CN106785819A - An electrically excited singlet oxygen generator - Google Patents

Abstract

A kind of electric excitation creating singlet oxygen generating means.The device is made up of following part：Electric discharge produces area, catalysis enhancement region and air-flow cooling zone.Electric discharge produces area to be made up of discharge cavity and sparking electrode, and discharge cavity is constituted for inside and outside two cylindric quartz glass tubes, and sparking electrode is made up of cylindrical metal pipe, positioned at the outside of discharge cavity；Catalysis enhancement region is located at the downstream that electric discharge produces area, and by many sliver transvers sections for the gas channel of regular hexagon is constituted, gas channel inwall scribbles oxide catalyst layer；Air-flow cooling zone is located at the downstream of catalysis enhancement region, and many cooling tubes are staggeredly distributed with perpendicular to airflow direction, and cooling Bottomhole pressure liquid coolant.This creating singlet oxygen generating means can effectively improve the absolute Particle number concentration of creating singlet oxygen, it is expected to be applied to electric excitation oxygen-iodine laser.

Description

An electrically excited singlet oxygen generator

technical field

The present invention relates to the technology of generating singlet oxygen by electrical excitation, specifically a method for effectively increasing the total gas pressure and flow rate of singlet oxygen generated by discharge, increasing the absolute concentration of singlet oxygen generated by discharge, and reducing the outlet gas temperature A device that can be used for electro-excited oxygen-iodine lasers.

Background technique

The electro-excited oxygen iodine laser uses oxygen discharge to generate singlet oxygen. It has more advantages due to its safe and non-toxic raw materials, full gas phase operation, and stronger adaptability. This device that generates singlet oxygen by means of a discharge is called an electro-excited singlet oxygen generator, and the factors that affect the performance of an electro-excited singlet oxygen generator generally include, singlet oxygen production rate (i.e. singlet oxygen percentage of total oxygen), total gas pressure, absolute concentration of singlet oxygen, percentage of harmful species (mainly oxygen atoms), outlet gas temperature, etc., these factors will affect the small signal gain of the electro-excited oxygen iodine laser and power scaling capabilities. Therefore, a good electro-excited singlet oxygen generator should have the following characteristics: high total gas pressure, high singlet oxygen yield, high absolute concentration of singlet oxygen, and low outlet gas temperature.

As we all know, the small-signal gain of the oxygen-iodine laser increases with the decrease of temperature, so the gas temperature in the optical cavity area is required to be very low, and it generally operates at supersonic speed. When supersonic expansion occurs, the temperature decreases rapidly, and the larger the Mach number, the more the temperature decreases, which is more beneficial for small signal gain. Considering that under a certain Mach number condition, the pressure of the optical cavity is proportional to the pressure of the upstream discharge cavity, so in order to ensure that the absolute concentration of singlet oxygen in the optical cavity area is high, the gas pressure in the discharge area must be very large. , that is to say, the discharge process should be operated at a higher gas pressure.

In addition, the gas temperature at the outlet of the discharge is generally very high. In order to reduce the gas temperature in the optical cavity area, in addition to the supersonic operation, the gas can also be pre-cooled before it enters the optical cavity, which requires the use of gas cooling unit.

The study found that oxygen atoms have a greater quenching effect on singlet oxygen, and it is mainly through the three-body collision quenching process: O ₂ (a ¹ Δ)+O+M→O ₂ +O+M, k = 1x10 ^-32 cm ⁶ /s, where M is the third body collision partner (typically O ₂ ). Therefore it can be seen that when the total gas pressure increases gradually, the production rate of singlet oxygen then decreases, and the higher singlet oxygen production rate is obtained at a lower discharge gas pressure (oxygen fraction pressure is less than 2torr). It can also be seen that singlet oxygen is also severely quenched when oxygen atoms are present, leading to a decrease in the yield of singlet oxygen.

In order to increase the discharge gas pressure, it can be achieved by shortening the distance between the discharge electrodes. The study found that when the distance between the discharge electrodes is shortened, the relative yield of singlet oxygen can not be significantly reduced under higher gas pressure.

