JPS5948123B2 - Precipitated solids removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for separating precipitated solids and liquids in a water treatment apparatus and transporting only the solids out of the system.

There are various types of solid-liquid separators in water treatment equipment, but in gravity-type solid-liquid separators, mechanical methods are most often used to transport separated solids.

An example of a conventional apparatus for discharging precipitated solids is shown in FIG.

In the gravity type solid-liquid separation tank a, the liquid to be treated flows in through the inflow pipe, and the solids in the liquid are precipitated at the bottom of the separation tank.
Solid-liquid separation is performed by depositing the solid and liquid components, and the liquid component is discharged through the outlet d.

The precipitated solids C are scraped up and carried out by a number of buckets f suspended from the cables e.

The precipitated solids carried out by the bucket f are carried out of the system by a belt conveyor g installed above the solid-liquid separation tank a.

Note that the cable e of the unloading device is driven by a transmission gear i connected to the drive device.

j is a pulley that guides the cable f.

In such a conventional device for discharging precipitated solids in the solid-liquid separation tank a, when the precipitated solids are carried out using the bucket f, the organic fine particles attached to the precipitated solids are also carried out as they are, but these organic signs and After the solids are transported out of the system, the particles will rot and cause serious damage to the water treatment equipment, so after transporting the precipitated solids out of the tank, first peel off the fine particles from the solids, and then remove the solids from the system. This requires a double operation of taking the product out to the outside, which makes the entire device complicated.

In addition, the power required for the transport device is the power required for collecting and transporting the precipitated solids and the power required for the fine particle peeling operation, but the majority of this is consumed for transporting and the fine particle peeling operation, especially when solids are removed using a bucket. When carrying out the process, the liquid must be carried out along with it, resulting in a large loss of power.

The present invention has been made for the purpose of eliminating the drawbacks of the conventional precipitated solid material transporting devices and to allow a single device to perform the two functions of transporting precipitated solids and removing fine particles attached to the solid materials. A spiral blade connected to a drive device at one end is disposed in a solid material delivery cylinder having a solid-liquid separation section configured by a screen, and the liquid and solid materials are separated by rotationally driving the spiral blade. The fine particles adhering to the liquid are discharged through the sieve mesh of the solid-liquid separation section by centrifugal force, returned to the solid-liquid separation tank, and only the solid matter is carried out of the system.

The present invention will be described in detail below with reference to the embodiments shown in FIGS. 2 and 3.

In the embodiment shown in FIG. 2, the gravity type solid-liquid separation tank 1 has a conical lower part, and the precipitated solids in the precipitated solid layer 2 are transported by the transport device according to the present invention, which is arranged approximately in the center of the tank. It is something to do.

The conveyance device includes a cylindrical vertical solid matter conveyance tube 3 installed almost perpendicularly to the surface of the liquid to be treated in the solid-liquid separation tank. A precipitated solids feeding section 4 having an open end 4a in contact with the solid matter feeding section 4, a solid-liquid separation section 5 provided adjacently above the precipitated solids feeding section 4, and an upper end portion of the precipitated solids feeding section 4 provided adjacently above the precipitated solids feeding section 4 communicating with the solids discharging port 6. It has a solid material conveying section 7.

The solid-liquid separation section 5 includes a large number of sieve meshes 5 of appropriately selected sizes.
The screen consists of a cylindrical screen having a diameter of 1.5 mm (Fig. 3), and this screen may be, for example, a screen made of ring-shaped wedge wires with a wedge-shaped cross section arranged in parallel, or a large number of straight wedge wires arranged in the axial direction of the delivery tube. An upright screen is suitable.

The solid-liquid separation section is arranged so that at least its upper part is exposed above the liquid surface of the liquid to be treated 8 .

A helical blade 9 is disposed within the solid material delivery tube 3 over its entire length.

The upper end of the spiral blade 9 is connected to a transmission mechanism 1 consisting of a planetary gear mechanism.
0 to the drive device 11.

Further, as shown in FIG. 3, the spiral blade 9 is divided into two parts: a blade part 9a that passes through the solid material conveying part 7 and the solid-liquid separation part 5, and a blade part 9b inside the precipitated solid material feeding part 4. .

The shaft 12a of the blade portion 9a is formed into a tubular shape.
Another shaft 12b passes through the hollow part 2a.

The lower end of this shaft 12b is fixed to the shaft 12c of the blade portion 9b.

Further, one end of the shaft 12b is connected to the drive device 11 via the transmission mechanism 10, and the blade portion 9b is designed to prevent the precipitated solids from being blown off by centrifugal force when taking in the precipitated solids. It is configured to rotate at a lower speed than 9a.

