filter tube 2. The sprinkling pipe 16 is washed by spraying the washing water onto the outer surface of the filter tube 2 by feeding high-pressure washing water into the pipe in which many small holes are formed. Fine particles adhering to the washing water and the outer surface of the filter tube 2 fall in the gap S.

  Referring to FIG. 3, a plurality of openings 7 a (dot portions in the figure) penetrating in the vertical direction are formed in the bottom plate 7 over almost the entire surface as the lower end of the gap S. Since the bottom plate 7 is also a structural member that supports the filter tube 2 and the screw 3, it is preferable to form as large an opening 7a as possible in consideration of strength, and here, four large openings 7a are formed. Yes. However, the shape and arrangement of the openings 7a are not limited, and for example, a large number of large circular openings may be formed. Further, cleaning water may be sprayed onto the surface of the bottom plate 7 using the water spray pipe 16. In addition, it is preferable to provide a reinforcing member on the lower surface of the bottom plate 7 where the opening 7a is not formed. The filtrate, washing water, and fine particles that have fallen through the gap S fall downward through the opening 7a.

  Part of the fine particles is deposited on the upper surface of the portion of the bottom plate 7 where the opening 7a is not formed. However, since the four large openings 7a are formed, the area of the portion of the bottom plate 7 where the openings 7a are not formed becomes small, so that the drainage is impossible, and the area is thin enough to adversely affect the operation of the vertical screw press 1. Granules do not accumulate on the bottom plate 7. Therefore, it is not necessary to disassemble and clean the cover tube 2 or the like in order to remove the fine particles accumulated on the bottom plate 7.

  With reference to FIGS. 1 to 3, a water collecting rod 17 (indicated by a two-dot chain line in FIG. 3) is provided below the bottom plate 7. The drainage basin 17 is wide open in an inverted conical shape so as to cover the entire bottom of the opening 7a, and the lower outlet is narrow. The filtrate, washing water and fine particles that have fallen from the gap S through the opening 7a are collected by the water collecting basin 17 and fall downward through the discharge port.

  Referring to FIG. 1, a filtrate treatment tank 18 is disposed below the water collecting tank 17. The filtrate processing tank 18 processes the filtrate, washing water, and fine particles that have fallen from the outlet of the water collecting tank 17. The filtrate treatment tank 18 includes a precipitation tank 18a and a drain tank 18b. The filtrate or the like that has fallen from the water collecting trough 17 is first received into the settling tank 18a. The fine particles are precipitated over time and are deposited at the bottom of the settling tank 18a. A flocculant may be added to agglomerate the fine particles to promote precipitation. The fine particles precipitated at the bottom of the settling tank 18 a are discharged by a pump (not shown) and sent back upstream from the supply pipe 9 to the vertical screw press 7. In this way, the fine particles that have fallen from the gap S through the opening 7a and the water collecting basin 17 settle on the bottom of the settling tank 18a and are supplied again into the filter cylinder 2 by the pump.

  A weir is provided between the settling tank 18a and the drainage tank 18b, and the supernatant of the water stored in the settling tank 18a passes through the weir and is discharged to the drainage tank 18b. The wastewater stored in the drainage tank 18b is sent to a miscellaneous drainage tank or the like.

Explanatory drawing which shows the vertical screw press of the sludge which concerns on one Embodiment of this invention. The front view which shows a vertical screw press. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vertical screw press, 2 ... Filter cylinder, 3 ... Screw, 4 ... Cover cylinder, 5 ... Frame, 6 ... Base, 7 ... Bottom plate, 7a ... Opening, 8 ... Receiving port, 9 ... Supply pipe, 10 DESCRIPTION OF SYMBOLS ... Shield plate, 11 ... Drainage chamber, 12 ... Discharge port, 13 ... Discharge shooter, 16 ... Sprinkling pipe, 17 ... Catchment tank, 18 ... Filtrate treatment tank, S ... Crevice

Claims (1)

A filter tube whose longitudinal direction is the vertical direction;
A screw rotatably disposed in the filter tube;
A cover cylinder that covers the periphery of the filter cylinder by providing a gap in the horizontal direction, and the object to be squeezed supplied into the filter cylinder is squeezed and dehydrated while being conveyed upward by the screw, and the separated water is A vertical screw press discharged from the filter cylinder into the gap,
A plurality of apertures penetrating in the vertical direction are formed in the bottom plate provided at the lower end of the gap over the entire surface, and the water discharged into the gap falls to be provided below the aperture and the aperture. A vertical screw press characterized in that it is accumulated in a filtrate treatment tank provided below the water collecting tank through the collected water tank.