Hot Air Circulating Oven
Drying Equipment
1. Product Overview
A hot air circulation oven is a chamber-style dryer that uses forced hot-air convection to bake and dry materials. It is built from an oven body, a heating system (steam / electric / thermal oil), a circulation fan, an exhaust (moisture removal) system, drying carts, and trays. Typical applications include pharmaceuticals, chemicals, food, and agricultural products. Key benefits: even airflow distribution, consistent temperature, broad applicability, simple operation and maintenance, and high batch capacity.
2. Working Principle
The heat source warms the air, which the circulation fan forces through the duct and across the material bed on the trays. Hot air transfers heat and carries away moisture; a portion of the humid exhaust is expelled by the exhaust fan, while the majority returns to the heating chamber for reheating and recirculation. The cycle continues until the material reaches the target moisture content.
3. System Classification
By Airflow Method:
Side-Air Oven: hot air enters from the side and passes through the trays — suited to conventional powders, granules, and lumps.
Bottom-Air (or Top-Air) Oven: hot air penetrates vertically from the bottom (or top) — for thick, deeply stacked materials with low air-resistance requirements.
Double-Door / Multi-Door Oven: an extended chamber with two or more doors — for large-batch continuous production.
4. Detailed Technical Parameters
4.1 Common Materials
| Material | Applicable Components | Remarks |
|---|---|---|
| 304 Stainless Steel | Inner chamber, trays, drying cart | GMP compliant, easy to clean |
| Carbon Steel Q235B | Outer shell, frame | External anti-corrosion coating, low cost |
| 316L Stainless Steel | Parts contacting corrosive materials | Excellent corrosion resistance |
4.2 Typical Specification Table
| Drying Capacity per Batch | Circulation Fan Power | Heat Dissipation Area (m²) | Number of Trays (640x460mm) | Steam Consumption (kg/h) |
|---|---|---|---|---|
| 50～100 | 0.75～1.5 | 15～25 | 24～48 | 30～60 |
| 100～500 | 1.5～5.5 | 25～60 | 48～96 | 60～150 |
| 500～1500 | 5.5～11 | 60～120 | 96～192 | 150～400 |
4.3 Design Conditions & Performance
| Parameter | Specification |
|---|---|
| Drying Temperature | 50℃～250℃ (depending on material and heat source) |
| Temperature Uniformity | ≤±2℃ (no-load steady state) |
| Fan Type | Low-noise centrifugal fan, high-temp resistant |
| Air Exchange Volume | Controlled by adjustable moisture exhaust dampers |
5. Electrical Parameters
| Region | Voltage | Frequency |
|---|---|---|
| China/Russia/Central Asia | 380V | 50Hz |
| Middle East/Southeast Asia/Africa | 400V / 415V | 50Hz |
| South Korea | 380V | 60Hz |
| Americas (if required) | 440V / 480V | 60Hz |
| Note: Circulation fan, exhaust fan, and electric heating tubes must have specified voltage and frequency. |
6. Core Component Selection
| Component | Brand/Material | Features & Applications |
|---|---|---|
| Circulation Fan | National standard/Custom | SS/Painted impeller, high-temp long-shaft motor |
| Heater | Custom matched | SS finned tube/Electric heating tube, high efficiency |
| Trays | Custom processing | 304 SS perforated/solid/one-piece formed trays |
| Insulation Layer | Rock wool/Silicate aluminum | 50～100mm thickness, low heat loss |
7. Typical Application Fields
Pharmaceuticals: drying of TCM slices, APIs, and granules.
Food: nut roasting, fruit and vegetable dehydration, meat drying.
Chemicals: pigments, resins, and chemical-powder drying.
Agricultural products: timber and agricultural by-product drying.
8. Design Standards & Certifications
| Standard | Description |
|---|---|
| JB/T 5520-2018 | Technical conditions for drying ovens |
| ISO 9001:2015 | Quality Management System |
| GMP | Good Manufacturing Practice |
| CE / EAC / GOST-R | Available upon request for international orders |
9. Custom Optional Configurations
| Option | Details |
|---|---|
| Heating Method | Steam / Electric / Thermal oil / Gas |
| Control Method | Digital temp controller / PLC + touch screen, auto temp & exhaust |
| Tray Type | Perforated / Woven mesh / Teflon-coated trays |
| Special Design | Explosion-proof / Exhaust condensation recovery / Insulation upgrade |
10. Warranty Terms
| Equipment Status | Warranty Period | Warranty Scope |
|---|---|---|
| Brand New | 12 months | Oven structure, heating system, fan system |
| Refurbished | 6 months | Oven structure, heating system, fan system |
| Idle | 3 months | Main functional components |
11. Packaging & Delivery
| Item | Packaging Method |
|---|---|
| Main Oven Body | Tarpaulin wrapped, wooden skid base |
| Carts / Trays | Bubble wrap protected, strapped down |
| Electrical / Fans | Waterproof sealed packaging in wooden cases |
| Container or bulk shipping. On-site installation and commissioning guidance available. |
12. Information Required for Inquiry
12. Information Required for Inquiry: material name, initial and final moisture content; material form and bulk density; batch capacity; drying temperature limits; heating source type; explosion-proof requirements; preferred equipment condition (new / refurbished / idle); delivery terms (FOB / CIF / DDP); destination port.