CN219785041U - Automatic control production system - Google Patents

Abstract

The utility model relates to the technical field of material crushing and mixing, and particularly discloses an automatic control production system, which comprises the following components: the device comprises a feeder, a conveyor, a crushing mechanism, a mixer and a controller; the feeder is connected with the conveyor and used for providing materials for the conveyor; the conveyor is used for conveying materials to a feed inlet of the crushing mechanism; the crushing mechanism is used for crushing the materials; the mixer is connected with the discharge port of the crushing mechanism and is used for carrying out a mixing procedure on crushed materials; the controller is electrically connected with the feeder, the conveyor, the crushing mechanism and the mixer and is used for controlling the start and stop of the feeder, the conveyor, the crushing mechanism and the mixer. The material can be carried for crushing mechanism through the conveyer in this scheme, cooperation controller realizes automated production, plays reduction staff's operating strength, improves the security and improves work efficiency's effect.

Description

Automatic control production system

Technical Field

The utility model relates to the technical field of material crushing and mixing, in particular to an automatic control production system.

Background

In the production process of recovering metal materials, nonmetallic ores and the like, the hard materials are required to be crushed and mixed; the existing crushing and mixing mode is generally that a worker manually throws materials into a crusher, so that the materials are crushed by the crusher and then screened, and then the oversize materials are thrown back into the crusher for repeated crushing, and the undersize materials are manually thrown into a feeding bin of a ball mill by the worker; after the materials are ball-milled into powder by a ball mill, the materials are shoveled into a mixer for mixing in a manual shoveling mode.

The existing material crushing and mixing mode needs workers to manually add materials during feeding, and has the problems of high labor intensity for the workers, high risk coefficient and low production efficiency.

Disclosure of Invention

Therefore, the utility model aims to provide an automatic control production system which is used for solving the problems of high labor intensity, high risk coefficient and low production efficiency of the existing material crushing and mixing mode.

In order to achieve the above technical object, the present utility model provides an automatic control production system, comprising: the device comprises a feeder, a conveyor, a crushing mechanism, a mixer and a controller;

the feeder is connected with the conveyor and used for providing materials for the conveyor;

the conveyor is used for conveying materials to a feed inlet of the crushing mechanism;

the crushing mechanism is used for crushing the materials;

the mixer is connected with the discharge port of the crushing mechanism and is used for carrying out a mixing procedure on crushed materials;

the controller is electrically connected with the feeder, the conveyor, the crushing mechanism and the mixer and is used for controlling the start and stop of the feeder, the conveyor, the crushing mechanism and the mixer.

Further, the crushing mechanism includes: the grinding device comprises a crushing assembly, a grinding assembly, a crushing hopper and a feeding machine;

the feed inlet of the crushing assembly is connected with the conveyor;

the feed inlet of the polishing assembly is connected with the discharge outlet of the crushing assembly;

the feed inlet of the crushing hopper is connected with the discharge outlet of the grinding assembly;

the feeding machine is connected with the crushing hopper and the mixer and is used for transferring materials in the crushing hopper into the mixer.

Further, the method further comprises the following steps: a crushed material amount sensor;

the crushing material quantity sensor is arranged on the crushing hopper and used for sensing the material quantity in the crushing hopper;

the controller is electrically connected with the crushed material quantity sensor and is used for starting the feeding machine and the mixing machine when the material quantity in the crushing hopper exceeds the preset crushed material quantity.

Further, the method further comprises the following steps: a mixture quantity sensor;

the mixture quantity sensor is arranged on the mixer and is used for sensing the quantity of materials in the mixer;

the controller is electrically connected with the mixture quantity sensor and is used for stopping the feeding machine when the quantity of materials in the mixing machine exceeds the preset quantity of mixed materials.

Further, the method further comprises the following steps: an auxiliary material hopper;

the auxiliary material hopper is used for storing mixed auxiliary materials;

the feeding machine is a vacuum feeding machine;

the feeding machine is respectively connected with the mixing machine, the crushing hopper and the auxiliary material hopper through four-way valves.

Further, a pneumatic hammer is arranged at the bottom of the crushing hopper and/or the bottom of the auxiliary material hopper.

