Our premier product line features state-of-the-art technologies that seamlessly integrate with our high-durability flour air locks to optimize material conveying, dust management, and milling processes.
Henan Jiujie Machine Co., Ltd. is a professional supplier of complete equipment and engineering services for the food production and grain processing industries. Our business covers a wide range of applications, including wheat flour milling plants, feed processing factories, and rice processing plants.
Our product portfolio includes conveying equipment, cleaning equipment, flour milling equipment, and other related machinery. Over the years, our products have been widely recognized by customers both in domestic and international markets. Since its establishment, Henan Jiujie Machine Co., Ltd. has been dedicated to the research and development of grain processing technology and machinery. With extensive industry experience, we are able to provide integrated solutions across the entire grain and food processing industrial chain. Our solutions cover multiple stages, including raw material collection, storage, cleaning, grading, sieving, grinding, mixing, shaping, production, and packaging.
In modern industrial flour milling and pneumatic conveying systems, the flour air lock (also referred to as a rotary airlock valve, star feeder, or rotary feeder) plays an absolutely indispensable role. Its primary mechanical function is to regulate the gravity-fed flow of dry bulk solids (such as wheat, semolina, flour, or bran) into a high-pressure or negative-pressure pneumatic conveying line while preventing any significant loss of air.
"A difference of just 0.05mm in rotor-to-housing clearances can decrease pneumatic conveying efficiency by up to 25%, causing severe pressure drop, product degradation, and high operational costs."
To maintain the required airtight barrier under pressure differences up to 1.5 bar, Henan Jiujie Machine utilizes extreme precision engineering. The radial and axial clearance between the rotor blades and the internal valve housing is strictly limited to between 0.10mm and 0.15mm. This ultra-tight configuration prevents air blowout, which is the primary cause of product blow-back, pipeline blockages, and hazardous dust emission.
Flour dust is highly combustible and poses severe dust explosion hazards within storage silos and conveying pipelines. The rotary air lock serves as an active explosion isolation barrier. In the event of an explosion propagation within the system, our heavy-duty, flameproof structural design blocks the propagation of pressure waves and flame fronts to other segments of the processing facility, meeting the highest international industrial safety standards.
Procurement agents, plant engineers, and project managers from global grain processing hubs (ranging from North America to Southeast Asia) must systematically navigate stringent regional regulations and distinct operational requirements. For instance, in European and North American food plants, the rotary air lock must strictly comply with the FDA (Food and Drug Administration) requirements and EU EC 1935/2004 regulations regarding direct contact with human food items.
Our engineers utilize premium materials to ensure zero degradation:
Rotors and housings are cast from SUS304 or SUS316L, polished internally to prevent micro-fissures where bacteria or pests could fester.
Used primarily for structural durability in dry-cleaning areas. Provides superior thermal stability and resists deformation over decades of constant friction.
Specially designed guide rails enable operators to quickly slide the rotor out for cleaning without disassembly of the entire conveying pipeline.
Henan Jiujie Machine Co., Ltd. does not merely supply stand-alone machines; we engineer comprehensive, macro-level industrial solutions. The flour air lock sits at critical interface points throughout the modern milling ecosystem:
Following the cleaning process, dust and chaff are separated in baghouses or cyclones. Our air locks ensure that collected debris is discharged continuously without losing static pressure within the negative-pressure aspiration system, keeping the overall factory dust-free and clean.
In automated wheat milling lines (such as 30T/24H to 500T/24H capacities), the air lock handles intermediate milling fractions like break stocks, middling stocks, and finished flour. The synchronicity between the roller mill speed and the air lock discharge rate is controlled via integrated PLC control systems to ensure smooth, non-congestive grain stream flow.
Our flour milling equipment has obtained the ISO9001 quality management system certification and CE certification. The environmental protection standards of our equipment comply with relevant EU requirements. Our grain cleaning process is designed to operate without water usage, ensuring no wastewater discharge and supporting environmentally friendly production.
