JPS6239912Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses sludge generated during the clarification treatment of water, wastewater, and other liquids, or flocculated sludge obtained by adding organic polymer flocculants or other flocculants to these sludges. This invention relates to an improvement of a screw press type dehydrator having an outer cylinder made of a cylindrical material, which can produce a dehydrated cake with an extremely low water content by continuously compressing and dewatering with screw blades and squeezing out the liquid.

As shown in Fig. 1, the conventional screw press type dewatering machine has an outer cylinder 3' of a cylindrical shape provided between the sludge supply port 1' and the cake discharge port 6' of the sludge hopper 2', and a and a screw shaft 5' having screw blades 4', and the volume of the annular gap formed by the outer cylinder 3', the screw shaft 5', and the screw blades 4' is sequentially reduced as appropriate, and the sludge is introduced into the sludge supply port 1'. The heated sludge is pushed out in the axial direction, that is, in the direction of the cake discharge port 6' by the rotation of the screw shaft 5', while heating fluid (e.g. steam) is extruded.
is introduced through the steam inlet 9' provided in the screw shaft 5' and is supplied into the screw shaft 5' to transfer heat to the sludge, and the sludge is sequentially squeezed while increasing the sludge temperature. 3', and the dehydrated cake is taken out from the cake discharge port 6'. In addition, 7′
8 is a drive shaft of the screw shaft, 8' is a drive device for the screw shaft, and 10' is a drain outlet.

By the way, in general, in press dewatering of sludge, the higher the solids concentration of input sludge, the shorter the time required for press dewatering, and the amount of solids processed per unit time tends to increase, or if the amount of solids processed is constant. The moisture content of the dehydrated cake produced tends to decrease, and for this reason, when operating vacuum dehydrators, pressure dehydrators (filter presses, etc.), belt press type dehydrators, screw press type dehydrators, etc. The sludge is pre-concentrated or pre-dehydrated to increase the solids concentration, and then fed into the dehydrator and compressed and dehydrated to increase the throughput of solids or reduce the moisture content of the resulting dehydrated cake. In addition, regarding the screw press type dehydrator, patent publication No. 16758 (1982)
As shown in May 6, 1955, Published in 1974-74562), the screw shaft has a special structure to pre-concentrate the input sludge and then press dewatering to increase the amount of solids throughput or increase the water content of the dehydrated cake produced. We are planning a decline in the rate.

In addition, as shown in Figure 1, when compressing and dewatering sludge while heating it, rather than applying heat to sludge with a low solids concentration, the input sludge should be pre-concentrated or pre-dehydrated in advance to solidify it. There is a tendency for dehydration to be possible with less heat if heat is applied after increasing the concentration of the substance. In addition, in FIG. 2, a rake 11 capable of scraping off sludge concentrate adhering to the inner surface of the sludge hopper 2, which has a sludge supply port, is attached to the arm 1.
It is known that the rotation shaft 12 is fixed to the rotary shaft 12 by a rotary shaft 12 and rotated by a rotary drive device 14.

For these reasons, conventionally, input sludge has been pre-concentrated or pre-dehydrated using equipment other than the screw press to further increase the solids concentration of the sludge, and then fed to the screw press for compression dewatering. Since a separate concentrating device is required, the devices need to be linked together, which poses the problem of complicating the dehydration process.

The object of the present invention is to economically provide a sludge dewatering machine that can effectively eliminate the above-mentioned drawbacks of conventional screw press type dewatering machines.

In the present invention, a screw shaft having screw blades on the outer periphery is rotatably arranged inside a cylindrical over-material outer cylinder having a sludge supply port and a cake discharge port, and the screw shaft is formed by the outer cylinder, the screw shaft, and the screw blade. In a screw press type dehydrator, the gap between the sludge and the sludge is gradually reduced toward the cake discharge port, and the sludge is compressed and dehydrated by rotation of the screw shaft and discharged from the cake discharge port. is formed of a material, and the height of the outer edge of the screw blade is gradually increased from the sludge supply port side to the cake discharge port side at the location where the sludge hopper is disposed,
A driven body is provided that comes into contact with the outer edge of the screw blade and the screw shaft in this part, and a rake is attached to this driven body via a connecting member so that it can reciprocate up and down, and the sludge adheres to the inner surface of the sludge hopper. This is a screw press type dehydrator characterized by a rake that scrapes off the sludge concentrate.

