JPS61238318A - Wind force classifier - Google Patents

Abstract

PURPOSE:To obtain the titled classifier for separating small pieces and fibers coexisting in fluffy ground pulp to classify the same, by providing a separation chamber having an air jet nozzle provided to the bottom part thereof and mounting a screen and a bag filter to the upper part of the separation chamber. CONSTITUTION:When a regulation valve 8 is operated after ground pulp was introduced into a separation chamber 5 to introduce air from an air jet nozzle 2, an air revolving stream shown by an arrow is generated and passed through a screen 6 and a bag filter 7. Small pieces in the ground pulp are separated while the ground pulp is carried by the air stream, and small pieces and fibrous pulp smaller than the mesh of the screen 6 are passed through the bag filter 7 to be collected. The ground pulp separated by the dispersing effect of the air stream while repeatedly collided with the screen 6 and only pulp pieces larger than the mesh of the screen 6 are left in the separation chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a classification device for separating small pieces and fibers coexisting in pulverized flocculent pulp according to particle size and measuring the degree of pulverization.

(Prior Art and Disadvantages) Pulp, which is generally the raw material for arsenic cotton, acetic acid cotton, CMC (carboxylic methylcellulose), and other cellulone derivatives, is in the form of a pulp, which improves the permeability of various chemicals. In order to promote chemical expansion, sheet pulg is crushed and used. The method and degree of grinding is related to reactivity with chemicals and also affects product quality.

In other words, properly pulverized pulp completes the reaction in a short time, resulting in good productivity and high product quality.

However, it is not only insufficiently crushed pulp pieces that have an adverse effect on reactivity and quality, but also fine cotton resulting from excessive crushing, which causes unfavorable results in terms of reactivity and quality due to thermal deterioration and compression during crushing.

Therefore, when pulverization is performed using a certain pulverizer, understanding the degree of pulverization is an extremely important issue for optimizing the pulverization process.

It is extremely common to measure the particle size distribution of pulverized products in order to quantify the degree of pulverization, but in the case of pulverized pulp, most of the shapes are flocculent and intertwined, and the particle size cannot be determined by normal classification operations. It is almost impossible to measure the distribution.

Conventional methods for classifying pulp include dispersing it in water and classifying it with a screen, but this method is not used because pulp becomes fibrous in water and cannot maintain its original shape.

In addition, dry sieving devices include vibrating or moving screens such as Chiron lids and Rotortub type sieve shakers, but these methods not only fail to separate entangled pulp, but also prevent the screen from being visible. Classification is difficult due to clogging.

Wind classification itself is used industrially, but it is only effective for mixtures that easily break apart.
In the case of highly entangled pulverized pulp, the classification effect is hardly achieved.

For example, even in a method such as a micron separator in which pulp is separated by rotating an impeller and then classified using a cyclone, the pulp is not well dispersed and separation using a cyclone is also difficult.

(Objects and Structure of the Invention) The present invention relates to the classification of pulverized pulp, and provides an air classification device consisting of a separation chamber using airflow, a screen, and a bag filter, which requires a strong intertwining system that has been difficult in the past. This enables classification of flocculent pulverized pulp by separating coexisting small pieces and fibers.

That is, the present invention provides a classification device for separating small pieces and fibers coexisting in pulverized flocculent pulp, which includes a separation chamber and a separation chamber having an air injection nozzle at the bottom for swirling the pulp in an air flow and discharging it upward. The above object is achieved by an air classifier equipped with a screen for sieving on the top of the screen and a bag filter on the top of the screen for collecting the particles and fibers that have passed through the screen.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view.

A cylindrical separation chamber 5 is installed on the base 3 and
As shown in FIG. 2, an air injection nozzle 2 is installed in the center.

The shape of the separation chamber 5 does not need to be cylindrical, and the shape is not limited. Further, it is preferable that the material be transparent glass or plastic because the separated state of the pulverized pulp can be seen, but other opaque materials may be used. The air injection nozzle 2 is preferably installed so that it blows in the direction of the screen 6, and the tip of the nozzle 2 is installed so that it does not protrude above the base 3, so as to improve the effect of swirling and separating the pulverized pulp. do better

A Nuclean 6 is installed in the upper part of the separation chamber 5, and its opening is selected depending on the particle size to be separated.

A bag filter 7 is attached to the top of the screen 6 to collect the pulp that has passed through the screen.

The air injection nozzle 2 is supplied with dehumidified compressed air through a conduit 1, and the flow rate of the air is regulated by a regulating valve 8.

The flow rate of air is determined in consideration of the size of the separation chamber 5, the distance between the air injection nozzle 2 and the screen 6, and the amount and density of the crushed puff legs.

The present invention having the above configuration operates as follows.

First, after putting the pulverized pulp into the separation chamber 5, the control valve 8
When the air is introduced by the air injection nozzle /l/2, a swirling flow of air is generated as indicated by the arrow in FIG.

The crushed pulp is separated into small pieces while rotating with the air flow, and small pieces smaller than the opening of the screen 6 and a
The male pulp is collected by the bag filter 7.

That is, the pulverized pulp that has been broken up by the dispersion effect of the air flow is separated while repeatedly colliding with the screen 6, and only pulp pieces larger than the opening of the screen 6 remain in the separation chamber 5.

In addition, the screen 6 is hardly clogged due to the cleaning effect of the air flow, and the particle size distribution can be measured by replacing the Nuclean 6 with one with a larger opening to one with a smaller opening, and performing repeated classification. It is possible to do so.

(Effects of the Invention) The present invention is as described above, and pulverized pulp can be classified quickly and easily. The results of classifying the pulverized pulp with a 4 to 14 mesh screen using the classifier of the present invention are shown in Table 1, which shows that the particle size distribution can be accurately measured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a view showing the air injection nozzle and the base from the north.

1... Air introduction pipe 2... Air injection nozzle 3・・・・・・・・・Base ４・・・・・・・・・Circle tube 5・・・・・・・・・Separation room 6...Song...Screen

Claims (1)

[Claims] A wind classifier for separating small pieces and fibers coexisting in pulverized flocculent pulp, characterized by a separation chamber having an air injection nozzle at the bottom, and a screen and a bag filter attached to the top of the separation chamber. .