Over 10,000+ customers' choice, Focus on screening industry 40+ years
Before understanding airflow screening technology, it is necessary to identify the specific problems that powdered sugar faces during screening.
1. Moisture absorption and caking. Powdered sugar crystals are fine and highly hygroscopic. Industry data shows that when relative humidity exceeds 75%, powdered sugar begins to cake; at 80% relative humidity, it can even completely deliquesce. During storage and screening, powdered sugar readily absorbs moisture from the air, forming hard lumps of various sizes. Once these lumps enter the production line, they cause a cascade of problems including screen blinding, batching imbalance, and raw material waste.
2. Electrostatic adhesion. Powdered sugar tends to generate static electricity during high‑speed motion, causing powder to adhere to screens, equipment walls and pipelines. Fine powder sticks to the screen surface, forming a "powder film" that reduces the effective screening area and lowers accuracy. Material retention leads to frequent stoppages for cleaning, seriously affecting production efficiency.
3. High fineness and easy dusting. Powdered sugar typically has a fineness of 80 mesh or finer, and some products require screening to 200 mesh or even higher. Ultra‑fine powder tends to become airborne on ordinary vibrating screens, causing material loss and contaminating the workshop environment.
These three problems overlap, making powdered sugar a recognised "difficult‑to‑screen" material in the screening industry. Traditional vibrating screens handling powdered sugar often require frequent stoppages for screen cleaning, severely reducing line efficiency.
The Gaofu QLSZ series centrifugal sifter uses a screening principle that is fundamentally different from ordinary vibrating screens. The equipment is based on the core technology of "airflow atomisation + centrifugal screening", with a cylindrical screen placed inside a sealed housing.
Step 1: Screw Conveying and Airflow Mixing
After material enters the equipment through a screw conveying system, it is thoroughly mixed and atomised with air at a certain pressure. The key to this step is "atomisation" – the powdered sugar is fully dispersed under the action of the airflow, and slight lumps begin to break up at this stage. For easily agglomerated materials such as powdered sugar, this pre‑dispersion treatment directly affects the subsequent screening performance.
Step 2: Dual Action of Centrifugal Force and Spiral Pushing Force
The atomised material enters the inner cavity of the cylindrical screen. Inside the cavity, high‑speed rotating impeller blades subject the material to two forces simultaneously:
Centrifugal force throws the material toward the inner wall of the screen;
Spiral pushing force moves the material forward along the screen cylinder.
Under the combined action of these two forces, the material passes through the screen in a "jetting" manner.
Step 3: Separation of Coarse and Fine Fractions
Acceptable fine powder smaller than the mesh openings exits through the screen and is discharged from the fines outlet. Coarse particles and impurities larger than the openings cannot pass through; they move forward along the inner wall of the screen cylinder and are finally discharged from the coarse outlet.
This design fundamentally changes the traditional screening method of "falling by gravity and jumping by vibration". The centrifugal sifter does not rely on vibration as the main driving force, but uses airflow as the power source, allowing the material to be separated quickly inside a sealed pipeline.
1. Airflow Dispersion – Breaking Lumps at the Source
Powdered sugar tends to form lumps during storage and transport. The centrifugal sifter achieves "pre‑dispersion" already at the feeding stage. The material is fully mixed and atomised with air in the screw conveying system and the inner cavity of the screen cylinder. The high‑speed airflow itself has a strong shear‑dispersion effect, loosening lightly agglomerated sugar before it reaches the screen.
For powdered sugar screening, the value of this mechanism is that lumps are effectively broken up before they reach the screen, preventing them from blocking the mesh openings or being rejected as waste.
2. Airflow Scouring for Self‑Cleaning – Saying Goodbye to Screen Blinding
When traditional vibrating screens handle powdered sugar, screen blinding is the most troublesome issue. The root cause is that once material adheres to the mesh openings, there is no external force to remove it.
During screening with the centrifugal sifter, the swirling airflow continuously scours the screen surface. This airflow scouring has two effects: on the one hand, it blows off fine particles adhering to the mesh openings, achieving "self‑cleaning"; on the other hand, the continuous airflow effectively disrupts electrostatic adhesion, keeping ultra‑fine sugar powder that would otherwise "stick" to the screen in a suspended state.
This means the equipment can run continuously for long periods without frequent stoppages for screen cleaning. For powdered sugar, which easily blinds screens, the self‑cleaning mechanism directly translates into improved production line efficiency.
