Dilution Water Device for Pulping Drum

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional pulping drums face challenges in reducing pulp consistency at the beginning of the screening section, leading to larger screen holes, increased energy consumption, and higher investment costs.

Innovation Solution

A device with an annular groove and curved tubes is installed at the end of the pulping section, allowing for continuous dilution of the pulp by directing dilution water into the pulping drum while preventing fiber clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If dilution water is added at the beginning of the screening section in conventional systems, then the pulp consistency is reduced, but the screen holes must be larger and the screening section must be longer, which reduces accept quality and increases costs

Engineering Contradiction:
Improvepulp consistencyVSAvoidaccept quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The device adds dilution water at the end of the pulping section before the screening section begins, performing the dilution action in advance at the optimal location. This preliminary dilution reduces pulp consistency to 5%-15% before fibers enter the screening section, allowing smaller screen holes (0.3-0.8mm) to effectively separate fibers while maintaining high accept quality.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If larger screen holes are used to handle high consistency pulp, then pulp consistency can be maintained, but accept quality deteriorates and energy consumption increases

Engineering Contradiction:
Improvepulp consistencyVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

By adding dilution water at the end of the pulping section, the system performs dilution in advance, reducing pulp consistency to 5%-15% before screening. This allows the use of smaller screen holes that create higher resistance to fiber passage, thereby increasing energy consumption for fiber separation and improving accept quality simultaneously.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If the screening section is made longer to handle high consistency pulp, then pulp consistency is maintained, but investment costs and operating costs increase

Engineering Contradiction:
Improvepulp consistencyVSAvoidscreening section length
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The device performs dilution at the end of the pulping section, reducing pulp consistency to 5%-15% before the screening section. This preliminary action allows the screening section to be shorter because fibers enter at lower consistency, enabling more efficient separation with smaller screen holes (0.3-0.8mm) and reducing both investment and operating costs.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If dilution water is added continuously at the end of the pulping section, then pulp consistency is reduced to 5%-15%, but the risk of fiber clogging in the addition device increases

Engineering Contradiction:
Improvepulp consistencyVSAvoidclogging resistance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

Instead of adding dilution water from the inside outward, the device uses curved tubes that project from the annular groove into the drum interior, with openings facing the direction opposite to drum rotation. This inverted configuration prevents fibers from entering the tubes during rotation, as fibers move with the drum rotation while water is injected against the rotation direction, eliminating clogging risk.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The device replaces complex mechanical clogging prevention mechanisms with a hydrodynamic solution. By injecting dilution water through curved tubes at an angle opposite to drum rotation, the water flow naturally prevents fiber entry into the tubes. The hydrodynamic force of the injected water flushes any potential fibers back into the pulping drum, providing passive clogging resistance without moving parts.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution reduces pulp consistency from 25%-30% to 5%-15%, enabling the use of smaller screen holes, improving accept quality, and reducing energy consumption and investment costs.

Implementation Method 1

Since the radially inner curved tubes are oriented counter to the direction of rotation of the drum, fibers cannot enter the curved tubes or the annular grooves during rotation of the pulping drum

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

In pulping drums, the pulping section is separated from the screening section by a separating plate with an opening in the middle... This scoop helps transport the dissolved fiber (pulp) forward to the screening section

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP3892773B1Device for adding dilution water and pulping drum with the same
Publication Date: 2025.06.18 ANDRITZ CHINA
  • EP3892773B1 patent drawingFigure 1~2
  • EP3892773B1 patent drawingFigure 3~4
  • EP3892773B1 patent drawingFigure 5~6

AI summary

The present invention relates to a device (100) for adding dilution water at the end of the dissolving section of a dissolving drum (200). The device (100) comprises an annular groove (110) arranged around the dissolving section of the dissolving drum (200), wherein the groove base (111) of the annular groove (110) forms the outer wall of the dissolving drum (200) and two opposing annular groove walls (112) project outwards along the radial direction of the dissolving drum (200). Several curved tubes (120) project from the annular groove (110) into the interior of the dissolving drum (200), the radial opening (121) on the inner side of each curved tube (120) being oriented against the direction of rotation of the dissolving drum (200). The annular groove (110) is covered by an annular groove cover (130), which is fixedly arranged. A supply line (140) and a drain line (150) for the dilution water open into the ring groove cover (130).