JP3056407B2 - Defoaming equipment for wastewater treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for mechanically destroying bubbles generated in a closed type wastewater treatment apparatus or an aeration tank.

[0002]

2. Description of the Related Art Conventionally, as a means for defoaming air bubbles in a closed type wastewater treatment apparatus, a method of adding a defoaming agent such as a silicon-based or wax emulsion or spray water alone or in combination has been used. The former requires the provision of a storage tank in addition to the cost of the defoamer, and the latter requires a large pump because it requires a large amount of water.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a defoaming apparatus which does not use an antifoaming agent and can save or reduce the installation space for defoaming-related devices such as a storage tank or a pump at low cost.

[0004]

According to the present invention, there is provided a cylindrical defoaming cylinder mounted through the upper part of a closed type wastewater treatment tank, wherein an annular spout with a water spout is formed at an inner edge of a lower end of the cylinder. A sprinkling disc with a lower blade attached to a vertical drive shaft is provided above the gutter and formed with a sprinkling drop gap between the spout and the inner wall of the body, and defoaming sprinkling on the sprinkling disc is provided. It is configured to be supplied. The watering gap between the watering disc and the body wall is such that water from around the disc can effectively flow down into the annular gutter, and the outer peripheral edge of the disc is located above the inner wall of the gutter. Good degree to do. The water spout of the annular gutter may be provided on the side surface in addition to the bottom surface of the gutter.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall view in which the apparatus is applied to a three-phase fluidized tank. Reference numeral 1 denotes a three-phase fluidized vessel, in which waste liquid to be treated is supplied by aeration with a microorganism-immobilized carrier. It is circulating inside. 3 is an aeration device, 4 is a buffer plate,
Reference numeral 5 denotes a current plate, reference numeral 6 denotes an overflow weir, and reference numeral 7 denotes a hood that seals an upper portion of the tank. Reference numeral 10 denotes a device of the present invention, and a cylindrical defoaming cylinder 11 is fixedly provided through the hood 7 as shown in FIG. 12 is a foam scattering prevention cylinder provided with a vent 12a,
13 is a motor stand, and 14 is a variable speed motor. 1
Reference numeral 5 denotes a rotating shaft, which penetrates the center of the bubble scattering prevention chamber 12 and has an intermediate portion provided with a foam stopper plate or a radial support frame 1 having a vent hole 16a.
The shaft end reaches the inside of the defoaming cylinder 11. A sprinkling disk 20 having a defoaming blade 21 on the lower surface is axially attached to the shaft end. The diameter of the disk is such that the outer periphery of the disk has a gutter inner wall 2 to be described later so as to form an annular gap P with the body wall.
It is good to be located just above the number 6. The blade 21 is formed by forming an L-shaped or flat plate on the lower surface of the disk 20 by 5 to 6 axial symmetries or FIG.
It is fixed in an eccentric radial manner as shown in FIG. 23 is the torso 1
An annular gutter 25 is formed on the inner edge of the lower end opening 24 at the inner edge of the lower end opening 24 by an inner wall 26 integrally connected to the body, and a water spout 27 is drilled at the bottom of the gutter. I have. Reference numeral 30 denotes a watering supply pipe, which is connected to a pump (not shown) and sprays water from a water discharge port 31 opened on the watering disk 20. In the above apparatus, the rotation speed of the watering disc is in a range where the circumferential speed of the blade tip is 3 to 6 m / s. It is not preferable because it scatters. Further, a watering amount of 10 to 50 L / Hr is sufficient. Further, when the superficial velocity of the air in the body becomes 0.7 m / s or more, the bubbles are lifted to the upper part of the main body.
It is preferable to set the throat portion diameter D so as to be in the range of m / s to 0.7 m / s. In the above device, the foam generated in the tank rises from the opening 24 and is crushed by the rotating blade 21, and the crushed small pieces try to rise through the gap P but move on the watering disc 20 by centrifugal force. Since the flowing water flows down from the peripheral edge through the gap, it is caught by the water and flows down into the receiving gutter 25 to be dropped from the water spouting port 27 into the tank. The droplets also contribute to breaking bubbles on the water surface.

[0006]

EXAMPLE A closed three-phase fluidized total wastewater treatment apparatus having an effective volume of 56 m ³ and an aeration rate of 11 Nm ³ / min was supplied with a superficial velocity of 0.5 m / m.
The apparatus shown in FIG. 2 and FIG. 3 in which the throat diameter D was set to 0.7 m so as to be sec. was used to treat wastewater from a water-soluble ink manufacturing plant. 5.23 m / s circumferential speed of rotating blades
(Motor rotation speed: 166 rpm), and by operating at a water spraying rate of 20 L / Hr, foam generated in the tank could be defoamed without using an antifoaming agent. The amount of water used when defoaming the wastewater by the spray method is 14,000 L / H.
r, a large amount of water and water supply is saved according to the invention.

[0007]

According to the present invention, a large amount of water required conventionally can be saved, or the treatment cost can be greatly reduced because no defoaming agent is used. Therefore, no special water supply facility or storage tank is required. This has the effect of saving the equipment area.

[Brief description of the drawings]

FIG. 1 is an overall view of the apparatus of the present invention installed on a three-phase fluidized vessel.

FIG. 2 is a sectional view of a main part of the device of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Defoaming cylinder 12 Foam scattering prevention room 16 Antifoaming plate 20 Sprinkling disc 21 Defoaming rotating blade 23 Body throat 24 Opening 25 Annular gutter 26 Inner wall 27 Sprinkling port 30 Sprinkling supply pipe 31 Discharge port

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-39260 (JP, A) JP-A-56-150407 (JP, A) JP-A-49-87564 (JP, A) 70802 (JP, U) Japanese Utility Model Showa 62-1709 (JP, U) Japanese Utility Model Showa 59-93605 (JP, U) Japanese Utility Model Showa 57-39605 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) B01D 19/02

Claims (2)

(57) [Claims] 1. A cylindrical defoaming cylinder mounted through the upper part of a closed type wastewater treatment tank, having an annular gutter with a sprinkling port formed at an inner edge of a lower end thereof and a lower surface axially mounted on a vertical drive shaft in the cylinder. A watering disc with a blade is located above the opening 24 surrounded by the annular gutter and is provided so as to form a watering drop gap with the inner wall of the body, and defoaming watering is supplied onto the watering disc. A defoaming device for a wastewater treatment device, characterized in that: 2. The defoaming device according to claim 1, wherein a foam scattering prevention chamber is provided above the watering disc via a foam stopper plate also serving as a bearing support for the drive shaft.