In order to minimize the damage of oxygen atoms to singlet oxygen, it is necessary to capture as many oxygen atoms as possible through chemical reactions, reduce the concentration of oxygen atoms, and increase the yield of singlet oxygen.

To sum up, in order to realize a good electro-excited singlet oxygen generator, the conditions that need to be satisfied should include: high gas pressure, low gas temperature, and low concentration of oxygen atoms.

In order to achieve this goal, we invented an electro-excited singlet oxygen generator that can convert oxygen atoms into singlet oxygen molecules through catalytic action, and can significantly reduce the outlet gas temperature.

Contents of the invention

The purpose of the present invention is to design and manufacture an electro-excited singlet oxygen generator with high singlet oxygen yield, high total gas pressure and low gas temperature, which is suitable for electro-excited oxygen-iodine lasers.

In order to achieve the above object, the present invention proposes an electric excitation singlet oxygen generator, and the specific technical solution includes: a discharge generation area, a catalytic enhancement area and an airflow cooling area.

The discharge generating area is composed of a discharge chamber and a discharge electrode. The discharge chamber includes two cylindrical quartz glass tubes, one is an inner tube with an open left end and a closed right end, and the other is an outer tube with openings at both left and right ends. In the outer tube, the cavity between the inner tube and the outer tube forms the discharge chamber; the discharge electrode includes two cylindrical metal electrodes, one is the inner electrode, which is placed inside the inner tube of the discharge chamber, and the other is the outer electrode. Sleeved on the outside of the outer tube of the discharge chamber;

The catalytic enhancement area is located downstream of the discharge generation area, and is composed of more than two parallel airflow channels. The inlet at the left end of the airflow channel is connected to the opening at the right end of the discharge chamber, and the inner wall of the airflow channel is coated with a catalytic layer of iodine oxide or mercury oxide;

The airflow cooling zone is located downstream of the catalytic enhancement zone. It is a cylindrical structure with openings at both left and right ends. The outlet at the right end of the airflow channel communicates with the left open end of the cylindrical structure. There are more than two cooling pipes distributed along the direction perpendicular to the airflow inside the cylindrical structure, and liquid coolant flows in the cooling pipes.

The gap between the outer wall of the inner tube and the inner wall of the outer tube is 2-8 mm.

The outer tube, the cylindrical metal electrode sheathed outside the outer tube, the inner tube, and the cylindrical metal tube inside the inner tube are coaxial.

The cross-section of the gas flow channel in the catalytic enhancement zone is a regular hexagon, the diameter of its circumscribed circle is 5 mm, and the wall thickness of the gas flow channel is 0.5 mm.

The temperature range of the liquid coolant in the cooling pipe is -30 to 30 degrees Celsius.

The catalytic layer can partially convert oxygen atoms into singlet oxygen; the shape of the cooling pipe is cylindrical, and the cooling pipe is made of metal copper with good thermal conductivity.

The beneficial effects of the present invention are:

1. By using the quartz glass circular sleeve as the discharge chamber, the present invention effectively reduces the discharge distance while maintaining the same channel area, and increases the discharge gas pressure while maintaining the relative yield of singlet oxygen.

2. The present invention can convert oxygen atoms into singlet oxygen by adding a catalytic enhancement device downstream of the discharge generation area. While improving the yield of singlet oxygen, the concentration of oxygen atoms is effectively reduced and the oxygen atoms are avoided. Strong quenching of singlet oxygen.

3. The present invention uses the cooling tube to cool the air flow by contacting heat exchange, which can significantly reduce the gas temperature without excessively increasing the flow resistance. Pre-cooling the singlet oxygen gas before it enters the optical cavity can effectively Lower the cavity gas temperature to increase the small-signal gain of the electro-excited oxygen-iodine laser.

Description of drawings

The present invention can be better understood through the accompanying drawings in combination with the foregoing text description.

Fig. 1 is a schematic diagram of the device structure of the present invention. 101 is a discharge generating area, 102 is a catalytic enhancement area, and 103 is an airflow cooling area.

Fig. 2A is a cross-section of a discharge generating region. 1 is an outer tube, 2 is an inner tube, 3 is an outer electrode, 4 is an inner electrode, and 5 is a discharge gas chamber.

