Balanced energy saving ball mill

Abstract

The application provides a balanced energy-saving ball mill, which comprises a rack, a drum, a driving mechanism and a counterweight device. The drum is rotatably installed on the rack, and the driving mechanism is used for driving the drum to rotate. The counterweight device comprises a counterweight mechanism which is engaged with the gear ring. The counterweight mechanism and the driving gear are respectively located on two sides of the drum. When the grinding ball in the drum falls to a critical point, the recoil force generated by the gear ring on the driving gear is counteracted by the traction force generated by the counterweight mechanism on the gear ring. The balanced energy-saving ball mill has the advantages of compact structure, low manufacturing cost, provided traction force, avoidance of secondary force of the motor, improvement of energy utilization rate and suitability for popularization and use.

Description

TECHNICAL FIELD

[0001] The present application relates to a ball mill, in particular to a balanced energy-saving ball mill. BACKGROUND

[0002] Ball mill, rod mill, tube mill are the most widely used grinding machinery in the field of power generation, mineral processing, chemical industry and building materials. It can grind objects of various hardness. In cement plants, it is used to grind cement raw materials and cement clinker; in power plants, it is used to grind coal; in mineral processing plants, it is used to grind various ores. In cement production, the crushed raw materials, clinker, coal and other mixed materials are ground in the mill, and the particle size of the feed is less than 20 mm, while the particle size of the discharge is as small as 0.080 mm, with a sieve residue of less than 5%.

[0003] The main body of the ball mill is a low-speed rotating drum horizontally mounted on two large bearings. The drum is equipped with grinding bodies of different sizes. The shape and material of the grinding bodies have various forms, including steel balls, steel columns (steel segments), steel rods, and porcelain balls. When the ball mill rotates, the grinding bodies adhere to the lining plate surface on the inner wall of the mill drum due to the action of centrifugal force, and rotate with the drum. When the grinding bodies are brought to a certain height, they fall freely under the action of gravity. When falling, the grinding bodies, like projectiles, crush the materials in the drum. Referring to Figure 1 When the ball mill is below the critical speed (the specified speed), the grinding bodies in the mill drum will move in a circular motion layer by layer according to their position. Referring to Figure 2 The grinding bodies move upward and downward in a cycle. In addition, during the rotation of the ball mill drum, the grinding bodies also slide and roll, resulting in grinding action between the grinding bodies, the lining plate, and the material, which grinds the material (under the action of shear force) and completes the grinding work.

[0004] Currently, the volume utilization rate of the ball mill is generally below 50%, so the work efficiency is low, and the power consumption per unit of production is large. The energy utilization rate of the ball mill is only 5-7%, so about 95% of the electric energy of the mill is wasted. The invention of a new type of low-energy ball mill is the need of the times, the industry, and the urgent need of carbon peak and carbon neutralization.

[0005] Force analysis of the rotation process of the ball mill shows that the movement of the grinding bodies in the ball mill is upward along the circular arc with the rotation of the drum. When reaching a certain height (point A), the grinding bodies are thrown out of the circular trajectory and form a parabolic trajectory. At this moment, the center of the grinding body is called the separation point. The connecting line of the separation points of each layer of grinding bodies is called the trajectory of the grinding ball separation point (falling point), as shown in Figure 2The center point of the grinding body at the moment when the grinding body falls along a parabolic trajectory and reaches the falling end point is referred to as a falling point. The trajectory of the falling points of the grinding bodies in each layer is referred to as a falling point trajectory, Figure 2 The CD arc line.

[0006] Referring to Figure 3 Specifically, when the ball mill is working, the drum rotates, and the grinding balls are mainly subjected to two forces in addition to the gravity G, i.e., the friction force F between the grinding balls and the lining (inner wall) and between the grinding balls and the grinding balls, and the normal reaction force N of the lining (inner wall) on the grinding balls when the drum rotates, as shown in Figure 3 The motion of the grinding balls under normal conditions can be divided into two stages: the circumferential motion of the drum and the falling motion of the drum. When the ball mill rotates, the grinding balls first move upward by means of the friction force F. When the grinding balls rise to a certain point, the gravity component mg.cos a (a is the acute angle between the falling point of the grinding ball and the vertical direction, referred to as the falling angle) of the grinding ball is greater than the centrifugal force when the grinding ball moves in a circle (N=0 at this time), and the grinding ball will fall down in a parabolic trajectory in a waterfall state. The impact force of the grinding ball will crush the material. In addition, during the rising process of the grinding ball, rolling and sliding will occur between the material, the grinding ball and the lining.

