JPS591362B2 - liquid surface decanter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a decanter, and is particularly invented as a decanter for decanting a clear liquid from a sedimentation treatment liquid.

Traditionally, a bell-mouth weir
Although various methods have been put in place to draw clarified liquid from the settling liquid, such as by the use of It is difficult to adapt to the surface quickly, is not easy to use, and requires substantial maintenance.

Additionally, although adjustable weirs have traditionally been provided, these require complex equipment to track liquid surface level, require maintenance, and can fail during use or stir up sludge on the bottom of the tank. It incorporated a slide joint.

It is therefore an object of the present invention to provide a liquid surface decanter which eliminates or reduces the above-mentioned disadvantages in a simple yet effective manner.

A liquid surface decanter according to the invention includes a rotatable support pipe disposed substantially horizontally below the surface of the liquid to be decanted, and a rotatable support pipe extending radially from said support pipe and communicating with the interior thereof. one or more downcomer pipes; a header pipe attached to the downcomer pipe at an end opposite the support pipe and communicating with the downcomer pipe and oriented substantially parallel to the support pipe; a floating float disposed to support the header on the liquid surface, and one or more grooves substantially horizontally provided on the back side of the header pipe when the header pipe is lowered; When supported on the surface of the liquid by a floating float, the liquid flows through the weir into the header pipe and flows down the descending pipe to the support pipe and is drained therefrom. It has become.

Next, a preferred embodiment of the present invention will be described as an example with reference to the accompanying drawings.

In a preferred embodiment of the present invention, a liquid surface decanter for decanting clarified liquid from the surface of a sedimentation liquid contained in a tank is constructed as follows.

The decanter is mounted in a tank having side walls 1 and containing liquid up to level 2.

The lower part of the decanter consists of a rotatable support pipe mounted at both ends in pin end bearings 4, one of which is on one side wall of the tank and the other on the outside of the tank.

The support pipe passes through the wall of the tank and is sealed with a gland seal 5 to allow rotation of the support pipe about the longitudinal axis.

A control device including an operating arm 6 is attached to the pipe,
An actuating mechanism, such as a hydraulic piston and cylinder assembly, is coupled to the outer end of the arm 6 to form a crank lever device, such that the support pipe can be rotated through a predetermined arc by actuation of the hydraulic piston and cylinder assembly. ing.

There are four descending pipes 7 extending radially from the support pipe 3 and communicating with the interior of the support pipe.

The four descending pipes are parallel to each other and have the same length.

A header pipe in the form of a circular pipe 8 is attached to and in communication with the descending pipe 7 at the opposite end of the descending pipe from the support pipe.

The header pipe is oriented substantially parallel to the support pipe 3.

There are provided floating floats 9 in the form of two cylindrical floats 10 arranged parallel to the header pipe 8 and supported at their outer ends by cross beams 11 (FIG. 2).

Both ends of the header pipe are pivotally connected to the cross beam at the midpoint of the cross beam by pivot pins 12.

The cylindrical float 10 is also connected to the cross beam by a pivot pin 13, but unlike the header pivot pin, the float pin 13 is off-center from the axis of the cylindrical float 10, and the float about the pivot pin 13 The rotation of the float allows the float to be raised and lowered relative to the beam.

To facilitate the raising and lowering of the floats, levers 14 are mounted near each end of each float and coupled in pairs across the header pipe to similar corresponding levers on opposing floats by turnbuckles 15. There is.

By adjusting the turnbuckles the floats can be raised and lowered about their pivot pins and thus the height of the header pipe 8 relative to the liquid surface 2 can be adjusted.

To facilitate adjustment of the turns and buckles, they are interconnected by a chain 16 which engages a sprocket 17 on each turnbuckle.

The header pipe extends laterally in its upper part and is provided with three weir grooves 18 so that when the header pipe is supported on the surface of the liquid by the float 9, the liquid hits the rear side of the arcuate downward movement of the header pipe. Referring to FIG. 3, the groove 18 is formed over an 80' arc 19, and the leading edge 20 of the groove is connected to the descending pipe. It is displaced from the centerline 22 of T by an angle 21 of 15°.

As the depth of the liquid in the tank decreases, the orientation of the groove 18 changes with respect to the liquid surface, and a point can be reached in the middle where no flow over the groove occurs.

