SU1217465A1 - Centrifugal mill - Google Patents

Description

The invention relates to the construction of a mill for the fine grinding of brittle materials.

The purpose of the invention is to increase the grinding fineness and reduce energy consumption for obtaining a unit of the finished product.

Fig, 1 shows the proposed centrifugal mill, a top view with a wire; in fig. 2 shows section A-A in FIG. one; in fig. 3 - the lower part of the additional loading nozzle in FIG. J 4 - view B in FIG. 3; in fig. 5 view B on fig.Z; in fig. 6 - part of the accelerating blade with a groove.

The mill contains a cylindrical body 1 and c-spiral flows 2, placed outside the cylindrical body of the mill, ending with additional loading nozzles 3 with a slot 4. In the case there is a rotor consisting of a shaft 5 and a disk 6, on which the acceleration vanes 7 are fixed with grooves 8 the entrance of the additional loading nozzles of the spiral flows. On the housing cover there is a loading nozzle 9 installed. The discharge nozzle 10 is tangentially located.

The mill works as follows.

The material being grinded through the loading port 9 is fed under the baffle part of the accelerating blade 7, loaded and thrown into the spiral overflow 2, taken out of the cylindrical mill body 1, through the spiral overflow material is passed through the air mill through the additional loading branch pipe 3 falls under the shock part of the backstop bar , the material is loaded and with the air flow through the spiral flow through the additional loading nozzle falls under the striking part of the accelerating blade. The operation is repeated until the material to be ground reaches the tangential discharge port 10.

High grinding fineness (100% less than 25 µm) is achieved by loading the material to be ground a certain number of times. The number of loads is determined by the number of spiral flows.

The loading rate of particles reaches 180-250 m / s. Energy reduction

.

,

ten

2174652

a cost of 25-20 kW / h / t is achieved by subjecting the material to be ground to an optimum number of perpendiculars. direct (direct) shocks, resulting in its grinding.

When the height of the spiral flow is less than the height of the mill body, part of the material converging from the rotor does not fall into the spiral flow, but hits the wall of the body, creating a circulating material layer, which reduces the material grinding fineness to 40–30 µm and increases 15 energy costs for grinding up to 50-60 KW / H / T. When the width of the spiral flow is less than 1 / L + 1 of the circumference of the mill casing, the material is crushed against the walls of the mill casing, flow turbulence increases, which leads to a delay of the material to be milled in the mill. This reduces the grinding fineness to 40-50 microns and increases the energy consumption for grinding to 70 - 60 KW / H / T. The variable cross section of the spiral flow leads to the maintenance of the velocity of the particles along the spiral flow.

The addition of the diameter of the additional loading nozzle of the spiral flow of more than 1/8 of the diameter of the mill housing leads to a drop in the speed of the material passing through the spiral flow, which reduces the grinding fineness to 50-60 µm and increases the energy consumption for grinding to 50-60 KWT / H / T.

20

25

thirty

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The reduction in the diameter of the additional nozzle of the spiral flow CBbmie 1/12 of the diameter of the mill body leads to an increase in the speed of the material in the spiral flow, to the material slipping without grinding

and reduce the grinding fineness to 40 - 30 microns and increase energy consumption to 40-50 KW / H / T.

With an increase in the width of the slot of the additional loading nozzle of the spiral overflow of 1/3 of the diameter of this nozzle, the material is sprayed over the mill, the formation of a piezo-air mixture inside the mill, which makes it difficult

the operation of the unit also leads to an increase in the finance of pmol to 80 μm and an increase in energy consumption to 70-80 krt / h / t. When reducing the width of the slot dopt

3

of the spiral feed flow pipe over 1/4 of the diameter of this nozzle, the particle flux density of the material going to grinding increases, resulting in shock absorption of particles upon impact and a decrease in grinding fineness to 70 microns and an increase in energy consumption to 65 kW / h / t.