Further, the crushing assembly includes: jaw crushers and hammer crushers;

the jaw crusher is arranged above the hammer crusher;

the feed inlet of the jaw crusher is connected with the conveyor;

the discharge port of the jaw crusher is connected with the feed port of the hammer crusher;

and a discharge hole of the hammer crusher is connected with the polishing assembly.

Further, the conveyor is a belt conveyor, and a skirt and/or a baffle are arranged on the conveyor.

Further, the grinding assembly includes: ball mill and hoister;

one end of the lifting machine is connected with the discharge port of the crushing assembly, and the other end of the lifting machine is connected with the feed port of the ball mill;

the crushing hopper is arranged below the ball mill, and a discharge hole of the ball mill is connected with the crushing hopper.

Further, a screen is arranged on the discharge port of the ball mill.

From the above technical solution, the present utility model provides an automatic control production system, including: the device comprises a feeder, a conveyor, a crushing mechanism, a mixer and a controller; the feeder is connected with the conveyor and used for providing materials for the conveyor; the conveyor is used for conveying materials to a feed inlet of the crushing mechanism; the crushing mechanism is used for crushing the materials; the mixer is connected with the discharge port of the crushing mechanism and is used for carrying out a mixing procedure on crushed materials; the controller is electrically connected with the feeder, the conveyor, the crushing mechanism and the mixer and is used for controlling the start and stop of the feeder, the conveyor, the crushing mechanism and the mixer. The material can be carried for crushing mechanism through the conveyer in this scheme, cooperation controller realizes automated production, plays reduction staff's operating strength, improves the security and improves work efficiency's effect.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the utility model, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of an overall structure of an automatic control production system according to an embodiment of the present utility model;

in the figure: 1. a feeder; 2. a conveyor; 3. a crushing mechanism; 4. a mixer; 5. a controller; 6. a crushed material amount sensor; 7. a mixture quantity sensor; 8. an auxiliary hopper; 9. a pneumatic hammer; 31. a crushing assembly; 32. a polishing assembly; 33. crushing a hopper; 34. a feeding machine; 311. jaw crusher; 312. a hammer crusher; 313. a steel frame platform; 321. ball mill; 322. a hoist; 341. and a four-way valve.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments disclosed in the specification without making any inventive effort, are intended to be within the scope of the utility model as claimed.

In the description of the embodiments of the present utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the embodiments of the present utility model and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present utility model.

In describing embodiments of the present utility model, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, interchangeably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediary, or in communication between two elements. The specific meaning of the above terms in embodiments of the present utility model will be understood in detail by those of ordinary skill in the art.

Referring to fig. 1, an automatic control production system provided in an embodiment of the utility model includes: a feeder 1, a conveyor 2, a crushing mechanism 3, a mixer 4 and a controller 5.

The feeder 1 is connected to a conveyor 2 for providing material to the conveyor 2, which in application may be e.g. a vibratory feeder, a pusher feeder or the like.

The conveyor 2 is used to transport material to the feed opening of the crushing mechanism 3, which in application may be e.g. a belt, a slide or the like. Specifically, the conveyor 2 comprises a feeding station and a discharging station; the feeding station is used for receiving materials provided by the feeder 1; after the material is transferred from the feeding station to the discharging station, the material enters a feeding port of the crushing mechanism 3. The blanking station can be connected with a feed inlet of the crushing mechanism 3, or can be positioned above the feed inlet of the crushing mechanism 3, and specifically, the material can enter the crushing mechanism 3 through the blanking station; for example, the conveyor 2 is a slide, and the material at the upper loading station slides to the lower unloading station, and then slides into the crushing mechanism 3. Similarly, the feeding station can be connected with the discharge port of the feeder 1, and can also be arranged below the discharge port of the feeder 1.

The crushing mechanism 3 is used for crushing the material. The mixer 4 is connected with a discharge hole of the crushing mechanism 3 and is used for carrying out a mixing procedure on crushed materials. Specifically, the materials used for the crushing and mixing may be, for example, one or more of metal or non-metal minerals, waste metal materials, silicate products, building materials, and other hard materials.