An embodiment of the present invention will be described with reference to FIG. 3. A screw blade 4 is provided protruding from the outer periphery of an outer cylinder 3 of a cylindrical material having a sludge supply port 1 and a cake discharge port 6 of a sludge hopper 2 made of a material. A screw shaft 5 provided with a steam inlet 9 and a drain outlet 10 is arranged so as to be rotatable by a drive shaft 7 and a drive device 8, and a screw shaft 5 is provided so as to be rotatable by a drive shaft 7 and a drive device 8. Plate rake 1
1 is disposed in conjunction with a plate-shaped member 16 of a driven member, which will be described later. Furthermore, a cam device using the screw blades 4 and the screw shaft 5 as cams is provided in the installation part of the sludge hopper 2, and the rake 11 is controlled by the cam device.
It is configured to move up and down in reciprocating motion. That is, the height (outer edge) of the screw blade 4 gradually increases from the sludge supply port 1 side toward the cake discharge port 6 side at a position directly below the sludge hopper 2, and the screw blade 4 in this portion Rod-shaped connecting member 15 on (outer edge of)
A cam device is provided in which a plate-like body 16 is provided through the screw blade 4 and the screw shaft 5 as a driving body, and a plate-like body 16 as a driven body. In the figure, reference numeral 17 denotes a rod-shaped support member, and a connecting member 15 and a rod-shaped arm 13 provided with a plate-shaped rake 11 are both attached to the support member 17.

In this example, the sludge hopper 2 has a rectangular cylindrical shape (or may be cylindrical), and the rake 11 is an annular plate with upper, middle, and upper parts arranged on the arm 13 at intervals within the height of the screw blades 4. It is provided horizontally in the lower three stages and at a position immediately adjacent to the inner surface of the sludge hopper 2.

Therefore, in this embodiment, the screw blade 4
The plate-like body 16 is pushed up by the force of the screw blade 4 and falls vertically onto the screw shaft 5 when the plate-like body 16 comes off the screw blade 4, causing the plate-like body 16, and therefore the rake 11, to reciprocate up and down.

In this case, the detailed movement relationship between the plate-shaped body 16 and the screw shaft 5 will be explained with reference to FIGS. 4 a, b to 7 a, b. A plate-shaped body 16 installed in is in contact with the screw shaft 5 and the starting end of the screw blade 4, and is at the lower end position of the vertical reciprocating motion. When the screw shaft 5 rotates further, the state shown in FIGS. 5a and 5b is reached. That is, by the rotation of the screw shaft 5, the plate-shaped body 16
is gradually pushed up by the screw blade 4 which is gradually raised higher than the screw shaft 5, and this movement is transmitted to the rake 11, which scrapes off the cake formed on the inner surface of the sludge hopper 2. When the screw shaft 5 further rotates, the state will be as shown in FIGS. 6a and 6b. That is, when the screw shaft 5 rotates, the plate-shaped body 16 is further pushed up by the screw blade 4, and the screw blade 4 is at the upper end position of the vertical reciprocating movement, and the plate-shaped body 16 is pushed up further by the screw blade 4.
The rake 11 is also raised parallel to the inner surface of the sludge hopper 2, and the cake formed on the inner surface is scraped off. When the screw shaft 5 further rotates, the state will be as shown in FIGS. 7a and 7b. That is, as the screw shaft 5 further rotates, the screw blade 4 pushing up the plate-shaped body 16 gradually moves in the direction of the cake discharge port 6, and eventually the plate-shaped body 16 is detached from the screw blade 4 and the plate-shaped body is removed. 16 and the support member 17, etc., it falls to the 5-axis plane of the screw shaft.

