JPH0440058B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a self-lifesaving device for carbon monoxide.

[Industrial application field]

Generally, carbon monoxide (hereinafter simply referred to as CO) is generated by incomplete combustion of carbon or carbon-containing compounds.
binds tightly to hemoglobin in the blood and releases CO
It forms hemoglobin and significantly inhibits the absorption and transport of oxygen in the blood, causing acute poisoning symptoms such as headache and dizziness. Furthermore, it is known that when the CO hemoglobin concentration in the blood reaches approximately 40% or more, death occurs in humans.

Conventionally, carbon monoxide self-life saving equipment (hereinafter simply CO
Masks are used to break through and escape from areas where CO gas is generated due to fires, explosions, etc. in buildings, coal mines, mines, etc. According to mine safety regulations, all miners working in mines are required to carry one.

[Conventional technology]

This CO mask not only has excellent CO removal performance, but also is as small and lightweight as possible so that it does not interfere with activities during normal work or even during emergency evacuation, and at the same time, it is designed to prevent burns in the mouth. There is a strong need for something that will minimize the rise in intake air temperature due to heat of oxidation of CO generated during use.

Conventionally, commercially available CO masks use a so-called hopcalite-based composite oxide catalyst, which is mainly a composite of manganese dioxide and copper oxide, as a CO removal agent (see Japanese Patent Publication No. 50-29599). This hopcalite catalyst has the disadvantage that its CO oxidation activity is significantly reduced by adsorbing moisture in the air, so in order to maintain its activity for a long period of time, it must be kept in a dry state at all times.

For this reason, the gas absorption canister of the CO mask must be filled with a moisture absorbent along with a completely dried and dehydrated hopcalite catalyst, and the entire CO mask must be sealed in a strong metal container and carried in a state where it is blocked from the atmosphere. Must be.

The weight of conventional CO masks on the market is over 600g, and when the weight of the airtight container is added, it reaches approximately 1.1kg. Furthermore, when using a conventional CO mask filled with a hopcalite catalyst and a moisture absorbent, when air containing moisture and CO passes through the mask body, the heat absorbed by the moisture into the moisture absorbent and
The temperature of the intake air rises to about 100℃ due to the heat of reaction accompanying the oxidation of CO on the hopcalite catalyst.
This has been pointed out as a problem when using it, as it can cause burns to the inside of the mouth.

Therefore, a mask has been proposed in Japanese Patent Application Laid-open No. 47-40892 to improve this problem, but since the structure of this mask also uses a hopcalite catalyst as a CO oxidation catalyst, it has a relatively large size. It is equipped with a moisture absorbent storage chamber in the space and a metal shell storage chamber for heat exchange to suppress the rise in intake air temperature, and has two openings, an intake port and an exhaust port, each having an intake valve and an exhaust valve. However, the structure is complicated and the volume and weight are large. Filled with such a hopcalite catalyst
It is difficult to say that CO masks necessarily have sufficient performance considering their weight and temperature rise of intake air.

[Problem that the invention seeks to solve]

The present invention was developed by focusing on the problems of conventional CO masks.It has an excellent CO removal effect, is small and lightweight, and has a small temperature rise in intake air.
As a result of various research aimed at providing a CO mask, we found that a catalyst with high CO oxidation activity, consisting mainly of both palladium salts and copper salts, was supported on a carrier and loaded into the CO mask. By utilizing the moisture in the inhaled and exhaled air without using a moisture absorbent, the catalytic reaction is further promoted and the CO removal effect is increased.
The inventors have discovered that the heat of the oxidation reaction can be effectively cooled, leading to the present invention.

[Means for solving problems]

That is, the present invention is a carbon monoxide self-saving device characterized in that a catalyst containing at least a palladium salt and a copper salt is supported and loaded on a carrier, and the intake hole and the exhaust hole are the same.

As palladium salts and copper salts as CO oxidation catalysts used in the present invention, respective chlorides, nitrates, sulfates, or mixed salts thereof can be used, and for copper salts, divalent copper Not only salts but also monovalent copper salts can be used. Furthermore, by adding a vanadium compound such as ammonium vanadate (NH ₄ VO ₃ ), sodium vanadate (NaVO ₃ ), vanadium pentoxide (V ₂ O ₅ ) to the above catalyst component as a third catalyst component, CO oxidation activity can be further improved.

Next, as a carrier for supporting the above-mentioned CO oxidation catalyst, γ-alumina, silica, silica-alumina, activated carbon, acid clay which is a double salt of silica and alumina, bentonite, or a combination of activated carbon and these inorganic oxides are used. A porous carrier such as a mixed composition with a specific surface area of 100 to 100 by the B・E・T measurement method.
Those having a surface area of 1500 m ² /g are preferably used.

