JP2969555B2 - Centrifugal classifier - Google Patents

Abstract

This centrifugal classifier has a cylindrical casing. Its classification air inlet (3) extends over the full height of the classification rotor (2). Both axial ends of the rotor shaft extend outwards through the fine material outlet volumes (17, 18), the latter having the same diameter as the classification rotor itself. In the improved new arrangement, each fines outlet volume (17, 18) has a re-entrant section (19, 20), to contain a rotor shaft bearing. The fines outlet volume widens axially outwards, in a screw- or spiral formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has an inlet for classification air which extends tangentially over the entire height of the classifier rotor in a substantially cylindrical housing, and wherein the rotor shaft has both shafts. At the directional end, a centrifugal classifier of the type extending outwardly through an outlet chamber for the fines-classification air, the diameter of which is approximately equal to the diameter of the classifier rotor.

[0002]

2. Description of the Prior Art A centrifugal classifier of this kind is already known from DE 2951819. Such a classifier is characterized in that it has a high processing ability, takes out fine particles efficiently, and has almost no coarse particles or substances of a specified size or more within the fine particles.

[0003] However, such known arrangements have the disadvantage that the shaft is relatively long and, consequently, heavy. In other words, the two outlet chambers for the fines-classification air are each formed by a knee-shaped tube element whose diameter approximately corresponds to the rotor diameter. The rotor shaft is guided on both sides through this raised outlet-tube member, in which case the shaft penetration must be well sealed against the outside air. One bearing for the shaft is provided on each side of the shaft penetration. At the upper end of the shaft is mounted a pulley or similar.

[0004] The rotor shaft and the classifier rotor are generally
To get the required strength and reduce vibration
It must be rugged and relatively solid in accordance with the large axial spacing between the two bearings.

[0005] In a centrifugal classifier already known from DE 28 25 400 A1, the rotating blades are fixed at both ends to one end ring, respectively, and both end rings are each at their outer periphery. Are mounted in hydrostatic, aerostatic or electromagnetic bearings. However, such bearings are considerably more expensive, especially when the diameter of the end rings is large.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the distance between rotor shaft bearings in a centrifugal classifier of the type described at the outset, and to maintain and maintain the bearings.
To allow access from outside for inspection and repair. In addition, the optimal conditions for obtaining fines that do not require further classification are an outlet chamber for the classification air,
This is achieved with short bearing spacing and good access to the bearings.

[0007]

SUMMARY OF THE INVENTION The above-mentioned object is achieved by an arrangement according to the independent claim. That is, in the centrifugal classifier of the present invention, each fine particle and the outlet chamber for the classified air have a protrusion extending inward in the axial direction, and a bearing for the rotor shaft is provided in the protrusion. The outlet chamber surrounding the bearing,
It is characterized in that it extends spirally or spirally outward in the axial direction.

The inwardly extending projections or ridges for receiving the bearings occupy relatively little space, so that the remaining cross section is for fines and classifying air (discharge air). Enough for the exit room.

At the point on the peripheral surface where the outlet chamber spiraling in the direction of flow achieves its maximum flow cross-section, it is necessary for the starting point of the spiral or helical configuration to be 3 °.
At 60 degrees or one turn, a preferably tangentially extending outlet conduit is connected.

Apart from the technically favorable arrangement of the flow of the spiral outlet chamber, it is achieved that the bearing housed in the projection in the axial direction is easily accessible from the outside. The axial height is reduced in a relatively large circumferential area around the starting point or starting point of the exit spiral or exit spiral.

Since the rotor shaft is lighter and thinner in accordance with the relatively small spacing between the bearings, the space required for the bearings is correspondingly smaller. In the same situation, the forces generated are smaller, so that a correspondingly smaller cross section or wall thickness is sufficient.

The distance between the bearings of the rotor shaft is such that the radial arms connecting the end rings of the classifier rotor with the rotor shaft are inclined inward to reduce the distance between both bearings. Can be further reduced by:

In particular, in the configuration of the present invention, the outlet chamber surrounding the bearing extends spirally or spirally outward in the axial direction.

