Airless Cleaning Systems

1

• Airless Cleaning Systems
• Solvent vs. Aqueous Cleaning

2
Like Dissolves Like

• Water is a polar solvent that dissolves ionic,
  inorganic soils like salts.
• Solvents are non-polar, and dissolve organic
  soils like oil, grease and wax.
• A cleaning process is selected based on the
  nature of the soils being removed, as well as the
  construction material and geometry of the parts
  being cleaned.
• Aqueous processes can be used to remove water
  insoluble soils, but there are tradeoffs in the
  process.

3
Aqueous Chemistry Selection

• Vast array of cleaning agents to choose from
  selection can be difficult.
• Metals compatibility must be carefully
  considered.
• Often require additives such as defoamers.
• Corrosion inhibitors must be used in the rinse
  stage when ferrous metals are being cleaned.
• Typically, aqueous corrosion inhibitors leave a
  mottled surface appearance.
• Many aqueous cleaning agents contain VOCs.

4
Solvent Chemistry Selection

• Many effective and safe solvents to choose from.
• TSC Airless systems are compatible with virtually
  all distillable organic solvents.
• Users of TSC Airless systems are not locked in
  to a particular solvent.
• Multi-metal compatible.
• Compatibility of plastics, elastomers, etc must
  be considered.
• Many processes do not require a corrosion
  inhibitor.

5
TSC Airless Compatible Solvents

• HFCs (DuPont Vertrel)
• HFEs (3M Novec Fluids)
• n-propyl bromide
• HCFCs (AK-225)
• Chlorinated solvents (trichloroethylene,
  perchloroethylene, methylene chloride)
• Azeotropes blends
• Hydrocarbons
• Isopropyl alcohol
• Combustible flammable solvents

6
Surface Tension Viscosity

• Water has a higher surface tension viscosity
  than solvents, meaning it has difficulty
  penetrating tight spaces.
• Solvents have low surface tension viscosity,
  and can easily penetrate tight spaces.
• Solvents provide more thorough cleaning of
  complex geometric surfaces.
• Solvents are effective at displacing particulate.

7
Energy Costs

• Water requires more energy to heat due to its
  high specific heat capacity.
• Water also requires more energy to dry.
• Solvents have low specific heat capacities, thus
  solvent processes are more economical.
• The TSC Airless System operates under vacuum, and
  the boiling point of the cleaning solvent is
  depressed, requiring less energy to operate than
  conventional solvent systems, and much less than
  aqueous systems.

8
Water Treatment Issues

• Tap water contains dissolved inorganic minerals
  that remain behind after drying as water spots.
• Dissolved minerals must be removed from water in
  precision cleaning requirements where surfaces
  must be residue free .
• Dissolved inorganics in water cause precipitation
  of scale on surfaces of tanks, nozzles, and
  heaters. Scaling can affect process performance,
  or system operation, and requires maintenance to
  remove.
• Deionized water is a costly utility that must be
  monitored and maintained for correct process
  operation.
• Solvent is totally organic, and none of the above
  apply.

9
Aqueous Process Costs

• The energy required to heat water is wasted in
  the aqueous cleaning process.
• Heat energy leaves the aqueous process via
  exhaust, effluent, and in the energy extracted by
  the parts being cleaned.
• Many aqueous processes require a continuous flow
  of fresh water to displace contamination entering
  the rinse stage from the wash stage. The
  displaced water must go to drain or some type of
  treatment system. Unless the heat energy of this
  water is recovered somehow, the energy is wasted.

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Process Cost Comparison
11
Solvent Process Costs

• Solvent use is at a minimum, so ongoing solvent
  costs are practically eliminated.
• Solvent cleaners require a fraction of the power
  required to operate aqueous processes.
• Total heat recovery (closed loop system).
• No costly water treatment required.
• Minimal exhaust required compared to aqueous.
• No drain required when using closed loop cooling
  system.
• Very low maintenance requirements.
• Minimal downtime.

12
Aqueous Process Control

• Aqueous processes are highly dynamic.
• The aqueous cleaning agent is reacting with the
  soils, the part surfaces, the air, etc, and its
  effectiveness varies.
• The aqueous cleaning agent and water may be
  evaporating at different rates, and a proper
  ratio must be maintained.
• More intensive process monitoring required.
• Corrosion inhibitors in rinse may be necessary.
• Defoamers or other additives may be required.

13
Solvent Process Control

• Solvent cleaning is very stable, repeatable,
  predictable and controllable.
• Less process variables than an aqueous process.
• TSC Airless cleaners have a plentiful supply of
  freshly distilled solvent, so cleaning is always
  done with high purity solvent.
• Virtually no solvent losses in process.
• Only requires monitoring of acid acceptance
  criteria for the solvent, and purity.

14
Dealing With Contaminants Aqueous

• Removal of soils from a cleaning system is
  critical to a proper process.
• Residual soils can redeposit on parts.
• Removal of soluble contaminants difficult.
• Floating oils may be skimmed, but total removal
  is usually not possible.

15
Dealing With Contaminants Solvent

• Removal of soils from a cleaning system is
  critical to a proper process.
• Low potential for soil redeposition.
• Easy and automatic removal of soluble
  contaminants, specifically oils, greases and
  waxes.

16
Aqueous Maintenance

• On average, requires several hours each week.
• Constant monitoring and adjustment of cleaning
  agent, additives, and corrosion inhibitors.
• Tanks must be drained flushed periodically.
• Descaling of all internal system surfaces.
• Nozzles, airknives, etc must be inspected and
  descaled.
• Filter media must be changed.

Mineral Scale In Tubing
17
Solvent Maintenance

• Takes only minutes weekly
• Acid acceptance testing of solvent.
• Contaminants that have been automatically
  concentrated in vapor supply tank must be
  drained.
• Filter media must be changed.

18
Aqueous Environmental Impact

• Water soluble soils are easily released into the
  environment via exhaust or effluent.
• Requires a high volume of water.
• Demands more electricity than a solvent process.
• Water effluent is analyzed for COD, BOD,
  suspended dissolved solids, temperature, oil
  grease, heavy metals, etc. All of which can be
  generated in an aqueous cleaning process.

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Solvent Environmental Impact

• Soils are concentrated automatically from the
  distillation vessel in the TSC Airless System.
• Requires no process water for cleaning. Systems
  need chilled water to operate for cooling
  condensation only, but closed loop chillers or
  refrigeration units are available.
• Requires a fraction of the electricity used in an
  aqueous process.

20
Water Disposal

• Water disposal can be costly.
• Process water effluent must be in compliance to
  local regulations.
• Aqueous cleaning agents and entrained soils in
  effluent stream may be unacceptable to go to
  sewer.
• Certain aqueous cleaning agents may contain VOCs,
  and exhausting to an external airspace may not be
  suitable.
• On site evaporation of water is an added utility
  and maintenance cost.
• Wastewater haulers charge a premium for aqueous
  waste streams due to the low fuel value as
  compared to organic waste streams.

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Solvent Disposal

• The TSC Airless Cleaner can recover up to 97 of
  solvent in its wastestream.
• Still bottoms are disposed of responsibly and
  thoroughly via fuel blending.
• Waste oils and organics have a higher fuel value
  than aqueous wastes and are typically disposed of
  at a lower cost.
• The TSC Airless Cleaner features an automatic
  contamination concentration disposal system.

22
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1-866-298-0098 Fax [phone] sales_at_tiyoda-serec
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