Multi-stage Pulp Lifter Guide for Rotary Mill Discharge

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Solution Overview

Problem

In rotary grinding mills, the existing pulp lifter designs face challenges in efficiently directing and discharging comminuted material, leading to potential flowback and accumulation issues, which can result in reduced processing efficiency and increased carryover of pebbles and slurry.

Innovation Solution

The pulp lifter assembly incorporates a unique configuration with guide members and transition dischargers that enhance the flow of material from the first section to the second section, utilizing curved guide members and transition channels to accelerate particles radially inward, ensuring effective discharge and minimizing carryover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional pulp lifter designs are used, then the structure is simple, but material flowback and accumulation occur reducing discharge efficiency

Engineering Contradiction:
Improvematerial discharge efficiencyVSAvoidpulp lifter structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The pulp lifter is divided into multiple sections (first section, second section, third section) with distinct functions. Each section handles material flow at different stages, preventing accumulation and flowback by creating sequential processing zones rather than a single chamber.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Guide members are introduced as intermediary elements between the pulp lifter sections and the discharge cone. These guide members actively direct material flow, preventing accumulation in the pulp lifter and ensuring efficient discharge to the cone by mediating the transition between sections.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If conventional discharge structures are used, then the device complexity is low, but particles accumulate and carryover increases

Engineering Contradiction:
Improveprocessing efficiencyVSAvoiddischarge structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The discharge cone is designed with a curved, conical surface that facilitates smooth material flow toward the discharge point. The curvature prevents material accumulation by directing particles along the sloped surface, eliminating dead zones where material could pool.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The guide members and curved discharge surface prepare material for efficient discharge before it reaches the cone. By pre-positioning and pre-directing material through the guide members, the system ensures particles are ready for optimal discharge paths, preventing accumulation upstream.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If simple guide members are used, then manufacturing is easier, but material flow direction control is insufficient

Engineering Contradiction:
Improvematerial flow controlVSAvoidguide member complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

Guide members incorporate curved surfaces that naturally direct material flow through geometric shape rather than complex mechanical mechanisms. The curvature provides passive flow direction control, achieving effective material guidance through simple geometric forms that are easy to manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 improves the efficiency of material discharge, reducing flowback and carryover, and increases the likelihood of particles reaching the discharge cone, thereby enhancing the overall processing efficiency of the rotary grinding mill.

Implementation Method 1

utilizing curved guide members and transition channels to accelerate particles radially inward

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

the material in the first section 15 of the pulp lifter 11A flows downward into the second section 16 of the pulp lifter 11B

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2531303B1Multi-stage discharger for tumbling mills
Publication Date: 2018.05.16 OUTOTEC FINDLAND OY
  • EP2531303B1 patent drawingFigure 1~2
  • EP2531303B1 patent drawingFigure 3~5
  • EP2531303B1 patent drawingFigure 6~8

AI summary

A pulp lifter assembly for a rotary grinding mill includes an outer pulp lifter having walls defining a pulp lifter chamber and an outlet opening for radially inward discharge of slurry from the pulp lifter chamber, and an inner discharger disposed radially inward of the outer pulp lifter and circumferentially offset from the outer pulp lifter. The inner discharger defines a passage for conveying slurry substantially radially inward. A transition discharger is disposed radially between the outer pulp lifter and the inner discharger. The transition discharger has a first wall bounding an interior space and a second wall dividing the interior space into first and second regions. The second wall includes a guide that bounds a channel connecting the outlet opening of the outer pulp lifter to the passage defined by the inner discharger.