Conical ball mill Introduction

The unique conical structure of the conical ball mill can naturally separate the grinding medium (steel balls). The large ball is located in the large diameter section of the cylinder, that is, the feeding end; the small ball is located in the conical section, that is, the discharging end. Coarse materials get a large impact energy under the action of the large ball at the feeding end to complete the coarse crushing operation; the small balls are located at the discharge cone end to obtain more surface area for fine grinding. The characteristic of the conical ball mill is that it is equivalent to installing a permanent classifier in the barrel of the ball mill. The materials are arranged in the barrel according to different particle sizes, and the finer the closer to the discharge port, there will be no over-grinding, which increases the useful work and reduces the useless work. , so as to achieve the goal of saving energy and reducing consumption.

Conical ball mill structure

Conical ball mill is consisted of the following parts: the shell, sliding shoes, bearing bush, trunnion, girth gear, pinion, liners, diaphragm, grinding media, transmission, lubrication system, cooling system.  

Mill Shell: The foundation of the conical ball mill, the mill shell, is a cylindrical structure made of premium-grade steel. Tongli heavy machinery is equipped with a large annealing furnace of 6.5x6.5x20m and a 6.5x6.5x20m large sandblasting room, which can conduct overall heat treatment and sandblasting on the ball mill to ensure the service life and appearance of the ball mill.

Trunnion: The trunnion (hollow shaft) of the conical ball mill is a steel casting manufactured in our metal casting workshop. It mainly plays the role of supporting and connecting the shell, it is the passage for the material to enter and exit. When the ball mill is operating, the trunnion is floating on the bearing bush with the aid of the forced high pressure lubrication system.

Girth Gear: The conical ball mill girth gear is a large gear ring encircling the ball mill, usually mounted on the shell of the ball mill. It is driven by a pinion gear, and together they form the primary drive unit to rotate the ball mill. The girth gear is casted and machined Tongli, the quality is assured.

Hood Cover: The discharge hood of the conical ball mill is installed at the discharge end of the ball mill, and there is a screen inside. After grinding, the material with a qualified size will enter the discharge hood through the screen and enter the next process. There is a vent on the upper part of the discharge hood, and a discharge funnel on the lower part.

Diaphragm: The ball mill Diaphragm (compartment plate) is fan-shaped plate or bow-shaped grate plate fixed in the conical ball mill with bolts. Its function is to divide the ball mill into two or more chambers, the material moves to the next compartment through the openings on the grate plate. The function of the compartment plate is to prevent the grinding media running from one compartment to another compartment, so that the materials can be reasonably finely ground.

Liner: The function of the liner is to protect the shell of the ball mill and the trunnion, some special-shaped liners can also design to lift the grinding media to a certain position. According to the shape of the liner, it can be divided into flat liner, beaded liner, corrugated liner, ribbed liner, stepped liner, etc.

Rod ball mill transmission: Central drive ball mill refers to the arrangement of the driving mechanism for the mill. In a central drive configuration, the motor and gearbox are positioned at the center of the mill, usually between the grinding chamber and the mill shell. This design is in contrast to an edge or end drive configuration where the motor and gearbox are situated at one of the ends of the mill. Central drive transmission systems typically involve a motor that powers a gearbox, which then transfers the rotational energy to the mill's main shaft. The central drive design can provide advantages in terms of power distribution and efficiency compared to other drive arrangements. It can also offer better control over the mill's operation.

PLC control system: A PLC is a digital computer-based system that is designed to control various industrial processes automatically. In the context of a ball mill, a PLC is used to monitor and control parameters such as temperature, rotation speed, air flow, fuel flow, and other critical variables that affect the performance of the ball mill and the quality of the products being processed. 

Design principles of conical ball mill

The rotation motion of the conical ball mill drives the internal steel balls or rods to squeeze the material to produce fine powder that meets the process requirements. The ball mill is composed of feeding part, discharging part, rotary part, transmission part and others.