The amount of palladium salt supported on these carriers is 0.3 to 1.5% in terms of palladium (in this specification, % is expressed by weight unless otherwise specified), which is enough to achieve the purpose, but if it is less than 0.3%, the CO oxidation activity is insufficient. It will be enough. In addition, the supported amount of copper salt is 2 to 6 in terms of copper.
%, preferably 4-5%, less than 2% and 6%
%, there is a tendency for the sustainability of CO oxidation activity to decrease.

Further, the CO oxidation activity can be further improved by adding the vanadium compound to the carrier in an amount of 1 to 3%.

Next, as a method for supporting the catalyst component on the carrier, the carrier powder is granulated and formed into a granular material of about 8 to 14 meshes, which is immersed in an aqueous solution containing both palladium salt and copper salt. The simplest method can be applied by heating and concentrating the solution using an evaporator such as a rotary evaporator, evaporating excess water, and depositing the catalyst component on the carrier.

Further, the vanadium compound may be supported at the same time as the palladium salt and the copper salt, or the vanadium compound alone may be supported on the carrier using the above-described dipping method, and then the palladium salt and the copper salt may be supported in the same manner. Methods can also be applied.

The particle size of the carrier supporting the catalyst is preferably about 8 to 14 mesh as mentioned above from the point of view of the ventilation resistance of the CO mask, but the carrier does not necessarily have to be granular and may be made of inorganic material or heat-resistant material. It is also possible to use a so-called honeycomb-shaped molded body made from a plastic material, etc., or a spongy ceramic body having countless communicating holes as a carrier, and use the above-mentioned catalyst as a carrier by a dipping method or the like. can.

FIG. 1 shows an example of the structure of the CO mask of the present invention, in which the above-mentioned granular carrier is placed in a can body 1 having a mouthpiece 2 at the top and an intake/exhaust port 3 at the bottom through a separator 4. It is loaded with a supported CO oxidation catalyst 5. Note that 6 is a dust removal filter.

[Effect]

Next, the action of the CO mask of the present invention will be explained.

In other words, the mixed catalyst of palladium salt and copper salt loaded in the CO mask of the present invention requires the presence of water in the CO oxidation reaction, so the presence of water, which is considered undesirable in conventional hopkaline catalysts, is reversed. It works effectively. Therefore, unlike hopcalite catalysts, it is not necessary to keep them in a dry state all the time, and they are usually kept in a state containing about 10 to 25% moisture. Therefore, the CO mask of the present invention
When air containing CO and moisture passes through the catalyst, an oxidation reaction occurs on the catalyst and generates heat, but the latent heat of vaporization of the moisture in the catalyst can reduce the heat generation to some extent. Furthermore, since the passing air also contains moisture with a high specific heat, its heat capacity is larger than that of dry air, and therefore the temperature rise of the passing air due to reaction heat is also suppressed.

Furthermore, unlike the hopcalite catalyst, the CO oxidation catalyst used in the present invention is moisture resistant and does not require the filling of a desiccant agent, so the structure of the CO mask is similar to that of the conventional CO oxidation catalyst.
There is no need to separate the exhaust port from the intake port as in a mask, and as shown in Figure 1, the intake and exhalation ports can be made the same, allowing the intake and exhalation to pass through the same catalyst layer. becomes. With this structure, moist exhaled air provides appropriate moisture to the catalyst, further promoting the oxidation reaction of CO by the catalyst, and also effectively cooling the catalyst layer whose temperature has risen due to the heat of the oxidation reaction of CO. It is something to do.

〔Example〕

Next, the present invention will be specifically explained based on examples.

First, the method of the present invention is carried out by various methods shown below.
A CO oxidation catalyst supported on a carrier loaded in a CO mask was prepared.

Preparation Example (1) An aqueous solution containing 7 g in terms of palladium and 44 g in terms of copper was prepared using palladium chloride and cupric chloride. In this aqueous solution, 1 kg of carrier prepared by mixing activated carbon and bentonite at a mixing weight ratio of 1:1 and granulating the mixture to a size of 8 to 14 meshes was immersed with occasional stirring. After 5 hours of immersion, the entire mixture was placed in a ventilation dryer at 120°C to evaporate water with occasional stirring. After 10 hours of storage in the ventilation dryer, the catalyst supported on the carrier was taken out from the dryer to obtain a catalyst (A).

Preparation Example (2) 1.3 of an aqueous solution containing 7 g in terms of palladium and 44 g in terms of copper was prepared using palladium chloride and cupric chloride, and γ-alumina granulated to a size of 8 to 14 meshes was added to this aqueous solution. 1Kg was immersed. After 5 hours of immersion, the mixture was placed in a ventilation dryer at 250°C to evaporate water with occasional stirring, and placed in the dryer for 12 hours. The catalyst supported on the γ-alumina carrier was removed from the dryer and the catalyst (B) was removed. Obtained.