[0007] However, each steel ball needs to rotate from the static balance position with the drum. The power consumption of the ball mill is mainly to overcome the rotating torque generated by the eccentric moment of the grinding ball. Since the ball mill grinding ball loading is 30-50%, the drum needs to move again with the movement of the grinding ball attached to the drum, and a new kinetic energy is needed to drive the drum to rotate again. At this time, it is equivalent to saying that a new force is added to make the drum move again. This is why the energy utilization rate of the ball mill is only 5-7%. SUMMARY

[0008] 【1】Technical problems to be solved

[0009] The technical problem to be solved by the present application is to provide a balanced energy-saving ball mill which can provide a traction force without the need to additionally apply a new driving force, so as to reduce the impact force caused by the torque and avoid the need for the motor to apply kinetic energy again to make the drum rotate again.

[0010] 【2】Technical solutions to solve problems

[0011] The present application provides a balanced energy-saving ball mill, comprising:

[0012] a rack 2 serving as a support and installation carrier;

[0013] a drum 1 rotatably mounted on the rack 2, the rotation axis of the drum 1 being parallel to the horizontal plane, and the drum 1 being internally formed with a cavity and forming a working cavity for accommodating material and grinding balls;

[0014] a driving mechanism comprising a gear ring 11 fixed on the lateral wall of the roller 1 and a driving gear 12 engaged with the gear ring 11, the driving gear 12 being connected with a driving motor and used to drive the roller 1 to rotate;

[0015] a counterweight device comprising a counterweight mechanism engaged with the gear ring 11, the counterweight mechanism being located on both sides of the roller 1 respectively with the driving gear 12, the recoil force f1 generated by the gear ring 11 on the driving gear 12 and the traction force f2 generated by the counterweight mechanism on the gear ring 11 being counteracted when the grinding balls in the roller 1 reach the falling critical point.

[0016] Further, the counterweight mechanism comprises one or more of gears, belts and sprocket chains engaged with the gear ring.

[0017] Further, the counterweight mechanism comprises a support rod rotatably mounted on the frame, the rotation direction of the support rod being parallel to the rotation axis of the roller 1, the end of the support rod being rotatably mounted with a counterweight gear 24 engaged with the gear ring 11, the frame being provided with an elastic mechanism or a tensioning mechanism that makes the support rod have a tendency to rotate towards the advancing direction of the roller 1.

[0018] Further, the support rod comprises a support rod base 21 rotatably mounted on the frame and a support rod body 23 axially fitted on the support rod base 21, the rotation axis of the support rod base 21 being parallel to the rotation axis of the roller 1, the counterweight gear 24 being rotatably mounted on the end of the support rod body 23, the support rod base 21 being provided with an elastic component 22 that makes the support rod body 23 have a tendency to move outward and makes the counterweight gear 24 press the gear ring 11.

[0019] Further, the tensioning mechanism comprises a tensioning wheel 27, a sprocket chain being connected between the counterweight gear 24 and the tensioning wheel 27, the side wall of the sprocket chain being fitted on the side wall of the gear ring 11 and the teeth of the side wall of the sprocket chain being engaged with the gear ring 11, the tensioning wheel 27 being provided with a tensioning mechanism that makes the tensioning wheel 27 have a tendency to move away from the counterweight gear 24 and close to the gear ring 11.

[0020] Further, the tensioning mechanism comprises a pull rod rotatably mounted on the frame and a tensioning wheel mounting rack axially fitted on the pull rod, the rotation axis of the pull rod being parallel to the rotation axis of the roller 1, the tensioning wheel being mounted on the tensioning mounting rack, a tension spring being provided between the pull rod and the tensioning wheel mounting rack, the tension spring making the tensioning wheel 27 have a tendency to move away from the counterweight gear.

