Liquid Ring Pump

• Accommodating to water & solvents
• Very Forgiving

Rotary Vane, Oil-Sealed Mechanical Pump

Rotary Vane Pump

•  Compact
• Sensitive to solvents

Dry Vacuum Pumps

One Stage Roots Blower Pump Assembly

Roots Blower Pump

• Dry Running
• High operating speeds

High Vacuum Pumps: Oil Diffusion Pumps

Pump Construction

How Diffusion Pumps Work

Condensers to Enhance Vacuum

pV = nRT è

• volume is reduces in transitioning from vapor phase to liquid phase, or vapor pressure decreases with temperature

Viscous and Molecular Flow

Viscous Flow: 

Distance between molecules is small; collisions between molecules dominate; flow through momentum transfer; generally P greater than 0.1 mbar

Transition Flow: 

Region between viscous and molecular flow

Molecular Flow: 

Distance between molecules is large; collisions between molecules and wall dominate; flow through random motion; generally P smaller than 10 mbar

Vacuum Pressure Ranges

Vacuum System Configuration

Vacuum pumps

• Liquid ring pump
• Rotary vane pump
• Roots vacuum pump
• ScrewLine pump
• Oil diffusion pump
• Pump sets

Pressure measurement

• Diaphragm vacuum gauge
• Pirani vacuum gauge

Vacuum Pumping Methods

Pressure of 1 Standard Atmosphere: 760 TORR, 1013 mbar or, at Sea Level, 0° C and 45° Latitude

Pressure Equivalents

Atmospheric Pressure (Standard) =

Vapor Pressure of Water at Various Temperatures

Pressure Ranges

General Equipment Considerations

Major Components

• 1 Feed
• 2 Product distribution plate
• 3 Heating fluid
• 4 Vacuum nozzle
• 5 Distillate
• 6 Cooling
• 7 Residue
• 8 Heating jacket
• 9 Roller wiper system
• 10 Internal condenser

Horizontal Section Through A Short Path Distiller

Tasks of the Wiper System

• Uniform distribution of the product onto the evaporator surface
• Permanent mixing of the product film
• Improvement of heat transfer from the heated wall into the product film
• Exclusion of “Hot Spots“
• Reduction of residence time

Characteristics of the UIC’s Roller Wiper System on all KDL and KDT Models

• Open wiper basket design
  minimizes pressure drop between evaporation and condensation
• Good mixing of the product film
  improves the evaporation of volatiles
• Overlapping of wiper rollers
  avoids unwiped spots and formation of “Hot Spots“
• Self-cleaning wiper elements
  minimizes maintenance
• Short residence time
  reduces temperature history of product

• 
• Evaporation occurs on the wall of a cylindrical evaporator as the feed product falls down the cylinder wall and is heated above its boiling point by heat applied to the exterior of the cylinder.
• Excludes the disadvantages of batch-distillation:
  • Lower pressure in the evaporator is possible
  • Reduces the residence time at high temperature, even in large units.

Result: Thermal decomposition is being avoided

Types of Thin Film Evaporators

• Single Tube Falling Film Evaporator w/external condenser
• Multiple Tube Falling Film Evaporator w/external condenser
• Falling Film Degasser (packing) w/external condenser
• Wiped Film Evaporator w/external condenser
• Short Path Evaporator w/internal condenser

Thin Film (Wiped Film) Evaporators

• Residence time:
  less than 1 minute
• Pressure range:
  down to 1 mbar
• Not an equilibrium device
• ~ 1 theoretical plate
• Condenser is external to Evaporator
• 30oC rule —

   pressure f( temperature)

Falling Film Evaporators

Residence time: several minutes

often with recycling

Pressure range: down to several mbar Not an equilibrium device

~ 1 theoretical stage

Short Path Evaporators
(a subset of Wiped Film Evaporator)

• Residence time:
  less than 1 minute
• Pressure range:
  down to 0.001 mbar
• Not an equilibrium device
• ~1 theoretical plate
• Condenser is inside the Evaporator
• 30oC rule

Wiped Film   vs. Short Path

• Thin Film Evaporator
  – External condensation
  –  Lowest operation   pressure: ~ 1 mbar
  –  Main application:
  Separation of high   contents of volatiles

• Short Path Distillator
  – Internal condensation
  –  Lowest operation   pressure: 0.001 mbar
  –  Main application:
  Distillation of heat   sensitive products

High Vacuum Short Path Distillation offers a number of benefits for processing superior cannabis concentrates.

• Boiling Points of materials are significantly reduced under vacuum (30oC rule)
• The partial pressure curves of different materials may indicate the application of vacuum will facilitate the separation process and purity of the distillate.
• Vacuum usually accelerates the evaporation rate to accomplish separation of materials more quickly.