AGITATOR REDESIGN FOR CORROSIVE ENVIRONMENTKate Karauda Luigi Abbate Will Fritzinger Peter Torab

Project Overview Sponsored by

Coating Technology Inc.

Goal is to redesign the agitator system for greater corrosion resistance and longer life

Current Tank Layout

Current Cam System

Failed Hardware Analysis

Failed Hardware Analysis

Failed Hardware Analysis

Failed Hardware Analysis

Failed Hardware Analysis

Failed Hardware Analysis First impressions:

Worm gear not suitable for this application

Current process puts severe load on motor/gearbox

Many wear points

Failed motor did not appear to be affected by corrosion Will conduct more detailed motor analysis

System Requirements

System Requirements

Solutions1 2 3 4 5 6

Sub Function

s1 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 tankStabilize 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

6Reduce corrosive

environment exposure of system

Move system away from tank vapors

Install vapor hood system

Corrosive vapor shielding Forced air

7 Increase corrosion resistance of materials

Select corrosion resistant materials

Apply corrosion resistance coating to

materials

8 Operating instructions Prepare handbook Prepare video Maintenance table Powerpoint Graphics on system

9 Cover moving parts ShieldingReduce 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

Morphological Chart

Datum 1 2 3 4

Sub Functions 1 Create flow over

entire surfaceMove 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

3 Minimize chemical bath degradation N/A Recollect fluid, seal

system No Change No Change Covered tank, less fluid used

4 Maintain bath temperature Current system

Use current systems, address if

neededUse current systems,

address if neededUse current systems,

address if needed Included Heater

5Maintain

homogeneous mixture

Keep solution agitated

Keep solution agitated

Keep solution agitated

Keep solution agitated N/A

6Reduce corrosive

environment exposure of

systemCover over tank N/A Move system away

from tank vaporsMove system away from tank vapors N/A

7Increase corrosion

resistance of materials

N/A Select corrosion resistant materials

Select corrosion resistant materials

Select corrosion resistant materials

Select corrosion resistant materials

8 Operating instructions Word of mouth Prepare handbook Prepare handbook Prepare handbook Prepare handbook

9 Cover moving parts N/A N/A Protective bars over

propeller Cover shaft N/A

10Limit operator

exposure to chemicals

Cover over tank Enclosed tank Cover over tank Cover over tank Enclosed tank

Pugh Chart

Spray Propeller Rotational Ultrasound

Criteria Datum 1 2 3 4 Criteria

A

DATUM

- 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

+ 6 10 11 11

Score - 3 0 1 1

S 3 2 0 0

Pugh Chart

System Design 1 - Rotational

Vertical Axis Rotary Motion

‘Carousel’ with part mounts

Corrosive resistant materials

Motor and gearbox moved away from vapors

System Design 1 - Rotational

Can utilize current tank framework

Limited corrosion exposure

Fewer moving parts than current system

Increased motor/ gearbox lifetime

Difficult to accommodate different size dies

Need new die fixtures

May be difficult to access parts

More custom parts

Pros Cons

System Design 2 - Ultrasound Off-the-shelf

ultrasonic cleaning unit

Built-in temperature control

Small unit can accommodate 1-3 dies

System Design 2 - Ultrasound

Significantly decreased cycle time

Built-in heater Smaller batches of

fluid used No minimum number

of parts to run/batch Versatile

High initial cost for commercially available systems

Completely replace current system

Repairs may be through an outside company

Pros Cons

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

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

https://edge.rit.edu/edge/P13656/public/WorkingDocuments/Review%20material/Variable%20corrosion%20Chart.pdf

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