For the solvent extraction of 
leafs, roots, herbs, barks, fruits, seeds, drugs, spices, teas etc.

For the distillation and extraction of essential or volatile oils.

For solvent recovery from extraction residuals.

INTRODUCING the TECHNOLOGY

The charging of the extractors takes place in batches and depends of the number of extractors the process takes place in single or multiple-stage, in current or counter current flow of solvent.

PRUESS extraction plants and percolators are developed for highest functionality and are optimised for most effective extraction application.

  • easy product change,
  • small or large quantities,
  • processing conditions adaptable,
  • highest extract quality and yield,
  • easy to clean (CIP) and sterilize,
  • GMP standard,
  • economical operation.

PRUESS extraction plants are largely adaptable according to individual product properties and desired operation conditions.

The extraction of the raw material is carried out with solvent at desired temperatures. As solvent can be used water or other solvents.

SINGLE STAGE EXTRACTION

The extraction takes place in only one percolator in one step. Either the solvent flows from the top to the bottom (Figure 1) or from the bottom to the top (Figure 2) and then release the system or it flows by recirculation (Figure 3) many times through the percolator before it release the system.

MULTIPLE-STAGE EXTRACTION

A multiple-stage or cascade extraction is a number of frequent connected extractors in series (consecutive) as battery (Figure 4). In the multistage counter-current system, the raw material is charged in a number of extractors and the solvent flows through each in turn.

In the 1st-stage of extraction the raw material is treated with solvent coming from the previous-stage extraction. The final-stage extraction takes places with fresh solvent.

The solvent passes through the raw material packing from the bottom to the top (or reverse) of the extractor and is recycled to the bottom (or top) by means of a pump.
The proposed cascade extraction process takes place in four-steps by using upgrading miscella concentration in counter current flow to downgrading extract concentration of raw material.

PRUESS EXTRACTION SYSTEMS

The advantages of the standard PRUESS extraction systems is to run the plant in

  • single stage,
  • multiple-stages,
  • with or without internal miscella circulation
  • and in combination.

The special piping system enables an operation to the individual requirements (Figure 6).

Further advantages:
  • high yield
  • low operation costs
  • easy handling
  • short extraction time
  • extract composition similar 
    to herb composition (phytopharmaca 
    and galenical preparation)
  • GMP conformity
  • validation qualifying
  • CIP-able
  • simple maintenance
PRUESS PERCOLATORS

PRUESS STANDARD PERCOLATORS

Types Volume

Litres
Effective
Capacity
Litres
Mean
Diameter
mm
Conical
Length
mm
Weight

kg
PKL 50 60 50 300 800 70
PKL 150 160 140 500 1000 140
PKL 500 600 500 800 1200 450
PKL 1000 1200 1000 1000 1600 700
PKL 2000 2000 1800 1200 2100 1100
PKL 3000 3300 3000 1400 2500 1600
PKL 4000 4250 4000 1500 2600 2200
PKL 5000 5400 4800 1600 2900 2300
PKL 6000 6800 6000 1700 3200 2600
All data without commitment.
ADVANTAGES
Proof construction
Easy to operate
Operational flexibility
Discharge without efforts 
by conical construction
No interferences by sensitive 
equipment
Plant extension is simply
Economical system
Special Designs:

Taylor made extractors or plants for individual products and operating conditions are manufactured (Figure 7) by PRUESS on request of
customers, for example:

  • percolators with jackets for heating or cooling
  • percolators with agitators
  • percolators for pressure
  • diverse construction materials
  • a great variety of designs
  • different sizes etc.
  • extractors for maceration.
INTEGRATED and ACCESSIBLE TECHNOLOGY
RAW MATERIAL PREPARATION AND FILLING OF PERCOLATORS

Generally the raw materials have to be prepared before extraction. They are dried, are partly cut, milled or roller crushed and partly sieved.
The charging of the extractors with prepared raw materials is done either by lifting flexible containers by a girder hoist, by means of conveyors, by pneumatic systems or manually.

DISCHARGE OF SPENT SOLIDS

The bottom of the extractor must be opened. The extraction residuals (spent solids) fall down into a movable, tiltable container beneath, which has to hold one load of one extractor. This container is discharged by tilting into an outdoor waste container.

SOLVENT RECOVERY (DESOLVENTIZING) (Option)

Spent raw material still contains adhering solvent after the extraction. This solvent can be recovered. The spent solids in the extractor will be stripped out with life steam injection. The vapour consisting of solvent and steam will be condensed subsequently.

VOLATILE OIL SEPARATION (OPTION)

Under the requirement (assumption) that only the production of essential or volatile oil is desired, we recommend our “Hydro Distiller”, specially designed for that application.

The separation of volatile oil is done by steam distillation. Volatile essential oils are stripped out of the raw material by life steam. The leaving vapour are condensed and subsequently separated in water and essential oil by gravity or by a small cream separator (disc-centrifuge).

FURTHER PROCESSING OF MISCELLA (Option)

After the extraction generally the extract/solvent solution (“fullmiscella”) is filtered and then concentrated by evaporation. Equipment for evaporation, filtration or others are separate.

CONTROL SYSTEMS

Different control systems are available

  • Process control system for pneumatic manual remote operation of main valves.
  • Process control system for automation, monitoring and remote operation of main valves. It is based on a PLC (programmable logical controller) system and process visualisation via Touch Panel or PC.

In function of the individual needs, the control system may be reduced or extended.

PRUESS Anlagetechnik GmbH | Blumenstr. 24 | D-85283 Wolnzach

TEL.: +49 (0) 84 42 / 18 00

FAX:  +49 (0) 84 42 / 42 62