Ring roller mills
The low consumption power of the ring roller mills is due to strong vertical ventilation, which blows out automatically the material after his treatment and avoids the over milling.
Range
Mills Type : BSS has elaborated twenty models of mills, which the grinding ring diameter varies by a step of 100 mm from 700 mm to 1000 mm and by a step of 200 mm, until 2500 mm.
Models Typology : our mill BP 702 is a mill of 700 mm diameter (grinding ring diameter). The last figure of the number is the number of grinding rollers, which fit the mill.
The power varies according to:
- the flow of the material
- the hardness of the material
- the rotation speed
| Model | Ring Diameter in mm | Rollers Number | Power in kW | Weight in Kg |
| From BP702 | 700 | 2 | de 7 à 13 | 3.000 |
| To BP2506 | 2.500 | 6 | de 383 à 785 | 39.000 |
We can manufacture mills of very big size and even reach diameter of 6000 mm. Our mills have a capacity from 200 kg/h to 80 000 kg/h.
The particles size distribution goes from 0 to 3 mm for the feeding and from 40µm to 150 µm for the final product.
Capacity
Due to the large of the materials, each problem is studied by our engineering department, which chose the suitable mill and specify the exact capacity according to the product. For example, the ring roller mill BP 2506 is able to grind 60 t/h with a raw material having a Hardgrove friability index of 85 and 90% under 150 µm. If the raw material already contains consists a large fine particles content, the capacity is increased consequently.
Power
The BP 60 ring roller mill with its ancillaries has a total installed power of around 800 kw.
Advantages
- Milling and drying are made simultaneously if necessary.
- Complete unit with low density air handling, entirely under negative pressure. Dust free plant.
- Very resistant and simple manufactories. All the shafts and hubs are smooth and groveless. All the connections are friction based releasable clamping assemblies.
- Minimal Power Consumption. The energy power consumption of the Ring Roller Mills is very low with regards to other mills.
- Because the grinded material is immediately blown out of the mill, due to the strong ventilation, there is no waste of power by over milling.
- Because the mill is balanced, the torque which is necessary to start the mill, is lower than the loading torque, and therefore the motor does not require power.
- Flexibility of fineness settings. The classifier is chosen according to the required fineness from 3 models which are fitted to our mills; each of them can be adjusted to obtain the right fineness according to the particle size curves.
- Highest efficiency monitored by our control system. It is based on the pressure loss in the air handling circuit allowing the mill to always grind at its nominal capacity and efficiency.
- Competitive Prices.
Description of a grinding plant
The mill rests on a base (1) surrounded by a housing for the air distribution.
The base is provided with blades enabling the air entering the mill to follow a suitable tangential direction; this produces a first classification.
The base supports the grinding ring (2) to which it is rigidly attached.
Above the base is the grinding chamber (3) made in sections in order to facilitate the dismantling of the grinding rollers during the maintenance periods.
The drive consists of a transmission and a bevel gear train mounted in an oil-filled gear box (4). All the shafts and hubs are smooth and groveless.
All the connections are friction based releasable clamping assemblies.
The lower end of the vertical shaft supports a star (5) with two, three or four arms. From each of the arms a vertical roller journal (6) is freely suspended by means of two bearings. At the end of each journal there is a freely rotating grinding roller (7).
As the star rotates, it drives the journals and grinding occurs under the pressure of the grinding roller (7) against the grinding ring (2).
The raw material is fed by the star feeder (8) and falls into the base where it is picked up by the ploughs (9) and projected between the grinding rollers and the grinding ring.
The ground material is conveyed to the classifier (10) which may be static (simple or double cone) or dynamic, depending on the degree of required fineness. The oversized materials fall back from the separator into the base in order to be recycled till the fineness you desire.
The feed flow is automatically adjusted by a control system. In addition it assures pressure and load indication and safety.
The grinding installation and the mill are under negative pressure.
This vacuum enables clean air to be used to create a gap between fixed and rotating parts, preventing entry of dust into the mechanism and the roller journals. This arrangement makes the use of mechanical seals unnecessary.
Our mills are of a very robust construction, specially designed to allow easy maintenance.
They are built in a wide range up to 900 HP.
Materials
