JPS58219931A - Granulation of magnetic powdery particle - Google Patents

Abstract

PURPOSE:To facilitate the separation of magnetic powdery particles, by a method wherein magnetic powdery particles in a fluid is excited by a magnet and the excited particles are vibrated by an ultrasonic vibrator to carry out granulation through the mutual adhesion of the magnetic powdery particles. CONSTITUTION:A fluid having fine magnetic powdery particles suspended therein is flowed to a pipeline 1 and the magnetic powdery particles are excited by a magnet 2 such as a D.C. electromagnet provided to the outer periphery of the pipeline 1. Subsequently, the fluid is introduced into a chamber 3 having a cross area larger than that of the pipeline 1 to lower the flow speed thereof and magnetic powdery particles are vibrated by an ultrasonic vibrator 4 provided in said chamber 3 to be mutually adhered to promote granulation. The fluid containing the granulated magnetic powdery particles is passed through the water passing orifice 6 provided to a rectifying plate 5 by drilling to be flowed into a separator 7 provided to the downstream side and the powdery particles can be easily separated and removed by a cyclone separator, a filter or an alternate magnetic field separator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for granulating fine powder particles suspended in a fluid, such as fine magnetic powder particles suspended in a secondary coolant of a nuclear reactor.

When removing magnetic powder produced in a nuclear reactor secondary system coolant etc. using a separator, if the particle size of the magnetic powder becomes approximately 3μ or less, the weight of the cyclone separator increases. In the case of an alternating progression type separator, the removal rate decreases due to magnetic sensitivity and sedimentation speed, and in the case of a filter, the mesh of the filter itself is fine and causes clogging, causing the flow path to become clogged. As the pressure drop increases, the frequency of filter replacement increases, leading to a decrease in work efficiency.

An object of the present invention is to granulate magnetic powder in advance in order to efficiently remove the magnetic powder, and the magnetic powder in the fluid flowing through the pipe is excited by a magnet. After that, the magnetic powder particles are vibrated with an ultrasonic vibrator so that the magnetic powder particles adhere to each other and are granulated.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, (1) is a pipe through which a fluid in which fine magnetic particles are suspended, (2) is a DC electromagnet or a permanent electromagnet installed on the outer periphery of the pipe (1), and (3) is an electromagnet with a permanent electromagnet. The chamber (4) is generally cut in the middle of the pipe (1) downstream of the part where the electric stone (2) is installed. - (3) is an ultrasonic transducer disposed in the chamber, (5) is a rectifier plate having a water passage hole (6), and (7) is a separator disposed downstream of the chamber (3). be. As the separator (7), a cyclone separator, a filter, an alternating magnetic field type separator, or the like is used.

Next, the operation of the present invention will be explained.

The magnetic powder in the fluid flowing through the pipe (1) is moved by an electromagnet (2).
) is excited and sent to the chamber (3).

Since the cross-sectional area of the chamber (3) is larger than the cross-sectional area of the conduit (1), the flow rate of the fluid is slow within the chamber (3). Therefore, the ultrasonic waves of, for example, 10 to 20 KHz emitted from the ultrasonic vibrator (4) vibrate the magnetized magnetic particles, causing the magnetic particles to adhere to each other, thereby performing granulation. Further, the granulated magnetic powder is sent to a separator and separated.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

According to the method for granulating magnetic powder and granules of the present invention, ■) Since the weight of one particle of the powder increases by granulation, the effect of centrifugal force and the sedimentation rate of the powder in the fluid are reduced. therefore, the removal efficiency in the separator increases by about 4 times.

W Since the magnetization effect is added, when an alternating magnetic field type separator is used as a downstream separator, the behavior of the powder and granules in the alternating magnetic field becomes sensitive.

When a filter is used in the separator downstream of the plate, the large particle size of the powder prevents clogging and reduces the frequency of filter replacement, improving work efficiency.

Various excellent effects can be achieved.

[Brief explanation of drawings]

The figure is a detailed explanatory diagram of the present invention. In the figure, (1) indicates a conduit, (2) an electromagnet, (3) a chamber, and (4) an ultrasonic transducer. Patent Applicant: Japan Atomic Energy Research Institute Patent Applicant: Ishikawajima-Harima Heavy Industries Co., Ltd. Continued from page 1 0 Inventor: Kore Majima - 1 Factory Applicant: 4 Ishikawajima-Harima Heavy Industries Co., Ltd. 2-2 Otemachi, Chiyoda-ku, Tokyo No. 1

Claims (1)

[Claims] 1) The magnetic powder particles in the fluid flowing through the pipe are excited by a magnet and then vibrated with an ultrasonic vibrator to cause the magnetic powder particles to adhere to each other and granulate. A method for granulating magnetic powder.