Environmentally Conscious Process Planning

1
Environmentally Conscious Process Planning
Prepared by Felipe Román
2
Last Week Today

• Last lectures
• Some ECDM assessment tools
• For processes process mapping I/O assessment
• For facilities regions EnviroFacts TRI
  Explorer
• Today
• Begin considering environmental concerns during
  the product development process particularly in
  the process planning stage

3
Learning Objectives

1. Know what is process planning and how it fits in
   the product development process
2. Understand how to carry out environmentally
   conscious process planning
3. Learn how to quantitatively assess manufacturing
   environmental loads

4
Focus Manufacturing Life Cycle Stage
Why manufacturing?...
5
Product Development
6
Environmentally Conscious Manufacturing Strategies

• Good housekeeping
• Training and supervision
• Waste handling
• Material substitution / elimination / addition
• In-process recycling
• Process modification
• Process Planning
• Part / product modification

Source http//www.fotosearch.com/ICL154/bim_139/
Adapted from (Sutherland and Gunter, 2001) and
(Skerlos 2005).
7
Process Planning
Process planning is the set of product
development activities that determines how a part
will be manufactured given product and production
specifications.

• Also known as
• Process engineering
• Manufacturing engineering
• Process design
• Process routing
• Resources
• Machines
• Auxiliary equipments
• Cutting tools
• Cutting fluids

8
Manufacturing Processes

• Metal Casting
• Bulk Deformation / Forming
• Sheet Metal Forming
• Material Removal
• Traditional Machining
• Precision Machining
• Deburring
• Advanced Machining
• Surface Preparation
• Cleaning
• Hardening
• Electro-plating
• Painting
• Joining and Fastening / Assembly
• Polymer Processing
• Rapid Prototyping

Source http//divisions.asme.org/med/enewsletter/
2003july/meTCreportWeb_files/image002.gif. More
information can be found at http//erc.engin.umich
.edu/.
9
Some Auxiliary Equipment (Supporting)

• Air compressors
• Coolant systems
• Water softeners
• Water Recirculation
• Material/waste handling
• Chillers
• Boilers
• Piping system

10
Some Auxiliary Equipment (Pollution Control)

• Oil/dust mist collectors
• Incinerators / oxidizers
• Wastewater treatment
• Gondolas roll offs
• Chip centrifuges / Chip wringers
• Briquetting machines

Source http//www.nationalconveyors.com/metal_chi
p_only/metal_chip_processing/chipwringers6.html
Source http//www.ars-inc.com/industrial.htm
11
Environmentally Conscious Process Planning

• For traditional machining (turning)
• Process selection
• Resource selection
• Machine selection
• Auxiliary equipment selection
• Cutting fluid selection
• Cutting tool selection
• Process parameter, operational sequence selection

12
Turning Process - Lathe
Source http//www.efunda.com/processes/machining/
turn.cfm
13
Turning Categories
14
Mass Energy Balances
Mass energy balances are your friend
Mass balance equation for an open system
CV
Energy balance equation for an open system
15
Machine-Level Assessment
Elec. f (x1,x2,x3)

• Identify process-related environmental
  Inputs/Outputs (I/Os)
• Quantify I/Os
• Electricity (kWh)
• Coolant (gals)
• Wet chips (lbs)
• Used coolant (gals)
• Oil mist (mg/m3)
• Identify mathematical relationship / function for
  I/Os

Mist f (y1,y2,y3,)
16
Some Machine-Level Models

• Electricity (kWh/yr)
• Coolant (gals/yr)
• Wet chips (lbs/yr)
• Used coolant (gals/yr)
• Oil mist (mg/m3)

17
Operational-Level Assessment
Coolant f (w1,w2,)
Energy f (z1,z2,)
18
Some Operational-Level Models

• For straight turning operations
• Cutting energy (kWh)
• Cutting force
• Machining time
• Coolant lost from machined part (gals)
• Density of cutting fluid
• Surface tension of cutting fluid
• Cross-sectional area of workpiece
• Oil mist generated from straight turning (mg/m3)

19
Different Cleaning Processes
20
Aqueous Cleaning Processes

• Direct consumption

• Closed-loop consumption

Source http//www.acme-fab.com/html_640/PROD_Mono
rail-washer.html
Source http//www.karcher.ca/CCE/HD20-20HDS20W
eb20Pages/Features/PowerNozzle20Spray20Others.j
pg
21
Aqueous Cleaning Inputs/Outputs

• Can you think of mathematical models for
  estimating these inputs/outputs for a closed-loop
  system?

22
Generic Process Map of an Aqueous System
Add chemicals and electricity to wastewater
treatment
23
Summary Main Points

• Showed how to estimate environmental loads of
  straight turning operation
• Similar approach should be applicable to other
  manufacturing processes (e.g., milling, cleaning,
  etc.)
• By estimating environmental loads impacts a
  process engineer can (quantitatively) tradeoff
  cost, quality and productivity objectives and
  make better process planning decisions

24
References

1. Sutherland, J.W. and Gunter, K.L., 2001,
   "Environmental Attributes of Manufacturing
   Processes," in Handbook of Environmentally
   Conscious Manufacturing, C.N. Madu, Kluwer
   Academic Publishers, pp. 293-316.
2. Skerlos, S.J., 2005, "Prevention of Metalworking
   Fluid Pollution Environmentally Conscious
   Manufacturing at the Machine Tool, under peer
   review for textbook," in Handbook of
   Environmentally Conscious Mechanical Design -
   Volume 2 Environmentally Conscious
   Manufacturing, John Wiley Sons.