JPH0111315Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an apparatus for sorting substances to be sorted by utilizing differences in physical properties of the substances to be sorted, Coulomb force due to static electricity, and gravity.

Recently, it has begun to be put into practical use to reuse kitchen waste components in municipal waste as compost through high-speed composting processing. In this method of composting municipal waste, the kitchen waste components, from which metals, relatively large glass, and plastics have been removed, are finely ground through a crushing process from the municipal waste delivered to a high-speed composting plant. Ru. The kitchen waste components that come out after finishing the post-ripening process through the fermentation process are fine granular pure compost in which the raw organic matter has sufficiently rotted and decomposed and hardened into lumps of soil, and the other is pure compost in the form of fine particles that have not yet fully decomposed and decomposed. It is a mixture of large lump components and other non-compostable materials (hereinafter referred to as contaminants) such as glass, vinyl, and ceramics that have been mixed into the raw materials. Here, large lump components whose decomposition has not progressed sufficiently through the vibrating treatment are taken out and collected in a coarse compost hopper, and the remaining mixture is sent to an electrostatic sorting device.

The electrostatic sorting device uses the difference in motion paths caused by the Coulomb force caused by gravity and static electricity that act on substances as a means of separating compost and impurities from a mixture, thereby separating the compost into a selective compost hopper. , and the contaminants are sorted into contaminants.

As an electrostatic sorting device used for this kind of purpose, electrode plates are arranged facing each other at a predetermined distance on a sorting table, and both are charged with different polarities. The material to be sorted mixed with compost is sent onto the sorting table, and the light compost is levitated toward the electrode plate by Coulomb force, and when the compost falls under its own weight, it is released outside the sorting table. Proposed.

However, in the above-mentioned electrostatic sorting device, when the insulator supporting the electrode plate becomes contaminated by the adhesion of floating compost, leakage current increases, the voltage applied to the electrode plate drops, and the sorting occurs. The disadvantage was that efficiency decreased.

This invention was made in order to eliminate the above-mentioned drawbacks, and by providing a means to detect the insulation state of the insulator that supports the electrode plate and issuing an alarm when the insulation of the insulator deteriorates, it is possible to reduce the efficiency. The object of the present invention is to provide an electrostatic sorting device that can be prevented from being operated in the open.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, a sorting table 1 is composed of an elongated flat plate 1a for transporting the material to be sorted, which is a mixture of compost and impurities before sorting, and guide side walls 1b and 1c provided on both sides of the flat plate 1a. . These side walls 1b, 1c are formed to be high on the entrance side 1X of the sorting table 1 and to become lower at a constant slope toward the exit side 1Y. A sorting table 1 is placed horizontally on a vibrating feeder 2. The vibration feeder 2
is vibrated in the direction indicated by arrow K by a motor (not shown), thereby causing the sorting table 1 to vibrate in the same direction.

A hopper 3 is provided above the entrance side 1X of the sorting table 1 to supply a fixed amount of materials to be sorted onto the sorting table 1, while a hopper 3 is provided below the outlet side 1Y of the sorting table 1. A chute 4 is provided to receive the collected foreign matter.

5 at a predetermined interval on the sorting table 1,
This is an electrode plate that faces the sorting table 1 and is arranged parallel to it. The electrode plate 5 is fixed to a suitable fixed frame (not shown) via an insulator 6. An appropriate DC high voltage is applied to the electrode plate 5.

Reference numeral 7 denotes a blower duct that sends wind that can blow away the compost floating from the sorting table 1 to the side of the sorting table 1, and its slit-shaped blow nozzle (not shown) connects the sorting table 1 and the electrode plate. It is provided in the direction along the gap with 5.

Reference numeral 8 denotes a nozzle for discharging air to blow away compost, dust, etc. adhering to the insulator 6, and is provided on both sides of the insulator 6, for example. Although FIG. 1 shows nozzles on only one insulator, all the insulators for supporting electrode plates are provided with nozzles, respectively.

Each nozzle 8 is connected to a source of pressurized air 10 via a suitable control valve 9, as shown in FIG.

Figure 3 shows the leakage current detection circuit.
Reference numeral 1 denotes an earth leakage detector, one end of which is connected to a frame 12 at ground potential, and the other end connected to a metal band 13 wrapped around a groove between the first and second layers of the insulator 6. Ru. The earth leakage detector 11 detects the voltage generated between the frame 12 and the metal band 13 due to the leakage current flowing along the path shown by the dotted line from the high voltage power supply 15 that supplies high voltage to the electrode plate 5, and this voltage is set to a predetermined value. When the voltage exceeds 100 kHz, a signal is generated at terminals 11a and 11b. The signal at this terminal 11a is the high voltage power supply 1
5 to cut off the high voltage power supply.

In addition, the signal at the terminal 11b is transmitted to the control valve 9 and the alarm 16.
is applied to

When the insulator 6 is clean and has high insulation resistance, a predetermined DC high voltage is applied from the high voltage power supply 15 to the electrode plate 5, and light compost among the materials to be sorted on the sorting table 1 is transferred to the electrode plate 5 and the sorting table. It floats up due to the electric field between 1 and 2, and is discharged to the outside of the sorting table by the air blown from the air duct 7.

In addition, heavy contaminants proceed on the sorting table 1 toward the exit side and are collected in the chute 4.

Due to contamination of the insulator 6, its insulation resistance decreases and leakage current increases, and when the voltage drop between the frame 12 and the metal band 13 exceeds a predetermined value, the leakage detector 11 generates a signal and issues an alarm. The device 16 issues an alarm, and the high voltage power source 15 is immediately shut off.

Note that when the signal from the leakage detector 11 is applied to the control valve 9, the control valve 9 opens and pressurized air is ejected from the nozzle 8, blowing away contaminants adhering to the insulator 6. It may be cleaned to increase its insulation resistance.

As detailed above, this device detects the insulation of the insulator that supports the electrode plate of the electrostatic sorting device, and issues an alarm when the insulation resistance decreases, so the voltage applied to the electrode plate is reduced. While descending,
It is possible to prevent failures that would cause the vehicle to continue operating at low efficiency.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an example of an electrostatic sorting device, Figure 2 is a diagram showing the relationship between the insulator and the nozzle, and Figure 3 is a diagram showing the relationship between the insulator and the nozzle.
The figure is a circuit diagram showing an embodiment of this invention. 1... Sorting table, 5... Electrode plate, 6... Insulator, 11... Leakage detector, 12... Frame, 1
3...Metal band, 9...Control valve, 15...
High voltage power supply.

Claims (1)

[Scope of utility model registration request] It has a sorting table and an electrode plate arranged above the sorting table and facing the sorting table,
A DC voltage is applied between the sorting table and the electrode plate, and the objects to be sorted are supplied from the inlet side of the sorting table, and the light objects in the objects are levitated by electrostatic force and removed from the sorting table. An electrostatic separator configured to discharge electricity to Electrical sorting equipment.