What is the difference between a pipe electric heater and an electric heater of the air duct?

Whether in industrial production or in scientific research, electric heater is a heating and insulation equipment which is frequently used frequently. During its processing, the temperature rise and fall are often strictly controlled. Under the impetus of computer technology, the electric heating of this kind of temperature control skill has also made great progress.

The control system of electric heater can be divided into two categories. One is the hybrid control mode. It needs to connect the electric heater and the control system first before it can be controlled. In contrast, the system of this control method is complex and the cost required is high.

On the other hand, due to the transformation links of output channels in electric heater, especially after the transformation of analog data, the nonlinearity is more serious, resulting in poor anti-interference performance and low control accuracy. In addition, the reliability of this control method is also poor, and it is easy to fail.

Another is the pure computer controlled electric heater, this control mode is completely different, at its output to remove the D/A transform, voltage signal expansion, high-voltage pulse signal transform link directly with the pulse signal TTL level to control the on-off of solid-state relay, and a solid state relay to control the on-off of the electric heater, which greatly simplifies the control process of electric heater.

Not only that, but also overcome the defects of the first control mode, giving full play to the advantages of computer technology, making the electric heater not only reduce the cost greatly, but also improve the handling accuracy greatly. In addition, its anti-interference function and reliability are also more guaranteed, which is the basis for the safe, efficient and stable operation of the electric heater.

There are two kinds of electric heaters that are often used to heat the air, one is a pipe type electric heater and the other is an electric heater of the air duct. These two devices have different features, and how do we choose the electric heaters suitable for ourselves?

The first thing to see is a tubular electric heater, which is mainly used to heat the required air flow from the initial temperature to the required air temperature, and the heating temperature is as high as 850 degrees. For the time being, this powerful electric heating has been widely applied to many laboratories, such as aerospace, ordnance industry, chemical industry and universities, etc., especially for automatic temperature control and large flow high temperature combined system and accessories test.

Pipeline type electric heater as a typical air electric heater, use a very wide range, not only can be heated for any gas, and produces hot air dry without water, no conductivity, no burning, no explosion, no chemical corrosion, no pollution, is absolutely safe and reliable.

Look at the air duct heaters that are completely different from the pipe electric heaters, which focus on heating the air in the air duct. If the temperature height is distinguished, the air duct heater can be divided into three forms of low temperature, medium temperature and high temperature.

The three kinds of air channel heaters have the same structure. They all use steel plate to support the electric heating tube, so as to reduce the vibration of the electric heating tube and connect the junction box with the over temperature control device. In the control of electric heater, besides the over temperature protection, the intermodal device must be added between the fan and heater to ensure that the electric heater must start after the fan starts.

In addition, it is necessary to add a differential pressure device before and after the heater of the air duct to prevent the failure of the fan. The pressure on the air of the air duct heater should not exceed 0.3Kg/cm2 generally. If it exceeds the pressure specification above, it needs to be replaced by a circulating electric heater.