After the crushing mechanism 3 crushes the materials, the crushed materials enter the mixer 4 for mixing; the mixing step performed by the mixer 4 may be, for example, mixing only a plurality of crushed materials, or may be mixing the crushed materials after adding other substances thereto.

In this embodiment, the crushing mechanism 3 may include a plurality of crushers to crush for a plurality of times, or may be a single crusher and provided with a screen, and the material passing through the screen enters the mixer 4, and the material not passing through the screen is sent back to the crusher by other conveying devices to crush repeatedly. Meanwhile, a conveying mechanism can be arranged between the crushing mechanism 3 and the mixer 4, so that the crushed materials of the crushing mechanism 3 are conveyed to the mixer 4; in application, the feeding port of the mixer 4 may be disposed below the discharging port of the crushing mechanism 3, so that the crushed material of the crushing mechanism 3 may be transferred into the mixer 4.

The controller 5 is electrically connected with the feeder 1, the conveyor 2, the crushing mechanism 3 and the mixer 4 and is used for controlling the start and stop of the feeder 1, the conveyor 2, the crushing mechanism 3 and the mixer 4.

The controller 5 may be, for example, a PLC controller. During production, the controller 5 controls the feeder 1, the conveyor 2, the crushing mechanism 3 and the mixer 4 to start, and materials provided by the feeder 1 are transmitted to the crushing mechanism 3 through the conveyor 2, so that workers can remotely control production without manually feeding, the labor intensity is reduced, the safety of the workers is ensured, the production cost is reduced by reducing the manual demand, and the working efficiency is improved.

In a more specific embodiment, the crushing mechanism 3 comprises: a crushing assembly 31, a grinding assembly 32, a crushing hopper 33 and a loader 34.

The feed inlet of the crushing assembly 31 is connected with the conveyor 2 and is used for receiving the materials conveyed by the conveyor 2 and performing crushing procedures on the materials.

The feed inlet of the grinding assembly 32 is connected with the discharge port of the crushing assembly 31, and is used for receiving crushed materials and performing a grinding process on the materials to obtain crushed materials.

The inlet of the grinding hopper 33 is connected to the outlet of the grinding assembly 32 for receiving and temporarily storing the ground material.

The feeder 34 is connected to the pulverizing hopper 33 and the mixer 4 for transferring the material in the pulverizing hopper 33 into the mixer 4.

In this embodiment, by setting the crushing assembly 31 and the polishing assembly 32, the crushing process and the polishing process can be performed on the material successively, so that the material is crushed more sufficiently. It should be noted that, the controller 5 is electrically connected with the crushing mechanism 3, which means that the controller 5 is electrically connected with the crushing assembly 31, the polishing assembly 32 and the loader 34 at the same time, so as to control the start and stop of the crushing assembly 31, the polishing assembly 32 and the loader 34.

In a further improved embodiment, further comprising: a crushed material amount sensor 6; the crushing material amount sensor 6 is arranged on the crushing hopper 33 and is used for sensing the material amount in the crushing hopper 33; the controller 5 is electrically connected to the crushed material amount sensor 6 and is used for starting the feeder 34 and the mixer 4 when the material amount in the crushing hopper 33 exceeds the preset crushed material amount.

Specifically, in practice, the rate at which the material is mixed by the mixer 4 may not coincide with the crushing rate of the crushing mechanism 3, and for this reason, in this embodiment, by providing the crushed material amount sensor 6, when the amount of material in the crushing hopper 33 exceeds the preset crushed material amount, the crushed material amount sensor 6 generates a first signal to the controller 5; after the controller 5 receives the first signal, the feeding machine 34 and the mixer 4 are controlled to be started, so that the materials in the crushing hopper 33 enter the mixer 4 through the feeding machine 34.

