SU827161A1 - Jet-mill ejector - Google Patents

Description

one

The invention relates to a technique for jet grinding of solid materials and may find application in the chemical, ore dressing and metallurgical industries, as well as in the building materials industry.

An ejector for a countercurrent jet mill is known, comprising a cylindrical horizontal body, a common fitting for introducing the material to be crushed and returning, a velocity pipe and an energy carrier pipe terminating in a nozzle.

one.

The disadvantages of the ejector of this design are large energy losses during the entrainment of the solid phase into the gas flow due to the large difference in the direction of movement of the material and gas at the time of their contact, as well as the uneven distribution of the material over the cross section of the outgoing gas flow, which is mainly caused by the flow of material to the bottom. the ejector housing. These drawbacks reduce the efficiency of the jet mill at work.

The closest in technical essence to the invention is an ejector of a jet mill, comprising a horizontal body with a lid, mounted on the lid fittings for introducing the return and the material to be ground, the accelerating pipe and the energy carrier pipe, ending with a coil, the slice of which is located at the inlet to the accelerating pipe coaxially with her 2.

This ejector also does not objectify the production of a gas stream with a uniform distribution of particles in the cross section, since particles of a different size are introduced into the flow locally at certain places around the nozzle.

The aim of the invention is to reduce the loss in mixing the material with the energy carrier and to increase the uniform distribution of the solid phase in the gas stream from the accelerating tube.

The goal is achieved by the fact that in the jet mill ejector containing a horizontal body with a lid, fittings for return entry and grinding material are mounted on the lid, the accelerating pipe and the energy carrier pipe ending with a nozzle, which section is located at the inlet to the accelerating pipe coaxially with it, unloading part of the nozzle for the return input is made in the form of a nozzle with a longitudinal, horizontal cross section in the direction of the energy carrier movement Trick nozzle part is rounded and abuts the bottom edge of the accelerating tube inlet, the nozzle section is formed inclined at an acute angle to the wall and the fitting for introducing material to be ground is located above the nozzle.

The separation of the return pipe by a partition into parts and the location of the cut-off of this pipe around the nozzle improves the uniformity of feeding the solid phase in the cross section of the accelerating pipe, and as a result of the pipe tilting in the direction of movement of the energy carrier and rounding the lower part of its entrance to the solid phase B, the flow practically coincides with by directing the movement of the energy carrier, due to which the energy losses to the introduction of material into it will be minimal.

FIG. 1 shows the proposed ejector, a longitudinal section; in fig. 2 - section A-A of FIG. one.

The ejector includes a horizontal housing 1 with a roof 2, on which fitting 3 is mounted for return feeding and fitting 4 for feeding crushed material from a hopper (not shown), accelerating pipe 5, pipeline 6, energy carrier nozzle 7 located coaxially accelerating pipe 5 at the entrance to it. The discharge part of the fitting 3 is made in the form of an inclined nozzle 8 with a longitudinal partition 9 located horizontally in the cross section of the nozzle.

To ensure uniform material unloading from the nozzle 8, its angle of inclination to the horizon is made somewhat larger than the angle of repose. The lower output part 10 of the nozzle 8 is rounded and adjacent to the lower entrance edge of the accelerating pipe 5. The cut of the nozzle 8 is made at an acute angle to the partition 9, and the nozzle 4 for introducing the material to be crushed is located above the upper part 11 of the nozzle 8.

The ejector works as follows. The return from the classifier entering the choke 3 (not shown in the drawing), due to the presence of a longitudinal baffle 4, is evenly distributed over the cross section of the nozzle 8 and is fed into the circular area around the nozzle. Due to the implementation of the lower part 10 of the nozzle 8 rounded to the direction of return movement at the exit of the nozzle 8 almost coincides with the direction of energy carrier exit from the nozzle 7 of the pipeline 6, therefore the involvement of the return to the tazoma stream accelerated in the accelerating tube 5 occurs almost without energy loss . The grinded material loaded into the nozzle 4 gets into the upper part of the nozzle 8 and is dropped along it into the nozzle section. Due to the oblique implementation of the cut-off of the pipe 8 is provided uniform

mixing larger ground material and smaller returns. The return flow, as a smaller product, into the middle part of the stream, also contributes to its intensive mixing with the ground particles of the material to be ground. The particles of the material being crushed and return picked up and mixed by the energy carrier stream are accelerated in the accelerating tube 5 and in the form of a high-speed gas stream of high homogeneity are introduced and the grinding in the grinding chamber (not shown). Low energy costs for the introduction of material into the stream, as well as high homogeneity of the gas flow at the exit of the ejector, provide high performance with lower specific energy consumption than the known structures.

Application for grinding in a jet laboratory mill, equipped with ejectors of this design, cummingtonite-magnetite quartzite of Dnepropet. Of the ore mining and processing plant, previously crushed to a size of 5 mm, increased the productivity of the mill compared to the known (2) from 3.2 to 5.2 kg / h, i.e. 63%, with

reduction of energy consumption by 39%. Grinding using known and proposed ejectors is carried out with the following, their identical values of the main parameters of the mill; the energy carrier temperature is 375 ° С, the energy carrier pressure is 0.5 MPa, the vacuum pressure of the fan is 600 PA, the frequency of the classifier is 500 rpm.

Claims (2)

Invention Formula The jet mill ejector, containing a horizontal body with a lid, mounted on the lid fittings for input return and comminuted material, the accelerating tube and the pipeline of power supply, ending with an nozzle, the cut of which is located at the entrance to the accelerating tube coaxially with it, differing so that, in order to reduce the loss of material mixing with the energy carrier and increase the uniform distribution of the solid phase in the gas stream flowing out of the expansion pipe, the discharge part of the nozzle for return input is made in the direction of the energy carrier of the nozzle with the Longitudinal, horizontal in cross section by a partition, and the lower outlet of the nozzle is rounded and adjacent to the lower inlet edge of the expansion pipe, the nozzle is cut inclined at an acute angle to the septum, and the fitting for introducing the comminuted material is located above the nozzle. Sources of information taken into account during the examination 1. Gorobets V. I. and Gorobets L. Zh. New direction of grinding, M., “Nedra, 1977, p. 149. 2. USSR author's certificate No. 309735, cl. On 02/19/06, 1970. 2