Fig. 2B is a longitudinal section of the discharge generating region. 1 is the outer tube, 2 is the inner tube, 3 is the outer electrode, 4 is the inner electrode, 5 is the discharge chamber, 6 is the inlet of the O ₂ /He/NO gas mixture, and 7 is the outlet of the active oxygen gas generated by the discharge.

Figure 3A is a cross-section of a catalytic enhancement zone. 8 is a regular hexagonal airflow channel, 9 is an oxide catalyst coating on the inner wall of the airflow channel, and 12 is the outer wall of the tube.

Figure 3B is a longitudinal section of the catalytic enhancement zone. 8 is a regular hexagonal gas flow channel, 9 is an oxide catalyst coating on the inner wall of the gas flow channel, 10 is a gas inlet, 11 is a gas outlet, and 12 is an outer wall of the tube.

Figure 4 is a longitudinal section of the airflow cooling zone. 13 is a liquid coolant, 14 is a heat pipe made of metal copper with excellent thermal conductivity, 15 is a discharge product gas to be cooled, 16 is a gas inlet, and 17 is a gas outlet.

detailed description

Example 1

As shown in the drawings, the device structure of the present invention includes three parts, a discharge generation area 101 , a catalytic enhancement area 102 , and an airflow cooling area 103 .

The singlet oxygen of the electro-excited singlet oxygen generator is mainly generated in the discharge generating area 101 by the oxygen-containing gas mixture O2/He/NO. The discharge generating area 101 is composed of a discharge chamber and a discharge electrode. The discharge chamber includes two coaxial cylindrical quartz glass tubes, one is the inner tube 1 and the other is the outer tube 2. The inner tube is placed in the outer tube, and the inner tube is placed in the outer tube. The cavity between the discharge chamber and the outer tube constitutes the discharge gas chamber 5; the discharge electrode includes two coaxial cylindrical metal electrodes, one is the inner electrode 4, which is located inside the inner tube 1 of the discharge chamber, and the other is the outer electrode 3, It is located outside the tube 2 outside the discharge chamber. The gap between the outer wall of the inner tube 2 and the inner wall of the outer tube 1 is 2-8 mm. The outer tube 1, the cylindrical metal electrode 3 sheathed outside the outer tube 1, the inner tube 2, and the cylindrical metal electrode 4 inside the inner tube are coaxial.

The gas to be discharged is O2/He/NO, enters the discharge gas chamber 5 through the gas inlet 6, and discharges and excites in the discharge gas chamber 5, and the generated active oxygen flows through the gas outlet 7 and continues to flow into the catalytic enhancement area 102. The active oxygen flow generated in the discharge gas chamber 5 contains more oxygen atoms, which will severely quench the singlet oxygen and reduce its yield.

After the active oxygen flow containing oxygen atoms generated in the discharge gas chamber 5 passes through the catalytic enhancement region 102, most of the harmful oxygen atoms are converted into singlet oxygen. The catalytic enhancement zone 102 is located downstream of the discharge generation zone 101 and is composed of many regular hexagonal airflow channels 8 . The cross-section of the gas flow channel 8 in the catalytic enhancement zone 102 is a regular hexagon, the diameter of its circumscribed circle is 5 mm, and the wall thickness between the gas flow channels is 0.5 mm. The inner wall of the regular hexagonal airflow channel 8 is coated with an oxide catalytic coating 9 such as iodine oxide (I ₂ O ₂ ) or mercury oxide (HgO). Atoms are converted to singlet oxygen, increasing the singlet oxygen yield.

The temperature of the gas flow after passing through the catalytic enhancement zone 102 is about 300-500 degrees Celsius, and then enters the gas flow cooling zone 103 to cool the active oxygen gas flow. The airflow cooling zone 103 is located downstream of the catalytic enhancement zone 102, and there are multiple cooling tubes 14 arranged in a staggered manner perpendicular to the airflow direction. The cooling tubes 14 are cylindrical in shape and made of metal copper with good thermal conductivity. is liquid coolant 13. The temperature range of the liquid coolant 13 in the cooling pipe is -30-30 degrees Celsius. The discharge product gas 15 to be cooled enters the gas flow cooling zone through the gas inlet 16, and the temperature of the cooled gas coming out of the gas outlet 17 is about 40-120 degrees Celsius.

