JPS5969113A - Thickener - Google Patents

Abstract

PURPOSE:To provide a thickener having improved functions for scraping and transferring deposits and thickening the same in a scraper which transfers the deposits by means of rotary rakes to the discharging port side at the thickener center by the constitution wherein the width of the rotary rake is calculated by the specific equation. CONSTITUTION:This thickener 10 is provided with a scraper which transfers deposits to the discharging port 11 side at the thickener center by means of plural rotary rakes 30 consisting of plural blades 3A disposed at an equal pitch P and a specified scraping angle (r) and disposed radially from the center of the thickener 10. The rakes 30 are constituted at the width of the rakes 30 by the approximate value calculated from the equation where the inside diameter of the thickener 10 is designated as D, the outside diameter of the port 11 as Du, the number of the rakes 30 as (n), the coefft. of allowance as (epsilon), the ratio between the inter-blade distance (d) of the object disposition with respect to the center of the thickener and the above-described D as (x), and the width of the rakes 30 as A. Then the scraping power is maximized by each blade 3A and the driving power required for turning the rake 30 is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thickening tank for sludge thickening, etc., which is equipped with a scraper that scrapes and transfers sediments settling at the bottom of the tank to the discharge port side in the center of the tank. .

Conventional examples of sludge thickening tanks are explained in Figures 1 and 2.
As shown in the figure, a sloped tank bottom (10a).

Discharge z-tot in the center of the tank (111, center post C121
, and Zhou! (IOh) Inside the sludge thickening tank (101), which has a drainage ditch installed at the top, there is a center truss (11) rotatably mounted on the center post via a bearing (1α), and a center truss (11) that protrudes radially from the center truss. A plurality of rotary rakes (2 to 4) arranged under the rake truss (21) and a plurality of blades (3α) arranged at equal pitch and at a constant raking angle. (31), a sludge scraper consisting of a drive motor (4) with a speed reducer, etc. The bottom of the tank (IOIZ) is rotated around the center of the tank.
) is rotated along the top as shown by the arrow, and the rotating rake (3)
The blades (3a,) forming the tank scrape off the sediment on the tank bottom (10 (Z) and move it toward the ill side, and the sediment transferred into the discharge port (old) is not shown). The sludge is taken out of the tank by a screw conveyor or the like, and the water after the sludge separation is discharged by overflowing into a drainage ditch (13).

Furthermore, the rotary rake (3) in the sludge scraper is
As shown in Fig. 2, a point P near the peripheral wall (1oh) of the sludge thickening tank αQ, a point P touching the outer circumference of the discharge port
Two straight lines connecting P11. The blades (3α) constituting the one-rotation rake (31) are formed to have a rotational rake width α set by l, and are arranged at equal pitches P and at a constant rake angle γ within the straight lines l and l. ,
As shown in FIG. 1, the structure is such that the blade height B is constant with respect to the tank bottom (10a).

However, in the conventional concentration tank equipped with the scraper,
It cannot be said that the ability of each blade (3α) of the rotary rake (3) to scrape and transfer the sediment sufficiently corresponds to the state of the sediment in each part of the tank bottom (Noα).
In particular, as shown in Figure 1, the ability of the blade (3α) near the discharge port 0Il side to scrape and transfer sediment is insufficient, causing a bulge of sediment as shown in the figure on the center side of the tank, causing sedimentation. There is a drawback that the material discharge function and the busbar function are significantly reduced.The present invention was developed to solve the above-mentioned drawbacks of the conventional concentration tank equipped with a scraper. It has a plurality of rotating rakes arranged radially from the center of the tank, which are composed of a plurality of blades arranged at a constant pitch and a constant scraping angle, and the rotating rakes move the sediment to the discharge port side of the center of the tank. What is the inner diameter of the thickening tank in the scraping machine? :D, the outer diameter of the discharge hoard is DW, the number of rotating rake is L, the allowance coefficient is ε, the ratio of the distance d between the plates of the target arrangement to the center of the tank and the above is X, and the width of the rotating rake is A.

The present invention is characterized in that it is equipped with a raking machine equipped with a rotary rake whose width is an approximate value calculated by the above formula.

By configuring the scraping and transfer capabilities of each blade of the rotating rake to correspond to the actual condition of sediment at each part of the tank bottom, we provide a thickening tank with enhanced functions of scraping, transferring, discharging, and concentrating sediment. be.

The present invention has the above-described configuration, and by setting the width of each rotating rake in the scraper installed in the thickening tank to the above-described configuration, each of the blades constituting the same rotating rake can Since it has the optimum sediment scraping and transfer ability corresponding to the actual condition of sediment in each part of the bottom, the sediment scraping and transfer function by the rotary rake is extremely effective throughout the entire area inside the thickening tank. As a result, the function of discharging and concentrating sediment in the concentration tank is significantly improved, and power consumption can be reduced significantly.

Below, five embodiments of the present invention will be explained with reference to illustrations.◎An embodiment of the present invention regarding a sludge thickening tank will be explained.This embodiment is based on a center truss (1) and a plurality of rake trusses (2) shown in Fig. 1. , a plurality of radially rotating rakes (31) disposed below the rake truss (2) and composed of a plurality of blades (3α), and a drive motor (4), etc. in the thickening tank (10). In the sludge scraper, by configuring the rotary rake (3) as described below,
The rotating rake is characterized by a configuration in which each blade, which is a component of the rotating rake, has an optimal ability to scrape and transfer sediment in response to the actual state of sediment, that is, sedimented sludge, in each part of the tank bottom. The rotary rake of this embodiment is constructed as follows.