Our products are characterized not only by stable performance but also by easy installation, convenient maintenance, and low operating costs. With advanced technology, reliable quality, and modern design, our equipment has earned high appreciation from clients worldwide.
Henan Jiujie Machine Co., Ltd. places strong emphasis on technological innovation and continuous improvement of manufacturing capability and product quality. We have introduced a series of advanced processing equipment, including CNC laser cutting machines, CNC bending machines, and CNC lathes.
In addition, we are equipped with CNC machining centers, CNC boring machines, surface grinding machines, planers, and other high-precision manufacturing equipment. We have also established an electrostatic spraying production line to further enhance product surface quality and durability.
Our manufacturing processes include steel plate laser cutting, CNC bending, CO₂ arc welding, argon arc welding, robotic welding, and electrostatic surface treatment. These advanced production technologies ensure consistent product quality and continuous innovation.
We utilize state-of-the-art manufacturing facilities to ensure precision down to the micrometer level. Below are authentic photographs representing key machinery and critical phases in our factory production line:
Cutting
Punching
Welding
Painting
Assembling
Laser Cutting Machine
CNC Lathe
Punching Machine
Bending Machine
Painting Line
Welding Machine
Sawing Machine
As a professional industrial solution provider, Henan Jiujie Machine Co., Ltd. delivers not only equipment but also comprehensive production solutions that enhance the overall value chain for our customers. By utilizing AutoCAD-based engineering design systems and advanced machining centers, we are able to provide high-precision, durable products at competitive prices. We are committed to offering complete pre-sales consultation, technical support, and reliable after-sales service.
Every processing facility has a unique structural footprint and volumetric throughput. To match these variables, we customize the flange configurations (round or square), drive mechanisms (chain-driven, direct-coupled, or variable frequency drive), and material finishes. This level of customization ensures that the air lock mounts seamlessly with your pre-existing grain hopper, cyclone, or gravity discharge chute without costly mechanical modifications.
Looking ahead into the grain processing sector of 2025–2030, air lock designs are transforming into smart devices. The next generation of Henan Jiujie rotary valves will incorporate real-time continuous clearance sensors. By continuously monitoring the distance between the rotor tips and the casing, the system proactively notifies the operator before clearances exceed the critical 0.20mm threshold, avoiding catastrophic conveying failure and maximizing uptime.
Additionally, the incorporation of high-temperature high-wear coatings such as tungsten carbide and chrome plating will extend the service life of rotary valves operating under high-abrasion environments (handling hard grains or impurities) by up to 300%. Our focus remains centered on sustainability—reducing energy consumption by optimizing rotor pocket geometries to prevent product packing and subsequent rotor drag.
Gain essential knowledge about flour air lock design, installation, and operation. These answers provide insight from our two decades of production experience:
For standard flour milling applications, the optimal clearance range is between 0.10mm and 0.15mm. If the clearance is narrower than 0.10mm, thermal expansion can cause the rotor to bind with the housing. If the clearance exceeds 0.20mm, high-pressure air leakage occurs, dramatically decreasing conveying system efficiency and increasing dust propagation.
Flour dust is highly combustible. During pneumatic conveying, electrostatic discharge or mechanical friction can trigger a dust explosion. A certified rotary airlock valve serves as a mechanical barrier that prevents the explosion shockwave and flame front from propagating into upstream storage bins or silos, protecting human life and assets.
Regular maintenance involves verifying rotor clearances using feeler gauges, checking shaft seal integrity, and lubricating the drive chain and outer bearings. Models fitted with quick-clean slide rails enable operators to inspect and clean internal surfaces rapidly without dismantling the structural pipeline components.
For food contact surfaces in the EU, the materials must comply with Regulation EC 1935/2004, whereas mechanical aspects must meet the Machinery Directive and carry a CE mark. For combustible environments, the components must have ATEX certification to guarantee suitability under dust-explosion hazard zoning.
Explore our comprehensive lineup of processing and sizing machinery. These units are frequently integrated alongside our air locks within mill flowsheets to optimize particle classification and packaging.
Jiujie Machine
