Product Overview: Hot Air Circulation Oven

A hot air circulation oven typically features heating elements and a circulating fan, making any oven with these characteristics a hot air circulation oven. This is because, regardless of the oven's structure, whether the air flow is horizontal or vertical, the essence is that hot air circulates within. Therefore, such ovens are commonly referred to as hot air circulation ovens, including electric hot air forced-air ovens, double-door high-temperature sterilization ovens, and more. However, in the industry, the term "hot air circulation oven" most often specifically refers to the oven shown in the image above. Other ovens are derived from this design. For instance, if high-temperature sterilization is required, the fan is replaced with a standardized air-cooled circulator fan, the door is changed to a double-door design, and the air duct is modified, resulting in a double-door high-temperature sterilization oven. The hot air circulation oven shown in the image comes in five standard models: single door, single car; double door, double car; double door, four cars; triple door, six cars; and quadruple door, eight cars.

Principle of Operation for Hot Air Circulation Oven

The hot air circulation oven's air circulation system utilizes a fan to circulate air evenly and efficiently. The air source is driven by a circulating fan motor (equipped with a contactless switch) to rotate the impeller through the intermediate heater, expelling hot air. This air then travels through the middle duct to the oven's inner chamber. Afterward, the used air is drawn back into the duct to become the air source for another cycle, heating and recirculating to ensure uniformity of the internal humidity. In the event of temperature fluctuations caused by door operations, the air circulation system quickly returns to operational status until it reaches the oven's set temperature.

Hot Air Recirculation Oven Control System

1. The oven features a digital temperature controller with PID control, equipped with a thermosensitive probe for automatic constant temperature control, offering precise and sensitive temperature control. The temperature range is from room temperature to 250°C, with any setting option. The oven's internal temperature can be directly read from the gauge. 2. Timer control for the oven: The timer range is from 0S to 99.9H, allowing customers to choose the oven's control method (start-up timing or constant temperature timing) based on their work requirements. After reaching the set time, the oven automatically cuts off the heating. The setting can be directly adjusted on the oven's control panel, with the code units being S for seconds, M for minutes, and H for hours. 3. The temperature control section is the core of the hot air circulation oven, mainly comparing the temperature signal detected by the sensor with the set value. If the sensor's reading is below the set value, the temperature controller outputs a pulse signal to trigger the thyristor control board, putting the oven in a heating state. If it's above or equal to the set value, the thyristor stops working, and the heating system is disconnected. Our product uses a PID controller, which includes three basic control laws: Proportional (P), Integral (I), and Derivative (D). Each control law serves a different purpose and can be applied individually or in combination. The controller employs an effective control method for objects with significant lag characteristics, known as the Anti-Integral Saturation PID control method: when there is a deviation between the actual and set values, the gauge outputs continuous heating until the actual value equals the set value. Due to the derivative's role, the gauge also has a lead adjustment function, improving dynamic control and shortening adjustment time, with the LCD displaying the readings. The sensor used is the commonly used Pt100, with switch output. This controller, along with an AC contactor and existing switches, fuses, and alarm lights, forms the control circuit, where AC220V is connected to the "normally open" terminal of the AC contactor, and the switch quantity of the temperature controller controls the energizing coil of the AC contactor to achieve the control purpose.

4. Hot air circulation ovens can also be configured with a PLC touch screen intelligent control system according to the actual needs of the customer.

Technical Parameters of Hot Air Circulation Oven

Heating Sources: Steam, Electric, Far-Infrared, and Electric Steam Dual-Use.

Operating Temperature: Steam heating: 50~140°C, up to 150°C. Electric and far infrared heating: 50~350°C.

8 Control Systems: The hot air circulation oven is equipped with an automatic control system and a computer control system.

Steam Pressure: 0.02-0.8 Mpa (0.2-8 kgf/cm²)

Power Consumption: Equipped with an electrically heated 0-type hot air circulation oven, calculated at 9kW, practical usage is 3-5kW/h. 5.

6. Special requirements for the oven should be stated upon ordering.

7. Please specify if the oven operating temperature is to exceed 140°C or fall below 60°C at the time of order.

Our factory's oven cars are factory-fresh, with uniform baking tray sizes that are interchangeable. 8.

9. Pan Size: 460x640x45mm。

V. Operation Procedure for Hot Air Circulation Oven

Use the oven within the temperature range specified on the oven label, ensuring the oven remains properly grounded.

No flammable items such as oil pans, barrels, cotton, and fabric shavings should be stored near the oven, and activities like washing, sanding, and painting should not be conducted beside the oven. 2

3. Select a high-temperature-resistant power cable of the appropriate specification and properly connect the ground wire as required.

4. To avoid disrupting the oven's constant temperature, minimize the number of door openings. If there is a glass door, observe through the glass.

5. No items, such as tools, equipment parts, or volatile oil substances, are to be stored inside the oven.

6. Parts and items that have been cleaned with gasoline, kerosene, alcohol, or香蕉水 (banana water) as flammable liquids, and items that have been painted, should be left at room temperature for 15-30 minutes after most of the flammable liquids have evaporated before being placed in an oven for baking. Ventilation in the room should be ensured.

7. Cleaning is prohibited while the oven is in operation, and it is strictly forbidden to wipe it with gasoline.

8. Non-metallic items should be heated in a hot air circulation oven, strictly following the process specifications.

9. Prior to use, inspect the self-control device of the hot air circulation oven. Ensure that the indicator signals are sensitive and effective, and that the electrical circuit insulation is intact and reliable.