The specific operation steps are as follows:

experiment procedure:

The first step is to connect the positive and negative electrodes, turn on the vacuum system, and ensure that the vacuum is normal.

In the second step, the O ₂ /He/NO gas mixture is injected from the gas inlet 6, and the power is turned on for discharge, and the discharge power is adjusted to the maximum value.

The third step is to gradually increase the oxygen flow rate according to the actual situation, and record the gas pressure P, the singlet oxygen spontaneous emission signal intensity I (wavelength is 1268nm) and the gas flow temperature T of the gas outlet 17 .

The fourth step is to end the experiment.

The present invention uses a quartz glass circular sleeve as a discharge chamber, effectively reduces the discharge distance while maintaining the same channel area, and increases the discharge gas pressure while maintaining the relative yield of singlet oxygen. By adding a catalytic enhancement device downstream of the discharge generation area, oxygen atoms can be converted into singlet oxygen. While increasing the yield of singlet oxygen, the concentration of oxygen atoms is effectively reduced, and the impact of oxygen atoms on singlet oxygen is avoided. strong quenching. The airflow is cooled by the contact heat exchange of the cooling tube, the gas temperature can be significantly reduced without excessively increasing the flow resistance, and the temperature of the singlet oxygen gas is pre-cooled before it enters the optical cavity.

Claims (6)

1. a kind of electric excitation creating singlet oxygen generating means, it is characterised in that：

Area, catalysis enhancement region and air-flow cooling zone are produced including electric discharge；

Electric discharge produces area to be made up of discharge cavity and sparking electrode, and discharge cavity includes two cylindric quartz glass Pipe, one is the closed inner tube of left end opening, right-hand member, and another is the outer tube of left and right both ends open, Inner tube is placed through in outer tube, and the cavity between inner and outer tubes constitutes discharge cavity；Sparking electrode includes two Individual cylindrical metal electrode, one is interior electrode, is placed through the inside of discharge cavity inner tube, and another is External electrode, is sheathed on the outside of discharge cavity outer tube；

Catalysis enhancement region is located at the downstream that electric discharge produces area, is made up of more than 2 parallel gas channels, Gas channel left end entrance is connected with discharge cavity right-end openings, applies aerobic on gas channel internal face Change the Catalytic Layer of iodine or mercury oxide；

Air-flow cooling zone is located at the downstream of catalysis enhancement region, and it is the tubular structure of left and right both ends open, gas Circulation road right-hand member outlet be connected with the left side openend of tubular structure, air-flow in tubular structure from a left side To right flowing, in tubular structure inside along the cooling tube that more than 2 are distributed with perpendicular to airflow direction, Cooling Bottomhole pressure has liquid coolant.

2. the electric excitation creating singlet oxygen generating means as described in claim 1, it is characterised in that：

Space 2-8 millimeters between outer wall of inner tube and outer tube wall.

3. the electric excitation creating singlet oxygen generating means as described in claim 1, it is characterised in that：

Cylindrical metal electrode, inner tube, the cylindrical metal on the inside of inner tube that outer tube, outer tube outside are arranged Pipe is coaxial.

4. the electric excitation creating singlet oxygen generating means as described in claim 1, it is characterised in that：

The cross section for being catalyzed enhancement region gas channel is regular hexagon, and its circumscribed circle diameter is 5 millimeters, gas 0.5 millimeter of circulation road wall thickness.

5. the electric excitation creating singlet oxygen generating means as described in claim 1, it is characterised in that：

The temperature range of liquid coolant is -30~30 degrees Celsius in cooling tube.

6. the electric excitation creating singlet oxygen generating means as described in claim 1, it is characterised in that：Catalysis Oxygen atom partly can be converted into creating singlet oxygen by layer；Cooling tube is shaped as cylindrical shape, cooling tube It is made up of the good metallic copper of heat conductivility.