The classifier rotor can be arranged horizontally or vertically. When placing the classifier rotor horizontally,
The granulated mixture to be classified is very simply fed into the classifier chamber together with the classification air, that is to say that the granulated mixture is already relatively fine-grained, so that coarse particles are also carried by the classification air stream. A large hopper-shaped outlet chamber is provided below the classifier rotor, in which the flow velocity is strongly reduced, so that coarse particles fall downward into the outlet hopper.

For the coarse mixture to be classified,
It is advantageous to arrange the classifier rotor vertically. In this case, the mixture to be classified can be introduced from above into the classification chamber surrounding the rotor, as usual.

At the lower end wall of the housing, a plurality of hopper-like coarse-grain outlets also open to the classifying chamber, each of which extends over a part of the peripheral surface.
The bottom surface of the classifying chamber can also be provided with a hard, abrasion-resistant and at the same time smooth coating, for example a ceramic light lubricant. The slippery the surface, the smaller the slope of the surface,
This results in a lower axial height.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

The centrifugal classifier of the present invention has a substantially cylindrical housing 1 arranged vertically, in which a classifier rotor 2 is rotatable. Housing 1
Has an inlet 3 for classified air extending tangentially over its entire height. A guide vane ring 5 is provided at a radial distance from the housing outer wall 4. Further, a thin plate ring or a rotary blade ring 6 of the classifier rotor 2 is provided at a distance from the guide blade ring 5 in the radial direction. In the cylindrical ring-shaped classifying chamber 7 formed between the guide blade ring 5 and the rotary blade ring 6, a granular mixture separated from above is put. Above the classifying chamber 7, an annular passage 8 for sucking the particulate mixture is provided, and a connecting pipe piece 9 is joined to the annular passage 8.

The rotary blade ring 6 is mounted between an upper end face ring 10 and a lower end face ring 11, and from these end face rings, an arm 13 extending in a substantially radial direction is connected to the shaft of the classifier rotor 2. It is fixed to 14 and extends to the boss 15.
In order to reinforce the rotating blade ring 6, a central retaining ring 10a is further provided, which is also connected to a radially extending arm 13a and which has a boss 15a.
Are fixedly connected to the rotor shaft 14.

On both end sides of the classifier rotor 2 there is an outlet chamber for discharging one fine particle and classified air, respectively.
17,18 are provided. The gap between each end ring 10, 11 of the classifier rotor 2 and the ring-shaped housing wall facing it is provided by the classifying chamber 7 where coarse particles are introduced into the outlet chambers 17, 18 for fines and classifying air. Sealed so that it cannot be reached. For this purpose, in each of the outlet chambers 17, 18 for both fines and classified air, one annular passage 16 with connecting holes 16a distributed over the peripheral surface is provided.
Is provided.

According to the invention, the outlet chamber 17 for the fines and the classification air above and the outlet chamber 18 for the fines and the classification air below each have a central part extending inward in the axial direction. It has projections 19, 20 in which one bearing 21, 22 for the rotor shaft 14 is fitted.
As a result, the distance between the two bearings 21 and 22 is significantly shorter than in the prior art, and the rotor shaft is correspondingly shorter and lighter.

The radial arm 13 between the end rings 10, 11 and the rotor shaft 14 is inclined inward, so that both bearings 21, 22 can be further displaced inward, In short, the rotor shaft is further shortened.

The respective bearings 21 and 22 are sealed to the inner chamber by annular gap seal members 24 and 25. The annular gap seal members have cleaning air passages 26 provided in the shaft.
The cleaning air is supplied axially and radially via.
Corresponding to the conical bearing housing, a conical ring 27 is provided on each end ring 10, 11 so that the flow is advantageously guided and an additional sealing gap is formed.

Two fines-outlet chambers 17, 18 for classified air
Are each arranged in a cylindrical outer annular wall 29, a cylindrical inner annular wall 30, and between these annular walls 29, 30 and spirally or spirally inclined outward in the axial direction. Alternatively, it is surrounded by a rising wall surface, that is, a circular ring-shaped end wall 31 in a plan view. In the inner annular wall 30 or in the aforementioned projections 19, 20, one bearing 21, 22 for the rotor shaft is accommodated respectively. In the peripheral area where the outlet helix starts, the bearing is easily accessible from the side.