The possibility of this flow being lost is eliminated by providing a plurality of notches cut along the trailing edge 23 of the weir groove, and the attitude of the leading edge 20 of the weir groove allows the liquid to flow over it directly into the header pipe. Liquid continues to flow over the weir into the header pipe until the point where it begins to flow into the header pipe.

As the liquid surface falls further, the liquid ceases to flow beyond the trailing edge 23.

The depth of the liquid above the groove and thus the rate of liquid intake from the surface into the decanter can be adjusted by raising and lowering the header pipe relative to the surface of the liquid by adjusting the turnbuckle 15. .

In use, when it is desired to decant liquid from the surface, the header pipe and the float are lowered onto the surface of the liquid by rotating the support pipe 3 via the operating arm 6, so that the header pipe is lowered onto the surface of the liquid.
0 on the surface of the liquid.

Then, the restraint is released from the operating arm 6, and the support pipe 3
The rotation of is controlled by lowering the float as the liquid surface level falls within the tank.

The flow rate of liquid into the header pipe, ie through the downcomer pipe T and the support pipe 3, is controlled by adjusting the weir opening of the header pipe relative to the liquid surface level by means of turnbuckles.

Once the desired amount of liquid has been decanted or the liquid level has fallen to the desired point, the header pipe is raised again by rotation of the support pipe via a hydraulic piston and cylinder assembly mounted on arm 6.

Liquid is discharged from the support pipe 3 via the shaft journal outlet 24.

Another feature of this decanter is the float 10 and the beam 1.
1 is arranged to form a scum baffle around the weir groove 18 to prevent solids floating on the surface from entering the weir groove.

A liquid decanter is thus created which is particularly effective in operation, simple and inexpensive to manufacture and which requires little maintenance during use.

The first feature of this decanter is that the amount of liquid taken into the decanter gradually decreases as the header pipe descends, thereby eliminating the problem of suction or stirring of settled sludge into the decanter. It is.

[Brief explanation of drawings]

FIG. 1 is a plan view of a liquid surface decanter according to the present invention,
Float is omitted. FIG. 2 is a plan view of the decanter of FIG. 1. FIG. 3 is a cross-sectional view of the header pipe of the same decanter. FIG. 4 is an end view of the same decanter. 1...Tank side wall, 2...Liquid surface,
3... Support pipe, 4... Bearing, 5...
... Seal, 6... Operation arm, 7...
...Descent pipe, 8...Header pipe,
9... floating float, 10... cylindrical float, 11... cross beam, 12...
... Pivot pin, 13 ... Pivot pin, 1
4... Lever, 15... Turn buckle, 16... Chain, 17... Sprocket, 18... Stub groove, 19. ...
...Circular arc, 20... Leading edge, 23... Trailing edge, 24... Exit.

Claims (1)

Claims: 1. A rotatable support pipe disposed substantially horizontally below the surface of the liquid to be decanted; and one or more rotatable support pipes extending radially from said support pipe and communicating with the interior thereof. a downcomer pipe; a header pipe attached to the downcomer pipe at an end opposite the support pipe and communicating with the downcomer pipe and disposed substantially parallel to the support pipe; The header pipe includes a floating float arranged to support the header pipe, and one or more grooves provided substantially horizontally on the back side of the header pipe when the header pipe is lowered, and the header pipe supports the floating float. When the liquid is supported on the surface of the liquid by the header pipe, the liquid flows into the header pipe through the trailing edge of the weir groove on the rear side of the arcuate descending linkage of the header pipe, and then flows along the descending pipe. A liquid surface decanter, characterized in that the trailing edge of the weir groove has a series of notches in the header pipe extending downwardly from the trailing edge. Liquid surface decanter according to claim 1, characterized in that the vertical positioning of the floating float is adjustable with respect to the header pipe, such that the position of the header pipe is adjusted with respect to the liquid surface. 4. A liquid surface decanter according to claim 1, wherein the floating float comprises two cross beams pivotally connected to opposite ends of the header pipe at an intermediate point, and the outer ends of the beams. two cylindrical floats arranged parallel to said header pipe between them, said cylindrical float being attached to said beam by a pivot pin offset from its axis and for rotating said cylindrical float about said offset pin; 5. A liquid surface decanter according to claim 3, further comprising an adjustment mechanism by which the central axis of the cylindrical float can be adjusted vertically with respect to the beam. Liquid surface decanter according to claim 1, characterized in that the support pipe forms a rotatable seal with the side wall of the tank in which the decanter is used. 6. A liquid surface decanter according to claim 5, further comprising a gland seal adapted to 0