Rotary Sifter-DAHAN Vibration Machinery

Introduction of Rotary Sifter

Rotary sifter separates particles of two different sizes by using centrifugal force. Smaller material is passed through a static cylindrical screen by rotating paddles, while oversized particles move along the screen to an outlet at the end of the unit. The centrifugal force generated by the paddles is also excellent for breaking up clumps and agglomerated powders, allowing them to pass through the mesh and increasing throughput, which can vary from more than 90 tons per hour to several kilograms.

The material to be screened is sent to the stationary cylindrical screen by the screw installed on the rotating shaft of the rotary sifter, and the non-contact rotating paddles in the screen press the material on the screen by centrifugal force, break up the soft agglomerates, and pass through the screen. The finely screened material (fine powder) of the mesh is discharged into a collection hopper at the bottom of the machine, and oversized material and hard lumps (which cannot be broken by hand) move down the length of the screen to the screen outlet.

Application of Rotary Sifter

In order to ensure the product quality of processed materials, the rotary sifter provides three main operating procedures:

Particle Separation: Separation of products with different particle sizes into two fractions, typically in the range of 40 µm to 5 mm.

Safety Screening: Remove foreign matter and debris before products enter the production process, or ensure product quality before filling.

Conditioning: Separation of foreign matter and regulation of product bulk density immediately before production or packaging.

Working Principle of Rotary Sifter

rotary sifter working principle

The screen of the rotary sifter is cylindrical and placed in the screen body. The screened material is mixed with the air flow through the conveying system, materialized and then entered into the mesh cylinder. When the material passes through the rotor blades in the mesh cylinder, it is propelled by centrifugal force and cyclone. Therefore, the material can be sprayed through the net and finally discharged from the fine material discharge port, while the material that cannot pass through the net is discharged from the coarse material discharge port along the wall of the net cylinder.

Benefits of Rotary Sifter

1. Suitable for low bulk density and lightweight products/applications (such as talc, pigments, silica sand, etc.), mesh size 80-500 mesh.

2. The penetration rate can reach 85-95%, the residue on the screen is 0 (it is difficult for ordinary vibro sifter to achieve), and the processing capacity is 5-10 times that of vibro sifter.

3. Provide a completely closed and dust-free environment without dust pollution.

4. The cantilever shaft is designed for easy cleaning and quick screen change.

Technical Parameters of Rotary Sifter

Model	Material	Power	Application
WQS18-65	Q235A	2.2KW	Screening below 500 mesh
	SUW304
WQS30-100	Q235A	4KW
	SUW304
WQS50-130	Q235A	5.5KW
	SUW304

Dfference between Rotary Sifter and Vibratory Sifter

The following table shows you the difference between rotary sifter and other sifters:

Comparison item	Rotary Sifter	Vibratory Sifter
Principle	Generated centrifugal force separates particles according to particle size	Vibration is used to separate particles according to particle size by means of fixed openings in the screen
Application	Low bulk density and light weight products, fine powders that are easy to agglomerate (such as talc, pigments, silica sand, etc.	powder, granule or liquid
Throughput	High-capacity continuous screening, the processing capacity is 5-10 times that of other sieves.	Good for small batch processing or lower throughput rates.
Custom options	to customize with different screen sizes and configurations, materials of construction, motor and drive configurations, and other features	May have more limited customization options, or may require more specialized equipment to meet specific application requirements

Structure of Rotary Sifter

Model	A	B	C	D	E	F	G	H	I	J
WQS18-65	1430	460	420	1005	135	230	250	330	340	210
WQS30-100	1845	655	766	1240	320	285	300	350	380	290
WQS50-130	2230	870	790	1775	280	515	150	660	400	485

1. Screen or Sieve: The screen or sieve is a cylindrical or drum-shaped mesh screen that rotates horizontally and separates the particles based on their size. The size and configuration of the screen can be customized to meet specific particle size distribution requirements.

2. Drive Mechanism: The drive mechanism consists of an electric motor and a gearbox that rotates the screen at a controlled speed. The speed of rotation can be adjusted to optimize the efficiency of particle separation.

3. Inlet and Outlet: The inlet and outlet are openings on opposite ends of the sifter. The material to be sifted is fed into the sifter through the inlet, and the separated particles are discharged through the outlet.

4. Housing: The housing is a rigid frame that supports the screen, drive mechanism, and other components. The housing is typically made of stainless steel or other durable materials.

