High-efficiency and stable operation reduced energy consumption labor-saving and maintenance-free

   The WGH series continuous grain dryer is a continuous-duty drying system developed by Zhengzhou Wangu Machinery for grain collection and storage depots, processing plants and seed-production operations. Built around a concurrent–mixed-flow drying process with multi-stage tempering and counter-flow cooling, the unit removes a large amount of moisture in a single pass and handles maize, paddy rice, wheat, soybean, sorghum and rapeseed as well as other oil crops. The vertical tower design allows stand-alone outdoor installation and integrates readily with cleaning, conveying and storage equipment to form a complete post-harvest handling line.

Drying Process

   After cleaning and weighing, grain is lifted to the tower top by the bucket elevator and then descends continuously under gravity through preheating, multi-stage concurrent–mixed-flow drying, inter-stage tempering and counter-flow cooling. Inside the drying sections the air and the grain stream cross and reverse several times, producing a repeating cycle of concurrent heating, mixed-flow equalisation and tempering. The grain surface is warmed first; the tempering stage then lets moisture inside the kernel migrate outwards, so the internal moisture gradient is reduced step by step and no surface crust forms to block further drying.

   Hot air is supplied by an independent furnace with its temperature capped by grain type — not above 55 °C for maize and not above 35 °C for paddy. Together with high air volume and low air temperature, this keeps grain temperature under control. Exhaust air recovered from the cooling section is ducted back to preheat incoming fresh air, raising overall thermal efficiency and cutting standard-coal consumption by roughly 7–8 %. Grain leaves the tower close to ambient temperature and can be binned immediately without a second cooling pass.

Configuration

· Tower body: segmental steel structure assembled on site, hot-dip galvanised, supplied with service platforms and ladders; suitable for outdoor installation without a building.

· Angular-duct air-distribution layers: staggered banks of angular ducts form the supply and exhaust channels, giving uniform air flow across the grain section with no dead zones.

· Bucket elevator: draws grain from the ground intake pit and lifts it to the tower top, with belt-deviation and slip monitoring and an adjustable feed rate.

· Top distributor: a rotating spreader scatters the grain stream so that the load surface stays level, preventing off-centre loading and local piling.

· Drying and tempering sections: alternate along the tower, with tempering volume enlarged stepwise by model to allow sufficient time for internal moisture migration.

· Counter-flow cooling section: cooling air rises through the descending grain bed, so discharged grain is close to ambient temperature.

· Discharge mechanism: variable-frequency impeller discharge with stepless output control, which sets residence time and final moisture.

· Heat source: coal, biomass, oil or gas hot-air furnace, or a steam heat exchanger, selected to match local fuel availability.

· Dust collection and air circuit: cyclone, ductwork and fan form an independent air circuit that controls dust in the exhaust and in the working area.

· Control system: PLC with touch screen, providing on-line moisture measurement, multi-point grain temperature monitoring, full-load and blockage alarms and interlocked shutdown.

Key Features

· High moisture removal per pass: grain at high moisture is brought to safe storage moisture in one pass, with up to 16 percentage points removed, cutting repeat runs and double handling.

· Uniform discharge moisture: where incoming non-uniformity does not exceed 3 %, discharge non-uniformity stays below 2 %, so batches can be binned together directly.

· Low kernel damage: the low-temperature, high-air-volume process keeps the paddy cracking increase below 1.5 % and broken-grain increase low, which suits seed grain and high-value crops.

· Strong energy performance: exhaust-air recovery and a compact process layout reduce installed power, saving 30–40 % electricity and 7–8 % coal at equal capacity.

· Multi-grain compatibility: stored recipes adjust air temperature, discharge speed and tempering time together when switching grain, shortening changeover and limiting cross-contamination.

· Durable construction: galvanised tower body plus wear-resistant buckets and discharge impellers support continuous full-load running through the harvest season.

· Site flexibility: outdoor installation with segmental transport and on-site assembly suits space-constrained greenfield projects and upgrades of existing depots.

· Certification support: several models hold agricultural machinery promotion certification, so buyers can apply for purchase subsidies under local rules.

Applications

   The dryer serves central grain depots, collection points, oil and grain processing plants, rice mills, flour mills, seed-processing companies and agricultural cooperatives, and is also used for turnover drying at drying centres, ports and logistics hubs. Heating is indirect: flue gas never touches the grain bed and the drying medium is clean air, so the discharged grain is uncontaminated. Once cooled, grain can be stored long term, reducing losses from mould and sprouting.

Packaging and Warranty

    The tower body ships as bare segments, while frames, fans and control cabinets are packed with reinforced protection against moisture, corrosion and impact; customised packing is available. Export shipments are loaded according to container or bulk-vessel stowage plans. Each unit is supplied with general arrangement drawings, foundation drawings, electrical schematics, an operation manual and a factory certificate. Production follows an ISO quality management system, and every unit is test-run and interlock-tested before dispatch.

    The main frame and core components carry a 12-month warranty. On-line technical support is provided during the warranty period, spare parts remain available afterwards, and engineers can be dispatched for on-site installation supervision, commissioning and operator training. Minimum order quantity: one unit. Delivery lead time: 40–50 days. Payment: T/T advance payment or sight L/C.

Selection and Quotation

   To determine the right model and configuration, please tell us your required daily capacity (t/d), the main grain to be dried and the fuel available locally. On that basis we will define the tower size, the drying-to-tempering ratio and the heat source, and issue a technical proposal with a formal quotation.