JPS6057437B2 - Screw press type dehydrator - Google Patents

Description

Detailed Description of the Invention The present invention relates to sludge generated during the clarification of water, wastewater, and other liquids, or flocculated sludge obtained by adding organic polymer flocculants or other flocculants to these sludges and flocculating them. This invention relates to an improvement in a screw press type dehydrator consisting of an outer cylinder of a cylindrical filter medium that can produce a dehydrated cake with a significantly low water content by continuously compressing and dewatering materials such as materials in a screw groove with screw blades and squeezing out the filtrate. It is.

As shown in Fig. 1, a conventional screw press has a sludge supply port 1' and a dewatered cake discharge port 6' of a sludge hopper 2'.
It consists of an outer cylinder 3' of a cylindrical filter medium provided between the outer cylinder 3' and a screw shaft 5' having screw blades 4' in the outer cylinder, and a screw groove between the outer cylinder 3', the screw shaft 5', and the screw blade 4'. (annular gap volume) is reduced in sequence as appropriate,
By rotating the screw shaft 5', the sludge introduced into the sludge supply port 1' is extruded and sequentially compressed in the axial direction, that is, in the direction of the dewatered cake discharge port 6', and the filtered sludge is squeezed out of the cylindrical filter medium. It has a structure and function in which the dehydrated cake is discharged from the cylinder 3' and taken out from the dehydrated cake outlet 6'.

Recently, as shown in Fig. 2, a screw blade 4 is attached to a part of the outer cylinder 3' of the cylindrical filter medium, which has a similar structure to that shown in Fig. 1.
A structure has been proposed in which a pressure foil 7' is provided almost perpendicularly to the screw shaft 5', and the sludge is dewatered by preventing the synchronization of the sludge with the rotation of the screw shaft 5'.

Generally, when sludge is dehydrated using a screw press, the sludge is compressed and dehydrated in the screw press and its water content decreases and becomes hard or sticky, or the surfaces of the screw shaft 5'' and screw blade 4'' are not smooth.
If the jam or resistance is large, the sludge and the screw blades 4'' and screw shaft 5'' do not slip within the screw breath, and the sludge rotates together with the rotation of the screw blades 4''.

This is called the sludge co-rotation phenomenon, and when this co-rotation phenomenon occurs, the movement of the sludge being pushed out in the screw shaft 5'' direction, that is, the dewatered cake discharge port 6'' direction, becomes difficult to keep up, and the sludge The blades 4'' and the screw shaft 5'' remain attached to the same position and rotate forever, and since there is no movement in the direction of the sludge dewatering cake discharge port 6'', the sludge is not sent to the screw groove narrowing part, and no pressure is applied to it and the sludge is compressed. Dewatering becomes impossible. In order to prevent this sludge rotation phenomenon, the surfaces of the screw blades 4'' and screw shaft 5'' are finished as smooth as possible to reduce the frictional resistance with the sludge and prevent the sludge from slipping. In addition, a pressure foil 7'' as shown in FIG. 2 is provided to prevent the sludge from spinning around.

However, as shown in Fig. 2, this pressure foil 7'' is a rotatable flat plate with a certain thickness, and has a cherry blossom-like or wave-like shape, although the number of petals varies, and the pressure foil 7'' is a rotatable flat plate with a certain thickness. The pressure foil shaft 8'' is mounted almost perpendicularly to the screw blade 4'' between any screw groove of the dehydrated cake discharge port 6''.Therefore, the screw blade 4'' and the pressure foil 7''
The movement is based on the same principle as that of a worm gear. In other words, the movement of the screw blade 4'' can be divided into horizontal movement and circumferential movement with respect to the screw shaft 5'', and the movement of the screw blade 4'' can be divided into horizontal movement and circumferential movement with respect to the screw shaft 5''. part) is caused by the horizontal movement of the screw blade 4'' with respect to the screw shaft 5''.
The blades of the pressure foil 7'' are pushed and rotated around the pressure foil shaft 8'', and the blades of the next pressure foil 7'' are inserted into the screw grooves by straddling the screw blades 4''.

The pressure foil 7'' is installed approximately at right angles to the screw blade 4'', and serves to prevent the sludge from moving in the circumferential direction with respect to the screw shaft 5'' caused by the rotation of the screw blade 4''. This mechanism mechanically prevents the sludge from rotating together, and allows the sludge to slip between the sludge and the screw blades 4'' to advance the sludge further toward the dewatered cake discharge port 6'', that is, the narrowed part of the screw groove. Since the water is compressed and dehydrated by sending it to the water tank, there are problems such as poor working efficiency and high power consumption.

The present invention provides a useful dehydrator that can accurately prevent sludge circulation using a method fundamentally different from the conventional method of preventing sludge circulation phenomenon in screw presses, and eliminate the drawbacks of the conventional methods. It is intended to provide.

