RU2198029C2 - Method and apparatus for producing material with predetermined milling fineness - Google Patents

Abstract

FIELD: milling method and equipment. SUBSTANCE: method involves providing sequential milling of material in at least two vibratory mills arranged one above another, with material being classified in each mill by means of perforated partition wall mounted in discharge branch pipe; dividing material into at least two flows in each discharge branch pipe. Apparatus has frame, at least two milling chambers with milling bodies arranged one above another and communicated with one another through discharge branch pipes. Perforated partition wall positioned at outlet end of each milling chamber in discharge branch pipe has openings of predetermined section. Each discharge branch pipe is split into at least two branches and is equipped with gate for changing direction of material flow. EFFECT: increased efficiency and provision for obtaining material of predetermined milling fineness. 3 cl, 4 dwg

Description

 The invention relates to the grinding of materials by means of vibration mills and can be used in food, chemical, pharmaceutical, mining and construction industries.

 A known method of dry grinding of materials in a mill with recirculation of the venting agent, including dividing it by size in an air-passage separator having external and internal cones, with the return of a large product to the mill, precipitation of the finished product in a cyclone (SU 1606189 A, 11/15/1990) .

 The disadvantage of this method is the impossibility of obtaining material with a given fineness of grinding, as well as the low productivity of the method and its high energy intensity.

 The closest to the method according to the technical essence of the invention is a method for the production of material with a specified grinding fineness, including sequential grinding of the material in at least two vibration grinding chambers located one below the other, communicated with each other by a discharge pipe, unloading the material (SU 1433499 A1, 30.10 .1988).

 The disadvantage of this method is the impossibility of obtaining material with a given fineness of grinding, as well as the low productivity of the method and its high energy intensity.

 Closest to the device according to the technical essence of the invention is a device for the production of material with a given fineness of grinding, including a frame, at least two grinding chambers with grinding bodies, located one below the other and communicated with each other by means of unloading nozzles, a loading nozzle and a vibro drive.

 The disadvantage of this device is the design complexity, low productivity, the inability to obtain material with a given grinding fineness, as well as the inability to isolate several fractions of the material with a given grinding fineness at one mill.

 This task is achieved by the fact that in the method of manufacturing a material with a given grinding fineness, including sequential grinding of the material in at least two vibration grinding chambers located one below the other, communicated with each other by an unloading nozzle, unloading the material. The material is classified in each grinding chamber using a perforated baffle installed in the discharge pipe, and then material is divided into two or more streams in each discharge pipe.

 The method is as follows.

Take the material for grinding with a fraction of 0.5-20 mm, load into a vibration mill, consisting of two grinding chambers, located one below the other. A perforated baffle is installed in the discharge pipe of the upper grinding chamber with a given hole cross section (equal to the specified grinding fineness, for example 2.5 mm), the vibrator is turned on, grinding is done, the milled material of the given fineness, for example 2.5 mm or less, enters the pipe, which forks into two (if necessary, it can branch into 3-4 branch pipes, if the mills are located in 2-3 parallel cascade lines). Flanges are installed in the nozzles, with the help of which the material flow is divided into two or more flows
In the case of directing one material flow to the grinding, the material enters the second grinding chamber in the discharge pipe, in which a perforated baffle with a given hole cross section, for example, 1.5 mm, is installed. The vibrodrive is turned on, grinding is made, and particles of material 1.5 mm or less enter the discharge pipe. Next, the classification cycle is repeated. The material enters the upper grinding chamber of the next vibration mill, which also consists of two grinding chambers. A perforated baffle with a predetermined hole cross section (for example 0.7 mm) is installed in the discharge pipe. The vibrator is turned on and the grinding and classification cycle is repeated. If necessary, direct the flow of material into the next grinding chamber with a predetermined cross-section of the holes of the perforated partition equal to, for example, 0.35 mm.

 Next, the classification cycle is repeated and the material enters the container. Thus, the material is classified into 4 sizes with a given grinding fineness (for example, 265 mm, 1.5 mm, 0.7 mm, 0.35 mm). If necessary, the classification can be expanded and changed by changing the cross-section of the holes of the perforated partition and increasing the number of mills.

 In addition, dividing the material flows into 2 or more allows unloading the grinding chambers, increasing the productivity of vibration mills, and reducing specific energy consumption.

 Example 1 (Fig. 1 and 2). Take 600 kg of granite chips with a particle size of 5-7 mm, from which it is necessary to obtain mineral powder with a fineness of 0.07 mm.

 Grinding is carried out on 2 vibration mills MV-60, located in cascade one below the other.

 Example 2. Take 800 kg of lime powder with a particle size of 7-10 mm It is required to obtain 200 kg of lime powder with fineness grinding - 3 mm; 200 kg with fineness grinding - 0.16 mm and 400 kg with fineness grinding - 0.1 mm. The equipment is the same.