The conical ball mill is equipped with a jacking device, which is convenient for maintenance and can be used for dry grinding or wet grinding with high efficiency. The inner lining of the overflow type ball mill shell is made of wear-resistant materials, so as to enhance the wear resistance and prolong the service life. The overflow ball mill equipment replaces the bush sliding bearing with rolling bearing, which not only saves energy but also reduces consumption.

Grinding Efficiency: Due to the conical shape and smaller grinding media, conical ball mills often have higher grinding efficiency compared to cylindrical ball mills.

Reduced Power Consumption: Conical ball mills may consume less power compared to cylindrical ball mills when grinding materials with similar hardness and properties.

Versatility: Conical ball mills are suitable for a wide range of materials and can be used in both wet and dry grinding processes.

Advanced manufacturing Equipment: Tongli has over 100 set of large-scale mechanical processing equipment, especially a 5.3x18-meter fully numerically controlled horizontal lathe to ensure the processing accuracy and concentricity of the ball mill.

Heat treatment: Tongli heavy machinery is equipped with a large annealing furnace of 6.5x6.5x20m and a large sandblasting room, which can conduct overall heat treatment and sandblasting on the ball mill to ensure the service life and appearance of the ball mill.

Process Control: Tongli has its own metal casting foundry, starting from the raw material to the finished product, Quality in every detail, from start to finish.

Lubrication system: Tongli ball mill is equipped with force lubrication system, there is an oil station equipped for thetransmission part, another oil station for the gearbox to ensure smooth operation and prolong service life of the ball mill.

Cooling system: The main bearing bush is equipped with a water cooling system, and a cooler is also installed in the lubrication system to forcibly cool the lubricating oil.

Transmission connection: Tongli’s ball mill is equipped with a transmission connection, which is welded on the cylinder and machined together with the ball mill shell to avoid assembly errors and ensure the concentricity of the ball mill.

Specifications of conical ball mill

Note: * Mill diameter refers to the inner diameter, while the mill length refers to the effective grinding length.

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Industry Knowledge extension:

What is the advantage of Conical ball mill?

Conical Shape: The main feature of the conical ball mill is its conical shape, which provides a larger grinding surface area compared to cylindrical ball mills. This design promotes better grinding action and leads to a more uniform particle size distribution.

Grinding Media: Conical ball mills typically use smaller grinding media (balls) compared to cylindrical ball mills. This allows for finer grinding of materials, producing finer particles.

Better Mixing: The conical shape of the mill enhances the mixing and blending of materials during the grinding process, resulting in a more homogeneous mixture.

What is the difference between Open-circuit and closed-circuit ball mill?

Closed-circuit grinding refers to that in the grinding operation, the material is fed into the mill and then classified after one grinding, the ore with unqualified particle size is returned to the mill for regrinding, and the ore with qualified particle size is sent to the next stage. The closed-circuit mill has a high crushing rate, and the quality of the obtained product is high. At the same time, the output of the closed-circuit production is relatively large, but its disadvantage is that the production process is relatively complicated and the input cost is high.The production process of the open circuit mill is relatively simple, and the input cost is low. And its disadvantage is that it has low production efficiency, because the qualified fine powder cannot be removed in time, so it produces a large energy consumption during production.

What is the difference between ball mill and vertical roller mill?

Both ball mills and vertical roller mills plays a vital role in the cement grinding plant. Ball mills are versatile and cost-effective, suitable for various materials and simple to maintain. On the other hand, vertical roller mills offer superior energy efficiency and particle size control, making them ideal for cement and ore grinding applications. The choice between the two depends on specific requirements, budget constraints, and technical expertise.

How to install A Ball mill?

The first step of ball mill installation is to Install the base frame of the ball mill. The base installation uses a large number of metal partitions as base pads, prepare metal partitions with different thicknesses in advance for backup. After the base is installed, the worker can adjust the position of the base and the number of partitions according to the actual situation, the width of the partition cannot be less than 80mm, and the external exposed part should exceed at least 10mm In order to move the baffle, after the location of the baffle is determined, a welding operation is required. After the ball mill chassis is installed, it is necessary to accurately measure the levelness and level of the chassis with a spirit level and a tracking instrument.