An annular passage 8 for the inflow of the mixture, radially outwardly of the top, adjoins the outer annular wall 29. According to FIG. 2, the connecting piece 9 is inclined and tangentially aligned with the annular passage 8. The lower side of the annular passage is provided with a helical section 8a which expands in the direction of flow, so that the fraction is evenly distributed over the circumference.

A ring-shaped plate 33 and a pedestal are provided above the upper outlet 17 for fine particles and classified air, and a motor or a driving device is incorporated in this plate. At the upper end of the projection, a thrust bearing 34 is provided, which supports the weight of the classifier rotor.

By providing the window 32 on the side of the projection 19, the bearing 21 and the seal member 24 can be easily accessed even when the driving device is arranged as described above. This window is a plate
It is provided below 33 and above bearing 21.

On the opposite side, in other words on the lower side of the housing, there are provided four hopper-like outlet chambers 35 for coarse particles, each of which extends over a quarter of the circumferential surface and Between these outlet chambers 35, the lower bearing 22 can be easily accessed from the side.

For this reason, each of the four coarse-grain outlet chambers 35 has an inner wall 35a and an outer wall 35b projecting outward in the vertical direction, and one outlet connecting pipe piece 35e extending in the radial direction. Walls 35c, 35d inclined toward the front.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a vertically arranged centrifugal classifier according to the present invention.

FIG. 2 is a transverse sectional view taken along the line II-II in FIG.

FIG. 3 is a transverse sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a transverse sectional view taken along the line IV-IV of FIG. 1;

FIG. 5 is a side view of the centrifugal classifier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Classifier rotor 3 Inlet for classification air 5 Guide blade ring 6 Rotating blade ring 7 Classification chamber 8 Annular passage 9 Connecting pipe piece 10 End ring 11 End ring 13 Arm 14 Rotor shaft 17,18 Fine-grain-classified air Outlet chamber 19,20 Projection 21,22 Bearing 24,25 Annular gap seal member 26 Cleaning air passage 29 Outer annular wall 30 Inner annular chamber 31 End wall 35 Outlet chamber for coarse particles

Claims (5)

(57) [Claims] 1. A classifying air inlet (3) extending tangentially over the entire height of a classifier rotor (2) in a substantially cylindrical housing, and a rotor shaft at both axial ends. In a centrifugal classifier of the type extending outwardly through an outlet chamber for fines-classification air, wherein the diameter of the outlet chamber is approximately equal to the diameter of the classifier rotor, each of the outlet chambers (17 , 18) has a projection (19, 20) extending inward in the axial direction, and accommodates a bearing (21, 22) for the rotor shaft in the projection, and further has a bearing (21, 20).
22) A centrifugal classifier characterized in that the outlet chambers (17, 18) surrounding (22) are spirally or spirally spread outward in the axial direction. 2. The radial arms (13) connecting the end rings (10, 11) of the classifier rotor to the rotor shaft (14) are directed inwardly toward each other to reduce the distance between the two bearings. The centrifugal classifier according to claim 1, wherein the classifier is inclined. 3. A housing and outlet chamber (35) are provided at the lower side of the housing, each of which extends over a part of the circumferential surface and is substantially wedge-shaped in side view. The centrifugal classifier according to claim 1 or 2. 4. An outlet chamber for each fines-classification air.
In (17, 18), an annular passage (16) for supplying cleaning air to one sealing member is provided in each of the end rings (10, 18).
The centrifugal classifier according to any one of claims 1 to 3, wherein the centrifugal classifier is provided between the housing (11) and a housing wall facing the housing. 5. The lower side of the annular passage (8) for receiving the classification material has a section (8a) spirally extending along the flow direction in order to distribute the classification material uniformly over the peripheral surface. The centrifugal classifier according to any one of claims 1 to 4, wherein the centrifugal classification is performed.