 In the discharge pipe of the first grinding chamber of the upper mill, a perforated baffle with a hole cross section of 3 mm is installed. The discharge port flap associated with the feed port of the second grinding chamber is opened 3/4 of the full size, and the branch flap connected with the container is 1/4 full. A perforated partition with a hole cross section of 1 mm is installed in the discharge nozzle of the second grinding chamber, the shutter in the discharge nozzle connected with the upper grinding chamber of the mill of the second cascade is fully opened, and closed in the branch. In the discharge pipe of the first grinding chamber of the lower mill, a perforated partition with a hole cross section of 0.16 mm is installed, the shutter in the discharge pipe connected to the loading pipe of the second grinding chamber of the lower mill is opened by 2/3, and in the branch associated with the container, - by 1/3. A perforated partition is installed in the discharge pipe of the second grinding chamber of the lower mill with a 0.1 mm hole section, the shutter in the discharge pipe is fully opened, and closed in the branch. Get 200 kg of lime powder with fineness of 3 mm or less; 200 kg with a fineness of 0.16 mm or less; 400 kg with a fineness of 0.1 mm or less. Thus, the proposed method allows to obtain mineral powders with a given fineness of grinding and in the right amount, to increase the productivity of the method, to reduce energy consumption.

 This problem is achieved by the fact that in the device for the production of material with a given grinding fineness, including a frame, at least two grinding chambers with grinding bodies located one below the other and communicated with each other by means of discharge nozzles, a loading nozzle and a vibratory drive, at the exit of each the grinding chamber in the discharge nozzle has a perforated partition with a predetermined hole cross section equal to the specified fineness of the grinding material, each discharge nozzle is branched into two or more and has a flap for changing the direction of movement of the material flow.

 In FIG. 1 shows a General view of the device; figure 2 is the same (side view); in FIG. 3 is a section along aa in figure 1; figure 4 - perforated partition. A device for the production of material with a given grinding fineness consists of a frame 1, loading 2, unloading 3 pipes, grinding chambers 4 with grinding bodies 5 placed therein, a vibratory drive 6, perforated partitions with a given section 7, shutters 8.

 A device for the production of material with a given fineness grinding works as follows.

 In the upper grinding chamber 4, located on the frame 1, through the loading nozzle 2, material is loaded, for example, lime powder (not shown in Fig.), A vibrator 6 is turned on, which gives the grinding chamber 4 rotational-vibrational movements that are transmitted to the grinding bodies 5, for example hex rods. The grinding bodies 5 perform complex rotational-vibrational movements, each around the longitudinal axis and all together around the longitudinal axis of the grinding chamber, repeatedly impacting with each other, grinding chamber 4 and the material. Such multiple collisions with the material lead to its fragmentation and grinding to smaller particles. When the particles reach the size of the holes of the perforated partition 7, the material falls into them and enters the discharge pipe 3 with the valve 8. The direction of movement of the milled material in the loading pipe of the second grinding chamber for further grinding depends on the position of the valve 8, into the branch pipe 3 for unloading into the container . When the second grinding chamber 4 enters the loading nozzle 2, the material is further milled until the size of the grinding particles is equal to (or less) the specified cross section of the holes of the perforated partition 7, while the section of the holes in the perforated partition 7 of the second grinding chamber 4 is selected based on requirements for fineness grinding material. The milled material from the second grinding chamber 4 through the discharge pipe 3 is sent either to the container, or to the grinding to the next mill, or simultaneously to the packaging and grinding, depending on the requirements for grinding fineness, and is regulated by the position of the shutter 8. The proposed solution allows for by separating the flows of material in the mill to increase its productivity while improving the quality of grinding, reduce grinding costs, since the material when it reaches the desired fraction is immediately removed from the grinding chamber classify the material depending on the requirements for fineness grinding.

 And the ability to change the perforated partitions 7 allows you to get material with different grinding fineness at the same mill with minimal energy consumption.

Claims (2)

 1. A method of manufacturing a material with a predetermined grinding fineness, comprising sequential grinding of the material in at least two vibrational grinding chambers located one below the other, communicated with each other by a discharge pipe, unloading the material, characterized in that the material is classified in each grinding chamber at the help of the perforated septum installed in the discharge pipe, and then in each discharge pipe, the material is divided into two or more streams.  2. Device for the production of material with a given grinding fineness, including a frame, at least two grinding chambers with grinding bodies, located one below the other and communicated with each other by means of discharge nozzles, a loading nozzle and a vibratory drive, characterized in that at the exit of each grinding chamber in the discharge pipe is a perforated partition with a given hole cross section equal to the specified fineness of the grinding material, with each discharge pipe is branched into two or more flap for changing the direction of material flow.

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