Vertical Roller Mill Feeder for Stable Grinding Beds
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Solution Overview
Problem
Traditional vertical roller mill apparatuses face limitations such as open sides allowing material escape, reduced grinding capacity due to centrifugal force, instability of the grinding bed, and vibrations, necessitating water addition for stabilization, which affects product quality and increases costs.
Innovation Solution
A vertical roller mill with a feeder system that directs particulate material into the grinding zone at controlled velocities and angles, using conveyors and air flow to create a stable grinding bed, reducing the need for water and minimizing vibrations, while allowing for finer grinding and increased throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If material is added to the middle of the grinding table and transported across the table to the grinding surface, then the material flow is assisted by table rotation, but at certain rotational speeds the majority of material leaves the table without passing through the grinding zones due to centrifugal force, limiting operational speed and grinding capacity
Solution Approach 1:
The patent introduces a new dimension by adding a conveyor system that feeds material directly onto the grinding surface from the side, rather than relying solely on radial transport across the table. This dimensional change in material delivery allows the table to rotate at higher speeds without material escape, as material is continuously supplied from an external source rather than from the table center.
2Ease of manufacture
If the sides of the grinding zone are left open, then the structure is simpler, but material escapes from the pressure in the grinding zone, severely limiting the effective grinding width and requiring excessively wide, heavy, and expensive grinding rollers and tables
Solution Approach 1:
The patent employs a flexible conveyor belt system that acts as a movable side wall or shell around the material flow. This flexible structure contains the material within the grinding zone, preventing escape while allowing the grinding zone width to be optimized independently of roller and table dimensions, thereby improving productivity without excessive structural weight.
3Stability of the object's composition
If water is added to the material to alleviate grinding bed instability, then the instability is reduced to some extent, but the product quality is affected and operating costs increase
Solution Approach 1:
The patent uses a conveyor system with controlled material flow rates and potential air flow assistance to stabilize the grinding bed. By precisely controlling the quantity and distribution of material fed onto the grinding surface, the system maintains bed stability through mechanical means rather than chemical additives like water, thus preserving product quality while reducing operating costs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances grinding efficiency, reduces vibrations, and increases capacity by stabilizing the grinding bed, enabling finer grinding without the need for water, thus improving operational stability and reducing costs.
Implementation Method 1
At a certain rotational speed, the majority of the material leaves the table without passing through the grinding zones under the rollers due to the centrifugal force created by the rotation of the grinding table.
Implementation Method 2
A vertical roller mill with a feeder system that directs particulate material into the grinding zone at controlled velocities and angles, using conveyors and air flow to create a stable grinding bed
Data Source
AI summary
A vertical roller mill comprising a grinding table and a grinding roller having a rotational axis, each having a grinding surface and arranged to define a grinding zone between the grinding surfaces grinds particulate material. A feeder feeds the particulate material to the vertical roller mill, with the grinding roller arranged to roll around a grinding path on said grinding table. The feeder receives a supply of the particulate material and directs that material to flow to the grinding zone of the vertical roller mill. The feeder can constrain the flow of material to a defined cross-section by applying a momentum to and/or pushing, or to compact the flow of material prior to directing the material, or combinations thereof. In particular, the disclosure is applicable to grinding particulate materials like mining ores, industrial minerals and chemicals, sand, slag, ash, clay, pigments for coatings, pharmaceuticals and cement raw materials.