INSTALLATION SITE PREPARATION FOR THE MYERS PILOT 15 CENTRIGUGAL MOLECULAR STILL

The Centrifugal Molecular stills were developed over 60 years ago by Eastman Kodak to separate Vitamin E from Vegetable oils. Over the years molecular distillation has proven to be one of the mildest ways of processing heat-sensitive materials.   The units have been used for removing unwanted characteristics from material (smell, color) & to increase product purity with removal of chemicals, solvents and other undesired materials.

The information provided in this packet is intended to assist the end user in the preparation of the installation site for the Pilot 15. Field service feedback has proven that failure to prepare in any one of the areas identified in the “User provided Equipment/Services” paragraph that follows results in significant delays

USER PROVIDED EQUIPMENT/MATERIALS

 The PILOT-15’s are very complete units, hence the only external requirements, in addition to power & water are: 

  • Suitable heated/cooled storage tank for the feed material.
  • Suitable tanks to collect Distillate and Residue.
  • Suitable cooling media for traps.
  • Properly prepared feed stock – minimum 5 gallons, recommended 10 gallons
  • Cooling system prepared for connection to the Pilot 15
  • Electrical Power: 3 phase ‘Wye’ 115/208 VAC, 5 wire 50/60 Hz with dedicated neutral and ground

SPECIFICATIONS

Throughput Capacity 10 – 80 lbs. /hr. (4.5 – 36.3 kg/hr.) Type Continuous

  • NOTE: Throughput is highly dependent upon process fluid and will vary
  • 80 lbs./hr. is the highest theoretical throughput not a guaranteed result for all process fluids

Pumping system ultimate pressure: 2 X 10-4 Torr

Operating Pressure 10 -3 Torr to Atmosphere

  • Operating pressures in the degasser circuit will vary greatly during operation

Mechanical Forepump >11 CFM

High Vacuum Pump 320 L/sec of air at 250C.

 

UTILITIES

Power: 10-15 KW/ hour 3 phase “wye” 115/208 V, 5 wire 50/60 HZ

  • Higher voltage systems can be utilized with the proper transformer
  • Electrical systems that do not utilize the US standard electrical power setup will need a transformer
  • Refer to the Electrical section for guidance on the electrical system requirements

Water: (20°C) 2 gal/min (7.6 L/min)

Liquid nitrogen consumption: 0.5 liters/ hour

  • LIQUID NTROGEN CONSUMPTION IS HIGHLY DEPENDENT UPON PROCESS MATERIAL PREPARATION
  • Liquid nitrogen tanks (Dewar) have a ‘natural’ bleed off of approximately 3-5% daily depending upon atmospheric conditions
  • Atmospheric conditions of the Dewar location have significant effect on the natural bleed off rate


Dimensions:

  • Height 69 Inches (1.75m), Width 34 Inches (.86m), Depth 59 Inches (1.5m)
  • Net Weight 1300 lbs.  (590kg)
  • Maintain a Four (4) foot radius around the machine for working space; ensure sufficient space is allocated for opening control cabinet door
  • Position machine at least six feet from any adjacent wall, bulkhead, or barrier to maximize 
  • mobility

EQUIPMENT IN DETAIL

The PILOT-15 will accept process material from the customer-supplied storage tank.

This material passes through stainless steel pipes through the variable speed feed pump. This pump controls the flow rate of material through the PILOT-15. From the feed pump the material passes along a length of heated pipe before entering the degasser.

Preheated material enters a rotating cup within the degasser and is spun onto the heated walls to quickly out gas the material. The media runs down and is collected on the heated base. A heating mantle surrounds the degasser walls. Degassed material passes, via a pipeline, to the distillation chamber feed pump. 

From the feed pump the material passes along a length of pipe, which is heated to reduce any heat loss, entering the distillation chamber. This temperature is adjustable by the customer. In the distillation chamber the material is introduced onto the center of the spinning rotor disk and is spread across the heated surface. The surface area increases exponentially as material travels across the rotor thus exposing more material to the surface for evaporation as it travels across. Some material will separate into a vapor phase, the distillate, depending on the operators’ combination choice of temperature and pressure. The remaining material is the residue. 

The distillate vapor is condensed on a water-cooled surface and flows down the chamber walls and out to the distillate pump. The residue passing across the full surface of the rotor is collected in a surrounding gutter and flows out of the chamber to the residue pump. On the exit of each pump is a non-return valve to isolate the distillation chamber from atmospheric pressure. 

Feed, distillate, and residue storage tanks are to be supplied by the customer, unless specified otherwise. Both the degasser and distillation chambers have independent vacuum pumping systems which are protected with individual traps.

