Inorganic Sludge Drying via Hot Slag Heat Exchange
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sludge drying technologies are costly and inefficient, particularly due to high energy consumption and ineffective utilization of waste heat from steel slag, which hinders continuous and rapid sludge treatment.
Innovation Solution
A hot slag drum process is employed to mix metallurgical slag and inorganic sludge at a specific ratio, allowing for simultaneous cooling, granulation, and drying of the sludge, utilizing the waste heat of slag for energy-efficient sludge treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electric heating or steam heating is used to dry sludge, then the water content can be reduced to 20% or less, but the energy consumption is high and the cost is high
Solution Approach 1:
The patent converts waste heat from steel slag, which would otherwise be wasted, into a useful drying medium for sludge treatment. The hot slag serves as both a heat source and a drying agent, transforming a waste product into a beneficial resource that reduces energy consumption while achieving the required water content reduction.
Solution Approach 2:
The sludge drying process utilizes its own water content to cool and granulate the slag, while the slag simultaneously dries the sludge. This mutual interaction creates a self-sufficient system where the sludge's moisture serves a dual purpose: cooling the slag and enabling the drying process without requiring external energy input.
2Loss of energy
If waste heat from steel slag is not utilized, then the slag can be stored or disposed of, but a huge amount of heat is wasted and the process is slow
Solution Approach 1:
The patent transforms the waste heat in steel slag from a harmful energy loss into a beneficial drying medium. By direct contact between the hot slag and sludge, the waste heat is efficiently transferred to evaporate water from the sludge, simultaneously solving the heat waste problem and achieving rapid sludge drying.
Solution Approach 2:
The hot slag acts as an intermediary medium that transfers thermal energy from the steel production process to the sludge drying process. Instead of using the slag merely as waste to be disposed of, it serves as a heat transfer medium that bridges the steelmaking operation and sludge treatment, enabling efficient energy utilization.
3Productivity
If mechanical dewatering is used first, then the water content is reduced to 75%-85%, but further drying to 20% or less requires high energy consumption
Solution Approach 1:
The patent creates a continuous drying process where mechanically dewatered sludge is immediately subjected to slag drying without interruption. The hot slag continuously contacts the sludge surface, maintaining a constant drying rate that efficiently removes the remaining moisture from 85% to below 20% water content without energy interruption or additional heating steps.
Solution Approach 2:
The patent changes the drying parameter from controlled thermal heating to contact drying with hot solid particles. By altering the drying mechanism from steam/electric heating to direct contact with hot slag, the process achieves efficient moisture removal at lower energy consumption, leveraging the high temperature and surface area of the slag particles.
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 method enables rapid, continuous, and cost-effective drying of inorganic sludge while granulating the slag, achieving a target water content of 3-15% and facilitating subsequent resource utilization, with a simple and efficient apparatus design.
Implementation Method 1
After the mass and heat transfer process of the slag and sludge, cold granular slag and dried sludge having the required water content are obtained
Implementation Method 2
drying the sludge is a necessary link to realize the harmlessness, reduction and recycling of the sludge
Data Source
Figure 1~2
AI summary
A method and apparatus for direct drying of inorganic sludge with a drum drawing process, comprising the following steps: 1) drum mixed drying of slag and sludge: respectively conveying the slag and sludge into a drum (1) in proportion, completing mixing, heat exchange, dehydration, cooling and crushing of the slag and sludge under the rolling action of the drum (1) and a steel ball to achieve cooling, crushing and drying of the slag and sludge, and directly discharging the obtained mixture; 2) slag and sludge separation: separating the steel slag and dry sludge in a manner of combining screening and rotary separation; 3) tail gas treatment: treating dusts, sulfides and organic compounds in tail gas generated by the dry sludge by using wet alkali washing and activated carbon adsorption, and discharging the treated tail gas; and 4) tailing sludge treatment: generating steam and dusts in the drum treatment of the slag and sludge, allowing dusts to enter a tail gas treatment device (4) with steam, aggregating the dusts after wet washing or spraying, and then conveying into a tailing sludge blending device (5) by means of a conveying device, mixing and stirring the tailing sludge and original sludge, conveying the obtained mixture into the drum (1), and drying the mixture to realize zero discharge of undried sludge.