JPH06254499A - Classifier - Google Patents

Abstract

PURPOSE:To obtain a rotary classifier easy in operation and capable of efficiently preventing Clogging without applying excessive load to a rotary drum. CONSTITUTION:A hollow cylindrical classifying drum 4 is provided in a main body 1 equipped with a charging port 1a and fine and coarse particle discharge ports 1b, 1c in a rotatable manner as a classifying screen member and a clogging preventing device is provided so as to come into contact with the outer peripheral surface of the classifying drum 4 in a shakable manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary classifier for classifying granular raw materials in a boiler, an incinerator or the like using granular fuel according to the particle size.

[0002]

2. Description of the Related Art Various classifiers have been conventionally used to classify granular raw materials according to their particle size by utilizing centrifugal force due to rotation. This classifier is, for example, as disclosed in JP-A-62-33583 and JP-A-1-262927, that a granular raw material charged in a wire-mesh-like classifying channel is used for high-speed classification of the classifying channel. It has a basic structure in which centrifugal force is applied by rotation and fine particles with a small weight are discharged from a screen provided around the flow path and classified with coarse particles.

In order to maintain the processing function in such a classifier, it is important to always keep a large number of holes formed in the screen for discharging fine particles in an open state.

However, some of the classified granular raw materials have various shapes and sizes, and their outer shapes are slightly larger than the holes of the screen, and some of them have protrusions slightly larger than the holes of the screen. Those that have a part are included. Such granular raw material enters the hole of the screen by the rotating force of the drum without being discharged to the outside, and centrifugal force acts on it, or when other granular raw material collides with the hole of the screen. It is completely bitten inside and difficult to remove easily. If the pores are clogged by such a granular material, the classifier is clogged as a result, which leads to deterioration of the processing function.

Therefore, the applicant of the present application previously filed Japanese Patent Application No. 4-2.
No. 56916, we applied for a rotary classifier that does not cause clogging.

This classifier has a plurality of slits formed along the entire length in the circumferential direction of the peripheral wall of the classifying drum in place of the conventional net or punching metal drum. Furthermore, a scraper that can be freely taken in and out of the slits is provided. I have it.

With such a structure, the granular raw material can easily escape from the slit cut in the circumferential direction, and clogging can be effectively prevented. Further, even if the slits are clogged with particulate matter, the scraper can be easily scraped out by inserting the scraper into the slit while utilizing the rotational force of the classification drum.

[0008]

However, since this classifier is designed to insert the scraper into the slit and rotate the drum when removing the clogged particulate matter,
If the meshing force of the granular material is strong, the scraper itself may be broken or the rotating drum may be overloaded. Further, when the scraper is worn out, there is a problem in operation such that it is necessary to perform a rotating operation and readjust the position of the scraper.

The problem to be solved in the present invention is to obtain a rotary classifier which is easy to operate itself and which can prevent clogging efficiently without imposing an excessive load on the rotary drum or the like. is there.

[0010]

A classifier according to the present invention has a hollow cylindrical classification drum as a screen member for classification in a main body having a charging port and a discharging port for fine particles and coarse particles. It is characterized in that it is provided rotatably and further has a clogging prevention device that swingably contacts the outer peripheral surface of the classification drum. Here, a rotating roller or a plate material can be used as the clogging prevention device.

[0011]

The granular material caught in the holes of the screen is relatively loose at first, and is gradually and securely held with the passage of time due to the centrifugal force and the colliding force of other granular particles during use. Therefore, the clogged particles can be removed relatively easily in the initial stage. Since the classifier of the present invention is rotatably driven while the clogging preventing device such as the rotating roller and the plate material is always in contact with the outer peripheral surface of the classifying drum, the part protruding from the screen member due to the clogging is clogged. It hits the abutment of the protection device and is pushed into the classification drum. This makes it possible to easily remove the particulate matter at an early stage of clogging without requiring any special operation. In addition, since the clogging prevention device is swingable, even if there is a granular material that is strongly caught in the screen, the clogging prevention device such as the rotating roller or plate material will pass over the granular material and the classification drum. Alternatively, the clogging prevention device will not be overloaded.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front vertical sectional view of a classifier according to the present invention, and FIG.
FIG. 2 is a vertical sectional view taken along the line AA of FIG.

In the figure, at the upper end of the body 1 of the classifier,
The charging port la for the granular raw material is provided so as to be biased to the left side, and the discharge port lb for fine particles and the discharge port lc for coarse particles are provided at the lower end, respectively. Then, a casing ld of the screw feeder having a charging hopper is incorporated in the lower portion of the charging port la.

A rotary spindle 2 is provided on the upper part of the main body 1 coaxially with the casing 1d.
It is supported by a pair of bearings 2a provided outside the vehicle, and a drive system is connected to the electric motor 2b via a chain 2c. Further, in order to prevent the leakage of dust generated during classification, a shaft sealing portion 2d such as a gland packing is provided between the main body 1 and the rotary spindle 2.

A screw feeder 3 is attached to the rotary main shaft 2 at a position corresponding to the lower part of the feeding hopper, and a classification drum 4 is connected to the right side of the screw feeder 3. The screw feeder 3 has a generally used spiral blade and has a function of feeding the granular raw material from the charging hopper and discharging it to the classification drum 4.

The classification drum 4 has a hollow cylindrical shape and is fixed to the rotary spindle 2 at both ends in the axial direction.
With four arms 4b extending radially from a,
It is integrated with the rotary spindle 2. Further, it has a framework structure in which a stay 4c installed parallel to the axis of the rotary main shaft 2 is connected to the tips of these arms 4b. For the clean 5 of the outer shell of the classification drum 4, a conventional metal net or punching metal in which holes having a predetermined diameter for classification are formed.

