Characteristics, uses, protection, and maintenance of laboratory electric constant temperature dryin

A、 box

a、 Box shell: The outer shell is made of thin iron plate (or thin steel plate). The box wall is mostly divided into three layers (including the outer shell), with two inner and outer layers formed between the three layers of iron plates. The outer layer is filled with insulation material (glass fiber or asbestos board), and the inner layer serves as a hot air convection layer.
b、 Constant temperature chamber: The space surrounded by the innermost iron plate is called a constant temperature chamber. There are 2-3 layers of mesh shelves indoors for placing items. The temperature sensing part of the temperature controller (i.e. the temperature sensing probe) extends into the constant temperature chamber from the left wall. There is an electric heating wire installed in the bottom interlayer.
c、 Box doors: usually double type. The inner door is a glass door used to observe baked items while reducing heat loss. The outer door is used for thermal insulation.
d、 Inlet and exhaust holes: There is an inlet hole at the bottom or side, through which dry air enters. There is a vent on the top of the box, and an adjustable exhaust window is installed at its outlet to allow steam to escape. Insert a thermometer into the exhaust window to indicate the temperature inside the box
e、 Side room: It is the control room. Generally located on the left side of the box, insulated from the constant temperature chamber. It is equipped with switches, indicator lights, temperature controllers, blowers and other electrical components. Opening the side chamber door allows for easy maintenance of circuits outside of the heating wire. Some electric heating boxes also have the control room located below the box
B、 Electric heater
The electric heater of the drying oven is usually composed of four parallel electric heating wires. The electric heating wire is uniformly wound around an insulation board made of refractory material. Generally divided into two groups, controlled by a conversion switch. The total power is (2-4) kW, with the highest power reaching up to 8 kW. The greater the power, the larger the box.
C、 Temperature controller
The temperature control system used on the drying oven usually includes two types: differential rod type and mercury thermometer type. The temperature control system used on drying ovens produced in recent years mainly consists of temperature sensors, temperature control circuits, relays, temperature settings, and temperature display parts.
3、 Main features
1. The electric heater is installed under the working chamber inside the box.

2. The drying oven can reach high temperatures of 250 ℃, 300 ℃, even 400 ℃, 500 ℃, and 1000 ℃.

4、 Preparation before use
1. The box is placed indoors in a dry and level place, without the need for other fixed devices.
2. One iron shell knife switch should be installed in the power supply line for the dedicated use of this box, and a wire twice the thickness of the power line should be used as the grounding wire and effectively grounded.
3. Before powering on, check if the voltage of this box matches, and calculate the current based on the total working rate. Connect the corresponding power cord.
4. When everything is ready, the test sample can be placed, the box door can be closed, and the power can be connected to start working.
5. The side door cannot be removed arbitrarily, causing confusion or changing the circuit. Only when the box malfunctions can the side door be removed. Check each line one by one. If there is a major malfunction, please contact our factory and maintenance center.  
Usage after power on:
6. After connecting to the power supply, the power heating switch can be turned on. When the desired temperature is above 150 ℃, it can be switched to high temperature mode. Otherwise, there is no need to turn on the high temperature switch. Just turn the temperature controller knob clockwise from the "O" position to the desired temperature point. At this point, the temperature inside the box will start to rise, and the green light on the instrument will light up as an indicator. At the same time, the blower switch can be turned on to start the blower.  
7. When the temperature reaches the required working temperature, the green light goes out and the red light comes on. The indicator light alternates between on and off at this point, which is the constant temperature setting. At the constant temperature point, it is likely that the temperature will continue to rise, which is due to the influence of residual heat and will stabilize after about half an hour. When the indoor temperature stabilizes, the red numbers of the 101A and 202A models will display. When the reading exceeds or falls below the desired temperature, the knob can be adjusted slightly to achieve the correct level.
8. After the temperature is kept constant, it can be kept constant for a certain period of time according to the needs of the experiment. During this process, an internal temperature controller can be used to automatically control the temperature without the need for manual management.
9. To observe the condition of the samples in the studio, you can open the box door and use a glass door or observation door inside the box to observe. But it is advisable to keep the door closed infrequently to avoid affecting the constant temperature, and when the temperature rises to 300 ℃, opening the door may cause the glass door to cool rapidly and break.
10. When using this box, please also read the instrument manual.
11. When using a new box, there should be humidity, which may cause hot air evaporation and paint burning smell. This is due to the evaporation of the constant temperature paint surface, which will disappear after one hour of use.