The traps in each vacuum line are refrigerated to protect from cross-contamination with the vacuum pump fluids. Both traps have drain taps, which are used to empty the traps while the PILOT-15 is shut down and at atmosphere. Trap collection vessels or gear pumps can be added to drain the traps while the PILOT-15 is running and are supplied by the customer or as an option. The degasser vacuum pump is a direct drive rotary vane positive displacement pump with exhaust to atmosphere. The distillation chamber vacuum pumps are a diffusion-ejector pump backed by a direct drive rotary vane positive-displacement pump with exhaust to atmosphere. System pressures are monitored at the degasser, distillation chamber, and the ejector pump’s fore line.

  1. Liquid Nitrogen LN2
    1. The LN2 automatic fill system is programmed to maintain cold trap temperature at approximately – 194 C
      1. When trap temperature rises above -194 C, the respective solenoid valve will open
        1. On initial start-up, the trap will fill until establishing the correct temperature
        1. Subsequently, when the trap temperature rises above -194 C, the solenoid valve will open for 3 second bursts until correct temperatures are re-established.
      1. If the solenoid valves should require replacement during the lifetime of the machine, you must ensure that the replacement valves are 120 VAC
        1. This is required due to the OEM’s part number for this valve being identical for both the 28 VDC and 120 VAC options of the solenoid actuating coil.
    1. LN2 Dewar
      1. The Dewar must be low pressure – 22 psig
      1. The recommended size is 160-180 liter
      1. Based on field data, a 180 L Dewar has an average service life for 2 ½ to 3 8-hour shifts
      1. The Dewar, regardless of size, will lose approximately 3-5% working capacity per day due to natural, inherent losses
        1. This natural loss will vary dependent on the atmospheric conditions of the storage location of the Dewar and physical condition of the Dewar mechanical joints & insulation system
      1. Actual service life of the Dewar is site specific and dependent upon a multitude of variables
        1. Feed stock preparation has a significant impact upon the liquid nitrogen consumption.
          1. If the feed stock is not properly prepared, the volume of off-gassing in the degasser will greatly increase causing a higher work load on the degasser cold trap
          1. This higher work load on the degasser cold trap greatly increases the amount of gasses passed into the trap which requires a greater amount of liquid nitrogen to facilitate the condensation of these gasses
          1. A similar effect is resultant in the chamber trap but to a lesser extent
  • Electrical
    • Verify electrical power at the source
      • Line 1 – Ground should be 110 – 115 VAC
      • Line 1 – Neutral should be 110 – 115 VAC
      • Line 2 – Ground should be 110 – 115 VAC
      • Line 2 – Neutral should be 110 – 115 VAC
      • Line 3 – Ground should be 110 – 115 VAC
      • Line 3 – neutral  should be 110 – 115 VAC
      • Neutral – Ground should be 0 VAC
      • Line 1 – Line 2 should be 208 – 220 VAC
      • Line 2 – Line 3 should be 208 – 220VAC
      • Line 1 – Line 3 should be 208 – 220 VAC
      • If there are any variations between theses provided voltages and those read at the source, verify the power source is three phase ‘wye’ and not delta or high leg delta
    • Electrical Power configurations.
      • The Pilot 15 requires 208 VAC 3 Phase electrical power in the WYE (‘Y’) configuration
        • The following components are supplied with power from two separate main power busses:
        • Rotor Heater (SCR 4) Lines 2 & 3
        • Diffusion Pump (R1) Lines 1& 2
        • Distillate Pump (MSC 4) Lines 1 & 3
        • Residue Pump (MSC 3) Lines 1 & 2
        • Rotor Feed Pump (MSC 2) Lines 1 & 3
        • Degasser Feed Pump (MSC 1) Lines 1&2
    • Operating on Three Phase Delta/High-Leg Delta can result in motor damage to the pumps and their associated motor controller cards as well as thermal breakdown of the heating elements on the rotor heater.
    • Additionally, operating without the dedicated neutral leg can result in the introduction of positive AC current into the neutral leg of the connected electronic components resulting in the failure of the electronics and their associated components.
 
