Automatic Scraper Bottom Discharge Centrifuge

Overview

The ZYLAB Automatic Scraper Bottom Discharge Centrifuge is a vertical automatic filtering centrifuge designed for efficient solid-liquid separation of suspensions containing fine- to medium-sized solid particles. It can also be used for separating fibrous materials from liquids.

The centrifuge operates according to a preset PLC program and can automatically complete feeding, centrifugal separation, cake washing, dewatering, scraping, and bottom discharge. With a high degree of automation, large processing capacity, remote control capability, and multiple safety interlocks, the centrifuge is suitable for industrial production and pilot-scale solid-liquid separation applications.

Fully Automatic Operation

The centrifuge uses a PLC and variable frequency drive (VFD) control system to automatically execute the complete batch separation cycle, including feeding, centrifugal filtration, cake washing, dewatering, scraping, and discharge.

Process parameters can be preset according to specific material and process requirements, reducing manual intervention and improving process consistency.

Efficient Solid-Liquid Separation

During high-speed rotation, centrifugal force drives the liquid phase through the filter cloth or filter screen, while solid particles are retained on the filter medium to form a filter cake.

The high centrifugal separation factor enables efficient separation of suspensions containing fine and medium-sized particles.

Automatic Scraper Bottom Discharge

After the filtration and dewatering process is completed, the centrifuge automatically reduces its speed to the preset scraping speed. The hydraulically or pneumatically operated scraper removes the filter cake from the inner wall of the rotating basket.

The separated solids are discharged through the bottom discharge outlet.

Liquid Damping Vibration Isolation

The flat-plate structure combined with a liquid damping vibration isolation system helps reduce vibration during high-speed operation and provides stable machine performance.

Large-Opening Cover

The large-opening cover provides convenient access to the basket and internal components, making inspection, maintenance, cleaning, and filter cloth replacement easier.

Online Cleaning System

An integrated online cleaning system allows the internal surfaces of the centrifuge to be cleaned without extensive disassembly. The smooth internal structure helps minimize dead zones and facilitates effective cleaning.

Hygienic and Corrosion-Resistant Design

The product-contact surfaces can be highly polished, with a surface roughness of approximately Ra 0.2–0.4 μm depending on configuration.

For corrosive materials, optional materials and surface treatments include:

• Titanium
• Special corrosion-resistant alloys
• Plastic lining
• Rubber lining
• PTFE lining

Working Principle

The Automatic Scraper Bottom Discharge Centrifuge is a vertical filtering centrifuge that separates solids from liquids using centrifugal force.

• Feeding
  The PLC control system opens the feed valve. The suspension enters the centrifuge through the feed pipe and is evenly distributed into the rotating basket through the independent inclined-disc distribution system.
• Centrifugal Filtration
  As the basket rotates at high speed, centrifugal force drives the liquid through the filter cloth or filter screen. The liquid phase passes through the filter medium and is discharged through the liquid outlet, while solid particles remain inside the basket and form a filter cake.
• Automatic Level Detection
  A material-level detector monitors the thickness of the filter cake. When the preset loading level is reached, the PLC automatically stops feeding.
• Cake Washing
  If required, washing liquid is introduced to wash the filter cake and remove residual impurities or mother liquor.
• Dewatering
  The centrifuge continues rotating at the required speed to remove residual liquid and achieve the specified moisture content.
• Scraper Discharge
  Once the desired separation and dewatering conditions are reached, the centrifuge reduces its speed to the preset scraping speed. The scraper is activated by a hydraulic or pneumatic drive to remove the filter cake from the basket.
• Bottom Discharge
  The scraped solids fall through the lower discharge outlet.

Applications

The Automatic Scraper Bottom Discharge Centrifuge is suitable for solid-liquid separation, filtration, washing, and dewatering in various industries.

Chemical Industry

For separation and washing of chemical crystals, inorganic salts, pigments, and other solid products.

Pharmaceutical Industry

Suitable for applications requiring hygienic design, enclosed operation, cleaning, and controlled solid-liquid separation.

Food and Beverage Industry

Can be used for separating crystalline or granular materials from process liquids where the appropriate hygienic configuration is selected.

Fine Chemicals

Suitable for fine chemical intermediates, crystallized products, and specialty chemicals.

Mineral and Inorganic Materials

Used for filtration and dewatering of suspensions containing fine and medium-sized solid particles.

Fibrous Materials

The filtering centrifuge can also be configured for solid-liquid separation involving certain fibrous materials.

1. Flat-Plate Structure

The machine adopts an integrated flat-plate structure. The housing and base plate are welded together, while the cover and housing are connected by a flange.

The cover adopts a quick-opening design driven by a hydraulic or pneumatic system.

The cover can be equipped with:

• Feed pipe
• Washing pipe
• Sight glass
• Explosion-proof lighting
• Scraper assembly
• Material-level detector
• Other customized process connections

External pipe connections use standard flanges.

2. Stainless Steel Construction

The flat plate is made of Q235 steel with stainless steel lining.

The rotating basket is mainly constructed from stainless steel, while the basket bottom adopts a cast-steel structure with stainless steel lining.

The housing and cover are made of stainless steel. The bearing housing can also be manufactured with a stainless steel lining.

3. Automatic Control System

The standard control system includes:

• PLC control
• Variable frequency drive (VFD)
• Energy-consumption or regenerative braking
• Material-level detector
• Vertical motor
• V-belt transmission
• Belt guard
• Local operation control box
• Liquid damping vibration isolator
• Mechanical and electrical safety interlocks

Optional corrosion-resistant materials and linings are available according to the characteristics of the process material.