[0021] Further, the tensioning mechanism comprises a cylinder or an oil cylinder 26 rotatably mounted on the frame, the rotation axis of the cylinder or the oil cylinder is parallel to the axis of the roller 1, and a tension pulley mounting frame is fixed on the output shaft of the cylinder or the oil cylinder, and the tension pulley 27 is rotatably mounted on the tension pulley mounting frame.

[0022] Further, the hinge point of the supporting rod is A, the hinge point of the counterweight gear 24 is B, the center of the roller 11 is C, and 120°≤∠ABC≤150°.

[0023] Further, the central angle between the counterweight gear 24 and the tension pulley 27 is greater than or equal to 20° and less than or equal to 40°.

[0024] Further, the included angle between the line BD connecting the centers of the tension pulley 27 and the counterweight gear 24 and the tensioning direction DE of the tension pulley 27 is greater than or equal to 150° and less than or equal to 170°.

[0025] 【3】Advantages

[0026] The balanced energy-saving ball mill is provided with a reverse counterweight device, which can offset the reverse impact force generated by the falling of the grinding body on the driving gear, so that the roller can continue to rotate at the above position without the need for additional new driving force, reduces the impact force caused by the torque, avoids the need for the motor to apply kinetic energy again to make the cylinder rotate again, improves the energy utilization rate, and reduces the energy consumption; the elastic mechanism or the tensioning mechanism is provided, the meshing force of the gear ring is improved, and the reliability and stability of the operation are improved; the reverse counterweight structure is various, can be selected according to specific needs, and has good adaptability; the balanced energy-saving ball mill has the advantages of compact structure, low manufacturing cost, traction force, avoidance of secondary force of the motor, improvement of energy utilization rate, and is suitable for popularization and use. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a working principle diagram of the ball mill;

[0028] Figure 2 It is a motion trajectory diagram of the grinding ball in the ball mill;

[0029] Figure 3 It is a motion and force analysis diagram of the grinding ball in the ball mill;

[0030] Figure 4 It is a structure diagram of the balanced energy-saving ball mill;

[0031] Figure 5 It is a partial enlarged view of the balanced energy-saving ball mill;

[0032] Figure 6This is a force analysis diagram of the balanced energy-saving ball mill of the present invention;

[0033] Figure 7 This is a schematic diagram of the reverse counterweight device of the balanced energy-saving ball mill of the present invention. Detailed Implementation

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] See Figures 4-7 This invention provides a balanced energy-saving ball mill, including a frame 2, a drum 1, a drive mechanism, and a counterweight device. The frame 2 serves as a support and mounting carrier for installing other components. The drum 1 is rotatably mounted on the frame 2. The drum 1 has a horizontal structure, meaning its rotation axis is parallel to the horizontal plane. A cavity is formed inside the drum 1 to create a working chamber for accommodating materials and grinding balls. The drive mechanism includes a gear ring 11 and a drive gear 12. The gear ring 11 is fixed to the side wall of the drum 1 and is coaxial with the drum. The drive gear 12 meshes with the gear ring 11 and is connected to a drive motor to drive the drum 1 to rotate. The drive motor is equipped with a reducer to increase torque while reducing speed.

[0036] The reverse counterweight device includes a counterweight mechanism meshing with the gear ring 11. This counterweight mechanism and the drive gear 12 are located on opposite sides of the roller 1, i.e., the roller 1 is located between the counterweight mechanism and the drive gear. When the grinding balls inside the roller 1 reach the critical point of falling ( Figure 3 At point K in the equation, the reaction force f1 generated by the gear ring 11 on the drive gear 12 counteracts the traction force f2 generated by the counterweight mechanism on the gear ring 11. The counteracting force is equal in magnitude but opposite in direction, wherein the direction is the normal direction of the roller gear ring. The counterweight mechanism includes one or more of the following: gears, belts, and toothed chains that mesh with the gear ring.

