EAF Load Feeding Control Using Ring-Plate Weight Measurement
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Solution Overview
Problem
Existing methods for controlling the continuous feeding of load material into electric arc furnaces lack precision, leading to inefficiencies such as prolonged smelting times, electrode damage, and human error due to unreliable manual operation.
Innovation Solution
An automatic system with dual-redundant weight sensors on support rollers measures the weight of the furnace shell and its contents, using strain gauges to optimize load flow based on energy supplied, preventing solid agglomerates and maintaining ideal temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct weighing of the furnace shell structure is used, then weight measurement capability is achieved, but measurement precision deteriorates because the load material constitutes only a limited percentage fraction of the total measured weight
Solution Approach 1:
The weighing system is segmented into multiple independent load cells distributed at different locations on the furnace structure. Each load cell measures a portion of the total weight, and the measurements are combined to obtain the total load material weight. This segmentation allows the system to measure small changes in load material weight more precisely by distributing the measurement function across multiple sensors.
Solution Approach 2:
The patent introduces intermediary structural elements (beams, support structures) that isolate the load material weight from the furnace shell weight. These intermediaries allow the weighing system to measure only the load material weight by separating it mechanically from the furnace structure, thus improving measurement precision by eliminating the need to measure the entire furnace shell weight.
2Measurement precision
If wheel mounted tilting furnaces with weighing systems on wheels are used, then weight measurement is enabled, but measurement precision deteriorates due to strong mechanical stress on the tilting system
Solution Approach 1:
The weighing function is extracted from the tilting mechanism by placing load cells on stationary support structures rather than on the moving tilting wheels. This separation removes the weighing system from the high-stress tilting operation, allowing precise weight measurement without the interference of mechanical stress and motion forces.
Solution Approach 2:
The patent incorporates cushioning elements and flexible connections in the weighing system to compensate for mechanical stresses and movements. These elements absorb the effects of tilting forces and thermal expansion, protecting the sensitive load cells from damage and maintaining measurement precision under varying operational conditions.
3Reliability
If manual regulation of scrap loading system speed is used, then operational flexibility is maintained, but control reliability deteriorates due to operator experience dependency and uncertain data reading
Solution Approach 1:
The system implements automatic feedback control by continuously measuring the furnace shell weight with load cells and using this data to automatically regulate the scrap loading speed. The control system compares the measured weight with the target weight and adjusts the loading rate accordingly, eliminating the need for manual operator judgment and improving control reliability through objective, real-time feedback.
Solution Approach 2:
The weighing system enables the furnace to self-regulate its loading process by automatically using weight measurement data to control the feeding rate. The system serves itself by eliminating the need for external operator intervention, continuously monitoring its own state and making autonomous adjustments to maintain optimal loading conditions.
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
Enhances productive efficiency by precisely controlling the energy-to-material ratio, reducing human errors, and preventing electrode damage, while allowing continuous and optimized feeding.
Implementation Method 1
a device to weigh the furnace shell, its contents and any other components it may support
Implementation Method 2
using strain gauges to optimize load flow based on energy supplied
Data Source
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AI summary
A system and equipment tomeasure and control the feeding of load material into an electrical arc furnace(EAF) includesan automatic control device feeding the load material;a measuring device positioned between the EAF and the tilting platform that includes an upper plate adapted to slide against the EAF, a lower plate engaged to the tilting platform, and a ring structure therebetween having a peripheral ring wall, a ring plate extending across the ring structure, and a contact member coupled to the ring plate that upperly contacts the upper plate and lowerly approaches, without contacting the lower plate; and one or more sensors measuring a deformation of the ring plate upon application of a load on the upper plate.