Regenerator Bulk Material Drainage to Prevent Grate Damage
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Solution Overview
Problem
Regenerators in steel production and chemical processes face mechanical and thermal stress due to thermal expansion of bulk material, leading to compaction and erosion, which damages the grates and reduces the service life of the bulk material.
Innovation Solution
A method where a defined quantity of bulk material is drained during the cold phase, cooled, and then gently conveyed back using a conveyor system, avoiding immediate reinsertion and reducing mechanical stress, with precise measurement and controlled backfilling to compensate for thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If bulk material is discharged during the hot phase to reduce compressive stress, then the mechanical stress on grates is reduced, but the bulk material suffers severe erosion and thermal shock
Solution Approach 1:
The bulk material is discharged during the cold phase, which is before the hot phase begins. This preliminary timing allows the material to be removed while cool, avoiding thermal shock during discharge, and then replaced with fresh material that will be heated in the upcoming hot phase without having undergone erosive discharge processes
Solution Approach 2:
The system alternates between cold phase (with discharge and refilling) and hot phase (with heat treatment). This periodic operation allows the bulk material to experience gentle handling during the cold phase and thermal processing during the hot phase, separating the mechanical discharge function from the thermal treatment function to avoid combined erosion and thermal shock
2Productivity
If bulk material is conveyed back immediately after discharge, then the process efficiency is improved, but the thermal cycling stress and mechanical erosion are intensified
Solution Approach 1:
The bulk material is discharged and replaced during the cold phase, which is prepared in advance before the hot phase begins. This preliminary replacement ensures that fresh, cool material is in place before heating starts, avoiding the need to convey hot material and reducing thermal cycling stress while maintaining process efficiency
Solution Approach 2:
The cold phase acts as an intermediary period between discharge and the hot phase. During this intermediary time, the bulk material is replaced while cool, and the system prepares for the upcoming hot phase. This intermediary cold phase buffers the thermal and mechanical stresses that would otherwise occur during immediate conveyance and heating
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 approach reduces thermal cycling stress, minimizes erosion, and extends the service life of the bulk material and regenerator components by gently handling the bulk material, thereby reducing mechanical stress on the grates and maintaining efficient heat transfer.
Implementation Method 1
In the hot phase, hot gases are passed through the fill and the sensible heat is stored in it
Implementation Method 2
In the hot phase, hot gases are passed through the fill and the sensible heat is stored in it
Implementation Method 3
In the blowing or cold phase, cold gases are passed through the bed in the opposite direction, as a result of which the heat is transferred from the bed to the cold gas
Implementation Method 4
In the blowing or cold phase, cold gases are passed through the bed in the opposite direction, as a result of which the heat is transferred from the bed to the cold gas
Implementation Method 5
It must be taken into account that the bulk material expands when it is subjected to thermal stress, i.e. when it is heated up
Data Source
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AI summary
The invention relates to a method for operating a regenerator (1) for generating hot blast air for a steelmaking or steel treatment process, or a chemical process, wherein cold gas and hot gas is cyclically guided through a bulk material located in an annular space (4) between a hot grid (2) and a cold grid (3) surrounding the hot grid (2), and wherein a quantity of bulk material is removed from the annular space (4) in recurring cycles. The invention further relates to a regenerator. In order to achieve that on the one hand, the bulk material expanding during the hot phase does not deform and/or destroy the cold grid (3), and on the other hand, the bulk material particles do not get further eroded under alternating thermal stress, according to the invention during the phase of the cold gas application, or shortly before, or shortly thereafter, a defined quantity of bulk material determined by measuring means (20) is discharged from the bulk material through floor openings of the annular space (4).