JPH03275181A - Separator - Google Patents

Abstract

PURPOSE:To perform sharp classification and to recover ultrafine powder by providing a plurality of annular baffles both to an annular supporting plate in the annular space of the ceiling inner face of a casing in addition to this ceiling inner face of the casing, moving and controlling a rotary shaft in the axial direction. CONSTITUTION:The inlet of an air flow companied with the body to be classified is provided to the lower part of a casing. The outlet thereof is provided to the upper part of the casing. A rotary shaft 1 is vertically hung from the ceiling of this casing in the inside of the casing 1 and the upper end is connected to a rotary driver. A plurality of sheets of classification blades 3 are directly or indirectly connected to the rotary shaft 1. An annular supporting plate 4 is connected to the upper ends of the classification blades 3 so as to join the respective classification blades. Air flow is classified by utilizing a rotary blade having the annular supporting plate 4. Two sheets of annular shielding plates 9-1, 9-2 for forming the annular space are provided to the ceiling inner face of the casing opposed to the upper face of the annular supporting plate 4. A plurality of annular baffles 11-1-11-4 are provided to both the annular supporting plate 4 in the annular space and the ceiling inner face of the casing. Further, the rotary shaft 1 is moved in the axial direction and controlled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a separator for removing coarse powder from powder containing coarse powder to obtain fine powder. The present invention relates to a separator that has good sealing efficiency in gaps between partitioned seal parts and is suitable for collecting ultrafine powder.

[Prior Art] As a method for obtaining fine powder by classifying powders such as clinker powder and granulated slag powder, air flow classification is preferred and currently practiced. As a separator used at this time, the airflow entrained with the powder is passed from the outside between the classification blades of a rotary blade that rotates at a desired speed, and the coarse powder is selectively knocked off to form a fine powder. A separator is known that allows only the slag to pass upward and collect it, and is currently also used as a separator for vertical roller mills that are widely used to crush and classify clinker and granulated slag.

However, in this type of separator, the inlet and outlet sides of the airflow are separated by bringing the upper surface of the annular support plate that connects the upper ends of each rotary blade close to the inner surface of the casing ceiling. Since it rotates at high speed, it is not possible to make complete contact between these close parts, and there is a slight gap, so there is a problem that coarse powder passes through this gap and mixes with the fine powder, especially clinker powder and water granules. This is a major problem when attempting to classify slag powder to obtain ultra-fine powder.

Therefore, various sealing structures have been proposed to improve the sealing efficiency of this part, but all of them are impractical because they are either not sufficiently effective or have complex or expensive structures. 150, etc.).

[Problems to be Solved by the Invention] The purpose of the present invention is to achieve sharp classification and recovery of ultra-fine powder by adopting an inexpensive and simple sealing structure that can efficiently prevent coarse powder from mixing with fine powder. The purpose is to provide a possible separator. Another object of the present invention is to provide a separator that can reduce the degree of contamination of coarse powder as necessary.

[Means for Solving the Problems] A separator is further characterized in that the rotating shaft is movable and adjustable in the axial direction.

The rotary blade of the separator of the present invention includes a rotating shaft extending in a substantially vertical direction whose upper end is connected to a rotation drive unit such as a motor, a plurality of classification blades connected directly or indirectly to the rotating shaft, and a plurality of classification blades connected directly or indirectly to the rotating shaft. It has an annular support plate connected to connect the upper ends. The connection between the rotating shaft and the classification blade is
It is also possible to directly connect the lower end of the rotating shaft and the lower end of the classifying blade by tilting the classifying blade, but it is also possible to do this by distributing the lower end of each classifying blade around a disk whose center part connects to the lower end of the rotating shaft. Indirect connection is preferable in terms of classification accuracy.

The rotary blade is installed in a casing having an inlet below for an air flow entraining the object to be classified and an outlet above, so as to hang down from the ceiling of the casing, and is connected to the annular support plate. The upper facing portion of the annular support plate that approaches the inner surface of the casing ceiling serves as a sealing portion that partitions the inlet side and the outlet side of the airflow. As a result of research conducted by the present inventor in order to solve the above-mentioned problems, the present inventor installed two seals in the area where the annular support plate that separates the airflow inlet and outlet and the inner surface of the casing ceiling are close to each other. It has been found that it is effective to improve the sealing efficiency by providing an annular baffle plate in addition to the annular seal plate, and to make the rotary blade movable to adjust the width of the gap at the approach portion as necessary. The invention has been completed.