With an increase in the height of the slot above 1/2 of the height of the accelerating blade, there is a breakthrough of the material without being loaded into the gap between the accelerating blade and the mill body, which leads to a reduction in the grinding fineness to 50-60 microns and an increase in energy consumption

up to 60 KW / H / T.

When the slot height is less than 1/3 of the height of the acceleration blade, a large part of the material up to 60% going for grinding moves along the rotor, and not in the air flow, the resistance of the fines increases and the grinding finishes decrease to 55-60 microns and the energy costs to 65, - - 75 KW .h / t.

When additional loading nozzles of spiral flows are located at a distance of more than 4/5 of the rotor radius, the impact part of the accelerating blade decreases, which leads to material slipping without loading and reducing the grinding fineness to 60-70 microns and energy consumption to 60-70 kWh / t.

If additional loading nozzles of spiral flows are located at a distance of less than 3/5 of the rotor radius, the particle loading rate decreases, which leads to a reduction in the grinding fineness to 50-60 µm and an increase in energy consumption to 50-60 KW, h / t.

When the slots are located on the accelerating blades at a distance of sva54

more than 4/5 or less than 3/5 of the rotor radius from the center of rotation of the rotor, they do not get additional overhead connections of the spiral flows of the mill, which makes it impossible for the structure to work.

When the height of the additional loading flow rises above 3/4 of the height of the accelerating blade, it exceeds: it sells a groove for the entrance of the additional loading nozzle, which makes it impossible for the structure to work.

When reducing the height of the additional loading nozzle less than 2/3 of the height of the accelerating blade, a part of the material slips without loading into the gap between the accelerating blade and the upper body of the mill. The result is that fineness

the grinding is reduced to 50-60 µm, and the energy consumption is increased to 45-55 KW, h / t.

With an increase in the depth of the paea on the accelerating blade, 3/4 of the height

the accelerating blade most of the material up to 70% going for grinding slides along the rotor, which leads to a reduction in the grinding fineness to 45-50 microns and an increase in energy consumption

up to 45 kWh / t.

When reducing the depth of the groove on the accelerating blade less than 2/3 of the height of the accelerating blade, the height of the additional loading nozzle decreases, which leads to the formation of dusty vortex flows in the gap between the accelerating blade and the mill body, which reduces the grinding fineness to 50-60 microns and increases energy consumption to 50 -60 kWh / t.

The proposed centrifugal mill provides increased grinding fineness and reduced energy consumption per unit of the finished product.

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Fig. /

A - x

Bii 5

, fig.Asostavitel L.Chubukova Editor N.Volovik Tehred M.Gergel Proofreader I.Musk

Order 1029/10 Circulation 583 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod., Proektna St., 4

(rig. 6

Claims (1)

CENTRIFUGAL MILL, containing a cylindrical body, a rotor with accelerating blades, loading and unloading nozzles, characterized in that, in order to increase the grinding fineness and. reducing energy costs for obtaining a unit of the finished product, it is equipped with spiral crossflows displaced behind the cylindrical body, having a height equal to the height of the cylindrical mill body at the entrance, a width equal to 1 / M + 1 of the circumference of the cylindrical mill body, and having a circular cross section at the exit and is also equipped with additional loading nozzles connected to spiral flows at their outlet with a height of 2 / 3-3 / 4 of the height of the upper blade, with a diameter of 1 / 8-1 / 12 of the diameter of the cylindrical body, filled with a slot at the end with a width of 1 / 4-1 / 3 of the diameter of the additional loading nozzle, with a height of 1 / 2-1 / 3 of the height of the accelerating blade, while the additional loading nozzles are located at a distance of ί4 / 5-3 / 5 of the radius of the rotor from the center of rotation rotor, and the angle between the radii of the rotor drawn through the inlet and outlet of the spiral overflow is 360 / n + 1, and the accelerating blades are made with grooves with a depth of 2 / 3-3 / 4 of their height, where And is the number of overflows. ^ b .. _m J217465 „