Grinding Roller Mill Inward Sloped Ring Design
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Solution Overview
Problem
Existing roller mills experience high vibration and noise levels, and roll skidding during fine grinding due to insufficient material retention between the rolls and grinding ring, leading to reduced mill throughput and increased power consumption.
Innovation Solution
The design incorporates a grinding ring with an inwardly sloped lower portion and a complementary curved lower portion on the grinding roll, along with a baffle to direct oversized particles back to the grinding zone and a ribbed tread on the roll to reduce slippage, enhancing material retention and grinding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the roller mill is used for grinding fine particle sizes, then the particle fineness is improved, but the vibration and noise levels increase
Solution Approach 1:
The grinding ring surface is modified by adding an inwardly sloped lower portion, changing the geometric parameters of the grinding surface to improve material retention and reduce vibration and noise during fine grinding operations
Solution Approach 2:
The grinding roll lower portion is given a curved shape that is complementary to the inwardly sloped grinding ring surface, creating a curved contact zone that improves material retention and reduces pounding between the roll and ring
2Manufacturing precision
If the roller mill grinds fine particle sizes, then the particle fineness is improved, but the roll skidding increases
Solution Approach 1:
The contact surface geometry is changed by adding the inwardly sloped lower portion to the grinding ring and complementary curved portion to the roll, creating better material retention that prevents roll skidding
Solution Approach 2:
The specially shaped grinding surfaces are designed to preliminarily retain material in the grinding zone before grinding occurs, ensuring material is present to prevent skidding from the outset
3Manufacturing precision
If the roller mill operates with fine particles, then the particle fineness is improved, but the mill throughput decreases
Solution Approach 1:
The grinding ring geometry is modified with an inwardly sloped lower portion that increases material retention, allowing more material to be processed through the mill while maintaining fine particle size output
Solution Approach 2:
The curved lower portion of the grinding roll working with the sloped ring creates an optimized contact zone that improves material utilization and increases throughput while maintaining fine grinding capability
4Manufacturing precision
If the roller mill operates with fine particles, then the particle fineness is improved, but the power consumption increases
Solution Approach 1:
The grinding surface geometry parameters are changed to improve material retention, reducing energy waste from roll skidding and pounding while maintaining efficient grinding for fine particles
Solution Approach 2:
The design converts what would be harmful empty roll rotation and pounding into beneficial grinding action by ensuring material is always present in the grinding zone through the specially shaped surfaces
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
This design reduces vibration and noise, increases mill throughput, and improves grinding efficiency by maintaining more material between the roll and ring, resulting in finer particle sizes and reduced power consumption.
Implementation Method 1
the airflow 30 having oversized particles fall back down to the grinding chamber 22
Implementation Method 2
A blower (not shown) generates an upward airflow 20 that draws fine particles upward through a grinding chamber 22
Implementation Method 3
a ribbed tread on the roll to reduce slippage
Implementation Method 4
The classifier has a centrifugal-type separator 25 that separates the oversize particles from the finer particles
Data Source
AI summary
A roller mill 10 for pulverizing fine material has a grinding mechanism that includes a plurality of grinding rolls 64 and a grinding ring 66 that coact to pulverize material within a mill housing. The grinding ring has an inner grinding surface wherein the inner surface includes an upper vertical portion and inwardly sloped lower portion. The lower portion of the ring provides a means for retaining more fine particles on the ring during pulverizing, as well as an increase in grinding surface. The grinding rolls have a generally cylindrical shape with an outer grinding surface that includes an upper vertical portion and a lower portion of the outer grinding surface. The outer grinding surface of the roll is complementary to the inner grinding surface of the grinding ring.