A regulating electric furnace is a heating device that can regulate the amount of heat generated

Electric furnaces, also known as electric heaters, are commonly used in elemental analysis instruments and are a commonly used heating equipment in analysis rooms. It generates heat by energizing a nickel-chromium alloy resistance wire, which is called an electric furnace wire. According to the structure and function of electric furnaces, they can be divided into two types: ordinary electric furnaces and universal electric furnaces. 1. Ordinary electric stove. An electric furnace wire is embedded in the groove of a circular furnace plate made of refractory clay. The furnace plate is fixed on a circular iron plate base with good mechanical strength and heat resistance. Both ends of the resistance wire are covered with many small porcelains. The tube is connected to the terminal, and the terminal is connected to the power cord, forming an ordinary disc electric stove. A disc-type electric furnace that completely covers the electric furnace wire with a thin steel plate is called a concealed electric furnace and is used for experiments that cannot be heated by an open flame. If the electric furnace is marked with "220V, 1000W", it means that when the power supply voltage of the electric furnace is 220V, its electric power is 1000W.

Universal electric stove. The universal electric furnace variable scale electric furnace is a heating device that can adjust the amount of heat generated. There are several types such as single, double, quadruple, and six. The front panel of the furnace shell is equipped with a temperature selection sign and a temperature adjustment knob for control. There are several contact points on the multi-position switch, and an additional resistor is installed between each two contact points. The additional resistors are covered with many sections of small porcelain tubes to avoid short circuits with each other, or contact with the furnace shell and leakage of electricity that could hurt people. . The multi-position switch uses the rotation of the sliding metal piece to change the size of the additional resistance in series with the electric furnace wire to adjust the intensity of the current passing through the electric furnace wire to achieve the purpose of adjusting the heat generated by the electric furnace.

Common precautions for using heating equipment

1. Electric constant temperature water bath

Electric constant temperature water baths are used in medical units, colleges and universities, scientific research departments and production units for evaporation, drying, concentration, constant temperature heating, etc.

When using an electric constant temperature water bath, you should pay attention to the following matters:

1) Before using the constant temperature water bath, be sure to inject an appropriate amount of purified water. Pay attention to replenishing clean water in time during use, because the furnace wire casing is welded and sealed. Heating without water will burn the casing, causing water to enter the casing and damage the furnace wire or cause leakage.

2) There is a bimetal spring-type device in the automatic temperature control box, which controls the temperature through the expansion or contraction of the bimetal or by connecting or cutting off the power supply. Be careful not to let the box get splashed with water or get damp to prevent control failure, leakage or damage.

3) The water bath should be kept clean and cleaned regularly to prevent rust, water leakage and electricity leakage. The water in the tank should be changed frequently. If it is used for a long time, all the water in the box should be drained and wiped dry with a cloth to avoid rust.

2. Safety technical operating procedures for box-type resistance furnaces

(1) Do not exceed the maximum temperature of the resistance furnace during use.

(2) Be sure to cut off the power supply when loading and removing samples to prevent electric shock.

(3) When loading and taking samples, the furnace door opening time should be as short as possible to extend the service life of the electric furnace.

(4) It is prohibited to pour any liquid into the furnace.

(5）Do not put samples stained with water or oil into the furnace, and do not use clamps stained with water or oil to pick up samples.

(6) Wear special gloves when loading and taking samples to prevent burns.

(7) The sample should be placed in the middle of the furnace and placed neatly. Do not place it randomly.

(8) Do not touch the electric furnace and surrounding samples casually.

(9) After use, the power and water source should be cut off.

(10) Resistance furnaces are not allowed to be operated without the permission of the management personnel, and operations must be strictly carried out in accordance with the operating procedures of the equipment.

3. Electric thermostat

The electric thermostatic oven commonly used in laboratories has a maximum temperature of 200°C or 300°C and is called a drying oven or industrial oven. The most commonly used temperature is 100-150°C, which is mostly used to dry samples or dry glass containers.

When using an electric thermostat, you should pay attention to the following matters:

(1) The drying box should be operated indoors, installed at a stable level, kept dry, moisture-proof and moisture-proof, and prevented from corrosion.

(2) The drying box should be placed at a certain distance, and it is recommended that it be at least 2M away from the wall on all sides.

(3) Check the voltage of the drying oven before use. The voltage required for the smaller oven is 220V, and the voltage required for the larger oven is 380V (three-phase four-wire). Install a power switch with sufficient capacity according to the power consumption of the oven. And select appropriate power cords. Grounding wire work should also be done well.

(4) After the above work is ready, the sample can be placed into the drying oven, then connect the power supply, turn on the oven switch, and the oven with a blower device must turn on the blower during the heating and constant temperature process, otherwise it will affect the temperature of the studio. uniformity and may damage the heating element. Then adjust the temperature suitable for drying the sample. The oven will enter the working state.

(5) The items to be baked should not be arranged too densely. Do not place objects on the bottom of the drying box (heat sink) to avoid affecting the hot air circulation. It is prohibited to bake flammable, explosive, volatile and corrosive items.

(6) After drying, cut off the power supply before opening the studio door. Remember not to touch the items being baked directly with your hands. Use special tools or wear insulated gloves to pick up the items being dried to avoid burns.

(7) The drying box working room should be kept clean.

(8) When using a drying oven, the temperature must not exceed the maximum operating temperature of the oven.