  • Cooling Water
    • On the side of the Pilot 15 opposite the control screen, the bottom left frame has five connection ports stacked horizontally.
    • The top two ports are inlet ports are 1/4“ FNPT for air and water connection
    • Air is used to purge water from and dry the quench and condenser plate cooling coils for long term storage
      • This connection is not required for most installations
      • When utilized, the maximum air pressure is 1.5psig
    • The remaining three ports are 1/8”  FNPT for return water removal from the diffusion pump main cooling, diffusion pump quench , and condenser plate cooling coils
    • In order, the ports service: diffusion pump cooling, quench, condenser plate
    • If the external cooling system configuration requires the three return connections to be combined into a single return line (typical chiller configuration), check valves must be installed on all three cooling return lines.
      • Style and placement are solely a choice of preference by the end user.
      • Regardless of the style or design of the check valve chosen, the lift pressure should not exceed 1-2 psig
    • On the middle horizontal frame brace on the side opposite of the control screen, there are three valves
      • Diffusion pump cooling: one way valve, controls cooling water to the diffusion pump cooling coil (upper coil)
      • Diffusion pump quench coil: two way valve, controls air/water to the diffusion pump oil sump quench coil (lower coil)
        • Used only when there is an abnormal shutdown preventing the normal cooldown period for the diffusion pump
      • Condenser plate cooling: two-way valve, controls air/water to the distillation chamber condensing plate.
  1. Condenser Plate configuration
  2. The condenser cooling plate must be oriented with the water connections at the 12:00 & 6:00 positions for proper water flow.
  3. The blue hose is the inlet and connects to the 6:00 position
  4. The yellow hose is the return and connects to the 12:00 position
The condenser chamber is baffled, placement of the cooling water inlet (blue hose) is critical for proper cooling effect
  • Return Lines
  1. Chiller
  2. If using a chiller unit, the chiller must be capable of handling a constant 12 KW heat load
  3. The data collected uses the specific heat of water. The major source of heat load for the chiller will be the condenser. Our test was conducted on a dry system during conditioning runs. The amount of heat absorbed by the cooling water will be significantly greater on an operating Pilot 15.
  4. Through combined experience of Company personnel, the determination that a 12 KW chiller should be sufficient to cover the wide range of industrial applications that utilize the Pilot 15
  5. Water inlet connection is a 1/4” Female NPT fitting
  6. Water outlet/return connections are 1/8” Female NPT fittings
  7. There is an installed ¼” Female NPT fitting for low pressure air (regulated to no greater than 1.5psig) – however, this connection is rarely required for use
  8. This connection is used purge the system of all cooling medium by using low pressure air
  9. This connection is not required for the majority of products processed through the Pilot 15.
  10. Connection of the low-pressure air purge is only required if you are using a cooling medium that is highly corrosive or is not compatible with the materials used in the cooling system (stainless steel, nylon tubing, copper tubing)
  11. If you wish to tie any of the cooling return lines together:
  12. When using a closed loop cooling system such as a chiller or a tap water cooling system that taps into drain piping, it is often a necessity to interconnect, or tie-together, the individual drain connections from the Pilot 15 cooling systems
  13. When this is done, the use of inline check valves is required to prevent interruption of cooling water flow
  14. Failure to install check valves will result in a ‘no-flow’ condition existing in the affected components.
  15. The diffusion pump cannot maintain proper vacuum levels without cooling and the associated mechanical pump is not expected to be capable of maintaining operating pressures when the unit is running in production mode
  16. The immediate concern is that continued operation of the diffusion pump, even for short periods of time, will result in rapid pressure increases in the foreline circuit.
  17. Feed
    • The ideal feed setup for the degasser feed pump is gravity feed from a heated container with an installed stirrer.
      • The outlet connection for this container should be at least 6 inches above the feed pump inlet connection
      • Container and associated piping should be heated to allow for proper flow of the feed material
    • Alternate methods use bottom suction piping/hoses to a heated container at or around floor level
      • This setup requires pump priming on initial startup and may be required periodically during the lifespan of the system
      • The most efficient method for priming the pump is the installation of a priming leg on the feed suction line to the pump – example provided in the feed section of this guide
      • Container and piping should be heated, container should be continually stirred
    • Proper preparation of the feed stock has proven to result in a higher quality of distillate
      • Extraction method has no distinct relevancy on the preparation of the feed stock
      • After the feed stock has been extracted it should be winterized
        • Mix extract with ethanol or suitable solvent in a ratio of five parts solvent to one part feed stock
        • Freeze in a sub-zero environment for 24 hours
          • To expedite the filtration process, also freeze the intended receiving container, funnel, and filter papers
        • After the 24 hours of freezing, remove the winterized extract and filter out the ethanol/process fluid mixture.
          • The fats/lipids will collect in the filter
          • Filtration is often conducted in a multi-step process of increasing filtration levels
          • Final filtration should be less than 10 microns
          • Remove the solvent by heating the mixture until it is boiled off
      • If the feed stock is not winterized properly, the distillate quality will be adversely affected in that it will not have the crisp clarity that is desirable
        • The distillate can be winterized after final collection using the same procedure as that of the feed stock (steps 1-3 in this paragraph.)

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