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Casting grinding

VIEWS: 25 PAGES: 49

									           Energy and
     Environmental Issues in
         Manufacturing
                3/3/09
Amie Ruhl
Lyndon Wong
Martin Koh
Teo Qing Ren
Yue Wei Chuan
Topics Covered
 Casting


 Machining
    Lubricants and coolants
    Dry Machining
    Other Technology


 Case Study
Casting
 Sales of $25 to $28 billion annually


 2,480 metal casting facilities located throughout the
  United States

 Employing approximately 161,000 people


 Metal forming technique for 90% of all manufactured
  goods and for all machinery for manufacturing
Casting: Energy
 Energy consumption estimated to be 200 and 250
 trillion Btu

 Representing about 1% of all U.S. manufacturing
 energy use

 55% of total energy costs can be attributed to melting
Positive Actions
 $1.25 billion invested annually in pollution prevention
  technologies and in meeting environmental standards

 Uses scrap metal (for which it pays $1 billion annually) as
  85% of its feedstock for ferrous castings

 U. S. Department of Energy (DOE), Office of Energy
  Efficiency and Renewable Energy (EERE), Industrial
  Technologies Program (ITP) Metal Casting Portfolio has
  funded research and development in cooperation with the
  metal casting industry to reduce its energy consumption
  and improve productivity
Experimental technologies
 Electron Beam Melting
 Immersion Heater (High-Temperature Melting)
 Infrared Heating
 Microwave Melting
 Plasma Heating
 Solar Furnace
Microwave Melting
 Originally developed by the DOE’s Y-12 National
 Security Complex for melting of uranium

 Conventional heating involves transferring of heat
 through the outer surface of the material to the
 interior

 Microwaves can penetrate the mass, enabling rapid
 transfer of high-intensity heat throughout the bulk
Microwave Melting
 Microwave melting could cut melting cost by 30%


 Germany and Japan are taking a strong lead in the
 microwave technology applications
Plasma Heating
 Plasmas are gaseous collections of electrically charged
  particles such as electrons and protons.

 As the ionized plasma flow hits the metal surface, it
  releases its energy melting the metal.

 The energy consumption rate is as low as 0.198 kWh/lb
  (of aluminum) compared to 0.345 kWh/lb (of
  aluminum) in induction melting.
Plasma Heating
 Minimizes metal loss due to
 oxidation and contamination

 Dross rate of melting aluminum
 is lowered to less than 1%
 compared to the conventional
  3 to 12%.
Coolant
Introduction to cutting fluids
and lubricants
Cutting fluid used in the following operations:

 Cutting

 Abrading

 Metal forming
Introduction to cutting fluids
and lubricants
Benefits of metalworking fluids(coolants):
 Better surface finish

 Longer tool life
 Narrower tolerance of the work piece size

 Cleaner cutting zone

 Better resistance to corrosion
Introduction to cutting fluids
and lubricants
Types of metalworking fluids:

 Straight metalworking oils

 Emulsifiable metalworking oils

 Synthetic metalworking fluids

 Semi-synthetic metalworking fluids
Facts about coolants
1984 figures:
 Estimated 100 million gallons of metal working oil
  used per year in U.S
 Coolant consumption is estimated higher than 100
  million gallons per year
 Cost of purchasing and disposal is about 48 billion a
  year.
Health effects
 About 1 million workers are exposed to coolant in U.S

 Chlorinated paraffin transformed to dioxin

 Mist droplets can cause cancers, breathing problems
 and respiratory illness
 Non water miscible fluids usually cause skin disorders
Health effects cont.
 In addition:
Health effects cont.
 Bacteria and fungi can grow in cutting fluids

 Responsible for most of the health problems
What is Dry Machining?
Dry Machining refers to machining
with no fluids
Motivation: total manufacturing cost
Motivation
 Disposal issues
 Permits
 Ecological compatibility
Dry Machining Today
 Currently possible for some materials and
 operations

  Nickel                    Milling
  Steel                     Turning
  Aluminium                 Drilling

          Decreasing Difficulty
  Cutting Fluids


Cool         Lubricate
Dry Machining Options


Alternative   Generate    Alternative
cooling       less heat   Lubrication
Alternate Cooling
 Chilled air or Carbon dioxide
 Liquid Nitrogen
Alternate Cooling: Cold
air gun
Alternate Cooling: Cold air gun




