Macro 36 Centrifugal Distillation Still

Myers-Vacuum Macro 36 Still

The Myers Macro-36 Centrifugal Molecular Still is intended for production of high-vacuum distillation of heat sensitive organic compounds.

With over fifty years of experience in the design and manufacturing of Centrifugal Molecular Stills, Myers can offer unique qualifications for supplying the system to our customers’ requirements.

Major advantages to be expected from the MYERS Macro-36 molecular still are:

  • High product percentage yields
  • Elimination of color bodies.
  • Elimination of odor fractions.
  • Reduction of acid values in ester distillation.
  • Removal of excess reactants.
  • Elimination of residual metal catalysts.
  • Minimized thermal hazards (a necessity for heat sensitive compounds).

For more detail listing of products and table showing distillation temperature of  some common products in vacuum,  go to still-applications/

Basic Description

The MYERS Macro-36 Centrifugal Molecular Still is designed for throughputs from 100-400 pounds per hour depending upon feed material characteristics.

The material is pumped into the center of the heated rotating disk housed in a vacuum chamber. The feed material is spread by centrifugal force in a thin film across the face of the rotor. Film thickness is in the order of 0.010-.100 inches (.25 -2.54 mm), depending on viscosity, feed rate, etc.

The surface area increases exponentially as the material travels to outer circumference decreasing film thickness and exposing more molecules to surface for evaporation.

By close temperature control of heaters, the lighter, lower molecular weight, fraction of the feed material evaporates and condenses on the internal water-cooled condenser.

The heavier unevaporated residue slides off the rotor into a collecting gutter; both fractions flow by gravity to discharge pumps and are transferred out of the still. The lower pressure developed by the vacuum pumps, reduces the boiling point of the material. This lowered pressure combined with the exponentially increasing surface area distills material at the most efficient rate per area of distilling surface, requiring less surface area per volume of production than other technologies and reducing the chance of thermal decomposition.


Performance Specifications

The MYERS Macro-36 Centrifugal Molecular Still is sized to accept up to 400 pounds per hour (dependent upon feed material characteristics) of degassed feed material on to the center of a 36-inch diameter heated spinning rotor within a concentric dished vacuum chamber. At a rotor speed of 350 R.P.M., the distilland mixture becomes a thin film by centrifugal force. The resultant film, whose thickness and speed are controlled by feed rate, radiates to the edge of the rotor.

Three separate electrically controlled heaters behind the rotor evaporate the lower boiling fraction of the material. The distillate condenses on the water-cooled dished head condenser. The un-evaporated liquid residue slides off the rotor into a concentric collecting gutter. Both distillate and residue gravitate through connecting pipelines to vacuum- sealed positive liquid gear pumps and discharge from the still to atmosphere. Vacuum equipment maintains operating pressures of 1-20 X 10-3 Torr in the still at maximum feed rates. The ultimate pressure of the Macro-36 molecular still is to be 1 X 10-4 Torr, clean, dry, and empty.

Still Assembly

Myers-Vacuum Macro 36 StillThe still chamber is comprised of a 300 series stainless steel base plate set at a 45° angle on a welded steel frame and a top- hinged stainless steel water-cooled dome. The base plate has a pumping port with a rear flange that mates to the vacuum pump though a multi-coolant trap which provides for entrapment separation and protection of pumping system. Centered on the base plate is the conical 36-inch diameter stainless steel rotor driven though a water-cooled vacuum feed-through.

A stainless steel water-cooled dome condenser is vacuum flanged to the base plate. Two sight glass viewing ports are provided in the condenser dome.

The feed material is pumped from the de-gasser to the center of the heated spinning rotor. Distillate condenses on condenser dome and passes to the distillate liquid gear pump. The unevaporated residue slides into a stainless steel gutter along the edge of the rotor and proceeds to the residue liquid gear pump.

Liquid transfer lines are fitted with check valves that allow continuous feed/discharge to and from still from/to atmosphere.

Direct-drive liquid-transfer pumps with variable speed motors for the rotor feed, distillate, residue and drip.

Glass flow meters are installed in residue, distillate, and drip lines to observe flow and set gear pump speed.

Water valve panel complete with valves and flow meters provide for cooling water flow control of components.

Control Console

HMI (human machine interface) touch screen controls all of the functions of the system. In operation you simply select or touch the screen in the location of the device. Once selected a pop up menu guides the user to control each device. The indicators change from red “OFF” to indicate that the devices output is turned off and green “ON” when the devices output is on.


The Macro 36 Control Center controls and displays the following:

  •  Maximum temperature that product is heated to
  • Pressure of the degasser
  • Pressure of the distillation zone
  • On/off of Vacuum pumps
  • Pressure of the High Vacuum pump foreline.
  • Control of both chamber and Degasser Vacuum Trap cooling
  • On/off of all Liquid transfer pumps
  • Adjustment and display of the speed of each of the Liquid transfer pumps
  • On/off of rotor and degasser rotation
  • Closed loop control of all heaters.
  • Actual and set point temperature of the degasser heater jacket.
  • Actual and set point temperature of the material in transfer lines (Degasser feed, rotor feed, residue, distillate and drip.
  • Actual and set point temperature of the rotor heater.

The operator controls the process by setting the feedstock rate (How thick the material will be on the rotor) and the rotor heater temperature.

Myers-Vacuum macro 36 StillVacuum Pumping System

The Vacuum Pumping System of the Macro-36 Centrifugal Molecular is a combination oil booster and mechanical pump. The High vacuum pump is the Myers KSM-2000 rated at 2500 liters/Minute in the 10-3 Torr pressure range. The Pumping System is supplied with necessary gaskets at vacuum connections to the Macro-36 still.


Space and Utility Requirements: Click here for space and utility requirements.

Myers staff of skilled Engineers are available to provide installation, maintenance and training of operators and support personnel.


macro36-4Additional condensing area – extra traps can be added to vacuum line in series with main traps in chamber or degasser

Direct-drive variable speed liquid transfer pumps to empty vacuum traps (chamber feed and trap drain) with valuable speed motors adjustable via control screen.

Degasser spray/falling film – 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 bottom. A heater surrounds the degasser walls. Degassed material passes, via a pipeline, to the distillation chamber feed pump.

  • chamber with heater bands and removable thermal covers
  • Trap which provides for entrapment and protection of pumping system.
  • Mechanical Roughing pump
  • Vacuum gauge
  • Liquid transfer pump
  • Line Heater

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