JPS59199012A - Filtering method without clogging - Google Patents

Abstract

PURPOSE:To prevent the clogging of a filter cloth and to filter continuously by radiating a high-powered ultrasonic wave to the filter cloth when a liquid contg. suspended matter is filtered by using the filter cloth. CONSTITUTION:An ultrasonic wave radiating device 4 is fixed in a frame 5 which is framed as coarsely as possible to the extent that a bag-shaped filter cloth 6 can be kept open. A discharge pipe 8 is provided to take out the liquid inside the vessel. A filter 2 is provided inside a settling tank 1, and the discharge pipe 8 is extended to the outside of the settling tank 1. A suspension to be filtered is charged from the upper part of the settling tank 1. Then the ultrasonic wave radiating device 4 is actuated by using an ultrasonic wave oscillator 3 provided elsewhere. The liquid is filtered by the filter cloth 6, and the filtrate is discharged to the outside of the tank through the discharge pipe 8. The suspended matter settles down gradually, and the sediment is taken out from a sludge discharging port 9, and disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for filtering a liquid containing suspended matter using a filter cloth.
This filtration method enables continuous filtration by emitting powerful ultrasonic waves to the filter cloth to prevent clogging of the filter cloth, and also removes suspended solids by sedimentation.

In the currently commonly used filtration method using filter cloth,
As filtration progresses, the filter cloth becomes clogged and the filtration ability gradually decreases, eventually making filtration impossible. To regenerate this, K must either replace the filter cloth or wash away the substances adhering to the surface of the filter cloth. When filtering liquids with a lot of suspended solids, regeneration frequency is high;
The effort and cost required for this will increase. The present invention eliminates these drawbacks and makes it possible to perform continuous filtration without clogging the filter cloth and therefore does not require regeneration.

When powerful ultrasonic waves are emitted into a liquid, a strong increase or decrease in the static pressure occurs in the liquid, creating a cavitation phenomenon. When a filter cloth is used to filter a liquid in which a strong cavitation phenomenon occurs, substances adhering to the surface of the filter cloth are always stripped off to prevent clogging. The filtration method of the present invention is constructed by utilizing this phenomenon. Next, this will be explained with reference to the attached drawings.

The ultrasonic emitting device (4) is fixed inside a container in which the frame (5) is assembled as loosely as possible to the extent that the bag-shaped filter cloth (6) can be held in an open state. Also, an outflow pipe (8) is attached so that the liquid inside the vessel can be taken out. Cover this vessel with a bag-shaped filter cloth, and secure the opening of the filter cloth to the vessel with a string or the like to close it. The filter (2) thus equipped is attached to the inside of the settling tank (1), and the outflow pipe is drawn out to the outside of the settling tank.

The suspension to be filtered is injected from the top of the sedimentation tank.

Next, the ultrasonic radiator is driven using a separately installed ultrasonic oscillator (3). The liquid is filtered with a filter cloth and flows out of the tank through an outflow pipe. Suspended substances contained in the liquid tend to collect and adhere to the outer surface of the filter cloth as the liquid flows, but the cavitation phenomenon occurring inside the filter penetrates through the filter cloth and removes them. For this reason, the filter cloth always allows continuous filtration without causing clogging. The suspended solids gradually settle out and become precipitates. This is taken out from the sludge outlet (9) and disposed of. Next, examples of the present invention will be shown.

An experiment was conducted using water in which aluminum hydroxide was suspended by adding sulfuric acid salt (A, /=15 pprn) to well water to perform a flocculation treatment. The filter cloth is made of Tetron plain weave, product name T.
-9A, surface area 12 blood 2 was used in the form of a bag.

The ultrasonic radiator used a single 28 KHz π-type transducer and was driven by an ultrasonic oscillator.

The selection of the type of filter cloth that was able to continuously remove aluminum hydroxide suspended in water without causing clogging with the device configured as described above was determined by The choice must be made depending on the quality and quantity of the substance, but as a result of experiments with various liquids, it was generally found that a strong, thin, fine-mesh liquid, and one to which suspended matter does not easily adhere, is suitable.

[Brief explanation of drawings]

The drawing is a sectional view showing the method according to the present invention. 01 is a settling tank, 2 is a filter 3 is an ultrasonic oscillator, 4 is an ultrasonic radiator 5 is a frame
6 is a filter cloth 7 is a stock solution injection pipe 8 is an outflow pipe 9 is a sludge discharge port Patent applicant: Toshihiko Kobayashi

Claims (1)

[Claims] (a) A bag-shaped filter cloth is fixed in an open state, and a device capable of emitting ultrasonic waves is attached inside it, and an outflow pipe is attached so that the liquid inside the filter cloth can be taken out. Make a filtration device with a sealed structure by submerging the filtration device from (B) and (B) into a tank containing the liquid to be filtered, and emitting ultrasonic waves from the outside of the filter cloth. Pass the liquid inside. This is allowed to flow out of the tank from the outflow pipe. (c) Suspended substances contained in the liquid are removed by settling at the bottom of the tank. The continuous filtration method configured as described above is characterized in that it does not cause clogging.