5. Bearings: The bearings support the rotating screen and allow it to rotate smoothly. The bearings are typically located at each end of the screen.

6. Discharge Mechanism: The discharge mechanism is a device that removes the separated particles from the screen and discharges them through the outlet. The discharge mechanism can be pneumatic or mechanical, depending on the specific application.

Available Options

Rotary sifters can be customized to meet specific industrial applications. Some common customization types include:

1. Screen Size and Configuration: The size and configuration of the screen can be customized to meet the specific particle size distribution required for the application. Screens can be made with different size openings, materials, and shapes, such as round, square, or rectangular.

2. Screen Material: The screen material can be customized to meet specific application requirements, such as corrosion resistance, abrasion resistance, or temperature resistance. Common screen materials include stainless steel, brass, plastic, and nylon.

3. Construction Materials: The construction materials of the sifter can be customized to meet specific requirements for durability, corrosion resistance, or sanitation. Common construction materials include carbon steel, stainless steel, and aluminum.

4. Motor and Drive Configuration: The motor and drive configuration can be customized to meet specific requirements for power, speed, and efficiency. Options for customization include variable speed drives, explosion-proof motors, and air-powered motors.

5. Inlet and Outlet Configuration: The inlet and outlet configuration can be customized to meet specific requirements for product flow, loading, and unloading. Options for customization include top, bottom, or side inlet and outlet configurations, as well as pneumatic or mechanical discharge mechanisms.

6. Sanitary Features: Sanitary features can be added to rotary sifters to meet specific requirements for cleanliness and hygiene in food, pharmaceutical, and other sanitary applications. Sanitary features may include smooth, easy-to-clean surfaces, quick-release clamps for easy disassembly and cleaning, and FDA-approved gaskets and seals.

Special Customized Products

There are several types of rotary sifters, different types of rotary sifters are designed to meet different requirements, and can be customized to meet specific application needs:

1. High-Capacity Rotary Sifters: These sifters are designed for large-scale industrial applications that require high throughput rates. They typically have larger screens and more powerful motors than other types of sifters.

2. Low-Profile Rotary Sifters: These sifters are designed to fit in tight spaces and have a low profile. They are often used in applications where space is limited.

3. Batch Rotary Sifters: These sifters are used for small batch processing. The material is loaded into the sifter, and the centrifugal force separates the particles based on their size.

4. Continuous Rotary Sifters: These sifters are designed for continuous processing of large quantities of material. The material is fed into the sifter, and the centrifugal force separates the particles based on their size as it flows through the sifter.

5. Sanitary Rotary Sifters: These sifters are designed for use in food, pharmaceutical, and other sanitary applications where cleanliness and hygiene are critical. They are typically made of stainless steel and have smooth surfaces to prevent bacteria buildup.

6. Dual-Drive Rotary Sifters: These sifters have two motors and can be used to process difficult-to-sift materials or to achieve greater control over the particle size distribution.

Customer Case

Food & Dairy		Chemical		Mineral
Material	Typical Capacity	Material	Typical Capacity	CALCIUM CARBONATE	1-70 TPH
COCOA POWDER	1-70 TPH	CALCIUM STEARATE	1-30TPH	EXPANDED PEARLITE	0.25-7 TPH
FISH MEAL	1-40 TPH	EXPANDED SILICA	0.5-6 TPH	GYPSUM	1-90 TPH
FLOUR	1-60 TPH	HYDRATED ALUMINA	1-30 TPH	MICA	0.25-10 TPH
GROUND COFFEE	1-30 TPH	IRON OXIDE	1-40 TPH
LACTOSE	5-300 GPM	LATEX	5-200 GPM
LACTOSE	(20-1850 LPM)	LATEX	(20-900 LPM)
MILK POWDER	1-30 TPH	PAPER FIBER	5-400 GPM
NON-DAIRY CREAMER	1-50 TPH	PAPER FIBER	(20-1800 LPM)
SPICES	1-40 TPH	PIGMENTS	1-40 TPH
STARCH	1-50 TPH	POLYMER BEADS	1-250 GPM
SUGAR	1-120 TPH	POLYMER BEADS	(20-1150 LPM)
TOFU	5-200 GPM	POWDER COATINGS	1-30 TPH
TOFU	(20-900 LPM)	TiO2 SLURRY	5-250 GPM
DISTILLERY SPENT GRAIN	10-150 GPM		(20-1150 LPM)