[0037] See Figure 6 The drive gear 12 is the driving wheel. Taking the meshing force at one of its nodes as the analysis object, when the grinding ball in the drum 1 is at the critical point of falling, it generates a force that resists the rotation of the drum, namely the recoil force f1 (circumferential force). This force is transmitted to the drive gear through the gear ring. At the same time, the counterweight mechanism gives the gear ring a traction force f2. This traction force f2 is in the same direction as the rotation (forward) of the gear ring, thereby offsetting the recoil force. This allows the drum to continue rotating at the above position without the need to apply additional driving force, thereby reducing the impact force caused by torque and avoiding the need for the motor to apply kinetic energy a second time to make the drum rotate again.

[0038] Specifically, the counterweight mechanism comprises a support rod rotatably mounted on the frame, the rotation direction of the support rod being parallel to the rotation axis of the roller 1, a counterweight gear 24 being rotatably mounted on the end of the support rod, the axis of the counterweight gear 24 being parallel to the axis of the roller, the teeth of the counterweight gear 24 being engaged in the gear ring, and an elastic mechanism (such as a tension spring or a torsion spring) or a tensioning mechanism being provided on the frame, the elastic mechanism or the tensioning mechanism making the support rod have a movement tendency of rotating towards the advancing direction of the roller 1, and Figure 4 in the present embodiment, the elastic mechanism or the tensioning mechanism uses the head of the support rod (the counterweight gear) to have a movement tendency of pressing down the gear ring, i.e. the counterweight gear presses down (obliquely) the gear ring.

[0039] In the present embodiment, the support rod comprises a support rod base 21 rotatably mounted on the frame, the rotation axis of the support rod base 21 being parallel to the rotation axis of the roller 1, and a support rod body 23 axially slidably fitted in the support rod base 21, the length (sliding) direction of the support rod body 23 being perpendicular to the axis of the roller, the counterweight gear 24 being rotatably mounted on the end of the support rod body 23, and an elastic component 22 being provided on the support rod base 21, the elastic component being a compression spring, the elastic component 22 making the support rod body 23 have a movement tendency of moving outward (away from the support rod base) to press the gear ring 11 by the counterweight gear 24.

[0040] The tensioning mechanism comprises a tensioning wheel 27, a toothed chain being connected between the counterweight gear 24 and the tensioning wheel 27, the side wall of the toothed chain being fitted to the side wall of the gear ring 11, and the teeth of the side wall of the toothed chain being engaged in the gear ring 11, and a tensioning mechanism being provided on the tensioning wheel 27, the tensioning mechanism making the tensioning wheel 27 have a movement tendency of moving away from the counterweight gear 24 while moving close to the gear ring 11, the tensioning mechanism being capable of tensioning the toothed chain and ensuring that the teeth of the toothed chain are fully engaged in the gear ring, in the present embodiment, the counterweight gear 24 is not directly engaged with the gear ring, the toothed chain tensioned between the counterweight gear and the tensioning wheel is engaged in the gear ring and provides the force.

[0041] The tensioning mechanism in the present embodiment can have different structures, which will be described below:

[0042] In the first embodiment, the tensioning mechanism comprises a tension rod rotatably mounted on the frame, the rotation axis of the tension rod being parallel to the rotation axis of the roller 1, the tension rod being perpendicular to the axis of the roller, a tensioning wheel mounting frame being axially slidably fitted on the tension rod, i.e. the sliding direction of the tensioning wheel mounting frame being perpendicular to the axis of the roller, the tensioning wheel being rotatably mounted on the tensioning wheel mounting frame, and a tension spring being provided between the tension rod and the tensioning wheel mounting frame, the tension spring making the tensioning wheel 27 have a movement tendency of moving away from the counterweight gear, thereby realizing tensioning.

[0043] In the second embodiment, the tensioning mechanism comprises a cylinder or an oil cylinder 26, the cylinder body of which is rotatably mounted on the frame, the rotation axis of which is parallel to the axis of the drum 1, and the length direction of the cylinder or the oil cylinder 26 is perpendicular to the axis of the drum, and a tension pulley mounting frame is fixed on the output shaft of the cylinder or the oil cylinder, and the tension pulley 27 is rotatably mounted on the tension pulley mounting frame, and the tensioning of the toothed chain is realized by the contraction of the cylinder or the oil cylinder 26.

