Precise Dosing for Stable Bleaching Performance

Bleaching is a key purification stage in vegetable-oil refining. Pigments, oxidation products, trace contaminants and other unwanted compounds are removed from the oil before downstream filtration and finishing steps. Bleaching earth, activated clay and bentonite-based materials are widely used for this purpose, and their performance depends strongly on the quantity delivered to the oil. VOLDE connects raw-material intake with the bleaching process through enclosed handling, vacuum transfer and gravimetric dosing. The design objective is not simply to move powder from a big bag to a tank, but to keep the bleaching-earth-to-oil relationship aligned with actual process demand.

| From Big Bag to Bleaching Tank

Bleaching earth is typically a fine, dusty powder, so its route through the plant is best kept enclosed. Bulk material can enter through a FREEBAG Big Bag Discharge System, while lower-volume auxiliary powders may be introduced at dedicated bag-dump stations. From there, vacuum conveying carries the material to VACUMATE receiving units positioned near or above the bleaching area.

This arrangement separates the operator’s raw-material handling zone from the dosing point without breaking the product path. Dust extraction can be concentrated where bags are opened, buffer capacity can be created close to the process, and one conveying architecture can serve more than one bleaching destination where the plant layout requires it.

| Gravimetric Dosing Linked to the Oil Process

The amount of bleaching earth matters in both directions. Excess addition increases powder consumption and may increase oil retained in the spent filter cake; insufficient addition can reduce pigment and impurity removal. For that reason, VOLDE bases the dosing function on measured mass flow rather than on a fixed running time or an operator-adjusted feeder speed.

Oil flow, tank level or production rate can be used as the process reference. The control system converts this reference into the required powder feed rate and updates the feeder set-point as operating conditions change. Recipe ratios, gravimetric feedback and actual consumption are therefore part of the same control loop instead of separate manual checks.

| Precise Dosing, Matched to Oil Flow

When oil flow changes, bleaching-earth demand changes with it. Linking gravimetric powder dosing to refinery process data keeps the addition rate aligned with the actual requirement of the bleaching stage.

| Automation, Consumption Control & Traceability

PLC/SCADA provides the operating layer for the complete system. Operators can see the active recipe, target dosing ratio, actual mass flow, bleaching-earth consumption, tank requests and alarms from one interface. Historical data also makes it possible to compare powder consumption across products, batches or operating periods.

• Recipe and oil-grade based dosing references
• Actual gravimetric feed and consumption history
• Batch, alarm and operator records with optional ERP/MES data exchange

Enclosed powder handling, vacuum conveying and process-linked gravimetric dosing therefore work as one refinery function rather than three separate equipment packages.