Segmented Pulp Lifter Guide for Mill Discharge
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Solution Overview
Problem
Existing pulp lifters in rotary mills experience reduced effectiveness at higher speeds due to carryover of comminuted material and backflow, leading to decreased grinding efficiency and accumulation of pebbles, which restricts slurry flow and forms pools.
Innovation Solution
The apparatus consists of two sections with a guide member directing material towards the outlet, preventing carryover and backflow by ensuring continuous flow through the guide member and discharge cone, allowing operation up to 90% of the mill's critical speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the mill rotation speed is increased above 75% of critical speed, then productivity increases, but carryover of comminuted material occurs in the collection compartment reducing grinding effectiveness
Solution Approach 1:
The pulp lifter is divided into two distinct sections: a first section (transitional compartment) that receives slurry through the grate, and a second section (collection compartment) that collects and discharges the slurry. This segmentation prevents carryover of comminuted material by containing it in the first section while allowing controlled discharge from the second section, maintaining grinding effectiveness even at high mill speeds up to 90% of critical speed.
2Device complexity
If conventional pulp lifter design is used, then结构简单性 is maintained, but pebbles accumulate in the pulp lifter limiting space for slurry and reducing flow gradient
Solution Approach 1:
The guide member is introduced as a separate component that extracts and directs pebbles and comminuted material away from the collection compartment toward the mill discharge. This prevents pebble accumulation that would otherwise limit slurry space and reduce flow gradient, maintaining high productivity without increasing overall structural complexity.
3Productivity
If pulp lifter chamber fills with slurry, then discharge capacity increases, but backflow through the grate occurs as the pulp lifter rises
Solution Approach 1:
The first section is designed to rotate with the mill and dynamically change its position relative to the grate, allowing it to fill with slurry during rotation. The guide member dynamically directs material flow to prevent backflow through the grate while maintaining discharge capacity, adapting to the rotating motion to eliminate harmful backflow effects.
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 configuration enhances material discharge efficiency by reducing carryover and backflow, maintaining a consistent flow gradient and preventing slurry pooling, even at higher mill speeds, thereby improving grinding efficiency.
Implementation Method 1
The apparatus consists of two sections with a guide member directing material towards the outlet, preventing carryover and backflow by ensuring continuous flow through the guide member and discharge cone
Data Source
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AI summary
A pulp lifter for installation in a grinding mill has a leading edge and a trailing edge with respect to rotation of the mill and comprises a first wall bounding an interior space and a second wall dividing the interior space into first and second sections. The first wall includes a leading edge wall formed with an inlet opening providing access to the second section and an inner edge wall formed with an outlet opening for discharge of slurry from the second section. The second wall includes a guide that extends substantially from an outer end of the leading edge wall to a trailing end of the inner edge wall, and the first section of the interior space is open at the trailing edge of the pulp lifter.