Further, an auxiliary shaft 7 is provided inside the main body 1 along the vicinity of the outer peripheral surface of the classification drum 4. The auxiliary shaft 7 is arranged in parallel with the axis of the rotary main shaft 2, and both ends of the auxiliary shaft 7 project outside the main body 1. This auxiliary shaft 7 has
As shown in FIGS. 2 and 3, a rotary roller 8 as a clogging prevention device is attached.

The rotating roller 8 is, as shown in the enlarged view of FIG.
It is composed of an arm 8a rotatably attached to the auxiliary shaft 7 and a roller 8b attached to the tip of the arm 8a and having the full width of the classifying drum 4. The roller 8b is attached to the classifying drum 4 by its own weight. The outer peripheral surface of the screen 5 is swingably abutted. The roller 8b is made of, for example, rubber or plastic and is worn by use as shown by the one-dot chain line in FIG. 3, but even in that case, the contact state with the surface of the screen 5 is secured. Further, when it is worn for a certain amount or more, only the roller 8b can be replaced.

In the above construction, the granular raw material charged from the charging port la is supplied to the screw feeder 3 from the casing ld. On the other hand, the rotating main shaft 2 is rotationally driven by the electric motor 2b, and the granular raw material is sent into the screen 5 by the screw feeder 3. Since the classifying drum 4 itself also rotates together with the rotating main shaft 2, fine particles of the granular raw material are collected from the hole 6 to the discharge port lb side, and large coarse particles are sent to the right end of the classifying drum 4 as they are. It is collected and collected on the discharge port lc side.

At the time of this classification operation, as the classification drum 4 rotates, the roller 8b of the rotary roller 8 automatically rotates while being in contact with the outer peripheral surface of the screen 5 of the classification drum 4. Therefore, as shown in FIG.
When the granular material M is bitten in, the roller 8 b hits the protruding portion of the granular material M and is pushed into the screen 5.
This makes it possible to easily remove the particulate matter at an early stage of clogging without requiring any special operation. Further, since the rotating roller 8 is not fixed but swingable, if the granular material M is strongly caught in the classifying drum 4, the roller 8b gets over the granular material M and the classifying drum 4 is overloaded. It does not become a load and the rotary roller 8 is not damaged.

FIG. 4 is a cross-sectional view showing another embodiment of the clogging preventing device. In this embodiment, a supporting portion 9a is rotatably attached to the auxiliary shaft 7 and is detachably attached to the supporting portion 9a. For example, a rubbing plate 9b made of a plastic board is attached, and the support portion 9a and the rubbing plate 9b constitute a clogging prevention device 9.

Due to its own weight, the rubbing plate 9b is in contact with the outer peripheral surface of the screen 5 of the classifying drum 4 with an appropriate pressure, and the granular material M is caught in the hole 6 of the screen 5 as in the previous embodiment. When it is included, the rubbing plate 9 is attached to the protruding portion of the granular material M.
b hits and is pushed into the screen 5. This makes it possible to easily remove the particulate matter at an early stage of clogging without requiring any special operation.

In the above-mentioned embodiment, a classifying drum or a punching metal which has been conventionally used has been described as the classifying drum. However, the classifying drum is not limited to this, and is applied in Japanese Patent Application No. 4-256916. It can also be used for the one having the slit formed therein.

[0024]

According to the present invention, the following effects can be obtained.

(1) Since the device for preventing clogging of the rotating roller, the plate material, etc. is always driven to rotate while being in contact with the outer peripheral surface of the screen of the classification drum, the clogging can be efficiently carried out without any special operation. Can be prevented.

(2) Since the clogging prevention device can be swung, even if there is a granular material that is strongly caught in the screen, an excessive load is not applied to the rotating drum or the like.

(3) The structure of the clogging prevention device is simple, the equipment cost is low, there are few failures, and maintenance is almost unnecessary.

[Brief description of drawings]

FIG. 1 is a front vertical cross-sectional view of a classifier of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is an enlarged vertical sectional view of a rotary drum portion of the classifier shown in FIG.

FIG. 4 is a vertical cross-sectional view of another embodiment of the clogging prevention device.

[Explanation of symbols]

 1 main body la population 1b, lc discharge port 1d screw feeder casing 2 rotating main shaft 3 screw feeder 4 classification drum 5 screen 6 hole 7 auxiliary shaft 8 rotating roller (clogging prevention device) 8a arm 8b roller 9 clogging prevention device 9a support part 9b rubbing plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuhisa Iwata 59 Nippon Steel Plant Design Co., Ltd. 46 Nakahara, Tobata-ku, Kitakyushu City, Fukuoka Prefecture (72) Inventor Takashi Ando 3-chome, Kaminomachi, Takamatsu City, Kagawa Prefecture No. 1-4 within Shiden Engineering Co., Ltd. (72) Inventor Yukishige Asada 3- 1-4, Kaminomachi, Takamatsu City, Kagawa Prefecture Within Dentsu Engineering Co., Ltd. (72) Masahiro Nitta, Takamatsu City, Kagawa Prefecture 3-4 Nonomachi Shiden Engineering Co., Ltd.

Claims (1)

[Claims] 1. A hollow cylindrical classifying drum is rotatably provided as a classifying screen member inside a main body having a charging port and a discharging port for fine particles and coarse particles. A classifier comprising a clogging prevention device that swingably contacts the outer peripheral surface.