CN214437818U - Gas purifier using plasma and catalyst - Google Patents

Abstract

The utility model provides an use gas purifier of plasma and catalyst, including a casing to and two magnetic sensing reeds of arranging in the casing, make a reed stretch out from an end wall of casing, another reed stretches out from another end wall of casing, and the free end of reed overlaps each other, has a little clearance between them, forms relative contact. The magnetic sensitive reed moves under the action of the magnetic force of the driving coil, so that the contact is opened and closed like a switch. This operation of the contacts and the contact loading coil causes a glow discharge and the gas is purged by the plasma. The catalyst is carried by the contacts or housing. Thus, the gas is synergistically purified by the action of the plasma and the action of the catalyst. A magnetosensitive reed or similar electrode can also be operated by an alternating voltage to cause a glow discharge.

Description

Gas purifier using plasma and catalyst

Technical Field

The utility model relates to a gas purifier using plasma and catalyst. More particularly, the present invention relates to a gas purifier using a catalyst effect and a plasma effect.

Background

Air pollution control is an important social problem. The purification of a large amount of pollutant gases discharged from factories and automobiles, including toxic components such as COx, CmHn, NOx, and SOx, is very important. In addition, in the space station, it is also necessary to purify a special gas such as methyl gas.

In order to control air pollution, large-sized gas purifiers such as centrifugal purifiers, emission purifiers, and desulfurizers are installed in factories. An exhaust emission control device using a catalyst is mounted on an automobile. These conventional gas purifiers purify the gas based on a single physical or chemical action, and thus have a limited purification efficiency.

Japanese unexamined patent publication (Kokai) No. 62-33527 discloses a gas purifier comprising an exhaust zone and a catalytic reaction zone located downstream of the exhaust zone. According to the method described in this publication, the exhaust gas is first routed to the exhaust zone and ionized into a plasma gas. The plasma gas is then routed to a downstream catalytic reaction zone. In addition, Japanese unexamined patent publication (Kokai) No. 63-242323 discloses a gas purifier in which a gas is treated by electric discharge and then the gas is passed through a catalyst.

In the above-mentioned japanese unexamined patent publication No. 62-33527, the discharge region includes a needle electrode to which a voltage of several kilovolts to several ten thousand volts is applied. In Japanese unexamined patent publication No. 63-242323, a mesh-shaped electrode or a rod-shaped electrode and a high voltage generator are used. Thus, the conventional gas purifier combines the function of plasma and the function of a catalyst, but requires a high voltage power supply to generate plasma.

In addition, by arranging the discharge zone and the catalytic reaction zone as separate stages, there arises a problem that the gas becomes a plasma-containing gas in the discharge zone, but the plasma content in the gas is reduced before the gas reaches the next catalytic reaction zone, and the combined effect of the action of the plasma and the action of the catalyst is not as high as expected.

SUMMERY OF THE UTILITY MODEL

The object of the present invention is to provide a gas purifier using plasma and a catalyst, which is compact in structure, can cause glow discharge under the condition of applying a relatively low voltage, and in this way can make the action of the plasma and the action of the catalyst combine synergistically.

According to the present invention, there is provided a gas purifier using plasma and a catalyst, which comprises a housing having at least two openings for allowing gas to flow through the housing, at least one pair of magnetically sensitive reeds disposed in the housing and having opposite contacts, a driving coil for opening and closing the contacts of the at least one pair of reeds, a contact loading coil connected to the at least one pair of reeds, and a catalyst disposed at least in the vicinity of the contacts of the at least one pair of reeds.

In the above arrangement, during the opening and closing operations of the contacts, glow discharge occurs at the contacts of at least one pair of reeds, and the polluted gases such as COx, CmHn, NOx, etc. are decomposed into elemental molecules or harmless gas molecules by the action of plasma generated by the glow discharge. In addition, the catalyst carried on or disposed near the reed contact surface further decomposes the contaminant gas into elemental molecules or harmless gas molecules. These gas purification methods play a synergistic role and achieve excellent gas purification effects.

Preferably, the gas purifier of the present invention comprises a housing having at least two openings for allowing gas to flow through the housing, at least one pair of opposed electrodes disposed in the housing, an ac power source for inducing a glow discharge at the at least one pair of electrodes, and a catalyst carried by the at least one pair of electrodes.

In the above arrangement, if at least one pair of electrodes is arranged in a manner similar to the above-described magnetic reed having the opposite contacts, glow discharge occurs when the contacts are opened during the opening and closing operation of the above-described contacts. In this case, too, therefore, gas purification is achieved by a synergistic combination of the action of the plasma and the action of the catalyst. In this case, moreover, the glow is generated substantially continuously by an alternating current source, preferably a high-frequency alternating current source. Here, the electrode is not limited to the above-described magnetosensitive reed, but may include a wide electrode thin film having a catalytic metal formed on the insulating layer by vapor deposition or sputtering.

The present invention may be more fully understood from the following drawings.

Drawings

Fig. 1 is a sectional view illustrating the present invention.

Fig. 2 and 3 are views illustrating connection of the driving coil and the contact load coil of fig. 1.