The present invention includes an outer cylinder made of a cylindrical bedding material, and a conical screw shaft concentrically arranged inside the outer cylinder and having screw blades on the outer periphery so as to be freely rotatable. It is configured as a screw-breath type dehydrator capable of dewatering, and is provided with a co-rotation prevention body that can be inserted and pulled out almost at right angles to the screw blades in the screw groove to prevent the syn-rotation phenomenon of sludge in which the sludge rotates with the screw blades. This invention relates to an improvement in a screwless dewatering machine characterized by forcibly sending sludge to a screw groove narrowing part and dehydrating it to produce a dehydrated cake with a low water content, or increasing the throughput of solids. be. Embodiments of the present invention will be described below with reference to FIGS. 3 to 7. In the example shown in FIG. 3, a sludge hopper 2 with a sludge supply port 1 is provided at one end, and a dewatered cake discharge port 6 is provided at the other end. A conical screw groove 5 with screw blades 4 protruding from the outer periphery is rotatably equipped in the outer cylinder 3 of the cylindrical door material. The gap between the outer surface of the screw groove 5 and the inner surface of the outer cylinder 3 is made smaller in the direction of the outlet so that the cake is discharged from the outlet 6, and the sludge hopper 2 of the outer cylinder 3 of the cylindrical door material is connected to the dewatered cake discharge. Exit 6
A storage part 9 is provided at a certain position between the screw blades 4 at almost right angles to the screw blade 4 and is large enough to accommodate the co-rotation prevention body 8, and the co-rotation prevention body moves up and down between the storage part 9 and the screw groove. 8 is installed almost perpendicularly to the screw blade 4 so that it can be inserted or pulled out up to the screw groove, and this co-rotation prevention body 8
and the adjusting body 7 provided in the screw groove in the sludge hopper 2 are connected by a connecting rod 12 having a fulcrum 10 approximately in the middle, and the starting end of the screw blade 4 on the sludge supply port 1 side is gradually moved from the screw shaft 5 to a predetermined position. The adjusting body 7 is pushed up by the screw blade 4, and the adjusting body 7 is disengaged from the screw blade 4 and falls vertically to the screw shaft 5, thereby generating a vertical movement. This is transmitted to the co-rotation prevention body 8 by the connecting rod 12, and when the screw blade 4 approaches the co-rotation prevention body 8 inserted in the screw groove, the co-rotation prevention body 8 is pulled out from the screw groove, and the screw blade 4 rotates co-rotation. After passing the position of the preventer 8 (slit), it is inserted into the screw groove again to prevent the phenomenon that the screw shaft 5 and the sludge rotate together, and the sludge is semi-forcibly fed into the screw groove narrowing part to be compressed and dewatered. It is possible to easily lower the moisture content of the cake or increase the throughput of solids.

In this case, the detailed movement relationship between the regulating body 7 and the co-rotating prevention body 8 will be explained with reference to FIGS. 4A to 4D. FIG. It is in contact with the shaft 5 and the starting end of the screw blade 4, and a co-rotation prevention body 8
is installed at a position above the screw groove where the screw blade 4 is about to pass, and the co-rotation prevention body 8 is suspended outside the screw groove by a connecting rod 12. When the screw shaft 5 rotates further, the state shown in FIG. 4B is reached.
That is, as the screw shaft 5 rotates, the adjusting body 7 adjusts the screw blade 4 whose height gradually becomes lower than that of the screw shaft 5.
It is gradually pushed up by In this state, the screw blade 4 has already passed the position of the co-rotation prevention body 8, and the co-rotation prevention body 8 is moved by the connecting rod 12 by the height by which the adjustment body 7 is pushed up via the fulcrum 10. It is inserted into the screw groove and functions to prevent movement of sludge generated by the rotation of the screw shaft 5 in the circumferential direction of the screw shaft 5. When the screw shaft 5 further rotates, Fig. 4C
It will be like this. That is, when the screw shaft 5 rotates, the adjusting body 7 is further pushed up by the screw blades 4.

The screw blade 4 is raised to a predetermined height, and the adjustment body 7 is also pushed up to this height. As a result, the co-rotation prevention body 8 is completely inserted into the screw groove, and serves to prevent movement of sludge in the circumferential direction of the screw shaft 5 caused by the rotation of the screw shaft 5. When the screw shaft 5 further rotates, a state as shown in FIG. 2D occurs.

That is, as the screw shaft 5 further rotates, the screw blade 4 pushing up the adjustment body 7 gradually moves toward the dehydrated cake discharge port 6, and eventually the adjustment body 7 separates from the screw blade 4, and the adjustment body 7 is removed. Dead weight of body 7 and weight 11
falls to the screw shaft 5 due to the weight of the screw. When the adjusting body 7 falls, this movement passes through the fulcrum 10 and connects the connecting rod 1.
At 2, the rotation is transmitted to the co-rotation prevention body 8, and the co-rotation prevention body 8 is lifted out of the screw groove. At this time, the screw blade 4 is approaching directly below the co-rotation prevention body 8, and this state is maintained until the screw blade 4 passes (the fifth
(see figure). Screw blade male screw shaft 5, adjustment body 7
, and the synchronization prevention body 8 perform related movements as described above.