Therefore, in the present embodiment, the controller 5 and the crushed material amount sensor 6 can automatically control the start and stop of the feeding machine 34 and the mixer 4 according to the material amount in the crushing hopper 33, so that when the material amount in the crushing hopper 33 is small, the crushed material can be temporarily stored in the crushing hopper 33 first, and the mixer 4 and the feeding machine 34 can stop working first without continuous operation, thereby playing a role in saving energy; when the amount of the material in the pulverizing hopper 33 exceeds the preset pulverizing amount of the material, the mixer 4 and the feeder 34 are started, and the material in the pulverizing hopper 33 is prevented from overflowing.

The crushed material amount sensor 6 may be, for example, a contact sensor, and when it contacts the material, it indicates that the material amount exceeds the preset crushed material amount; the crushed material amount sensor 6 may also be, for example, a scale, that is, it senses how much material is inside the crushing hopper 33 by measuring the weight of the crushing hopper 33.

In practical application, the feeding amount of the feeding machine 34 after starting may be a fixed value or the starting time may be a fixed value; for example, after the feeder 34 is started for a preset time, the feeder 34 is turned off until the next crushed material amount sensor 6 triggers the first signal, so as to realize quantitative feeding.

In one embodiment, further comprising: a mixture amount sensor 7; the mixture quantity sensor 7 is arranged on the mixer 4 and is used for sensing the quantity of materials in the mixer 4; the controller 5 is electrically connected to the mixture sensor 7 for stopping the feeder 34 when the amount of material in the mixer 4 exceeds a preset amount of mixed material.

Similarly, the mixture amount sensor 7 may be a contact sensor or a scale. By the mixture amount sensor 7, after the feeder 34 is started, when the feeding amount of the mixer 4 reaches a preset mixture amount, the feeder 34 is stopped to continue feeding, and then the mixer 4 performs a mixing process on the internal materials.

In another embodiment, the method further comprises: an auxiliary material hopper 8; the auxiliary material hopper 8 is used for storing mixed auxiliary materials; the feeder 34 is a vacuum feeder; the feeding machine 34 is respectively connected with the mixer 4, the crushing hopper 33 and the auxiliary material hopper 8 through the four-way valve 341.

The auxiliary material hopper 8 is used for storing mixed auxiliary materials; the mixing auxiliary materials are used for mixing with the materials in the mixer 4. In this embodiment, since the feeder 34 is a vacuum feeder, the feeder 34 is connected to the auxiliary material hopper 8 and the pulverizing hopper 33 through vacuum pipes, and then the pulverizing hopper 33 or the auxiliary material hopper 8 can be controlled to feed according to the opening/closing of different valves.

Specifically, the feeding machine 34 is respectively connected with the mixer 4, the crushing hopper 33 and the auxiliary material hopper 8 through the four-way valve 341, and when the materials in the crushing hopper 33 need to be extracted into the mixer 4, the four-way valve 341 is communicated with the vacuum pump of the feeding machine 34, the crushing hopper 33 and the interior of the mixer 4; when the mixed auxiliary materials are required to be extracted into the mixer 4, the four-way valve 341 is communicated with the vacuum pump of the feeding machine 34, the auxiliary hopper 8 and the interior of the mixer; the mixing auxiliary materials can be extracted according to a set proportion through the feeding machine 34.

In this embodiment, the four-way valve 341 should be understood in a broad sense, specifically, the feeding machine 34 may be connected to the pulverizing hopper 33, the auxiliary material hopper 8 and the mixer 4 through pipes, and the valves may control the opening and closing of the pipes respectively; the four through openings of the four-way valve 341 can be respectively provided with a pneumatic valve, so that the on-off condition of the four through openings of the four-way valve 341 can be controlled by controlling the opening and closing of different pneumatic valves.

As an embodiment, the mixer 4 may be a horizontal mixer, and an indicator lamp may be provided on the mixer 4. After the start of the mixer 4, the mixing process is performed for a predetermined mixing time, which may be, for example, 30 minutes. After the mixing time is over, the indicator lights are turned on to remind workers that the materials are mixed, and then the pneumatic valve and the discharge valve of the discharge port of the mixer 4 are controlled to be opened by the controller 5 to discharge.

In this embodiment, the feeder 1, the conveyor 2, the crushing assembly 31, the polishing assembly 32, the crushing hopper 33, the mixer 4 and the feeder 34 may be flexibly connected to each other, so as to avoid resonance between the devices and avoid dust overflow.