[0044] In order to achieve the optimal balance effect, in the embodiment, the hinge point of the supporting rod is A, the hinge point of the counterweight gear 24 is B, the center of the drum 11 is C, the hinge point of the tension pulley 27 is D, and the hinge point of the pull rod (or the oil cylinder or the cylinder) is E, and 120°≤∠ABC≤150°, 20°≤∠BCD≤40°, and 150°≤∠BED≤170°, wherein the above-mentioned ∠BCD is the central angle between the counterweight gear 24 and the tension pulley 27, and ∠BED is the included angle between the connecting line BD of the centers of the tension pulley 27 and the counterweight gear 24 and the tensioning direction DE of the tension pulley 27.

[0045] The working principle thereof is briefly described as follows:

[0046] When the ball mill works, the drum 1 rotates, and the grinding balls are mainly subjected to two forces in addition to the gravity G, one is the friction force F between the grinding balls and the lining plate (inner wall) and between the grinding balls, and the other is the normal reaction N of the inner lining (inner wall) on the grinding balls when the drum 1 rotates. The movement of the grinding balls under normal circumstances can be divided into two stages: the circumferential movement with the drum 1 and the falling movement away from the drum 1. When the ball mill rotates, the grinding balls first move upward by means of the friction force F, and when the grinding balls rise to a certain point, the gravity component mg.cos a (a is the acute included angle between the disengagement point of the grinding ball and the vertical direction, which is referred to as the disengagement angle) of the grinding ball is greater than the centrifugal force when the grinding ball moves in a circle (at this time, N=0), and the grinding ball will disengage from the drum 1 and fall down in a parabolic trajectory in a waterfall state. The impact force of the grinding ball will crush the material, and in addition, the material, the grinding ball and the lining plate will also roll and slide in the upward process of the grinding ball. When the grinding ball is at the falling critical point, that is, at the end K point of the parabola, it generates a relative friction force F' on the drum, which is transmitted to the driving gear 12 through the gear ring 11, and forms a counter-thrust, and at the same time, the counterweight gear or the toothed chain meshing with the gear ring generates a force in the opposite direction, which forms a traction force in the same direction as the forward direction of the drum, so that the drum can continue to rotate at the above-mentioned position without the need to additionally apply a new driving force, so as to reduce the impact force caused by the torque, avoid the need for the motor to apply driving energy twice to make the drum body rotate again, and thus realize the energy-saving effect of the drum balance.

[0047] In the application, the counterweight device can also have other forms, and the other forms are briefly exemplified as follows:

[0048] In the third embodiment, the counterweight mechanism, such as a flywheel, is arranged to engage with the gear ring on the side wall of the drum. The flywheel has a large mass and a large inertia. During the rotation of the drum, the inertia force (which is greater than or equal to the recoil force) can offset the recoil force of the gear ring on the driving gear. The flywheel can directly engage with the gear ring or can be connected to the gear ring or the outer wall of the drum through a transmission mechanism (such as a gear assembly, a belt, etc.).

[0049] In the fourth embodiment, a counterweight ring is arranged on the side wall of the drum. The counterweight ring is a whole annular ring, coaxial with the drum and rigidly connected to the side wall of the drum. The counterweight ring has a large mass and a large inertia, which increases the overall inertia of the drum. During the rotation of the drum, the inertia force of the counterweight ring can offset the recoil force on the driving gear.

[0050] The balanced energy-saving ball mill has a reverse counterweight device, which can offset the reverse impact force on the driving gear when the grinding body falls. The drum can continue to rotate at the above position without the need for additional new driving force, reducing the impact force caused by the torque and avoiding the need for the motor to apply driving force again to rotate the drum body, thereby improving the energy utilization rate and reducing the energy consumption. The elastic mechanism or the tensioning mechanism is arranged to improve the engagement force of the gear ring, thereby improving the reliability and stability of the operation. The reverse counterweight structure is various and can be selected according to specific needs, which has good adaptability. The balanced energy-saving ball mill has a compact structure, low manufacturing cost, and can provide traction force to avoid the secondary force of the motor, thereby improving the energy utilization rate and being suitable for popularization and use.

