Pin Mill with Segmented Rotor and Dynamic Door
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing milling machines are inefficient in disintegrating biological materials into fine powders or slurries, often causing undesirable heating, non-uniform particle sizes, and difficulty in cleaning, which can lead to contamination and impaired sterilization.
Innovation Solution
A pin mill design featuring concentrically spaced circular arrays of pins on a rotor and stator with vane knives that interdigitate to break down materials, incorporating a cylindrical screen for uniform particle size and minimal noise, and aerodynamic features to prevent heating and facilitate cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional milling machines are used to disintegrate biological materials, then material processing is achieved, but undesirable heating occurs and particle size uniformity is poor
Solution Approach 1:
The milling chamber is segmented into multiple zones with different pin configurations. The rotor contains multiple pin arrays rotating at different speeds, creating varied shear forces throughout the material processing path. This segmentation allows progressive size reduction while maintaining uniform particle distribution and preventing localized overheating.
Solution Approach 2:
The invention employs dynamic pin configurations where pins are arranged in multiple concentric arrays that rotate at different velocities. The outer pins rotate faster than inner pins, creating dynamic shear zones that adapt to material flow patterns. This dynamic configuration ensures uniform particle size distribution while distributing heat generation across multiple zones rather than concentrating it in a single area.
2Productivity
If traditional milling machines process materials, then disintegration is achieved, but cleaning and sterilization are difficult
Solution Approach 1:
The pin arrays are designed as removable components that can be extracted from the rotor assembly. Each pin array can be independently removed through access ports in the housing, allowing thorough cleaning of all surfaces including previously inaccessible areas. This extraction capability maintains high disintegration efficiency while enabling complete cleaning and sterilization of all component surfaces.
Solution Approach 2:
The milling mechanism is divided into multiple independent pin arrays that can be separately accessed and cleaned. The rotor assembly is segmented into modular sections with access ports that allow cleaning tools to reach all surfaces. This segmentation enables maintaining productivity through quick reassembly while facilitating complete cleaning and sterilization of each component.
3Strength
If door hinges are fixed to the housing, then structural stability is maintained, but pin collision occurs when the door opens
Solution Approach 1:
The hinge system is made dynamic through the addition of translator pins that allow the door to move in multiple stages. When the door opens, the translator pins first translate the door laterally to clear the pin arrays, then the hinge allows rotational opening. This dynamic motion path eliminates pin collision while maintaining structural stability through the robust hinge and translator pin construction.
4Productivity
If the mill processes materials quickly, then productivity is improved, but noise and vibration increase
Solution Approach 1:
The material processing is divided into multiple sequential stages across different pin arrays rather than single-stage aggressive milling. Each pin array performs a portion of the size reduction task at optimized speeds, distributing the mechanical energy input across multiple zones. This segmentation achieves high overall productivity while reducing peak noise and vibration levels compared to single-stage high-speed milling.
Solution Approach 2:
The differential rotation speeds of the pin arrays create dynamic balance in the system. The outer pins rotating faster than inner pins generate complementary vibration patterns that partially cancel each other out. This dynamic configuration maintains high processing speed while reducing overall noise and vibration compared to uniform high-speed rotation of all pins.
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 pin mill effectively disintegrates materials into uniform fine particles with minimal noise and heat generation, ensuring easy cleaning and sterilization, thus preventing contamination and improving processing efficiency.
Implementation Method 1
The vane knives also include aerodynamic features which entrain cooling air into the macerating volume of the mill
Implementation Method 2
The materials are rapidly macerated and broken into finer sized particles between rotating and stationary sets of pins within the disintegrating volume
Data Source
AI summary
A pin mill includes a rotor plate mounted on a shaft and having concentrically spaced-apart circular arrays of pins arise from an end face. The rotor pins interdigitate with complementary concentric arrays of pins arising from a face of a stator mounted on a door. The door swings open on a hinge mounted on two translator pins so that the door can translate the interdigitated pins before swinging open so that the pins arrays do not collide with each other while the door is opening. The rotor operates within a rotatable cylindrical screen which retains particles being broken up until they are small enough to exit. The rotor includes a circular array of vane knives which sweep closely within the screen and also entrain cooling air into the macerating volume of the mill. Oversized particles trapped in the screen also get cleared and split apart by the passing vane knives.