Screw blade 4, screw shaft 5, plate-shaped body 1
6 and rake 11 perform related movements as described above.

As shown in FIG. 3, the sludge introduced into the sludge hopper 2 having the sludge supply port 1 is discharged from the sludge hopper 2 and adheres to the inner surface as a cake (concentrate). This cake is scraped off by the rake 11 and flows into the annular gap formed by the outer cylinder 3, the screw blade 4, and the screw shaft 5. The liquid is discharged from the outer cylinder 3, and the cake is discharged by the rotation of the screw shaft 5. While being conveyed to the outlet 6 side, the volume of the annular gap is reduced so that the dehydrated cake is sequentially filtered and squeezed and taken out from the cake discharge port 6, or when the sludge needs to be heated, the steam blower of the screw shaft 5 is used. It has functions such as blowing steam through the inlet 9 to heat the screw shaft 5 and transmitting this heat to the sludge to increase the temperature of the sludge, sequentially filtering and squeezing it, and taking out the dehydrated cake from the cake discharge port 6. ing.

That is, by attaching the sludge hopper 2 made of material in the screw press of the present invention and also attaching the rake 11 close to the inner surface of the sludge hopper 2, it is possible to pre-concentrate the input sludge in this part, Concentrated sludge flows into the annular gap formed by the outer cylinder 3, screw blades 4 and screw shaft 5 and is compressed and dehydrated, increasing the throughput of solids or stably producing a dehydrated cake with a low moisture content. There are effects such as being able to obtain. Furthermore, when dewatering sludge while blowing steam through the steam inlet 9 of the screw shaft 5, the input sludge is pre-concentrated in the sludge hopper 2 section, and the sludge with increased solids concentration is heated by the steam onto the screw shaft 5. Since heat is transferred through contact with the external surface, it is possible to heat the sludge with a small amount of heat, which has the effect of increasing economic efficiency.

Furthermore, the arm 13 in the device shown in FIG.
is the length corresponding to the difference between the height of the sludge hopper 2 and the longest height (height of the screw blade 4) after halfway around the starting end of the screw blade 4, and its installation position is in the state shown in Figure 4 a and b, that is, plate-shaped. It is preferable to install the sludge hopper so that the lower end of the arm 13 and the lower end of the sludge hopper 2 are aligned when the body 16 is in contact with the screw shaft 5. The pitch of the rake 11 attached to the arm 13 is the screw blade 4.
It is preferable that the height be within the maximum height after half a turn of the starting end, so that the entire surface of the sludge hopper 2 in the height direction can be scraped by the rake 11 moving up and down by the rotation of the screw shaft 5.

The smaller the clearance between the rake 11 and the inner surface of the sludge hopper 2, the better. If the clearance is large, cake that cannot be scraped off by the vertical movement of the rake 11 will remain on the inner surface of the sludge hopper 2, and the larger the clearance, the thicker the cake will be. This cake clogs the material of the sludge hopper 2, making it difficult to drain the liquid. Therefore, the smaller the clearance, the better, and it is desirable to attach the rake 11 so that it is as small as possible structurally.

The length of the plate-shaped body 16 (the dimension in the axial direction of the screw shaft) shown in FIG. 3 of the present invention is preferably about 0.6 to 0.8 times the pitch of one screw blade 4. The plate-shaped body 16 makes one reciprocating movement up and down as shown in FIGS. 4 to 7 during one rotation of the screw shaft 5. In other words, the rake 11 moves two times during one rotation of the screw shaft 5.
The inner surface of the sludge hopper 2 will be scraped off.
The length of the plate-shaped body 16 is one pitch of the screw blade.
If it is less than 0.5 times, the rake 11 will scrape the inner surface of the sludge hopper 2 twice (reciprocating) while the screw shaft 5 makes half a turn, and the rake 11 will not move during the remaining half turn, causing the rake to The time intervals of actuation become unbalanced. When the length of the plate-shaped body 16 is one pitch or more of the screw blade 4,
This cannot be inserted between the screw blades 4, 4. As described above, the length of the plate member 16 is preferably approximately 0.6 to 0.8 times the length of one pitch of the screw blade 4 in view of operating time or installation work.