Detailed Description

Fig. 1 shows a gas purifier according to a first embodiment of the present invention. Gas purifier 10 includes a housing 12, and a pair of magnetically sensitive reeds 14 and 16, as electrodes, disposed in housing 12 and each having a pair of substantially parallel opposing faces. The housing 12 includes two openings 18 and 20 as an inlet and an outlet for the gas to flow in a manner such as shown by arrows G, with the opening 18 serving as the inlet and the opening 20 serving as the outlet in fig. 1, but the openings 18 and 20 need not be designated as the inlet and outlet for the gas. The housing 12 is made of metal or glass and it is not corroded by the gas to be purified.

The springs 14 and 16 extend in opposite directions from the outside of the housing 12 to the inside of the housing 12 and have contacts 14a and 16a at their free ends, which oppose each other with a small gap therebetween. When the housing 12 is made of metal, an insulating layer (not shown) is placed between the reeds 14 and 16 and the housing 12. These reeds 14 and 16 are made of a magnetically susceptible material such as permalloy.

A drive coil 22 is wound around the housing 12. The driving coil 22 has terminals a and b. As shown in fig. 2, one terminal a of the driving coil 22 is connected to a power supply of 5 to 12 volts, for example. The other terminal b of the driving coil 22 is connected to the pulse generator 24. The pulse generator 24 generates, for example, a rectangular pulse. When the pulse generator 24 generates a pulse, the drive coil 22 is energized, causing the contacts 14a and 16a of the springs 14 and 16 to close as the spring switch closes. Thus, current flows between reeds 14 and 16. When the pulse generator 24 is not generating a pulse, the drive coil 22 is not energized and the contacts 14a and 16a of the reeds 14 and 16 are open. Then, the current between the reeds 14 and 16 is cut off.

The contacts 14a and 16a of the reeds 14 and 16 are plated with catalyst layers 26 and 28. The catalyst layers 26 and 28 are selected from metals having a catalytic action (for example, 21 transition d metals: Hf, Ta, Zr, Nb, W, Ti, V, Mn, Cr, Mo, Re, Ni, Co, Tc, Os, Ir, Ru, Pt, Rh and Pd). Preferably, the catalyst layers 26 and 28 include at least one of a noble metal group consisting of platinum (Pt), palladium (Pd), rhodium (Rh), and ruthenium (Ru). The leaves 14 and 16 made of permalloy are gold plated and then the gold plated leaves are plated with a catalyst layer 26 or 28.

In fig. 1, a contact load coil 30 is wound around the drive coil 22. As shown in FIG. 3, one end c of the contact load coil 30 is connected to a DC power supply of, for example, 12 to 24 volts. The other end d of the contact load coil 30 is connected to a switch S composed of the contacts 14a and 16a of the reeds 14a and 16. The contact load coil 30 has an inductance L and thus the reeds 14 and 16 are connected to a circuit having an inductance L.

When the contacts 14a and 16a of the reeds 14 and 16 are opened by the closing of the pulse, a reverse electromotive force e (e ═ L (di/dt)) is induced at the contacts 14a and 16a due to the provision of the inductance L, and the inventors have found that the presence of the reverse electromotive force e causes a glow discharge to occur immediately after the contacts are opened, as shown in fig. 1. In this case, the glow discharge is formed at a relatively low applied voltage. The inventors have also found that the glow discharge voltage and glow duration tg vary depending on the value of the inductance L and the kind of gas in the housing 12. Therefore, it is preferable to determine the value of the power supply voltage and the value of the inductance L contacting the load coil 30, and to select the materials of the catalytic layers 26 and 28, according to the kind of gas to be purified.

For example, when a gas containing a nitrogen component is to be purified, the power supply voltage contacting the load coil 30 is 12V, the inductance L is 1 henry, and rhodium is selected as the material of the catalyst layers 26 and 28. In this case, it is assumed that the following reaction is promoted by the plasma generated by glow discharge.

e+2NO--N.sub.2+O.sub.2+e。

e+2NO.sub.2--N.sub.2+2O.sub.2+2e；

In addition to the above plasma action, another gas purification action occurs when the gas comes into contact with the catalyst layers 26 and 28 made of, for example, rhodium, which action is known in conventional automobile exhaust emission control devices. These two types of gas purification are performed simultaneously to provide a synergistic purification effect and to obtain excellent gas purification performance.

As described above, the present invention provides a gas purifier which can induce glow discharge at a relatively low voltage, and by which the action of plasma and the action of a catalyst are synergistically combined together. Accordingly, a gas purifier capable of treating various gases can be provided.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible by converting the above structure. Accordingly, the scope of the present invention should not be limited by the foregoing description and the appended claims.

Claims (4)

1. A gas purifier using plasma and a catalyst, comprising a housing having at least two openings for allowing gas to flow through the housing; at least one pair of opposed electrodes disposed in the housing, each pair of opposed electrodes having a respective pair of substantially parallel opposed surfaces with a gap therebetween, the opposed surfaces being formed by a catalyst comprising a transition metal; and an alternating current power supply for inducing a glow discharge on at least one pair of the opposing electrodes.

2. A gas purifier using plasma and catalyst according to claim 1, wherein the counter electrode comprises a magnetically sensitive reed having a counter contact.

3. A gas purifier using plasma and catalyst according to claim 2, further comprising a driving coil for opening and closing the contacts of at least one pair of the reeds.

4. A gas purifier using plasma and catalyst according to claim 1, wherein the counter electrode comprises a wide electrode film extending between at least two of the openings.

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