That is, the present invention provides a rotating shaft that hangs down from the ceiling of the casing and has an upper end connected to a rotary drive device, in a casing that has an inlet for the airflow that entrains the object to be classified in the lower part and an outlet in the upper part. A separator that performs airflow classification using a rotary blade having a plurality of classification blades connected directly or indirectly to the rotating shaft and an annular support plate connected to the upper end of the classification blade so as to connect each classification blade, In a separator having two annular seal plates forming an annular space on the inner surface of the casing ceiling facing the upper surface of the annular support plate, a plurality of annular baffle plates are provided on the annular support plate in the annular space and on the inner surface of the casing ceiling. Two annular seal plates are provided on the inner surface of the casing ceiling so that an annular space is formed between the upper surface of the annular support plate and the inner surface of the casing ceiling facing the upper surface of the annular support plate. In addition, in the separator of the present invention, a plurality of annular baffle plates are provided on the annular support plate in the annular space and on the inner surface of the casing. Due to the action of the baffle plates, the velocity of the airflow passing through the gap increases at each baffle plate portion, and conversely slows down at the portion between each baffle plate.

Then, when flowing from the part between the baffle plates to the baffle plate part, coarse powder is difficult to pass through. When the inventor conducted an experiment,
When the number of baffle plates is three or less, the effect of the baffle plates is not so significant. Further, it is preferable to provide at least one, preferably two, each on the inner surface of the casing ceiling and the upper surface of the annular support plate.

If installed only on one side, the effect of the baffle plate will be small.

Further, in the separator of the present invention, the rotating shaft of the rotary blade is movable in the axial direction, and the width of the gap between the seal portions can be adjusted. The structure in which the rotary shaft is movable is such that the upper part of the rotary shaft is rotatably attached to a flange with a bearing structure, and the gaskets are sandwiched and stacked and fixed to the flange provided in the casing ceiling opening corresponding to the flange. At the same time, there is a structure in which a clearance adjustment bolt is provided so that it penetrates only one flange and the tip contacts the contact surface of the other flange. According to this structure, the clearance adjustment bolt can be tightened or loosened. As a result, the flange to which the rotating shaft is attached moves up and down, and the rotary blade moves in the direction of the rotating shaft.

[Effect]

The reason why the separator of the present invention can efficiently collect ultrafine powder is that the annular baffle plate in the gap between the sealing parts plays a role of improving sealing efficiency and preventing the incorporation of coarse powder, and the rotating shaft of the rotary blade is movable in the axial direction, the width of the gap between the seal parts can be adjusted, and by narrowing the gap as necessary, the degree of incorporation of coarse powder can be reduced.

〔Example〕

The range row 1 is provided with a plurality of bolt holes that do not penetrate the flange 6-2, and clearance adjustment bolts 8-1.
8-2 is attached. When the gap adjusting bolt 8-1, 8-2 is tightened while loosening the fixing bolt, the rotating shaft 1 moves upward, and when the fixing bolt is tightened while loosening the gap rJll adjustment bolt, it moves downward.

The upper surface of the annular support plate 4 of the rotary blade is close to the opposing inner surface of the casing ceiling, and on the inner surface of the casing ceiling there is an annular seal plate 9-1 whose inner circumference is larger than the outer circumference of the annular support plate 4; An annular seal plate 9-2 whose circumference is approximately the same size as the inner circumference of the annular support plate 4 and whose lower end is at a height above the annular seal plate 9-1 is provided concentrically with the annular support plate. , the upper surface of the annular support plate and the casing ceiling I
An annular space is formed between the O inner surface and the O inner surface. In the annular space, there are four concentric annular baffle plates, in order from the outside: annular support plate upper surface side 11-1, casing ceiling inner surface side 11-2, casing ceiling inner surface side 11-3, annular support plate upper surface. The present invention will now be described in detail with reference to the drawings.

