RU199423U1 - JET COUNTER-FLOW MILL WITH ADDITIONAL GRINDING CHAMBER - Google Patents

Abstract

The utility model relates to mechanical engineering. A counter-flow jet mill with an additional grinding chamber is proposed, containing a feed material hopper, in which axial nozzles are built for supplying the main energy carrier, which are included in the accelerating tubes, coaxially introduced into the counter-flow grinding chamber. In the upper part of the counterflow grinding chamber, a connecting pipe is fixed vertically, made in the form of a truncated cone, inside which a splitter cone is installed coaxially with its apex downward, and the connecting pipe is connected to an additional grinding chamber, which is made in the form of a hollow cylinder, the lower base of which is the base of the cone - splitter, to the cylindrical part of the additional grinding chamber tangentially installed nozzles for supplying additional energy carrier, located diametrically opposite to each other, at a height equal to half the height of the additional grinding chamber. The utility model is aimed at increasing the fineness of the finished product. 2 ill.

Description

The utility model relates to mechanical engineering, in particular to equipment for grinding, namely, jet grinding mills to obtain ultrafine grinding of bulk materials, and can be used in the construction, food and chemical industries.

The known design of a counter-current jet mill [Karpachev D.V. Improvement of the technology of grinding and beneficiation of ore and nonmetallic materials. Vestnik BGTU im. V.G. Shukhov. 2013. No. 2. S. 103-107], containing a built-in cell magnetic catcher, which allows you to obtain fine powders with increased requirements for their dispersion and impurity content.

Known design of the jet mill [USSR inventor's certificate for the invention No. 1076141, IPC - В02С 19/06; declared 04/22/1982; publ. 28.02.1984, bul. No. 8]. The mill includes a collector of an energy carrier, gas from which a grinding chamber enters through nozzles, an inner side surface which is made in the form of a polyhedron, a loading device made in the form of one or more injectors with material supply nozzles, pipes of fine and coarse fraction installed along the axis of the chamber, a collector of the coarse fraction located under the nozzle of the coarse fraction, a reflective element installed coaxially with the nozzles of the coarse and fine fraction, made in the form of a cylinder with a conical bell in the lower part, acting as the upper flap of the grinding chamber, and baffle plates fixed on the outer surface of the cylinder.

The disadvantage of the known mill is the low efficiency of grinding due to the insufficient effect of the energy carrier on the ground material.

The closest technical solution, selected as a prototype, is a counter-flow jet mill [RF inventor's certificate for invention No. 2188077, IPC - В02С 19/06; declared 11/16/2000; publ. 27.08.2002, bul. No. 24]. The counter-flow jet mill contains bunkers of raw material, in which axial nozzles of injectors for supplying the main energy carrier are built, connected to the main air duct, entering the accelerating tubes, coaxially introduced into the counter-flow grinding chamber. Coaxial to the booster tubes, there are retaining pipes with built-in nozzles for supplying additional energy carrier, with a gap forming a channel with the outer surface of the accelerating pipes and the inner surface of the retaining pipes, the nozzles of which are connected to an additional air duct, while the retaining pipes at the entrance to the counter-flow grinding chamber are equipped with crimp nozzles, each of which is made in the form of a truncated cone with an annular element on a smaller base and with an annular element on a larger base for rigid attachment to the retaining pipe, the outer surface of the annular element on the smaller base rests along the perimeter on the inner surface of the counterflow grinding chamber.

The following set of prototype features coincides with the essential features of the claimed utility model: bunkers of the source material, in which axial nozzles are built for supplying the main energy carrier, included in the accelerating tubes, coaxially introduced into the counter-flow grinding chamber.

The disadvantage of the prototype is the low efficiency of grinding due to the insufficient impact of the energy carrier on the ground material.

The utility model is aimed at increasing the fineness of the finished product due to the additional impact of the energy carrier on the crushed material in the additional grinding chamber.

This is achieved by the fact that a counter-flow jet mill with an additional grinding chamber contains a source material hopper, in which axial nozzles are built for supplying the main energy carrier, which are included in the accelerating tubes, coaxially introduced into the counter-flow grinding chamber. In the proposed solution, in the upper part of the counter-current grinding chamber, a connecting pipe is fixed vertically, made in the form of a truncated cone, inside which a splitter cone is installed coaxially with its top downward. The connecting pipe is connected to an additional grinding chamber, which is made in the form of a hollow cylinder, the lower base of which is the base of the splitter cone. To the cylindrical part of the additional grinding chamber, nozzles are tangentially installed for supplying an additional energy carrier, located diametrically opposite to each other, at a height equal to half the height of the additional grinding chamber.

