Palm fruit digester
Heated mixing that breaks down the mesocarp and ruptures the oil-bearing cells.
What this machine does
The digester prepares the pressing. Stirring arms work the fruit in a heated vessel: the mechanical action breaks down the mesocarp while the heat lowers the viscosity of the oil and weakens the walls of the oil-bearing cells. Without this stage, the press has to overcome both the cohesion of the pulp and the resistance of intact cells, which shows up as high residual oil in the cake — that is, as lost yield.
Two parameters govern the operation: temperature, which must be held close to the boiling point of water to be effective, and residence time, long enough for the breakdown to be complete without holding up production. A digester that is not held at temperature, because its steam is insufficient or its lagging has failed, lowers the extraction rate of the whole mill, with the problem visible nowhere except in the material balance.
See the sector Oil palmAt a glance
- ReferencePAL-MAL
- SectorOil palm
- PurposeHeated mixing that breaks down the mesocarp and ruptures the oil-bearing cells.
A detailed PDF data sheet will be available in the document centre once produced.
The parts that do the work
Heated vertical vessel
Heating by direct steam or jacket, with lagging limiting losses.
Shaft with stirring arms
Continuous agitation breaking down the pulp and evening out the temperature throughout the mass.
Level control
Filling governs residence time: a partly filled digester works badly.
Outlet to press
Bottom discharge feeding the press in a steady flow.
Technical data and configurations
| Characteristic | Indicative value |
|---|---|
| Working volume | according to mill capacity |
| Working temperature | approximately 95 to 100 °C |
| Residence time | 15 to 25 min |
| Installed power | 7.5 to 30 kW |
| Heating | direct steam or jacket |
| Materials | steel suited to the process, lagged |
| Feed | continuous from the stripper |
| Outlet | bottom discharge to the press |
These are usual design ranges for this type of machine, intended to guide early thinking. The contractual characteristics of the equipment actually manufactured — throughputs measured at acceptance, absorbed power, real footprint and weight — are established by the SOTIC design office and stated in the technical offer.
Available configurations
- Several volumes according to line throughput.
- Direct or indirect steam heating according to the site's steam configuration.
- Digesters in series for large capacities.
Installation requirements
- Raised position allowing gravity feed to the press.
- Lagged steam connection with a trap at the low point.
- Support structure sized for the loaded mass, with maintenance access.
- Collection of oily drips at the foot of the equipment.
Maintenance and safety at the workstation
A machine lasts as long as its maintenance does. The points below appear in the preventive maintenance plan handed over at acceptance and are covered during operator training.
Preventive maintenance
- Check wear of the stirring arms, parts under constant abrasion.
- Check the lagging: heat losses translate directly into lost yield.
- Check the stuffing boxes and shaft sealing.
- Monitor the real temperature of the mass, not just the steam pressure.
Safety
- Full isolation before any opening: the shaft retains inertia.
- High burn risk, the vessel and its contents being close to 100 °C.
- Protected access at high level and guardrails on platforms.
Before ordering this machine
Technically yes, but with markedly higher residual oil in the cake: part of the oil stays locked in intact cells. Over a full season, the cumulative loss far exceeds the running cost of the digester. This is not a station to remove in order to save money.
By the appearance of the mass at the outlet — a well broken-down, uniform mesocarp at the right temperature — and above all by monitoring residual oil in the cake after pressing. If that value rises, the cause is frequently in the digester: insufficient temperature, partial filling or worn arms.
Request a quote: Palm fruit digester
Tell us the throughput you are aiming for, the material to be processed and the energy available on your site: we come back with a reasoned configuration and a price, rather than a catalogue rate.
- Technical answer: we first check that this machine genuinely matches your need.
- Tailored configuration: size, drive, options and wear parts defined with you.
- Complete pricing: equipment, transport, erection, commissioning and training.
- Next steps: civil works, connections and maintenance where required.
First reply target: 48 working hours.
Other machines in the Oil palm
Bunch steriliser
Steam treatment of bunches: the operation that sets the acidity of the entire production.
Bunch stripper
Separates fruit from empty bunches after sterilisation, in a rotating barred drum.
Palm oil press
Mechanical extraction by reducing-pitch screw, with counter-pressure adjustable while running.
Oil filter
Clarifies crude oil by filtration, before storage or refining.