SU893263A1 - Unit for disintegrating powder materials - Google Patents

Description

one

The invention relates to the grinding of powder materials, in particular, equipment for manufacturing magnetic recording media, in particular, equipment for processing ferropowders for magnetic varnishes.

In the currently used technology of preparation of ferropesagia for magnetic tapes of ball mills 1, the agglomerates and particles are crushed simultaneously with disaggregation, which makes it impossible to classify them.

In addition, the operation of such grinding is long (up to 68 hours), which causes deterioration of the magnetic properties of ferropowders due to work hardening, and the cyclical nature of the process to. does not allow to mechanize full manual operations.

Closest to the proposed technical essence is an installation for grinding powder materials, containing a shock-mill, in the lower part of the grinding chamber of which feed ducts, a rotor and a baffle plate are located, and in the upper part a classifier with a conical ring surrounding it, and connected to

a mill through an air duct bag filter 2.

The disadvantages of the known installation are that it can only crush non-magnetic powders due to the tendency of ferropowders to clumping disaggregated needle-shaped particles in dead zones, in particular, between

10 by the fender plate and rotor, the impossibility of classifying particles by the lower limit, as well as the ingress of particles of large sizes through the classifier into the duct.

15

The purpose of the invention is to increase the homogeneity of the obtained product of a given fractional composition.

This process is achieved by the fact that in an installation for grinding powdered, materials containing a centrifugal impact mill, in the lower part of the grinding chamber of which are located feed ducts, the rotor and the baffle plate, and in the upper part

25 parts - a classifier with a conical ring enclosing it, and a bag filter connected to the mill via an air duct; the baffle plate is made in the form of perforated30. washers and fitted with additional supply air ducts, a reverse cone ring is mounted in the cavity of the cone ring, the smaller base of which covers the classifier at the level of its base, and also equipped with cyclones, each of which is connected by an upper nozzle with an air duct connecting the fritter and filter.

Elimination of dead zones with a baffle plate, made in the form of a ring with a grid around the periphery, to which. Additional air ducts are installed, it permits to treat ferropowders without clumping, and the reverse conical colio allows to isolate two oncoming air flows and eliminate the occurrence of vortices, thereby improving the reliability of the classifier.

Depending on the purpose of the ferropor, the cyclones built in between the mill and the bag filter trap particles of certain sizes by mass, thus ensuring the provision of specified magnetic properties.

FIG. 1 shows the proposed installation, a general scheme; in fig. 2, section A-A in FIG. one; in fig. 3 section BB in FIG. 2

The installation consists of a shock centrifugal mill 1, cyclones 2, the number of which is given by the intended purpose depending on the specified particle sizes and bag filter 3, which are interconnected by ducts 4.

The shock cent grinding mill 1 is a dismembrator with a horizontal rotor 5, on which the blades (or pins) are fixed. . In the upper part of the grinding chamber there are classifier b with a reducer and an autonomous engine, and in the lower part there is a tapered ring 7 with a reverse tapered ring 8 built in it and a baffle plate 9 in the form of a ring with a ring 10 mounted around the periphery. additional air 11

The device works as follows.

The initial ferropowder with particles of 3-4 mm comes from the bunker 12 to the ejector 13, from where it is directed by a stream of compressed air supplied to the inlet duct 14 to the grinding chamber. Disaggregation is accomplished by a pin suspended in a stream of air granulocytes porous conglomerate ferroporevdka rtora of turbine blades 5, and rotor head and the annular grid 10. The air flow supplied through the duct 11 to the setke10t carries dezaregirovannye particle classifier to the rotor blades 6. promote entrainment of particles increasing air pressure

With the help of a conical ring 7 and a reverse cone ring 8 built into it, heavy and light particles are separated by mass, while the reverse cone ring 8 does not allow two oncoming air streams to create a vortex flow and thereby prevents the passage of heavier particles. to classifier. The light particles are carried away through the classifier b, the maximum size of the particles carried away is governed by the speed of rotation of the classifier through the gearbox, as well as by the air flow through the air ducts 11.

The capture and classification of particles according to the minimum size is carried out by cyclones 2, from where disaggregated and classified ferropowder enters the mixers 15.

Small particles that are not caught by cyclones are carried away to the quick-change bag filter. From there, the disaggregated powder can also be fed to the mixers as intended.

The use of the invention makes it possible to stabilize the technology and improve the quality of magnetic recording media by improving the copy-effect, noise, electro-acoustic performance.

Claims (2)

1. USSR author's certificate 22.7076, CL. At 02 .0 17/16, 1965 ,. 2. Gundorov I.M., et al. Grinding plant for powder paints .-. Paintwork materials and their application. 1977, 1, p. 52-53. / 2 four