AGITATOR REDESIGN FOR CORROSIVE ENVIRONMENT. Kate Karauda Luigi Abbate Will Fritzinger Peter Torab

Transcription

1 AGITATOR REDESIGN FOR CORROSIVE ENVIRONMENT Kate Karauda Luigi Abbate Will Fritzinger Peter Torab

2 Project Overview Sponsored by Coating Technology Inc. Goal is to redesign the agitator system for greater corrosion resistance and longer life

3 Current Tank Layout

4 Current Cam System

5 Failed Hardware Analysis

6 Failed Hardware Analysis

7 Failed Hardware Analysis

8 Failed Hardware Analysis

9 Failed Hardware Analysis

10 Failed Hardware Analysis First impressions: Worm gear not suitable for this application Sliding friction causes excessive wear Current process puts severe load on motor/gearbox Many wear points No evidence of corrosion in failed motor Will conduct more detailed motor analysis

11 System Requirements

12 System Requirements

13 Sub Functions Morphological Chart Solutions Create flow over entire surface High pressure spray Low pressure mist Move fluid via propeller Move parts linearly Move parts radially Ultrasonic vibration 2 Create flow through capillaries High pressure spray Move fluid via propeller Move parts vertically Move parts horizontally Move parts radially Ultrasonic vibration 3 Minimize chemical bath degradation Decrease cycle time Limit contaminates above/around tank Cover tank Stabilize bath temperature and properties 4 Maintain bath temperature Use current systems, address if needed Heater 5 Maintain homogeneous mixture Keep solution agitated Circulate via pump 6 7 Reduce corrosive environment exposure of system Increase corrosion resistance of materials Move system away from tank vapors Select corrosion resistant materials Install vapor hood system Apply corrosion resistance coating to materials Corrosive vapor shielding Forced air 8 Operating instructions Prepare handbook Prepare video Maintenance table Powerpoint Graphics on system 9 Cover moving parts Shielding Reduce number of joints and pinch points Controls in safe spot 10 Limit exposure to chemicals Move system away from tank vapors Install vapor hood system Personal respiration devices (PPE) Increased ventilation Cover tank

14 Sub Function s Pugh Chart Datum Create flow over entire surface Move parts vertically High pressure spray Move fluid via propeller Move parts radially Ultrasonic vibration 2 Create flow through capillaries Move parts vertically High pressure spray Move fluid via propeller Move parts radially Ultrasonic vibration Minimize chemical bath degradation Maintain bath temperature Maintain homogeneous mixture Reduce corrosive environment exposure of system Increase corrosion resistance of materials Operating instructions Cover moving parts Limit operator exposure to chemicals N/A Current system Keep solution agitated Cover over tank N/A Recollect fluid, seal system No Change Use current Use current systems, systems, address if address if needed needed Keep solution agitated N/A Select corrosion resistant materials Keep solution agitated Move system away from tank vapors Select corrosion resistant materials No Change Use current systems, address if needed Keep solution agitated Move system away from tank vapors Select corrosion resistant materials Covered tank, less fluid used Included Heater N/A N/A Select corrosion resistant materials Word of mouth Prepare handbook Prepare handbook Prepare handbook Prepare handbook N/A N/A Protective bars over propeller Cover shaft Cover over tank Enclosed tank Cover over tank Cover over tank Enclosed tank N/A

15 DATUM Pugh Chart Spray Propeller Rotational Ultrasound Criteria Datum Criteria A - S + - A Cost B B Operating costs C C Ease of use D D Availability E S E Maintenance F F Corrosion resistance G G Fatigue H H Lifetime I I Aesthetics J + S + + J Performance K S K Safety L S L Ergonomics Score S

16 System Design 1 - Rotational Vertical Axis Rotary Motion Carousel with part mounts Corrosive resistant materials Motor and gearbox moved away from vapors

17 System Design 1 - Rotational Pros Can utilize current tank framework Limited corrosion exposure Fewer moving parts than current system Increased motor/ gearbox lifetime Cons Difficult to accommodate different size dies Need new die fixtures May be difficult to access parts More custom parts

18 System Design 2 - Ultrasound Off-the-shelf ultrasonic cleaning unit Built-in temperature control Small unit can accommodate 1-3 dies

19 System Design 2 - Ultrasound Pros Significantly decreased cycle time Built-in heater Smaller batches of fluid used No minimum number of parts to run/batch Versatile Cons High initial cost for commercially available systems Completely replace current system Repairs may be through an outside company

20 Design Areas Not Yet Complete Rotational motion vs. Ultrasonic Complete capillary force calculations Corrosion testing and process validation Off-shelf part selection Detailed component design

21 Corrosion Testing Polarization Cell Measured current is proportional to the rate of metal stripping Stripping rate will be proportional to bath decomposition rate. Variable Corrosion Testing cuments/review%20material/variable%20corrosion% 20Chart.pdf

22 Project Schedule Current Action Items: Pick a design to satisfy customer needs Defining test conditions for the prototype design Document and investigate previous failure modes Invite the customer for Systems Decomposition Review