Bottom-Drying Sludge Dryer With Scraping Stirring Mechanism

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Solution Overview

Problem

Existing sludge drying technologies face challenges such as high energy consumption, inefficiency, and difficulty in reducing moisture content due to sludge viscosity and tendency to cake, leading to environmental pollution and increased costs.

Innovation Solution

A bottom drying type sludge drying device with a stirring assembly that constantly cuts, breaks, and stirs sludge in a first drying chamber, and a bridge-shaped element above a communication opening to facilitate drying gas flow, combined with a scraping mechanism to prevent clogging and enhance gas contact, improving sludge looseness and drying efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fluidized bed drying method is used, then drying can be achieved, but energy consumption is high and drying efficiency is low

Engineering Contradiction:
Improvedrying efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent inverts the conventional top-down drying approach by implementing bottom-up drying. The drying chamber receives dried sludge from the drying chamber above, allowing drying gas to rise through the sludge layer from bottom to top. This inversion improves heat transfer efficiency and reduces energy consumption while maintaining high drying productivity.

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

Solution Approach 2:

The patent introduces a drying chamber as an intermediary between the sludge receiving chamber and the discharge chamber. This intermediary chamber allows drying gas to be generated and controlled separately, then introduced to the sludge layer, improving overall drying efficiency while reducing direct energy input requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If sludge is piled on the partition for drying, then drying can proceed, but the communication opening becomes clogged and drying gas flow is blocked

Engineering Contradiction:
Improvedrying efficiencyVSAvoidgas flow smoothness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent extracts the communication opening from the partition structure and relocates it to the side wall of the drying chamber. This separation prevents sludge accumulation at the communication opening, ensuring continuous gas flow while maintaining effective drying. The opening is positioned where it cannot be blocked by the sludge layer.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the spatial dimension of the communication opening from a vertical position (on the partition where sludge accumulates) to a horizontal position (on the side wall). This dimensional change allows gas to flow laterally into the drying chamber without being blocked by the vertically piled sludge, maintaining both drying efficiency and gas flow reliability.

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

3Productivity

If sludge is not stirred during drying, then the structure is simple, but the interior and exterior portions have uneven dryness

Engineering Contradiction:
Improvedrying uniformityVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic stirring mechanism that rotates to mix the sludge layer during the drying process. This dynamic action ensures uniform moisture distribution and prevents caking, achieving even drying throughout the sludge mass. The stirring mechanism is designed to be simple in structure but effective in function, rotating on a horizontal axis to continuously redistribute the sludge.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The stirring mechanism operates periodically, rotating at intervals during the drying process to maintain uniform moisture distribution. This periodic action ensures that the sludge does not cake while avoiding excessive mechanical complexity. The stirring is synchronized with the drying phases to maximize effectiveness.

Inventive Principle:
Principle #19Periodic action

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 solution achieves high drying efficiency with low energy consumption, adaptability, and reduced floor area, effectively transforming coarse sludge into particles and powder, thereby improving drying efficiency and reducing energy usage.

Implementation Method 1

a stirring assembly in a first drying chamber cuts, breaks and stirs the sludge constantly so that the sludge contacts the drying gas frequently

Methodology Applied
Scientific EffectMechanical mixing: Stirring

Implementation Method 2

The drying gas enters from the second drying chamber into the first drying chamber via a curved path from the communication opening to the lateral aperture

Methodology Applied
Scientific EffectGas flow: Convection

Implementation Method 3

arrangement of a blowing device, a draught inducing device and/or a heating device may not only increase the speed at which the drying gas flows into the drying chamber but also increase the speed at which the drying gas flows out of the drying chamber

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 4

effective sludge treatment is very important in a sewage treatment process. A sewage treatment plant usually reduces moisture content of the sludge from over 90% to between 60% and 80%

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3243802B1Bottom-drying sludge drying device and method
Publication Date: 2020.02.05 SWISON CREATIVE ENVIRONMENTAL SOLUTIONS CO LTD
  • EP3243802B1 patent drawingFigure 1
  • EP3243802B1 patent drawingFigure 2
  • EP3243802B1 patent drawingFigure 3

AI summary

The present disclosure provides a bottom drying type sludge drying device, comprising: a housing in which a curved-face partition is provided for separating space in the housing into first and second drying chambers; a feed gate and an outlet provided on an upper portion of the first drying chamber, and a discharge gate provided on the circumferential wall of the first drying chamber. An inlet is provided on a side wall or bottom of the second drying chamber. The curved-face partition comprises a depressed area in which a communication opening is formed, and a bridge-shaped element is provided above the communication opening, forming a lateral aperture between the bridge-shaped element and the partition. A sludge stirring assembly is provided in the first drying chamber, which comprises a rotary shaft and a stirring unit fixed on the rotary shaft, and the stirring unit is configured to cut, break and stir the sludge and/or that a front end thereof faces and is close to the lateral aperture, such that the front end scrapes the sludge in or at the communication opening as the stirring unit rotates. The present disclosure further provides a method of drying sludge using a sludge drying device.