What is a trommel screen?
The trommel screen is a new type of self-cleaning screen. It is widely used for screening all kinds of solid materials, such as stone (granite, cobblestone, basalt, etc.), coal, coke, white ash, compound fertilizer, topsoil, sand, municipal solid waste, aggregates, etc.
It is suitable for fertilizer plant, agriculture, chemical industry, mining, power plant, building materials, metallurgy and other industries.
Feeding and discharging size of trommel screen
The trommel drum can generally screen materials with a particle size of 50-150 mm. The maximum undersize product is less than 100 mm, and the finest can be less than 3 mm.
The capacity of the trommel screen
The capacity of the trommel screen is closely related to the screen size. If you choose a 2 mm sieve, the output is 12-35 m³/h (19.2-56 t/h); its output can reach 175 m³/h (280 t/h) with a larger sieve (30 mm), which can meet the requirements of large-scale production.
How does a trommel screen work?
The barrel, inclinedly installed on the frame, is connected with the motor through a coupling and rotates around its axis.
When the materials are fed into the tilted and rotating barrel, they turn and roll on the screen. Then the qualified materials (undersize product) are discharged through the outlet at the bottom of the rear end of the barrel, while unqualified materials (oversize product) are discharged through the discharging port at the end of the barrel.
The materials stuck in the sieve mesh can be ejected due to their turning and rolling to prevent the sieve mesh from being blocked.
The wearing parts of the trommel screen
The bearing bears the full load of the trommel drum machine. Good lubrication has a great relationship with the bearing life, directly affecting the service life and operation rate of the machine.
|Greasing frequency||Every 2 months|
|Cleaning and inspection frequency||Every year|
|Grease||No.2 lithium grease|
|Bearing temperature||≤ 75°C|
|Bearing temperature rise||≤ 45°C|
Generally, the screen of the trommel can be divided into the woven type and punched one with one or two layers. These two screen plates will be introduced in detail below.
|Punched plate (circular hole)||
1. Durable and widely used.
2. For materials with higher hygiene or special requirements, 304 stainless steel/carbon steel can be selected.
|Small effective area and lowest screening efficiency||> 5 mm|
|Woven screen (square hole)||Middle screening efficiency||
1. Once the material is too heavy, the screen will be deformed and leakage.
2. Complex production and high cost.
3. Once damaged, it is difficult to reinforce.
4. Oblong holes are easy to make long strips and flake materials pass through, resulting in uneven product size.
|Relatively light bulk materials|
|Woven screen (oblong hole)||
1. The largest effective area and the highest screening efficiency.
2. The screen holes are not easy to be blocked.
|Relatively light plate materials|
3. Reducer and motor
The tension of the belt will loosen the screw between the reducer and the motor. You should check the tightness of the bolt and the belt to avoid belt slip.
4. Discharging port
The discharge port is often blocked, so it is recommended that its angle should be as perpendicular to the ground as possible and the diameter should be larger to facilitate the discharging of materials.
The performance characteristics of Fote trommel screen
1 Diverse feeding modes. The feeding port of the trommel screen can be designed according to the site. The feeding will be smooth whether by belt, funnel or other feeding methods.
2 High screening efficiency. The sand lump breaking device in the trommel drum can break up the clumps of sand. The cleaning device installed on the trommel screen can clean up the adhered sand by itself to prevent the mesh plugging.
3 Large screening capacity. The area of the circle is larger than that of other shapes under the same size, so its screen capacity per unit time is larger.
4 Low energy consumption. With low power but large processing capacity motor, the running time of materials is only one-half of other screen types, so its energy consumption is low.
5 Good working environment. The entire screening cylinder can be sealed with an isolation cover, which completely avoids the dust, noise, etc. during the screening cycle.
6 Easy to install, disassemble and transfer. Because the whole equipment is a box-shaped frame structure, only flat ground is required. The high integrity of the equipment is convenient for storage or transfer on the construction site.
Notes for the operation of trommel screen
Installation and debugging
- The deviation of the machine in the horizontal range should be less than 2 mm per meter.
- When the equipment is stopped for more than 30 days and restarted, the motor insulation should be shaken to avoid the motor from burning.
- It should be determined whether the trommel screen is flexible by manual turning. If it is not, it can be adjusted by adjusting bolts.
The trommel screen must be started without any load.
After the power is turned on and the device is running normally, feed materials evenly to the feeding inlet until full load.
Fote trommel screen in operation
After the machine runs for 8 hours, the bearing temperature should be below 70 degrees Celsius.
Check every hour for the particle size of the discharged material, leakage and dust.
- Make sure that all materials in the trommel screen have been screened before downtime.
- After the downtime, check the whole equipment. If any abnormality is found, it needs to be deal with it immediately.
Fote trommel screen case in India—quartz sand magnetic separation production line
|Project||Quartz sand magnetic separation production line|
|Processed materials||Quartz and feldspar|
|Grade of concentrate||> 63|
|Main equipment configuration||Trommel screen, jaw crusher, ceramic ball mill, spiral classifier, magnetic separator (3 sets), concentrator, etc.|
The magnetic separation production adopts a two-stage grinding process, in addition to the good screening effect of the trommel screen, which not only reduces the ore sludge caused by the mineral over-grinding and low grinding efficiency, but also increases the output and achieves the required grinding fineness.
Three magnetic separators are adopted for selection. One magnetic separator is used for the first stage, another for rough concentration and the third for concentration in the second stage to achieve the requirement of concentrate grade above 63.
Advantages of trommel screen in quartz sand magnetic separation production line:
The trommel screen is better than the linear sieve. The quartz sand magnetic separation line is usually equipped with a trommel screen.
Because the quartz sand is in the form of mineral particles, the mineral powder smaller than the sieve hole will fall during the continuous rolling of the trommel, while the other will be distinguished according to the diameter.
The linear sieve is swaying or jumping forward, so the trommel screen is more suitable for mineral powder.
|Sieve hole(2mm)||Sieve hole(30mm)|
|Sieve hole(2mm)||Sieve hole(30mm)|