Preparation Example (3) A γ-alumina carrier similar to that used in Preparation Example (2) was preliminarily loaded with 1.3% NH ₄ VO ₃ by a dipping method.
This was further heated at 500℃ for 2 hours and converted into V ₂ O ₅ .
γ-alumina supported at 1.0% was prepared. A catalyst (C) was obtained in which palladium chloride and cupric chloride were supported on 1 kg of this carrier in the same manner as in Preparation Example (1) so that the supported amounts were 0.7% as palladium and 4.4% as copper.

Preparation example ( ₄ ) Add a _commercially available cordierite honeycomb body (diameter 100 mmφ,
Height 3535mm, weight 115g, number of cells 112 cells/inch ² )
A carrier whose surface had been coated with 10% alumina sol to form a γ-alumina layer was immersed,
After 2 hours, the honeycomb body was taken out and dried at 150°C.
After repeating this immersion and drying three times, the honeycomb body was further heated at 500℃ for 2 hours, and the surface of the honeycomb body was
V ₂ O ₅ was precipitated. V ₂ for the carrier in this case
The amount of O ₅ supported was about 1.2%. The honeycomb body pretreated in this way was immersed for 1 hour in 500 ml of an aqueous solution containing 0.05 mol of palladium chloride and 0.5 mol of cupric chloride, and then dried at 150°C, resulting in a supported amount of palladium of 0.46% and a supported amount of copper of 2.8%. % of catalyst (D) was obtained.

Next, a CO mask with the structure shown in Figure 1 was made,
8 to 14 mesh granules of conventionally used hopcalite catalysts, catalysts (A), (B), and (C) are contained in the can.
The CO removal performance and intake air temperature were measured for a CO mask in which 160 ml of each was separately loaded and a CO mask loaded with catalyst (D) without using a moisture absorbent. In addition, as a comparative example, hopcalite catalyst
Conventional commercially available product loaded with 160ml and 190ml of moisture absorbent.
Similar measurements were made for the CO mask. Regarding the measurement of intake air temperature, a comparison was made between a CO mask of a comparative example and a catalyst (C) with good CO removal performance.

In addition, the measurement is based on JIS standard M for CO removal performance.
-7611 method. That is, 1
Air at a relative humidity of 95% and a temperature of 25°C containing % CO
CO was flowed into the mask body at a flow rate of 32/min, and the CO concentration in the inhaled air at the mouthpiece was measured using a non-dispersive infrared spectrophotometer. At the same time, the intake air temperature at the mouthpiece was measured under these conditions.

The measurement results are shown in Figure 2.
While the CO removal performance of masks rapidly decreases in a short period of time due to the influence of moisture, in the case of the CO masks of the present invention loaded with catalysts (A) to (D), all JIS
It demonstrated CO removal performance that fully satisfies the standards (average CO concentration in intake air equivalent to 200 ppm or less). In particular, catalysts like catalyst (C), in which a vanadium compound was added in addition to palladium salts and copper salts, had significantly superior CO removal performance. Catalyst (D) is also an example in which a vanadium compound is added, but the reason why the concentration in the intake air in this case is higher than that of catalyst (A) is that the amount of catalyst supported on the carrier is smaller than that of catalyst (A). This is thought to be due to the following.

Also, regarding intake air temperature, conventionally commercially available
When using a CO mask, the temperature rises to over 100°C, but when catalyst (C) is used, the temperature rises to only slightly above 60°C, which is extremely low. Furthermore, the present invention used in this example
The weight of the CO mask is 350 to 450 g, which has been demonstrated to be significantly lighter than conventional commercially available CO masks, which weigh approximately 600 g.

〔Effect of the invention〕

As explained in detail above, the CO mask of the present invention contains both a palladium salt and a copper salt as a CO oxidation catalyst, and a vanadium compound as a CO oxidation promoter, which is supported on a carrier. Because it is loaded inside the mask,
Unlike conventional Hopcalitz catalysts, CO removal performance that fully satisfies JIS standards can be obtained without simultaneously loading a moisture absorbent, and the intake air temperature is also significantly lowered, reducing the risk of burns in the mouth when using conventional CO masks. Danger is also completely prevented. Furthermore, the CO of the present invention
According to the mask, there are many advantages such as no need to provide a separate space for accommodating the moisture absorbent or separate intake and exhaust chambers with attached valve bodies, the structure is extremely simple and compact, and the weight is also reduced. is obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of the self-lifesaving device for carbon monoxide of the present invention, and FIG. 2 is a diagram showing the self-lifesaving device of the present invention loaded with various catalysts used in the present invention and conventional catalysts. It is a graph showing changes in CO concentration in intake air and intake air temperature over time. 1...can body, 2...mouthpiece, 3...intake/exhaust port,
4...Separator, 5...CO oxidation catalyst.

Claims (1)

[Scope of Claims] 1. A self-saving device for carbon monoxide, characterized in that a catalyst containing at least a palladium salt and a copper salt is supported and loaded on a carrier, and the intake hole and the exhaust hole are the same. 2. The self-lifesaving device for carbon monoxide according to claim 1, wherein the catalyst contains a vanadium compound in addition to a palladium salt and a copper salt.