Aluminium Smelter Anode Adjusting Mechanism With Directional Braking
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Solution Overview
Problem
The existing anode adjusting mechanisms in aluminum production, particularly the lifting screw drives, experience inefficiencies due to differing power requirements between lifting and lowering movements, leading to imprecise adjustments and increased manufacturing costs, especially under dynamic conditions where self-retention is weak.
Innovation Solution
The mechanism incorporates a brake structure with axial clearance in the worm shaft, allowing friction surfaces to engage during lowering and disengage during lifting, optimizing power requirements by utilizing friction surfaces to enhance braking in the lowering direction, thus achieving similar power demands in both directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lifting screw drive is used with self-retention feature, then the anode can be held in position without additional braking, but the stopping distance in downward direction becomes 5 to 10 times longer than in upward direction
Solution Approach 1:
The patent applies dynamics by making the brake system dynamically active only when needed. The brake is engaged during downward movement to provide strong braking force, and disengaged during upward movement to allow efficient lifting. This dynamic switching resolves the contradiction by having the system adapt its braking characteristics to the direction of movement, achieving both reliable positioning and precise adjustment.
Solution Approach 2:
The patent changes the friction parameter of the brake system based on movement direction. By using a brake that can be engaged or disengaged, the friction coefficient effectively changes from high (when engaged during downward movement) to zero (when disengaged during upward movement). This parameter change allows the system to achieve strong braking when needed while maintaining efficiency during lifting.
2Manufacturing precision
If the pitch of the screw is decreased to improve downward stopping, then the load-carrying capacity is weakened and power requirement increases
Solution Approach 1:
The patent segments the control function into two independent parts: the screw drive mechanism for lifting and the brake mechanism for downward stopping. This segmentation allows each component to be optimized for its specific function without compromising the other. The screw maintains its optimal pitch for lifting capacity while the brake provides the necessary downward stopping force, avoiding the need to decrease screw pitch.
Solution Approach 2:
The brake acts as an intermediary element that mediates the downward movement control. Instead of modifying the screw parameters to achieve downward stopping, the brake introduces an additional control mechanism that specifically addresses downward movement without affecting the screw's lifting capability or power requirements.
3Manufacturing precision
If a brake motor with electromagnetic brake is used, then precise positioning in both directions is achieved, but the system cannot operate in high temperature environments and the cost increases
Solution Approach 1:
The patent uses a simple mechanical brake system instead of a complex electromagnetic brake motor. The mechanical brake is more robust, temperature-resistant, and cost-effective. While electromagnetic brakes provide precise control, the mechanical brake suffices for the application requirements and offers better environmental adaptability to high temperature smelting conditions.
Solution Approach 2:
The brake system is designed to be self-actuating through the axial movement of the worm shaft. The axial clearance in the bearing allows the shaft to move axially during lowering, which automatically engages the brake through friction surfaces. This self-service mechanism eliminates the need for complex control systems and enhances reliability in harsh environments.
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 ensures precise and identical anode positioning in both directions, reducing the inefficiency gap and enhancing the accuracy of anode adjustments relative to the cathode, thereby improving the overall efficiency and reducing manufacturing costs.
Implementation Method 1
the axial force produced through helical toothing is made to press a friction surface of a brake structure coupled to the rotating part in the anode lowering direction, which brakes the rotating movement
Implementation Method 2
a rotating part of the adjusting device mechanism is braked when the anode is being lowered down... the axial force produced through helical toothing
Data Source
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AI summary
The invention relates to a method for operating an anode adjusting device mechanism of an aluminium smelter and to a corresponding adjusting device mechanism. In the method, an aluminium production cell being used comprises a cathode forming a base of the production tank, and an anode held at a suitable distance above the cathode by lifting and lowering the anode. According to the invention, some rotating part of the adjusting device mechanism is braked when the anode is being lowered down and the bearing (9, 10) of the rotating part, such as a toothed shaft (4), allows movement of the shaft in the axial direction such that the axial force generated by the toothing presses a friction surface of a brake structure coupled to the rotating part in the anode lowering direction, braking the rotating movement. The adjusting mechanism comprising a lifting screw (3) carrying the anode, a worm gear (2) supporting the lifting screw, and a worm shaft (4) rotating the worm gear (2) and coupled with a power device for its rotation in both directions, the adjusting device mechanism comprises a brake mechanism (13) coupled to the worm shaft (4) for braking the worm shaft when the anode is being lowered, and that the worm shaft (4) is fitted with a bearing so as to rotate as well as to move in its axial direction to a small amount, the brake mechanism (13) comprising a brake element (11) supported to the worm shaft (4), and a friction material (12) at a distance from it when the anode is being lifted and engaged to the brake element due to said axial movement when the anode is being lowered.