                            Valve
      Vortex generation
      chamber
Generate Less Heat
 Tool Geometry
  - Use of positive rake edges to reduce temperature
  - Chip grooves to break chips
 Process change
  - Higher speeds
Generate less Heat:
Positive Rake edges




  Positive rake with chip moving down
  top face of tool bit
Generate Less Heat




 Inserts with positive rake edges
- Chip groove to break chips into smaller
sizes
Alternative Lubrication
 Minimum quantity lubrication (MQL)
 Lubricious coatings
Alternative Lubrication MQL
 MQL involves lubricating the workpiece with a very
  fine mist of coolant
 The coolants used are usually synthetic esters and fatty
  alcohols
Alternative Lubrication MQL
      Characteristic of Minimum Quantity Fluids
Synthetic Esters                      Fatty Alcohols

-Chemically modified vegetable oils   -Long chained alcohols from mineral
                                      oils
-Biodegradable
                                      -Poor lubrication properties
-Good lubrication properties
                                      -Better heat removal due to evaporation
-Good corrosion resistance            latent heat

-Vaporises with residuals             -Little residuals
Alternate Lubrication MQL




       Typical MQL system
Alternate Lubrication:
Lubricious coating
  Insulate tool from heat
  Lower friction for chip removal
  Coating usually achieved via Physical Vapor
   Deposition (PVD)
  Many possible coatings
   -TiAlN, TiCN, MoS2
   -combinations
  Other Processes
Includes: forming, joining and assembly, surface
treatments, rapid prototyping and heat treating

Concerns
   Increasing energy consumption
   Greenhouse gas emissions


Must combined technical feasibility, cost effectiveness,
& ecological benefits
Clean Process Design & Process
Modification- Assembly
 Isolate processes identified as hazardous
   Eliminates direct hazards
   Auxiliary systems required
   Process Modification
Green Assembly Plants
 Run out of “easy fixes” such as scrap elimination,
  energy efficient machines and solvent elimination
 Manufactures responsible for where and how they get
  the material- supply chains
 End-of-life management
Application of solid lubricants-
Turning
 Boric Acid- feasible alternative to the conventional
  cutting fluids
 Reduces cutting forces and tool wear
 low coefficient of friction at the tool work piece
  interface with the formation of lubricating film
Feed System: Boric Acid
Government Incentives
 Renewable energy credits
 Tax incentives
 Energy Star
Case Study: Ford Motor
Company and Pollution
Prevention

                Dry Machining
                       at
  Visteon Indianapolis Steering Systems Plant
Description of the Facility
- 1.9 million square foot facility in Indianapolis, Indiana.
- Operating since 1957
- Production of steering columns, gears, and automotive
components.
 Primary production operations
      machining, heat treatment, and
      assembly of components.
Description of the Opportunity Being
Addressed

Six thread grinding machines were being used to produce
power steering carbon steel worm gears.

These grinding machines required the use of cutting oil.

Oil mist emissions generated by these machines required
an air emissions permit (potential emissions of 18 tons per
year) and the use of pollution control equipment.
Description of the Improvement
Six grinding machines were replaced with five whirl milling machines (no cutting
oil.)

The quality of the finished part was significantly improved to that produced by the
old
process. Chips are removed via a drag belt chip conveyor. Significant benefits of this
improvement include:
    · No oil mist
    · No odor emissions
    · No requirement for pollution control equipment or an air emissions permit
    · No waste oil generation
    · 75% less chip waste
    · Chip waste is recyclable
    · Cutting tips are recyclable
    · No sludges to be landfilled
    · No dermatitis risk
    · Elimination of fire protection requirements
    · Plant recognition - Governor's Award for P2
Substance Addressed Reduction Obtained
Cutting oil 100%
Oil mist emissions 100%
Odors 100%
Sludge 100%


SAVINGS REALIZED (OPERATIONAL) $650,000 / YEAR


CAPITAL / OPERATIONS INVESTMENT: $2.6 MILLION PAYBACK: 3.5 YEARS

ENVIRONMENTAL HIERARCHY LEVELS: Source reduction and waste stream
elimination.
Conclusion
-Manufacturing processes contributes to pollution and harms the environment.

-Existing processes and facilities must minimize flows and loads wherever
possible, and nontoxic substances must be substituted for toxic substances
wherever possible.

- Cleaner and more advanced processes that does less harm to the environment
are available and to be discovered.
Questions?

								
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