[0051] The above only describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the technical principles of the present application. These improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A balanced energy-saving ball mill, characterized in that, include: Including the frame, which serves as a support and mounting carrier; A roller is rotatably mounted on the frame, the axis of rotation of the roller is parallel to the horizontal plane, and a cavity is formed inside the roller to form a working chamber for accommodating materials and grinding balls; The drive mechanism includes a gear ring fixed to the side wall of the drum and a drive gear meshing with the gear ring. The drive gear is connected to a drive motor and is used to drive the drum to rotate. The reverse counterweight device includes a counterweight mechanism that meshes with the gear ring. The counterweight mechanism and the drive gear are located on opposite sides of the drum. When the grinding balls inside the drum reach the critical point of falling, the recoil force f1 generated by the gear ring on the drive gear and the traction force f2 generated by the counterweight mechanism on the gear ring counteract each other. The counterweight mechanism includes a support rod rotatably mounted on the frame, the rotation direction of the support rod being parallel to the rotation axis of the drum, and a counterweight gear meshing with the gear ring being rotatably mounted at the end of the support rod. The frame is provided with an elastic mechanism or tensioning mechanism that causes the support rod to have a tendency to rotate in the forward direction of the drum.

2. The balanced energy-saving ball mill as described in claim 1, characterized in that: The support rod includes a support rod base rotatably mounted on the frame and a support rod body axially slidably mounted on the support rod base. The rotation axis of the support rod base is parallel to the rotation axis of the roller. The counterweight gear is rotatably mounted on the end of the support rod body. The support rod base is provided with an elastic component, which causes the support rod body to have an outward movement tendency and causes the counterweight gear to press against the gear ring.

3. The balanced energy-saving ball mill as described in claim 1, characterized in that: The tensioning mechanism includes a tensioning wheel, and a toothed chain is connected between the counterweight gear and the tensioning wheel. The sidewall of the toothed chain is attached to the sidewall of the toothed ring, and the teeth of the sidewall of the toothed chain mesh with the toothed ring. The tensioning wheel is provided with a tensioning mechanism, which causes the tensioning wheel to have a tendency to move away from the counterweight gear and closer to the toothed ring.

4. The balanced energy-saving ball mill as described in claim 3, characterized in that: The tensioning mechanism includes a pull rod rotatably mounted on the frame and a tension wheel mounting bracket axially slidably mounted on the pull rod. The rotation axis of the pull rod is parallel to the rotation axis of the drum. The tension wheel is mounted on the tension wheel mounting bracket. A tension spring is provided between the pull rod and the tension wheel mounting bracket. The tension spring causes the tension wheel to tend to move away from the counterweight gear.

5. The balanced energy-saving ball mill as described in claim 3, characterized in that: The tensioning mechanism includes a cylinder or hydraulic cylinder rotatably mounted on the frame, the rotation axis of the cylinder or hydraulic cylinder being parallel to the axis of the roller, and a tension wheel mounting bracket fixed on the output shaft of the cylinder or hydraulic cylinder, the tension wheel being rotatably mounted on the tension wheel mounting bracket.

6. The balanced energy-saving ball mill as described in claim 1, characterized in that: The hinge point of the support rod is A, the hinge point of the counterweight gear is B, the center of the roller is C, and 120°≤∠ABC≤150°.

7. The balanced energy-saving ball mill as described in claim 3, characterized in that: The central angle between the counterweight gear and the tensioning wheel is greater than or equal to 20° and less than or equal to 40°.

8. The balanced energy-saving ball mill as described in claim 4, characterized in that: The angle between the line BD connecting the center of the tensioning wheel and the center of the counterweight gear and the tensioning direction DE of the tensioning wheel is greater than or equal to 150° and less than or equal to 170°, where B is the hinge point of the counterweight gear, D is the hinge point of the tensioning wheel, and E is the hinge point of the pull rod.

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