The essence of the utility model is illustrated by graphic material, where in Fig. 1 shows a sectional view of a counter-current jet mill with an additional grinding chamber, FIG. 2 - section A-A in Fig. 1.

A counter-flow jet mill with an additional grinding chamber consists of a counter-flow grinding chamber 1, which is arranged horizontally. Inside the counter-flow grinding chamber 1, accelerating tubes 2 are coaxially fixed (for example, with a flange joint). Coaxially with the accelerating tubes 2, an ejector unit 3 is fixed (for example, with a flange joint), over which a feed material hopper 4 is installed. The ejector unit 3 is connected (for example, by welding) with the source material hopper 4. Inside the ejector unit 3, coaxially with the accelerating tubes 2, axial nozzles 5 are installed to supply the main energy carrier. In the upper part of the counterflow grinding chamber 1, a connecting pipe 6, which is made in the form of a truncated cone, is fixed vertically (for example, by welding) with a smaller base.

With a large base, the connecting pipe 6 is connected (for example, by a flange connection) with an additional grinding chamber 7. Inside the connecting pipe 6, with its top downward, a divider cone 8 is installed, so that its axis coincides with the axis of the connecting pipe 6, and the base of the cone is the divider 8 coincided with the lower plane of the additional grinding chamber 7. The additional grinding chamber 7 is made in the form of a hollow cylinder, the lower base of which is the base of the divider cone 8, and the upper base is the disc 9. The disc 9 is made with a hole in the center, the axis of which is collinear to the axis connecting pipe 6, and is connected (for example, by welding, flange connection) with the outlet pipe of the finished product 10. To the cylindrical part of the additional grinding chamber 7, nozzles 11 are tangentially installed for supplying additional energy carrier, for example, circular section, located diametrically opposite to each other, at a height equal to half the height of the additional grinding chamber 7.

The principle of operation of a counter-flow jet mill with an additional grinding chamber is based on the destruction of the material in a combined way: initially by impact in the counterflows of the gas mixture, and then by abrasion of material particles against the walls of the additional grinding chamber 7.

Material, for example red lead, from the feed material hopper 4 enters the ejector unit 3, in which the material is captured by the main energy carrier, for example, compressed air flowing out of the axial nozzles 5, and is directed to the accelerating tubes 2. In the accelerating tubes 2, the material is accelerated under the influence of the energy carrier, and enters the counter-flow grinding chamber 1, where the primary destruction of the material occurs by impact and abrasion in counter flows. Further, the material rises along the connecting pipe 6 into the additional grinding chamber 7. The divider cone 8 allows you to direct the material and energy carrier to the periphery of the additional grinding chamber 7. The material, falling on the periphery of the additional grinding chamber 7, is pressed against the walls of the additional grinding chamber 7 under the action of centrifugal force. additional flow of energy carrier, for example compressed air, which is supplied from tangentially installed nozzles 11. Grinding occurs due to abrasion of the material against each other and against the walls of the additional grinding chamber 7, which leads to an increase in the fineness of the finished product. After grinding, the material through the disk 9 is directed to the branch pipe for the outlet of the finished product 10 is sent to the classifier (not shown in the figure), where separation into fractions occurs. The finished product enters the dust collector (not shown in the figure), and the coarse fraction is returned for re-grinding to the feed material bin 4.

This solution improves the fineness of the finished product due to the additional impact of the energy carrier on the ground material in the additional grinding chamber.

Claims (1)

A counter-flow jet mill with an additional grinding chamber, containing a feed material hopper, in which axial nozzles for supplying the main energy carrier are built, entering the accelerating tubes, coaxially introduced into the counter-flow grinding chamber, characterized in that a connecting pipe is vertically fixed in the upper part of the counter-current grinding chamber, made in the form of a truncated cone, inside which a splitter cone is installed coaxially with its apex downward, and the connecting pipe is connected to an additional grinding chamber, which is made in the form of a hollow cylinder, the lower base of which is the base of the splitter cone, nozzles are tangentially mounted to the cylindrical part of the additional grinding chamber for supply of additional energy carrier, located diametrically opposite to each other, at a height equal to half the height of the additional grinding chamber.

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