KR980008328A - Recovery method of magnetic powder - Google Patents

Abstract

The present invention can effectively recycle the magnetic fine powder passed through the cigarette dust collector during the toner manufacturing process before collecting it in the bag filter, thereby enabling the reprocessing of the magnetic powder which can not be reprocessed, thereby improving the productivity by improving the yield. The present invention relates to a method for recovering a magnetic powder.

A feature of the present invention is that the magnetic fine powder is attracted to the magnet by using the magnetic fine powder adhered to the magnet at a high speed and is attached to the magnet by lowering the flow rate of the magnetic powder at a high speed and is rapidly increased in the specific velocity, To continuously collect, separate, and discharge automatically.

Description

Recovery method of magnetic powder

FIG. 1 shows the dust collecting efficiency according to the operating conditions in collecting the fine powder.

FIG. 2 is a schematic view showing a process for producing a toner through a conventional air cyclone dust collector; FIG.

FIG. 3 shows a conventional process for producing a fine powder, which is an example of a conventional process in which all processes are linked to each other to set an optimum condition.

FIG. 4 shows a process for preparing a complemented fine powder of the third pottery, which is an example of a process in which each process is separated and independent, mutual interference is blocked, and an optimal condition setting is easy.

FIG. 5 is a process diagram showing a process of re-collecting a fine powder that has been passed through a filtration bag to a cyclone dust collector.

FIG. 6 is a view showing an example of an experimental apparatus presented for the purpose of determining the relationship between the recovery rate, the fluid velocity, and the distance between the magnets.

FIGS. 7 to 9 illustrate a duct installation to be installed in the process of FIG. 5, and FIG. 7 is a front view.

FIG. 8 is a plan view. FIG.

9 is a side view;

BRIEF DESCRIPTION OF THE DRAWINGS

D: Duct 10: Pneumatic cylinder

20: Scraper 30: Rod permanent magnet

40: separation area 50: dust collecting magnet

60: valve 70: timer

The present invention relates to a method of recovering a magnetic powder during air transfer in a toner process, and is a method of recovering a magnetic powder of about 0.5 탆 to 5.0 탆 which should not be transferred to the next process or discharged to the outside.

Conventionally, it is a generally known method for collecting fine powder by collecting by a primary cyclone (Cyclone) and then collecting by using a bag filter.

The above methods are used in accordance with various process conditions. However, in the dust collecting process of the cyclone, only the optimal operation condition management is focused on without introducing an effective device for maximizing the efficiency.

As shown in Fig. 1, it is obvious that the dust collection efficiency increases as the operating condition becomes closer to the optimum condition, and it is very important that the dust collection efficiency is directly linked to profitability.

However, the air cyclone dust collector for collecting the fine powder having a particle size distribution of D50 = 3 μm is generally constructed in such a manner that the amount of the air passing therethrough is expected to some extent. Actually, in the toner production, a small quantity of various products is produced, and the content, hardness, The air cyclone dust collector operated under the operating conditions of the front and rear process without any controllability even when the operation condition changes greatly due to many factors such as specific gravity, crushing strength, powder concentration, It is very impossible to pass through some of the transfer amount.

As shown in FIG. 2, the inflow speed of the air cyclone dust collector (a) should be kept constant at an optimum condition in order to obtain the highest efficiency in the conventional equipment, while the classifier (b) (d), the amount of dispersion air (d) is adjusted in order to match the difference between the amount of raw material and the concentration of the raw material and the optimum particle size of the product (i) having a different particle size distribution according to each production standard, The operating conditions of the impeller air flow g (g) are changed and the efficiency is changed from about 50% to 95%.

In addition, when influence (h) of the other process is present in the impurity gas flow inlet (g), it becomes difficult to maintain the optimum condition.

This problem has been widely recognized in the process of powder handling, and its importance has been widely recognized. In recent years, a system has been developed that can always be operated in optimum conditions as in the fourth solution to solve this problem effectively.

That is, in order to constantly control the inflow rate (flow rate), which has the greatest effect on the efficiency, among the conditions introduced into the air cyclone dust collector in the process, an automatic flow rate control device is installed, It is possible to maintain optimal conditions at all times by intercepting mutual interactions.

However, this new system has a problem that the number of facilities increases, the equipment cost becomes very high, and it is difficult to partially apply to existing facilities.

According to this necessity, the following method minimizes the amount of passing of the fine powder passed through the ciclon, thereby maximizing the efficiency of the ciclon dust collector.

Most of the fine particles passing through the air cyclone dust collector are subjected to a re-collecting process. The same method as the bag filter shown in FIG. 5 is a common method widely used.

