Inorganic Salt Crystallization Pusher Centrifuge

A pusher centrifuge is usually installed after the crystallizer or slurry thickening stage.

Typical process route:

Brine / solution concentration → Crystallization → Pusher centrifuge → Wet crystal cake → Dryer → Cooler → Screening → Packaging

For processes requiring washing:

Crystallizer slurry → Pusher centrifuge → Cake washing zone → Mother liquor removal → Wet cake discharge → Drying

In a complete inorganic salt production line, the centrifuge does not work alone. Its performance is closely related to crystallizer operation, crystal size distribution, slurry concentration, mother liquor composition, washing demand, and downstream drying capacity.

The inorganic salt slurry enters the rotating basket through the feed pipe. Under centrifugal force, mother liquor passes through the screen openings and is collected as filtrate, while salt crystals remain on the screen surface and form a filter cake.

The pusher mechanism moves the crystal cake forward step by step along the screen basket. During this movement, the cake continues to lose liquid. If washing is required, wash liquid can be sprayed onto the cake to reduce residual mother liquor or soluble impurities.

Finally, the dewatered salt crystal cake is discharged continuously from the basket end and sent to the dryer, cooler, screening machine, packaging section, or the next process stage.

Crystal size is one of the most important factors for pusher centrifuge selection.

Coarse and uniform crystals usually form a stable filter cake and are easier to dewater. Fine crystals may pass through the screen, block the screen openings, increase filtrate turbidity, or reduce cake permeability.

For inorganic salt crystallization projects, crystallizer operation should be checked together with centrifuge selection. If the crystal size distribution is unstable, the centrifuge alone cannot fully solve moisture or solids loss problems.

The feed solids content affects throughput, cake thickness, pushing load, and screen filtration performance.

A very low solids concentration may reduce cake formation stability. A very high solids concentration may increase pushing resistance, torque load, and discharge pressure. The ideal feed condition depends on the crystal type, particle size, liquid viscosity, and target capacity.

Inorganic salt mother liquor can be highly concentrated, corrosive, alkaline, acidic, or high in chloride content. These properties affect material selection, sealing design, filtrate collection, and maintenance frequency.

For sodium chloride, potassium chloride, calcium chloride, nitrate, or soda ash processes, the liquid composition should be confirmed before selecting the wetted material.

Lower cake moisture can reduce dryer load and steam or fuel consumption. However, the final moisture depends on crystal size, cake permeability, screen basket design, centrifugal force, residence time, and washing requirement.

For some salt products, extremely low moisture may not be practical only through mechanical dewatering. The goal should be to provide a stable and suitable wet cake for the downstream dryer.

Some inorganic salt crystals require washing to remove residual mother liquor, soluble impurities, or surface contamination. In this case, the washing zone, spray distribution, cake thickness, residence time, and wash liquid ratio should be considered.

A pusher centrifuge is suitable for continuous cake washing because the crystal cake moves forward in a controlled manner through the filtration and washing areas.

Inorganic salt crystals may be abrasive, while the mother liquor may be corrosive. The centrifuge should be configured according to the actual material.

Common considerations include:

stainless steel or duplex stainless steel wetted parts

corrosion-resistant screen basket

wear protection on pushing components

reinforced discharge area

suitable sealing structure

anti-corrosion treatment for filtrate collection areas

Final material selection should be based on chloride concentration, pH, temperature, crystal hardness, and cleaning method.

Continuous Operation for Crystallization Lines

The pusher centrifuge is suitable for continuous inorganic salt production. It can receive crystallizer slurry continuously and discharge wet crystal cake steadily.

Stable Mother Liquor Removal

The screen basket allows mother liquor to pass through while retaining the crystal cake. This helps reduce free liquid before drying.

Lower Downstream Drying Load

By reducing mechanical moisture before the dryer, the centrifuge can help improve dryer stability and reduce unnecessary thermal load.

Optional Crystal Washing

When product purity or impurity control is required, the centrifuge can include a washing section to reduce residual mother liquor on the crystal surface.

Suitable for Salt Chemical Applications

The equipment can be configured for sodium sulfate, potassium chloride, sodium chloride, soda ash, calcium chloride, nitrate salts, and other inorganic salt crystallization processes.

Customizable Material Selection

Wetted parts, screen basket, process housing, and discharge areas can be selected according to brine composition, corrosion level, temperature, and crystal abrasiveness.