Raw material ball mill Introduction

The raw material ball mill is an important equipment in the cement production line. After the raw material is crushed by the crusher, it enters the raw material ball mill through bucket elevators and belt conveyors. The rotation motion of the ball mill drives the internal steel balls to squeeze the material to produce fine powder that meets the process requirements, so that the subsequent calcination in the rotary kiln can fully react and produce high-quality clinker. Raw material ball mill is also extensively used in other industries such as thermal power generation, metallurgical industry, chemical industry and others, encompassing a diverse range of materials. Tongli integrates technological expertise, core manufacturing finesse, cutting-edge solutions and meticulous quality control into our TL series ball mills.

Raw material ball mill structure

Mill Shell:The foundation of the raw material 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.

Bearing Bush: Ball mill bearing bush ensures the smooth rotation of the ball mill and empowers the ball mill to maintain optimal grinding conditions. It is equipped with a forced lubrication system and also cooling system. It has alloy surface and 3 rolling rods on the bottom to make sure when the ball mill trunnion moves, the position of the bearing bush can be adjustable. 

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 on our 5x18m CNC controlled horizontal lathe to avoid assembly errors and ensure the concentricity of the ball mill.

Hood Cover: The discharge hood of the 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 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.

Cement 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 raw material ball mill

The material is directly fed into the coarse grinding chamber in the barrel of the raw material ball mill with the feeding chute in the feeding device, and the material is crushed under the impact grinding action of the grinding body (steel ball) with a large average diameter, and is crushed to a certain particle size through the gap between the coarse sieve plates of the compartment plate, enter the combined compartment plate, and the grinding body of the coarse grinding compartment is blocked by the compartment plate.

The material is further screened and analyzed by the fine sieve plate in the combined compartment plate, the over-coarse material is screened out and returned to the coarse grinding chamber, while the fine material smaller than the sieve size of the fine sieve plate enters the fine grinding chamber through the fine sieve plate. The material is further ground by the small grinding body in the fine grinding chamber, and the fine powder that meets the requirements passes through the discharge grate plate and the discharge pipe into the discharge device and is discharged.

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 the transmission 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 raw material 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 you should know about Ball mill installation?

Before installing the ball mill, it is necessary to formulate a specific installation plan. The installation plan needs to include related work such as instrument calibration. After the plan is determined, the staff should focus on checking whether the position of the embedded bolts of the raw material ball mill and whether their elevation is consistent with the design drawing of the ball mill. Once the bolts are found If the holes are misplaced, of different sizes, or of different lengths, they must be reported immediately.

Datum point and central target plate are the core references for raw material ball mil installation and post-calibration work. Before the ball mill is installed, it is necessary to properly maintain the reference point and the center mark, including cleaning the reference point and leveling the surrounding land. The staff should remove dust from the pre-embedded nuts at the reference point and related equipment, and if necessary, apply a layer of glycerin on the surface of the nuts, which can effectively improve the lubricity of the equipment during installation, especially when installing a ball mill. A level must be used for magnetic instruments such as gravimeters, lubrication can effectively reduce errors.

What is the difference between central drive ball mill and edge drive ball mill?

Central Drive Ball Mill and Edge Drive Ball Mill are two common types of grinding mills used in various industrial applications. 

Central Drive Ball Mill: In this configuration, the motor is positioned in the center of the mill, and the shaft is driven directly through the central axis. The motor's power is transmitted to the mill via a gear unit, resulting in a balanced and efficient power distribution.

Edge Drive Ball Mill: In contrast, the edge drive mill utilizes a gearbox located on the periphery of the mill. The motor's power is transmitted to the mill through the gears, which are positioned around the shell. This design offers certain advantages in terms of installation and maintenance.

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.