Eccentric Rotor Pulper with Conical Base

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Solution Overview

Problem

Existing pulpers face challenges in efficiently and economically dissolving air-dried pulp or waste paper, with previous optimizations such as angular containers and asymmetrical rotors not significantly improving the infeed process or circulation flow.

Innovation Solution

A pulper design featuring an eccentric rotor arrangement within a cylindrical container with a truncated cone-shaped base and a vertical flow barrier, enhancing the infeed of material and circulation flow, allowing for faster and more efficient dissolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional vertical cylindrical container with a rotor in the bottom area is used, then the pulper can generate a vortex flow and circulate the suspension, but the infeed of material is slow and the dissolution process is time-consuming

Engineering Contradiction:
Improvedissolution speedVSAvoidpulping time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The rotor is arranged eccentrically with respect to the vertical center line of the container, creating an asymmetric configuration that improves material infeed and circulation. The eccentricity E is preferably 5 to 20% of the diameter D1 of the container, which optimizes the flow patterns and reduces pulping time while maintaining effective dissolution.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The bottom of the container is designed with a truncated cone shape instead of a flat base, introducing a conical dimension that directs material toward the rotor. This geometric modification enhances the circulation flow and improves the drawing of material into the rotor area, thereby increasing dissolution speed.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the rotor is arranged symmetrically in the center of the container, then the structure is simple, but the circulation flow is insufficient and material infeed is slow

Engineering Contradiction:
Improvecirculation flowVSAvoidrotor arrangement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The rotor is deliberately positioned asymmetrically with an eccentricity E of 5 to 20% of the container diameter D1. This asymmetric arrangement creates more effective circulation flow and improves material infeed, while the complexity remains manageable through standardized eccentric rotor designs.

Inventive Principle:
Principle #4Asymmetry

3Productivity

If the container is made angular to improve feeding, then material infeed is enhanced, but the circulation flow is not significantly improved and application is limited

Engineering Contradiction:
Improvematerial infeedVSAvoidapplication range
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

Instead of changing the container shape to angular, the invention modifies the bottom geometry to a truncated cone shape. This conical bottom design improves material infeed while maintaining a cylindrical container body that is easier to manufacture and more versatile for different applications.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Ease of operation

If multiple complex rotors are used within the same pulper container, then circulation is improved, but the device complexity increases and cost rises

Engineering Contradiction:
ImprovecirculationVSAvoidnumber of rotors
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention improves circulation by modifying the container bottom to a truncated cone shape, which creates effective flow patterns with a single rotor. This approach achieves good circulation without requiring multiple complex rotors, thereby avoiding increased device complexity and cost.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 pulper achieves faster dissolution and better machine utilization with energy savings, as evidenced by reduced speckle content in the fiber suspension, and improved handling of both virgin and waste paper.

Implementation Method 1

a vortex flow is generated in the suspension with the help of the rotor, in which the substance is sucked down by the rotor in the central area and pressed radially outwards in the bottom area, resulting in a circulating flow

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 2

the crushing and suspension of the paper stock is brought about by hydraulic forces and by contact between the rotor 2 and the paper stock

Methodology Applied
Scientific EffectHydraulic forces: Hydraulic Press

Data Source

PatentEP2122047B1Pulper for comminuting and suspending papermaking material, and its use
Publication Date: 2015.08.12 VOITH PATENT GMBH
  • EP2122047B1 patent drawingFigure 1~2
  • EP2122047B1 patent drawingFigure 3~5

AI summary

The pulper is used for comminuting and suspending papermaking material. It has a container (1) which is open at the top and which has a cylindrical side wall (5) and a driven rotor (2) which is disposed eccentrically in relation to the centre of the container (1). The base (7) of the container (1) may carry one or more frustoconical elements (10, 11).