A non-jet atmospheric pressure large-volume microwave plasma generation method

Abstract

The invention discloses a method for generating non-jet flow atmospheric pressure large-volume microwave plasma, which belongs to the field of microwave plasma technology, and is characterized in that it comprises the following steps: a. Start the igniter, inject the generated small plasma or chemical flame into In the conical cavity; b. Start the microwave source, and input microwaves into the reaction cavity through the microwave feed port; c. Turn off the igniter, increase the microwave power of the microwave source, and the small plasma in the conical cavity is amplified to obtain a non-jet flow , Atmospheric pressure high power and large volume microwave plasma. The invention can achieve sufficient and uniform heating of the gas to be treated, improve the reaction efficiency, and can be uniformly distributed within the set space range, can effectively prevent destructive breakdown discharge, and is easy to control the heat dissipation balance, in the case of minimizing heat dissipation Under this condition, the temperature of the entire generator is guaranteed to be reasonable, the structure is stable, and long-term operation stability is realized; the entire operation process is simple, reliable, and easy to control.

Description

technical field [0001] The invention relates to the technical field of microwave plasma, in particular to a non-jet atmospheric pressure large-volume microwave plasma generation method. Background technique [0002] Plasma is the fourth state of existence of matter, usually refers to ionized or partially ionized conductive gas, which includes six typical particles: electrons, positive ions, negative ions, excited atoms or molecules, ground state atoms or molecules and photons. Whether it is partially ionized or fully ionized; the total number of negative charges is equal to the total number of positive charges, so it is called plasma, and it is generally electrically neutral in time and space at the macroscopic scale. The stricter definition is: Plasma is a collection of electrons, positive ions and neutral particles that are electrically neutral as a whole. [0003] Plasma is divided into two categories according to temperature: high temperature plasma and low temperature...

AI Technical Summary

Problems solved by technology

However, a large amount of auxiliary gas is required to effectively confine and orient the plasma, and a large amount of gas to be treated cannot pass through the plasma region and cannot produce effective reactions; and the gas passing through the plasma region may have adverse side reactions due to excessive temperature, making the Material utilization, processing efficiency and processing effect have all become poorer

In addition, if the microwave power is too large and the plasma temperature and concentration are too high, it will be difficult for the auxiliary gas to reliably confine the plasma and form a jet, which will eventually lead to unstable operation or damage to the device

Moreover, the addition of a large amount of auxiliary gas not only increases the processing burden of the microwave plasma device, but also increases the separation burden of subsequent devices, and also reduces the reaction efficiency.

In addition, because the plasma start-up area of ​​this type of device is the same area as the subsequent continuous work area, the microwave power density in the work area is very high during low-power operation. If a high-power plasma device is required, the microwave power density in the work area, plasma The body temperature and concentration will be extremely high. At this time, limited by the microwave transmission system structure and heat dissipation, the microwave power that can be loaded is small and the upper limit of the power is low, which is greatly limited. For industrial applications, tens of kilowatts, hundreds of kilowatts, The long-term continuous application of the kilowatt level is still unsatisfactory

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