Scraper Bottom Discharge Centrifuge for Evaporative Crystallizer Slurry Dewatering

The Scraper Bottom Discharge Centrifuge is designed for dense, high-solids crystalline slurry that requires controlled feeding, stable cake formation, centrifugal dewatering, and automatic bottom discharge.

It is particularly suitable when the crystal-to-liquor ratio is high, slurry concentration fluctuates between batches, or upstream crystallization produces intermittent peak loads that require controlled basket filling and reliable cake discharge.

For high-solids slurry, the main challenge is not only liquid removal. The equipment must also handle dense feeding, maintain an even cake layer, avoid basket overload, control cake thickness, and discharge the dewatered crystals reliably. The scraper bottom discharge design is well suited for these requirements.

Peony provides the crystal dewatering section between the evaporative crystallizer and downstream drying or screening system.

Evaporative Crystallizer → Agitated Slurry Buffer Tank → Controlled Feed → Scraper Bottom Discharge Centrifuge → Mother Liquor Recycle / Purge → Optional Cake Washing → Dryer / Screen / Storage

Peony can provide:

• Slurry buffer tank and controlled feeding arrangement
• Scraper bottom discharge centrifuge with automatic cake discharge
• Filter medium selection based on crystal size and slurry condition
• Optional cake washing system
• Mother liquor collection, recycle, or purge connection
• PLC control integration and corrosion-resistant material configuration

The final solution is selected according to crystal size, slurry solids concentration, mother liquor properties, target cake moisture, and downstream handling requirements.

1. Crystal Slurry Feeding

Crystallizer slurry is transferred from the slurry buffer tank into the rotating basket through a controlled feed system.

2. Mother Liquor Filtration

Concentrated mother liquor passes through the filter medium and leaves through the filtrate outlet.

3. Crystal Retention

Crystals remain inside the basket and form a layer on the inner basket surface.

4. Filter Cake Formation

As feeding continues, the retained crystals gradually form a stable filter cake.

5. Optional Cake Washing

Compatible wash liquid can be applied to reduce residual mother liquor, soluble impurities, or unwanted salts retained between crystals.

6. Spin Drying

The basket continues rotating at high speed to remove free liquid from the crystal cake before discharge.

7. Automatic Scraping and Bottom Discharge

After the programmed cycle is complete, the scraper removes the dewatered cake from the basket wall and discharges it automatically through the bottom outlet.

Stable Link Between Crystallization and Drying

The centrifuge creates a controlled transition between upstream crystallization and downstream drying or finishing. It removes mother liquor before crystals enter the dryer, reducing liquid carryover and improving handling.

Automatic Crystal Cake Discharge

The scraper removes the dewatered cake automatically. This reduces manual handling and supports repeatable batch operation in crystallizer-based production lines.

Mother Liquor Recovery

The filtrate can be returned to the crystallizer, evaporation section, recycle tank, or controlled purge stream according to the process design.

Optional Crystal Washing

The cake can be washed before final spin drying when lower mother liquor carryover or improved product purity is required.

Suitable for High-Solids Crystal Slurry

The machine is suitable for concentrated slurry from evaporative crystallizers where crystals can form a stable, permeable, and removable cake.

Can this centrifuge connect directly to an evaporative crystallizer?

It can receive slurry from an evaporative crystallizer, but an agitated slurry buffer tank is normally recommended between the crystallizer and centrifuge. This helps stabilize feed concentration and match continuous crystallizer output with automatic batch separation.

Can it handle high-solids crystallizer slurry?

Yes, provided the slurry remains pumpable and the crystals can form a stable, permeable cake inside the basket.

Can the mother liquor be returned to the evaporation system?

Yes. The filtrate can be recycled to the crystallizer, evaporator, mother liquor tank, or a controlled purge stream, depending on the process balance and impurity accumulation level.

Can crystals be washed inside the centrifuge?

Yes. Optional cake washing can reduce residual mother liquor and improve product cleanliness. The wash liquid and wash volume should be selected carefully to control product loss.

Is this machine suitable for continuous crystal discharge?

The centrifuge itself is an automatic batch machine. It is suitable for continuous or semi-continuous crystallization systems when a slurry buffer tank is used to match the two operating modes.