The screw blade 4, which is gradually higher than the screw shaft 5 in the sludge hopper 2 portion, reaches a predetermined height (the height of the blade in the portion of the screw blade 4 that presses and dewaters the sludge) within half a circumference of the screw shaft 5. It is better to do so. This is plate-shaped body 1
6, the length of the plate-like body 16 is 0.6 to 0.8 times the pitch of the screw blade 4, so that it takes more than half a revolution of the screw shaft 5 for the screw blade 4 to reach a predetermined height. In this case, the plate-shaped body 16 will come off before the screw blade 4 reaches the predetermined height, or as soon as the rake 11 reaches the predetermined height. If the cake falls to the set position and the cake formed on the top of the sludge hopper 2 cannot be scraped off, or the rake 11
The balance between operating time and rest time is lost.

In this way, the device of the present invention attaches a sludge hopper made of material to the sludge supply port of a screw press type dewatering machine, and also provides a rake within the sludge hopper movably close to the inner surface of the hopper. This makes it possible to discharge the liquid from the input sludge in the sludge hopper, and the pre-concentrated sludge flows into the annular gap formed by the outer cylinder, screw blades and screw shaft and is compressed and dewatered. Compared to a screw press type dehydrator, it is possible to increase the throughput of solids and to stably obtain a dehydrated cake with a low moisture content, and since the rake drive device is driven by the rotation of the screw shaft, a dedicated drive is required. It is possible to omit the source, and since it moves in sync with the rotation of the screw blade, it is well-balanced and waste-free. It has a simple structure, can be manufactured at low cost, and is easy to maintain. It offers many benefits. .

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views of the conventional method, FIG. 3 is a longitudinal cross-sectional view of the embodiment of the present invention, and FIGS. Figures a to 7a are longitudinal sectional views of the main parts, and Figure 4b is the - of Figure 4a.
5b is a sectional view taken along the - line in FIG. 5a, FIG. 6b is a sectional view taken along the - line in FIG.
FIG. 7b is a sectional view taken along the line -- in FIG. 7a. 1, 1'...Sludge supply port, 2, 2'...Sludge hopper, 3, 3'...Outer cylinder, 4, 4'...Screw blade, 5, 5'...Screw shaft, 6, 6' ...Cake discharge port, 7,7'...Drive shaft, 8,8'...Drive device, 9,9'...Steam inlet, 10,1
0'...Drain outlet, 11...Rake, 12
... Rotation shaft, 13 ... Arm, 14 ... Rotation drive device, 15 ... Connection member, 16 ... Plate-shaped body, 17
...Supporting member.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A screw shaft having screw blades on the outer periphery is rotatably disposed within a cylindrical overfill outer cylinder having a sludge supply port and a cake discharge port, and
A screw press type in which the gap formed by the outer cylinder, the screw shaft, and the screw blade is gradually reduced toward the cake discharge port, and the sludge is compressed and dehydrated by rotation of the screw shaft and discharged from the cake discharge port. In the dewatering machine, the sludge supply port is formed of a sludge hopper made of a material, and the height of the outer edge of the screw blade is set such that the height of the outer edge of the screw blade is directed from the sludge supply port side to the cake discharge port side at the location where the sludge hopper is disposed. A driven body is provided which comes into contact with the outer edge of the screw blade and the screw shaft in this part, and a rake is attached to this driven body via a connecting member so that it can reciprocate up and down, and the inner surface of the sludge hopper is A screw press type dehydrator characterized by having a rake installed to scrape off sludge concentrate adhering to the sludge. (2) The dehydrator according to claim 1, wherein the screw shaft is provided with a flow path for a heating medium therein.