In one embodiment, the bottom of the crushing hopper 33 and/or the bottom of the auxiliary material hopper 8 is provided with a pneumatic hammer 9.

The pneumatic hammer 9 may impact the bottom of the crushing hopper 33 and/or the bottom of the auxiliary material hopper 8, assisting the crushing hopper 33 and/or the auxiliary material hopper 8 in discharging.

In one embodiment, the crushing assembly 31 comprises: jaw crusher 311 and hammer crusher 312; the jaw crusher 311 is arranged above the hammer crusher 312; the feed inlet of the jaw crusher 311 is connected with the conveyor 2; the discharge port of the jaw crusher 311 is connected with the feed port of the hammer crusher 312; the discharge port of the hammer crusher 312 is connected to the grinding assembly 32.

Specifically, the crushing assembly 31 may also include a steel frame platform 313; the jaw crusher 311 and the hammer crusher 312 are arranged on the steel frame platform 313 in an up-down distribution.

Taking the material conveyed by the feeder 1 as a waste target material as an example. The feeder 1 transmits waste target materials with the length of 5-10 cm to the conveyor 2 through vibration, the waste target materials are transmitted to the jaw crusher 311 through the conveyor 2, the jaw crusher 311 primarily crushes the materials into particles with the length of 10-15 mm, and then the materials enter the hammer crusher 312 for secondary crushing; the hammer crusher 312 hammers the material into 3 to 5mm particles and then into the grinding assembly 32 for grinding.

In a further improved embodiment, the sharpening assembly 32 includes: a ball mill 321 and a lifter 322; one end of the lifter 322 is connected with a discharge port of the crushing assembly 31, and the other end is connected with a feed port of the ball mill 321; the crushing hopper 33 is arranged below the ball mill 321, and a discharge port of the ball mill 321 is connected with the crushing hopper 33.

Wherein the discharge port of the crushing assembly 31, i.e. the discharge port of the hammer crusher 312; the lifter 322 may be a screw lifter, and is used to lift the material from the outlet of the hammer crusher 312 to the highest point, and then the material is turned into the inlet of the ball mill 321 by turning the material box in the lifter 322. The feed inlet of the ball mill 321 drives a screw rod to convey particles to the inner cavity of the ball mill 321 through a motor, and the cylinder of the ball mill 321 rolls to drive the steel balls to do parabolic motion so as to smash the materials.

Further, a screen may be disposed on the discharge port of the ball mill 321; in the interior chamber of the ball mill 321, material smaller than 30 mesh may pass through the screen and fall into the pulverizing hopper 33.

In one embodiment, the conveyor 2 is a belt conveyor and the conveyor 2 is provided with skirts and/or baffles.

Specifically, the inlet of the jaw crusher 311 disposed on the steel frame platform 313 may be higher than the outlet of the feeder 1, and for this purpose, the conveyor belt 2 may be used to transport materials from bottom to top, and the skirt and/or baffle may be disposed on the conveyor belt 2, so as to ensure that the materials will not slip down or fall into the conveyor 2 during the conveying process.

It should be noted that, in the embodiment provided by the present utility model, the conveyor 2 may be a sealed conveyor, where a feeding station is connected with a discharge port of the feeder 1 in a sealing manner, and a discharging station is connected with a feed port of the jaw crusher 311 in a sealing manner. Correspondingly, the jaw crusher 311, the hammer crusher 312, the elevator 322, the ball mill 321 and the crushing hopper 33 are all in sealing connection, so that powder overflow is avoided.

According to the automatic control production system, automatic feeding and crushing, feeding and polishing and automatic mixing can be realized, the automatic degree is high, the operation is convenient, the manual material conveying and material quantity judgment are not needed, the labor intensity of personnel is reduced, the material transferring mode is simple and convenient, the environmental pollution risk and the product pollution risk are reduced, the reasonable product crushing and pulverizing production can be performed, the production cost is saved, and the production efficiency, the production safety coefficient and the product quality are improved.