The adjustment body 7 falls from the top of the screw blade 4 to the screw shaft 5 due to the weight of the weight 11, but instead of the weight 11, the spring 13 is attached to the outer cylinder side plate via the support member 14, as shown in FIG. The adjustment body 7 may be configured to be fixedly installed, the weight 11 and the spring 13 may be used together, or the adjustment body 7 may be made thicker to increase its own weight so that the weight 11 or the spring 13 is not attached and the adjustment body 7 falls due to its own weight. You may also do so.

The length of the adjusting body 7 and the synchronization prevention body 8 must be equal to or less than the screw blade pitch.If the length is longer than the screw blade pitch, the length of the adjustment body 7 and the synchronization prevention body 8 is
does not fit into the screw groove. Further, if the length is a ratio of 0.5 to 1.0 of the pitch length of the screw blade 4, the screw blade 4 will come into contact with the synchronization prevention body 8 while the synchronization prevention body 8 is inserted into the screw groove. Or, when inserting the co-rotating prevention body 8 into the screw groove, the screw blade 4
Accidents may occur, such as not being able to insert the card because it is directly below it.

In order to avoid this, if the lengths of the adjustment body 7 and the synchronization prevention body 8 are very small compared to the pitch of the screw blades, the majority of one revolution of the screw shaft 5 is caused by the synchronization prevention body 8.
is lifted out of the screw groove, and the effect of preventing synchronization of sludge is reduced. Therefore, the length of the adjusting body 7 and the synchronization prevention body 8 is 0.5 or less when the screw blade pitch length is 0.5 or less. The closer the better. For the purpose of explanation, we have described the device in which one set of the adjusting body 7 and the co-rotating prevention body 8 is attached, but several sets of the adjusting body 7 and the co-rotating preventing body 8 may be attached. Since one of the anti-rotation bodies 8 is inserted into the screw groove, it is more effective, and the fulcrum of the connecting rod is near the center of the connecting rod, making the weight of the adjustment body heavier than the co-rotation prevention body. It is also effective. Fig. 7 shows an example in which a regulating body 7 is placed outside the sludge hopper 2, and comes in contact with and follows a cam plate 15 provided at the end of the screw shaft 5, and a spring 13 or a weight 11 is attached as necessary. be done.

As described above, the present invention provides a screw breath type dehydrator with a co-rotation prevention body that can be inserted and pulled out almost at right angles to the screw blades in the screw groove, and this co-rotation prevention body is provided at the starting end of the screw blade at the sludge supply port. The regulating body is connected by a connecting rod with a fulcrum approximately in the middle, and the regulating body is moved up and down by the rotation of the screw shaft.As a result of this vertical movement, the co-rotating prevention body is inserted into the screw groove, and the sludge rotates with the screw blade. The sludge is forcibly sent to the screw groove narrowing part and dehydrated by compression, which increases the throughput of solids and reduces the moisture content of the dehydrated cake, which is a drawback of conventional screwless dehydrators. This has the benefit of ensuring economical and stable operation by removing water and helping to efficiently dewater and save energy.

[Brief explanation of the drawing]

Figures 1 and 2 are longitudinal cross-sectional views of the conventional example, Figure 3 is a vertical cross-sectional view of the embodiment of the present invention, Figures 4A-D are explanatory views of the operating state, and Figure 5 is prevention of co-rotation. FIGS. 6 and 7 are longitudinal sectional views of a portion of another embodiment. 1...Sludge supply port, 2...Sludge hopper, 3...Outer cylinder, 4...Screw blade,
5...Screw shaft, 6...Dehydrated cake outlet, 7...Adjusting body, 8...Co-rotation prevention body, 9... Storage part, 10...Fully point, 11... Weight, 12... Connection rod, 13
...Spring, 14...Support material, 15...
...Cam board.

Claims (1)

[Scope of Claims] 1. A conical screw shaft having screw blades on the outer periphery is rotatably installed in an outer cylinder made of a cylindrical filter medium having a sludge supply port and a cake discharge port. In order to compress and dehydrate the sludge and discharge it as a cake from the cake discharge port, the gap between the outer surface of the screw shaft and the inner surface of the outer cylinder is made smaller in the direction of the discharge port. A co-rotation prevention body storage section is provided, a co-rotation prevention body that moves up and down between the storage section and the screw groove is disposed in the screw groove formed by the screw blade, and a co-rotation prevention body is provided on the sludge supply port side. A screw press type dewatering system in which the starting end of the screw blade is gradually raised to a predetermined length, an adjustment body is disposed at this part, and the co-rotation prevention body and the adjustment body are suspended via a connecting rod having a fulcrum. Machine. 2. The dehydrator according to claim 1, further comprising a weight suspended from the end of the connecting rod on the side from which the adjustment body is suspended. 3. Claims in which the adjusting body is provided with a spring at the end of the connecting rod on the suspended side, and the end of the spring is fixed to the outer cylinder side plate via a support material. 1st
Dehydrator as described in section. 4. The fulcrum of the end of the connecting rod is located near the center of the connecting rod, and the weight of the adjustment body is heavier than the anti-rotation body. Dehydrator.