Scraper Bottom Discharge Centrifuge for Petrochemical By-Product Salt Separation

The Scraper Bottom Discharge Centrifuge is designed for solid-liquid separation, cake washing, and dewatering of crystallized by-product salts generated in petrochemical wastewater treatment, brine concentration, evaporation, and crystallization systems.

Petrochemical by-product salt streams may contain sodium chloride, sodium sulfate, mixed inorganic salts, residual mother liquor, trace organics, suspended solids, and process impurities. After evaporation or crystallization, the salt slurry must be separated efficiently to recover crystals, reduce residual moisture, and minimize mother liquor carryover.

Compared with manual discharge centrifuges, the bottom scraper design reduces labor intensity, improves operating consistency, and supports cleaner handling of petrochemical by-product salts.

Petrochemical by-product salt separation often involves several operating challenges:

• Variable salt composition and mixed crystal systems
• High chloride concentration and corrosion risk
• Residual organics or process impurities in mother liquor
• Fluctuating solids content caused by evaporation and crystallization conditions
• Requirement to recover mother liquor or reduce salt loss
• Need for cake washing to improve product purity
• High labor intensity during manual cake removal
• Need for enclosed and cleaner salt handling
• Potential explosion-proof requirements in solvent-related applications
• Need for stable and repeatable batch separation performance

The Scraper Bottom Discharge Centrifuge addresses these requirements through centrifugal filtration, optional cake washing, automatic scraper discharge, corrosion-resistant material selection, and PLC-controlled batch operation.

The crystallized salt slurry is fed into the rotating basket lined with filter media.

Under centrifugal force:

1. Mother liquor passes through the filter medium and is collected through the filtrate outlet.
2. Salt crystals and insoluble solids are retained inside the basket.
3. A filter cake gradually forms on the inner surface of the basket.
4. Optional wash liquid is sprayed onto the cake to reduce residual mother liquor, chloride, sulfate, organics, or soluble impurities.
5. High-speed rotation removes residual moisture from the salt cake.
6. The scraper automatically removes the dewatered cake from the basket wall.
7. The separated by-product salt is discharged through the bottom outlet for downstream drying, packaging, reuse, disposal, or further treatment.

The complete batch cycle is automatically controlled through PLC operation to ensure stable and repeatable separation performance.

Efficient Mother Liquor Removal

The centrifuge separates mother liquor from crystallized by-product salts and helps reduce liquid carryover into downstream drying or salt handling systems.

Automatic Cake Discharge

The scraper mechanism automatically removes the salt cake after dewatering, reducing manual cleaning and improving batch efficiency.

Optional Cake Washing

A washing system can be integrated to reduce residual mother liquor, salts, organics, alkali, or other soluble impurities retained in the cake.

Lower Cake Moisture

High-speed centrifugal dewatering helps reduce residual moisture before drying, packaging, disposal, reuse, or further processing.

Suitable for Crystallized Salt Slurries

The centrifuge is suitable for filterable salt crystals with moderate to high solids concentration and stable cake-forming behavior.

Enclosed Batch Operation

The closed structure supports cleaner operation and reduces splashing, material loss, and operator exposure.

Corrosion-Resistant Construction

Wetted parts can be customized in SS304, SS316L, Duplex Stainless Steel, Super Duplex Stainless Steel, titanium, Hastelloy, or other special materials.

PLC-Controlled Operation

The complete operating sequence can be automatically controlled, including feeding, filtration, cake washing, spin drying, scraper discharge, and safety interlock protection.

What petrochemical by-product salts can this centrifuge handle?

It is suitable for filterable crystallized salts generated from petrochemical wastewater treatment, evaporation, and crystallization systems, including sodium chloride, sodium sulfate, and some mixed inorganic salt streams.

Can the centrifuge recover mother liquor?

Yes. Mother liquor passes through the filter medium and can be collected for return to the evaporation system, crystallization loop, wastewater treatment system, or further recovery process.

Can the centrifuge wash the salt cake?

Yes. An optional wash system can spray water, brine, condensate, or another compatible wash medium onto the cake before final spin drying.

What cake moisture can be achieved?

Final moisture depends on crystal size, salt type, cake permeability, feed solids concentration, mother liquor viscosity, basket speed, and cycle time. A sample test is recommended before confirming the final moisture target.

Is the centrifuge suitable for mixed salt from ZLD systems?

It can be suitable when the mixed salt is crystalline, filterable, and able to form a stable cake. For fine, sticky, high-organic, or strongly compressible mixed salts, testing is recommended before equipment selection.