3. Re‑Crushing Function – Secondary Treatment of Caked Material
Hard lumps that form during powdered sugar storage sometimes cannot be completely broken by airflow dispersion alone. The Gaofu centrifugal sifter has a re‑crushing function for caked material. During screening, lumps that fail to pass through the screen are continuously impacted by the impeller blades, further broken down, and then re‑screened.
This function effectively reduces raw material waste caused by caking and improves the yield of powdered sugar.
4. Fully Enclosed Structure – Two Lines of Defence – Hygiene and Moisture Protection
As powdered sugar is a food ingredient that comes into direct contact with the consumer, the hygiene standards for production equipment are extremely strict. The Gaofu centrifugal sifter has a fully enclosed, sealed structure, with no dust leakage during operation.
The fully enclosed design provides three assurances: first, it effectively blocks external moisture to prevent secondary moisture absorption during screening; second, it prevents dust escape, improving the workshop environment; and third, it avoids material moisture and cross‑contamination.
Based on the characteristics of powdered sugar – easy moisture absorption, caking tendency, and static generation – the Gaofu centrifugal sifter offers the following special configurations:
304 food‑grade stainless steel. Powdered sugar is directly used in food applications, so the safety of the equipment material is critical. All material‑contact parts of the Gaofu centrifugal sifter are made of high‑quality 304 food‑grade stainless steel, with a finely polished surface, no dead corners, and easy to clean – eliminating material residue and cross‑contamination.
Positive and negative pressure air systems. The equipment can be used as a single unit or in combination with multiple units, and can be integrated into positive or negative pressure air systems for long‑term continuous operation with high safety and reliability.
Gas protection system. Purified air can be delivered to both ends of the equipment, effectively reducing the temperature generated during operation, while forming an air barrier around the bearings to prevent dust ingress and extend bearing life, reducing maintenance frequency.
Flexible screen mesh configuration. The Gaofu centrifugal sifter is designed specifically for ultra‑fine powders from 80 to 635 mesh. The screen mesh can be changed at any time according to production requirements, adapting to the fineness requirements of different powdered sugar products.
De‑agglomeration function. The equipment has a re‑breaking function for false agglomerates, further improving screening efficiency and product yield.
About Gaofu
Xinxiang Gaofu Machinery Co., Ltd. was originally founded in the 1980s. After more than 40 years of development, the company has become a "National Specialized and Sophisticated 'Little Giant' Enterprise", a "National Green Factory", a "National High-tech Enterprise", a "National Intellectual Property Advantage Enterprise", and the "President Unit of the Vibration Association". It also hosts the "Henan Provincial Industrial Design Center", the "Henan Provincial Engineering Technology Research Center for Intelligent Online Screening Systems", and the "Xinxiang Municipal Engineering Technology Research Center for Fine Screening". The company has been granted more than 500 invention, utility model and design patents, has received the "Science and Technology Achievement Award" issued by the Ministry of Industry and Information Technology, and has participated in drafting four "National Standards".
Gaofu's product portfolio covers several series and hundreds of varieties, including vibrating screening equipment, conveying equipment, coal crushing equipment, filtration equipment, and automated material handling systems. Its main products include vibrating screens, screening machines, vibrating sifters, rotary vibrating screens, ultrasonic vibrating screens, linear screens, air flow screens, gyratory screens, roller screens, dewatering screens, bar screens, vacuum feeders, dust-free feeding stations, ton bag feeding stations, feeding systems, automatic powder feeding systems, automatic slag discharge filters, leaf filters, clay filters, toothed roll crushers, coal crushers, and other equipment. These are widely used in many industries such as food, pharmaceuticals, chemicals, metallurgy, building materials, mining, thermal power, and environmental protection, earning the trust and praise of over 10,000 customers worldwide.
Gaofu products are not only popular in Greater China but are also exported to more than 100 countries and regions, including Russia, Canada, the United States, New Zealand, Japan, Brazil, South Africa, etc. The company adheres to its mission: "Enhance material quality and efficiency, meet customer needs", walking side by side with customers for harmonious and win-win cooperation. Today, Gaofu has become an approved supplier to many Fortune 500 companies, including CNPC, Sinopec, Sinochem Group, China Resources Group, Sinopharm Group, COFCO Group, China National Building Material Group, China Aerospace, and Jinchuan Group.
Gaofu Machinery – Global No.1 in Vibrating Screen Sales. In May 2024, Frost & Sullivan, an international authoritative advisory firm, based on its research on the global vibrating screen market and calculated according to global vibrating screen sales volume in 2023, issued a market position confirmation certificate to Gaofu Machinery.
