Mill Liner Bore Sealing Assembly for Slurry Ingress Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mill bolt sealing systems fail to effectively prevent slurry ingress into the mill drum, leading to erosion and damage, while also disrupting torque measurements and maintenance schedules due to gasket failure and washer deformation.
Innovation Solution
A mill liner bore sealing system featuring a mill bolt with a retaining washer and a sealing washer, where axial movement of the retaining washer compresses the sealing washer radially, ensuring a secure seal by deforming the sealing washer to fit tightly around the bolt and mill drum, preventing slurry leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gasket is placed between the bolt head and mill liner to prevent slurry ingress, then sealing effectiveness is improved, but the gasket fails after prolonged exposure to heat and vibration allowing slurry to seep into the bolt hole
Solution Approach 1:
The patent employs a sacrificial seal ring made of soft, deformable material that is intentionally designed to be replaced frequently. This disposable sealing element deforms under bolt tension to create a seal, and when it wears out or fails, it is simply replaced rather than repaired, mirroring the mill liner replacement strategy and avoiding the high cost of drum repair
Solution Approach 2:
The patent changes the physical state and properties of the sealing material by using a soft, deformable substance that transitions from an undeformed state to a compressed state when the bolt is tightened. This deformation allows the seal ring to conform to the bolt hole geometry and create an effective barrier against slurry ingress, with the material properties specifically selected to withstand the thermal and vibrational environment
2Reliability
If operators continually tighten the nut on the bolt to improve the seal, then sealing may be improved, but the washer deforms or dishes causing torque measurement skew
Solution Approach 1:
The patent replaces the reusable, torque-critical washer with a disposable seal ring that is not intended to maintain precise torque relationships. The seal ring absorbs the effects of tightening and deformation through its soft, compliant material, allowing operators to achieve sealing without concern for precise torque measurements or washer deformation
Solution Approach 2:
The patent changes the mechanical properties of the sealing element by using a soft, compliant material that can deform under load without causing measurement errors. This deformable seal ring accommodates the tightening process and operational vibrations without the rigid washer geometry that would otherwise deform and skew torque readings
3Reliability
If mill drum is repaired or replaced when damaged, then mill integrity is restored, but repair time and operational downtime increase significantly
Solution Approach 1:
The patent segments the sealing function from the mill drum structure itself by introducing a separate, replaceable seal ring component. This allows the sealing system to be maintained independently of the drum, enabling quick replacement of the seal ring without time-consuming drum repair operations
Solution Approach 2:
The patent employs a sacrificial seal ring that is replaced frequently and inexpensively compared to mill drum repair. This disposable sealing element prevents slurry ingress that would otherwise damage the drum, allowing the expensive, time-consuming drum to be protected and avoided from repair or replacement
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 system provides a durable and reliable seal that maintains mill integrity, prevents slurry leakage, and allows for accurate torque measurement, reducing downtime and maintenance costs by ensuring consistent bolt security.
Implementation Method 1
Axial movement of the retaining washer against the sealing washer imparts radial compression of the sealing washer
Implementation Method 2
Axial movement of the retaining washer against the sealing washer further imparts axial deformation of the sealing washer
Data Source
AI summary
A mill liner bore sealing system includes a mill liner bolt having a shank and an oblong head, a nut configured to threadably engage with the bolt, a retaining washer including a tapered inner wall, and a sealing washer including a tapered outer surface. The retaining washer is configured to slide over the mill liner bolt, and the sealing washer is configured to nest under the retaining washer with the outer surface of the sealing washer in oblique confrontation with the inner wall of the retaining washer.