FIG. 1 is a partial sectional view showing an embodiment of the separator of the present invention. FIG. 2 is a sectional view showing details of the rotating shaft support part of the embodiment shown in FIG. 1.

FIG. 3 is a sectional view showing details of the seal portion of the embodiment shown in FIG. 1.

The rotary blade includes a rotating shaft 1, a disk 2 whose upper center is connected to the lower end of the rotating shaft 1, a plurality of classification blades 3 whose lower ends are connected to the periphery of the disk 2, and an upper end of each classification blade 3. The main part is an annular support plate 4 connected to the lower surface.

The rotating shaft 1 of the rotary blade is connected to the motor at the upper end and can be rotated as necessary.A support ring 5 is fixed around the middle part, and the support ring 5 is connected to the flange 6-1.
It is rotatably connected to the top surface using a bearing structure. The flange 61 is fixed to a flange 6-2 installed in the opening of the ceiling of the casing from above with a gasket 7 interposed therebetween by overlapping fixing bolts. What's more, it's being ignored. Further, the inner surface of the upper end portion of the baffle plate 11-1 and 11-4 provided on the upper surface side of the annular support plate is a slope.

In addition, the rotary blade is surrounded by a guide vane 12 having a large number of slits through which the airflow carrying the object to be classified passes, and the lower end of the guide vane 12 has a tip located below the rotary blade. An inverted cone-shaped cone 13 with an opening is connected. The cone 13 functions to return the coarse powder knocked off by the classification blade 3 to the powder supply source. On the other hand, the airflow passing through the rotary blade and entraining only fine powder flows to the downstream process from the airflow discharge pipe 14 branching from the side wall of the casing above the rotary blade.

FIG. 4 is a sectional view showing details of a sealing portion of a conventional separator. As is clear from a comparison between FIG. 4 and FIG. 2, the conventional separator has poor sealing efficiency because it does not have a baffle plate.

[Example of fine powder production]

A granulated slag powder was produced by pulverizing granulated slag using a roller mill equipped with the separator of the present invention shown in FIG. For comparison, granulated slag was pulverized to produce granulated slag powder under the same conditions except that a conventional separator without a baffle plate was used in the sealing part.

Table 1 shows the rotational speed of the rotary blade, the flow rate of hot air blown into the mill, other grinding conditions, and the Blaine specific surface area of the obtained granulated slag powder. From this result,
It can be seen that when the separator of the present invention is used, granulated slag powder with a high degree of powder can be produced under the same conditions as when a conventional separator is used. In particular, when a conventional separator is used, the Blaine specific surface area is 1000
It was not possible to produce ultrafine powder exceeding 0al=/g.

FIG. 1 is a partial cross-sectional view of an embodiment of the invention.

FIG. 2 is a cross-sectional view of a rotating shaft support part according to an embodiment of the present invention. FIG. 3 is a sectional view of the seal portion of the embodiment of the present invention. FIG. 4 is a sectional view of a sealing portion of a conventional separator.

Table 1 [Effects of the Invention] According to the separator of the present invention, when classifying powder containing coarse powder and recovering fine powder, it is possible to efficiently prevent the coarse powder from being mixed into the fine powder. It is now possible to efficiently collect fine powder with high powder content, which was difficult to do.

[Brief explanation of drawings]

2

Claims (1)

[Claims] (1) A rotating shaft that hangs from the ceiling of the casing and has an upper end connected to a rotary drive device, in a casing that has an inlet for the air flow that entrains the object to be classified in the lower part and an outlet in the upper part;
A separator that performs airflow classification using a rotary blade having a plurality of classification blades connected directly or indirectly to the rotating shaft and an annular support plate connected to the upper end of the classification blade so as to connect each classification blade, In a separator having two annular seal plates forming an annular space on the inner surface of the casing ceiling facing the upper surface of the annular support plate, a plurality of annular baffle plates are provided on the annular support plate in the annular space and on the inner surface of the casing ceiling, and A separator characterized in that the rotating shaft is movable and adjustable in the axial direction.