That is, in the present embodiment shown in Fig. 6.4, each blade (3A) which is the main body of the rotary rake 00 is arranged at a plurality of blades (7 in the illustrated example) at a constant pitch P, as shown in Fig. 6. )
and the scraping angle γ of each blade (3A) in relation to the coefficient of friction f in the sludge on the tank bottom (10α).

By setting the scraping angle γ calculated by the above formula (1), the scraping ability of each blade (3A) can be maximized. The power required to turn the rake (7) once! 11' can be minimized, and the scraping angle of each blade (3A) is set to the same γ based on the friction coefficient f, that is, the sludge to be concentrated.

Also, regarding the height B (see Fig. 1) of each blade (3A) placed upright on the tank bottom (10α).

W: Fixed material load 9/m2h (base of concentration tank settings) N: Rotating rake rotation speed γ, p, h (usually within 18077 L/h of peripheral speed on the tip side) γ5: Specific gravity of sludge to be concentrated lay/m 3Sf: sludge discharge concentration, kg/yu ε: allowance coefficient (usually 1.2 to 1.3) D2 compression tank inner diameter m DllL: discharge port outer diameter m n, 2 transfer rake number.

The above formula (21) allows the blade height Bl to be set to an appropriate value, and the above +21
As is clear from the equation, the blade height B can be easily set based on the basic design specifications of the thickening tank and scraper and the sludge to be concentrated.

However, in the rotary rake of the sludge scraper configured as described above, each blade ( 3A) can be expressed by the width A of the rotating rake as shown in FIG. Let the distance be d (see Figure 3), and the ratio of the distance d to the above distance be X.

The rotating rake width is set as shown in Fig. 4 using the curve 71+71 calculated using the above equation (3), and the equal pitch P is set as shown in Fig. 6.
and each blade (3A
) to the curve 11.1! When the length reaches □, each blade (3A) corresponds to the actual condition of the sedimented sludge at each part on the tank bottom (10a, ) and has an optimum scraping capacity 1.
This makes it possible to create an ideal configuration that has the ability to read and migrate.

However, in reality, the rotating rake width calculated using the above formula (3) becomes a complicated curve as shown in Figure 1, which is not practical.
The straight line 13 parallel to the above (song obtained by formula 31, %>
Let the point Y P3 intersect with 711, and the points P□ and 23
A straight line lηL connects the two points, and a straight line e connects the points P3 and P2.
n, and define the rotating rake width A by the straight lines 1m and 13r, . . By setting the rotating rake width to A, each blade 6A of the rotating rake can be set almost in the same ideal manner as described above.
3 (maximum likelihood point) in each DtL/D curve shown in FIG.

It can be defined as follows.

Since the illustrated embodiment has the above-mentioned configuration, the width of the rotating rake is determined by the approximate value of the rotating rake width calculated by the formula (31), and each blade constituting it is The structure can be configured to have the optimum scraping and transfer ability corresponding to the actual condition of the sedimented sludge in each part of the bottom, and the function of scraping and transferring the sediment by the rotary rake is extremely effective throughout the entire area inside the thickening tank. This eliminates the build-up of sediment that occurs at the center of the tank as in the past, and the function of draining and concentrating sediment in the thickening tank is significantly improved.Therefore, the power required for the scraping machine is also significantly reduced. Be able to do that.

In addition, although the sludge thickening tank was explained in the above example,
The present invention is applicable to concentration tanks of various plants.

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to these embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a concentration tank equipped with a conventional scraper;
Fig. 2 is a plan view showing the structure of the rotary rake portion of the scraper in Fig. 1, Fig. 6 is a plan view of the rotary rake portion showing an embodiment of the present invention, and Fig. 4 is Fig. 6 FIG. 5 is a characteristic curve diagram for setting an approximate value of the rotating rake width. 1: Center truss 2 Elm-kit truss 6A Niblade 4: Drive motor 10: Concentrator tank 10α: Tank bottom 11
: Discharge port 12: Center post 13: Drain groove
30 = Rotating rake A: Rotating rake width P: Pitch γ
：Kakiyori-kaku sub-agent, Masu burying person, Okamoto important cultural heritage, 2 people, 2nd (2), 3rd figure, 4th figure, 5th figure 'f)-D
α

Claims (1)

[Claims] It has a plurality of rotating rakes arranged radially from the center of the tank, which are made up of a plurality of blades arranged at equal pitches and at a constant raking angle, and the rotating rakes discharge sediment from the center of the tank. In the scraping machine that moves to the port side, the inner diameter of the concentration tank is
The outer diameter of the discharge port is Dμ. When the number of rotating rakes is 几, the allowance coefficient is ε, and the ratio of the distance d between the plates of the target arrangement with respect to the tank center is x1 and the rotating rake width YA. A concentration tank characterized by a scraper equipped with a rotating rake having a rotating rake width determined by an approximate value calculated by the above formula.