While the utility model has been described in detail with reference to the examples, it will be apparent to those skilled in the art that the foregoing description of the preferred embodiments of the utility model may be modified or equivalents may be substituted for elements thereof, and that any modifications, equivalents, improvements or changes will fall within the spirit and principles of the utility model.

Claims (10)

1. An automated control production system, comprising: a feeder (1), a conveyor (2), a crushing mechanism (3), a mixer (4) and a controller (5);

the feeder (1) is connected with the conveyor (2) and is used for providing materials for the conveyor (2);

the conveyor (2) is used for conveying materials to a feed inlet of the crushing mechanism (3);

the crushing mechanism (3) is used for crushing materials;

the mixer (4) is connected with the discharge port of the crushing mechanism (3) and is used for carrying out a mixing procedure on crushed materials;

the controller (5) is electrically connected with the feeder (1), the conveyor (2), the crushing mechanism (3) and the mixer (4) and is used for controlling the start and stop of the feeder (1), the conveyor (2), the crushing mechanism (3) and the mixer (4).

2. The automatic control production system according to claim 1, characterized in that the crushing mechanism (3) comprises: the grinding machine comprises a crushing assembly (31), a grinding assembly (32), a crushing hopper (33) and a feeding machine (34);

the feed inlet of the crushing assembly (31) is connected with the conveyor (2);

the feed inlet of the polishing component (32) is connected with the discharge outlet of the crushing component (31);

the feed inlet of the crushing hopper (33) is connected with the discharge outlet of the polishing assembly (32);

the feeding machine (34) is connected with the crushing hopper (33) and the mixer (4) and is used for transferring materials in the crushing hopper (33) into the mixer (4).

3. The automated production system of claim 2, further comprising: a crushed material amount sensor (6);

the crushed material quantity sensor (6) is arranged on the crushing hopper (33) and is used for sensing the material quantity in the crushing hopper (33);

the controller (5) is electrically connected with the crushed material quantity sensor (6) and is used for starting the feeding machine (34) and the mixing machine (4) when the material quantity in the crushing hopper (33) exceeds the preset crushed material quantity.

4. The automated production system of claim 3, further comprising: a mixture quantity sensor (7);

the mixture quantity sensor (7) is arranged on the mixer (4) and is used for sensing the quantity of materials in the mixer (4);

the controller (5) is electrically connected with the mixture quantity sensor (7) and is used for stopping the feeding machine (34) when the quantity of materials in the mixer (4) exceeds the preset mixture quantity.

5. The automated production system of claim 3 or 4, further comprising: an auxiliary material hopper (8);

the auxiliary material hopper (8) is used for storing mixed auxiliary materials;

the feeding machine (34) is a vacuum feeding machine;

the feeding machine (34) is respectively connected with the mixing machine (4), the crushing hopper (33) and the auxiliary material hopper (8) through a four-way valve (341).

6. The automatic control production system according to claim 5, characterized in that the bottom of the comminution hopper (33) and/or the bottom of the auxiliary material hopper (8) is provided with a pneumatic hammer (9).

7. The automatic control production system according to claim 2, wherein the crushing assembly (31) comprises: a jaw crusher (311) and a hammer crusher (312);

the jaw crusher (311) is arranged above the hammer crusher (312);

the feed inlet of the jaw crusher (311) is connected with the conveyor (2);

the discharge port of the jaw crusher (311) is connected with the feed port of the hammer crusher (312);

the discharge port of the hammer crusher (312) is connected with the polishing assembly (32).

8. The automatic control production system according to claim 1 or 7, characterized in that the conveyor (2) is a belt conveyor and that the conveyor (2) is provided with skirts and/or baffles.

9. The automated control production system of claim 2 or 7, wherein the grinding assembly (32) comprises: a ball mill (321) and a lifter (322);

one end of the lifting machine (322) is connected with the discharge port of the crushing assembly (31), and the other end of the lifting machine is connected with the feed port of the ball mill (321);

the crushing hopper (33) is arranged below the ball mill (321), and a discharge hole of the ball mill (321) is connected with the crushing hopper (33).

10. The automatic control production system according to claim 9, characterized in that a screen is provided on the discharge opening of the ball mill (321).