GZS Series Roller Screen Technical Description
Roller Screen Overview
Product Features
GZS type Roller Screen is based on the original design with new design concepts. Each group of screen shafts (four shafts/group) is driven by an independent driving device. A screen cleaning device is installed under each group of screen shafts to keep the screen surface clean. The screen plates of Roller Screen can be made of manganese steel or NM360. After many years of operation experience and continuous improvement, our Roller Screen has the advantages of reasonable structure, high screening efficiency, large production capacity, good sealing performance, low noise, low vibration, automatic screen surface cleaning, no screen blockage, convenient installation, safe and reliable operation, and has gained unanimous recognition from customers.
Main Applications and Operating Environment
GZS type Roller Screen is one of the important equipment in coal-fired power plants and coal conveying systems. It is mainly widely used in metallurgy, chemical industry, coal systems and other industries.
GZS type Roller Screen can operate under the following environments
Altitude not exceeding 3000m;
Operating ambient temperature: -30℃～+35℃ (when the site temperature is lower than -15℃, the reducer is equipped with a heating device and suitable lubricating oil is used);
In an environment protected from dripping water;
Relative humidity of surrounding air not exceeding 95% (at 25℃);
In an environment without gases or vapors that damage insulation;
Pollution level: Class 3;
Installation category: Class III.
Structural Features
The main components of GZS type Roller Screen include the drive unit (including motor, reducer, coupling), roller shafts (including screen shafts, blades, etc.), feed end screen plate, feed inlet, screen box, inspection door, comb plate, bottom support and base.
Drive Unit
The drive unit is the power part of the Roller Screen. The coupling can absorb excessive impact force and torque generated during screening. Through the coupling, the load can start smoothly, improve the starting characteristics, and reduce the impact current on the power grid during startup. The reducer is a hard tooth surface reducer, featuring large overload capacity and long service life.
Screen Shaft Assembly
Screen shafts, screen plates and other wearing parts are easy to replace. The screen plates adopt plum-shaped screen plates with staggered arrangement, which not only helps coal material conveying, but also reduces dead zones formed between adjacent screen shafts and avoids blockage. It is suitable for materials such as bituminous coal, anthracite, lignite and coal gangue.
Each screen shaft can be driven directly or indirectly by the motor reducer drive. Each standard section is equipped with a set of driving device to provide driving force. The reducer output shaft is connected with the active screen shaft of the Roller Screen through a coupling. Other screen shafts are connected with the active roller shaft through double-row roller chains in sequence. When any screen shaft inside a standard section fails, the standard section will stop and give an alarm. Other standard sections will also stop sequentially, effectively preventing damage to the motor, reducer and other driving equipment.
Automatic Cleaning Device
An automatic cleaning device is installed under the screen shafts, which can effectively remove sticky coal from the sides and roots of the screen plates and prevent coal blockage.
The ends of the screen shafts adopt a wear-resistant liner wrapped disc structure, which completely solves the problem of large lumps being stuck between both sides of the box and the screen plates, ensuring normal operation of the equipment.
Bearing Lubrication
The bearings in the bearing housings are lubricated with calcium-based grease instead of oil lubrication, which is convenient for maintenance and inspection. The bearing seals use oil seals to ensure no grease leakage. The bearing temperature rise is generally not higher than 40℃, and the bearing temperature does not exceed 70℃.
Electrical Protection
Each screen shaft of the Roller Screen is equipped with electrical protection. When the equipment is overloaded or the screen shaft is blocked, the motor current increases and exceeds the critical value, an alarm signal will be issued to provide electrical protection.
Fault Analysis and Troubleshooting
Under normal maintenance and operation conditions, the Roller Screen itself has very few failures. The following table shows some common faults and corresponding solutions.
The screen plate shape of the Roller Screen is an irregular oval shape. The screen openings between adjacent screen plates on the same shaft are V-shaped, and the screen openings between two adjacent screen shafts are serrated. During operation, materials fall into the V-shaped space between two screen plates. The screen plates clamp the materials and rotate. Materials smaller than the screen opening fall through the serrated openings, while materials larger than the screen opening continue moving forward until they are discharged from the oversize material outlet and enter the crusher.
Since the screen shafts, screen plates and materials cannot move synchronously, relative movement and friction exist between them. Therefore, materials will not stick to the screen plates. The screen surface has a self-cleaning function, remains unobstructed, and does not become blocked. The screening efficiency is greatly improved compared with the original screen surface.
Roller Screen coal blockage or overload trip:
1.Large foreign objects block the screen shaft, causing the rotation speed to slow down or stop.
Solution: Stop the machine first and remove the large foreign objects.
2.Foreign objects accumulate on the screen surface and affect coal flow passage.
Solution: Stop the machine and remove foreign objects from the screen surface or screen shafts.
3.Coal flow rate is too large or coal viscosity is too high.
Solution: Mix an appropriate amount of dry coal and control the coal flow rate.
4.Drive shaft, gear or bearing damage.
Solution: Repair the drive shaft or replace the bearing.
5.Coal hopper blockage.
Solution: Remove accumulated coal from the coal hopper.