The shafts 12a, 12c are supported by intermediate bearings 13 fixed to the precipitated solids feeding section 4.

Each blade portion 9a, 9b of the spiral blade has a rotation speed and blade angle commensurate with the physical properties of the precipitated solids.

Note that 14 is an inflow pipe, 15 is an outlet, and 16 is a belt conveyor.

Next, the operation process of the above-mentioned unloading device will be explained.

Since the lower part of the gravity type solid-liquid separation tank 1 has a conical shape, the precipitated solids 2 gather at the center of the lower part of the tank, and are sent from the precipitated solids feeder 4 to the solid-liquid separator 5.

The fed precipitated solids move in the vertical direction on the spiral blade surface due to the effects of gravity and centrifugal force, while the balance between both effects is repeated.

During this repeated balancing operation, fine particles adhering to the precipitated solids are peeled off and released into the liquid of the solid-liquid separation tank 1 through the sieve mesh 5a of the solid-liquid separation section 5.

Next, the solid layer from which the fine particles in the precipitated solids have been removed is sent to the solid material discharge section 7, conveyed in the vertical direction, discharged from the solid material discharge port 6 onto the bell 1-conveyor 16, and transferred to the belt conveyor. 16, it is taken out of the system.

In addition, since the liquid component of the centrifugal force field in the solid separation section 5 is communicated with the solid-liquid separation tank 1 through the sieve mesh 5a, the water head loss is kept to a minimum.

In addition, since the upper part of the solid-liquid separation section 5 is installed so as to be exposed above the liquid surface of the solid-liquid separation tank 1, in this part, the precipitated solids after the removal of fine particles are drained by centrifugal force. will be held.

Therefore, the next solid material conveyance operation is facilitated, and driving power is reduced.

In the above embodiment, the bottom of the gravity-type solid-liquid separation tank 1 is formed into a conical shape, but the bottom is not limited to this, and the bottom may be flat, for example. If you install multiple units, you can get good results.

As an example of an operation experiment of the device according to the present invention, the results of using the device in a municipal sewage treatment system will be described.

As is known, in sewage treatment equipment, the solids contained in sewage are classified into sand and suspended particles with a solid particle size of 0.2 mm or more, and the treatment of these is called the primary treatment process.

In this experiment, the sieve opening of the solid-liquid separation section 5 was set to 0.15.
mm, the number of revolutions of the helical blade, and the blade angle were treated as functions of the internal friction coefficient of the precipitated solid, that is, the angle of repose in the range of 15 to 20 degrees, and were set within these values.

In the experimental results, the weight distribution of sand containing particles with a particle size of 0.2 mm or less in the sand carried out from the solid matter carrying out section 7 was approximately 10% or less, and the organic solid layer was within a range of approximately 3% or less. At present, the content of the initial solid layer discharged to the outside of the solid-liquid separation section 5 with a particle diameter of 2 mm or more was almost negligible.

Therefore, according to the device of the present invention, not only can a single device perform the two functions of transporting precipitated solids and removing fine particles resistant to precipitated solids, but also the solid-liquid separation section 5
By changing the mesh size of the screen, the particle size limit of the solids to be removed can be arbitrarily set.

Furthermore, as is clear from a comparison of FIG. 1 and FIG. It has various excellent effects, such as a reduction in operating power as a result of this process.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional precipitated solid matter transport device;
FIG. 2 is a diagram showing an embodiment of the precipitated solid material transport device according to the present invention, and FIG. 3 is an enlarged view of the main part of the solid material transport cylinder. DESCRIPTION OF SYMBOLS 1...Solid-liquid separation tank, 3...Solid material delivery cylinder, 4...Settled solid material feeding section, 5...
...Solid-liquid separation section, 7...Solid transport section, 9...
...Spiral blade, 11... Drive device.

Claims (1)

[Claims] A precipitated solids feeding section having an open end in contact with the precipitated solids layer in the solid-liquid separation tank, a solid-liquid separating section having a large number of sieve meshes, one end connected to the solid-liquid separating section and the other end feeding the solids. A solid material transport tube having a solid material transport section communicated with the transport port is installed in a direction substantially perpendicular to the liquid surface of the liquid to be treated, and is attached to a hollow shaft passing through the solid-liquid separation section and the solid material transport section. a first blade portion that is attached to the lower end of the other shaft passing through the hollow shaft and located in the precipitated solids feeding section; A serpentine spiral blade whose upper end portions are each connected to a drive device is disposed in the solid material delivery cylinder, and the first blade portion and the second blade portion of the serpentine blade are rotated at different rotational speeds. A device for discharging precipitated solids, characterized in that it rotates.