However, the filtration bag method is different from each other in color or color, and powder having different function of powder is completely collected and cleaned. However, The powder becomes impossible to be reused, resulting in loss of raw materials

The present invention solves the problems such as the reliability of the product incorporation, the contamination due to dust scattering, the avoidance of the worker of the cleaning worker, and the inability to expect a perfect cleaning work by recovering the magnetic fine powder at the front end before entering the filtration bag .

The magnetic fine powder in the toner process is produced by kneading a material having a coercive force with another material such as a resin, and then pulverizing and present in a fine powder state. The present invention is an invention configured to continuously collect, separate and discharge the powder in a duct being conveyed at a high speed. The present collector collects data on the fluid mechanics such as the distance between the magnetic force and the distance, the arrangement of the magnets, the velocity of the moving powder, the specific gravity, the grain size and the concentration. Generally, conventional magnetic dust collectors are mostly used when they are stationary or at low speed due to gravity. However, when air having a speed of about 1 m / sec or more is transported, it is necessary to consider various hydrodynamic factors as in the present invention, can do.

In addition, since the powder air transferring method has a high speed and a high pressure, there is a need for a method of continuously discharging powder collected in a device having pressure without stopping the process.

For the purpose of the present invention, in order to continuously recover the magnetic powder particles by sequentially operating the dust collecting, separating and discharging through a method of separating under the influence of the effective dust collecting ability and the magnetic force, Respectively. Hereinafter, the embodiment of FIG. 6 will be described in more detail.

The raw materials used in the present invention are dispersed and kneaded at a blending ratio as shown in Table 1 and pulverized by an air jet mill. The physical properties of the powders are shown in Table 1 below.

Table 1

In order to know the relationship between the recovery rate, the fluid velocity and the distance between the magnets, the experimental apparatus is constructed as shown in FIG. 6 to operate the damper 3 while operating the blower motor 1, And the damper 3 was operated while viewing the blower motor 1 to set a desired oil cake. 40 g of the magnetic fine powder (toner fine powder) having the physical properties shown in Table 1 in the blower motor 1 for 10 minutes was set in the dispersing mechanism 4, The magnetic powder is adhered to the magnet 5.

At this time, the efficiency of the dust collector can be calculated from the amount supplied from the dispersion mechanism (4) and the amount recovered from the magnet (5).

The amount of undissolved powder was calculated as the throughput.

(formula)

D1 = amount supplied to the dispersion mechanism (g)

D2 = amount remaining after dispersion (g)

Wt = total amount of fine powder supplied (g)

Wm = Amount recovered attached to the magnet (g)

D1-D2 = Wt

Dust collection rate (%) = Wm / Wt x 100

Table 2 shows the results of the test.

Table 2

It was found that the recovery rate rapidly increased at a flow rate of 3 m / sec as in the case of this embodiment, and the increase in the recovery rate further increased the apparatus sharply, and was not economical in terms of cost.

Based on this data, the following seventh to ninth equipments are produced and installed in the actual site of the place shown in Fig. 5, and this embodiment will be explained in detail through the seventh to ninth figures.

Seven to nine figures are drawn on a front view, a top view and a side view. Seven permanent bar magnets (30) having a diameter of 30 mm on a stainless steel duct (D) of 600 mm in length, 600 mm in height and 600 mm in height,

The steel pipe is inserted in a steel pipe and fixed to the duct (D). The arrangement is as shown in the side view,

And the magnetic powder in the air conveying at a pressure of -120 mbar and a flow velocity of 30 m becomes a low flow velocity in the extended duct and attached to the bar permanent magnet 30 and fixed to the feed cylinder 10 by the timer 70 The magnetic powder is moved while the scraper is slowly pushed, separated from the magnet-free portion, and discharged through the valve (60).

As a result of the above operation, satisfactory results as shown in Table 3 were obtained.

Table 3

As can be seen from the above description, the present invention can continuously recover the magnetic powder by continuously operating the dust collecting, separating, and discharging through a method of separating from the influence of the effective dust collecting ability and the magnetic force, There is an effect.

Claims (3)

A magnetic particle powder collecting method, comprising the steps of continuously collecting magnetic fine powder during conveying air using a magnet as a facility for collecting the magnetic powder passed through an air cyclone dust collector during a toner manufacturing process, without interruption of the process. The magnetic powder of claim 1, wherein the magnetic fine powder is discharged from an air cyclone dust collector and attached to a permanent bar magnet having a diameter of 30 mm and a diameter of 30 mm or more of 4000 Gauss or more immediately before being introduced into a bag filter, Powder recovery method. The magnetic powdery material recovery method according to claim 1, wherein the magnetic fine powder under air transfer is adhered to the magnet at a high efficiency of 80% or more at a distance of 120 mm between the magnets and at a conveying speed of 3 m / sec or less. ※ Note: It is disclosed by the contents of the first application.