JPS5926859B2 - total heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a total heat exchanger that removes harmful gases contained in the air by disposing a harmful gas removing agent in the airflow passing through the total heat exchanger. Attempts were made to combine it with a total heat exchanger to provide a so-called air purifying effect, and a filtration filter was sometimes installed in order to have a dust removal effect. Heat exchangers have the effect of removing harmful gases, especially carbon monoxide,
There was nothing that could remove nitrogen oxides.

One application of a total heat exchanger is as a ventilation fan, but when using it as a ventilation fan for various purposes, there is a problem that pollutants may flow in from outside due to ventilation, so it is not necessary to use ventilation in conjunction with cooling or heating. Although efforts were made to introduce fresh air, the situation was still in poor condition and had a negative impact on health.

The present invention is designed to ensure that the air introduced from outside becomes truly fresh air when performing ventilation using a total heat exchanger in an air conditioning ventilation fan.
To provide a new total heat exchanger having a harmful gas removing effect, which removes contained harmful gases and also prevents air flowing out from indoor space from becoming a source of polluting outdoor air.

Therefore, it is applicable not only for general household use, but also for general household use.
It can be widely used for air conditioning in large buildings, underground malls, underground parking lots, other ventilation equipment, and as ventilation equipment in automobile interiors.

Ventilation design is carried out with the aim of maintaining indoor air far-sightedness of good quality for the human body, but carbon dioxide concentration is used as a measure of pollution for ease of calculation.

The required amount of ventilation is determined based on the size of the room, the number of people in the room, the generation of indoor pollutants, etc., but it is especially important from the perspective of energy conservation when temperature control such as cooling or heating is being implemented. It is desirable to recover the heat loss caused by ventilation using a total heat exchanger, and it is economical, including power costs, to keep the amount of ventilation as small as possible within the range where the indoor air quality is not harmful to the human body. desirable.

The target value for ventilation design based on carbon dioxide is 700p.
pI [1~11,000pp] is adopted as a standard, but this is based on experience that carbon dioxide becomes harmful to the human body if it exceeds this concentration, but indoor pollution including bad odors becomes a concern. Based on correlation.

In this way, it is good to recover heat using a total heat exchanger for the set ventilation, but the problem of contaminated air flowing in from outside defeats the purpose of ventilation itself. This is a fatal problem.

Substances that are considered problematic air pollutants today include carbon monoxide, sulfur dioxide, oxidants, nitrogen dioxide, and other particulate suspended solids, but various countermeasures have been effective and all but nitrogen dioxide have been eliminated. , the general atmosphere satisfies the respective farsightedness standards.

However, regarding the problem of localized high concentration harmful gas pollution,
Regarding automobiles, which are the largest source of local pollution, although the amount generated individually has been reduced, the absolute amount of automobiles is increasing and the problem of local pollution in areas along roads with heavy traffic is becoming an even more serious problem. It is becoming.

The pollutants that pose the most serious problems related to automobiles are carbon monoxide and nitrogen oxides, and in the United States, the revision of ventilation design standards, which has been strongly promoted from the perspective of energy conservation, is being implemented. , carbon dioxide; the plan to amend the standard for 10oop disorder to 2500p1111), the biggest issue was also carbon monoxide and nitrogen oxides.

The present invention provides a new total heat exchanger that completely solves one of the fundamental problems regarding the application of total heat exchangers as ventilation fans today.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory diagram of a total heat exchanger.

The total heat exchanger 1 has an inner cylinder 2 and an outer cylinder 3, and the space between the two cylinders is divided into a plurality of chambers by a total heat exchange wall that partitions the cylinder in the radial direction.

The total heat exchange wall is made of a moisture permeable material such as paper.

The total heat exchanger shown in FIG. 1 shows some of its multiple chambers.

The total heat exchange wall 4 is, for example, ABCD, A'B'C'σ,
A″Bf CI D /.

Total heat exchange wall 4 indicated by ABCD and total heat exchange wall 4 indicated by A/B/C/D/Now, in the partitioned room, CDD'C
The fan forming part 5 formed at A is closed, and the other end A
The fan-shaped portion 6 formed by B B'A' is open.

Further, the opening 7 opens in the circumferential direction in the vicinity of the closed-side fan-shaped portion 5 of the chamber.

A/B/C/D/ total heat exchange wall 4 and AI B
In the chamber partitioned by the total heat exchange wall 4 of fC//D/, the fan-shaped part 8 formed by A'B'B//A// is closed, and the other end C'D' The fan-shaped portion 9 formed by TJ/C// is open.

Further, the opening 10 opens in the circumferential direction in the vicinity of the closed fan-shaped portion 8 of the chamber.

FIG. 2 is a sectional view of the total heat exchanger 1 when it is installed.

In FIG. 2, the total heat exchanger 1 is installed on a wall 11, the opening 10 is installed indoors 12, and the opening 7 is installed outdoors 13.

In FIG. 3, 14 is a harmful gas removing agent, which is added to the surface of the total heat exchange wall.

The harmful gas remover 14 uses at least one of a dry absorbent for removing nitrogen oxides (particularly nitrogen dioxide) and a catalyst for catalytically oxidizing carbon monoxide with air.

In FIG. 4, the harmful gas remover 14 protrudes from both sides of the total heat exchange wall 4 and is arranged so as to be in contact with the inflow and outflow, respectively.

In FIG. 6, the harmful gas remover 14 is in contact with one end of the heat exchange wall and the other end of the adjacent heat exchange wall, so that each layer of the harmful gas remover 14 is applied to the inflow and the outflow. It is arranged so that it passes through.

In FIG. 1, a flow a flowing in from an opening 7 passes through a chamber partitioned by total heat exchange walls ABCD and A'B'C'D', and flows out from a fan-shaped part 6.

(However, the fan is not shown) Also, the flow b flowing from the opening 10 flows through the total heat exchange walls A'B'C'D', AI
It passes through a chamber divided by 'B//C/'I)'/ and flows out from the fan-shaped part 9.

As shown in FIG. 2, a flow a is air from outside 13 flowing into the room 12, and a flow b is air from inside 12 flowing out to outside 13.

At this time, a total heat exchange wall 4 shown as A'B'C'D'+trowel in FIG. Sensible heat and latent heat are transferred (from a to b during indoor cooling, and from b to a during indoor heating in winter).

Therefore, it is possible to ventilate the room without increasing the number of heating and cooling equipment in the room.

Since the harmful gas remover 14 is placed against the inflow and outflow of air associated with such ventilation, nitrogen oxides and carbon monoxide are removed as pollutants, and reverse contamination due to inflow and outflow is prevented. be done.

The specific composition of the harmful gas remover is a remover for removing nitrogen oxides, especially nitrogen dioxide, and a remover for oxidizing carbon monoxide with oxygen in the air and converting it into less harmful carbon dioxide. It is better to use a removal catalyst.

The present inventors have discovered that a composition containing powdered activated carbon, an alkali, and a cement agent as main components can reduce the environmental concentration of NOx at room temperature.
It has been found that it has particularly excellent performance in removing NO□.

Figure 7 shows the composition (i.e., a composition obtained by kneading and molding with a blending ratio of 2 parts of powdered activated carbon, 3 parts of potassium carbonate, 3 parts of hydroxide, and 2 parts of calcium sulfate. However, the blending ratio is a weight ratio. ]) shows the characteristics of NO3 removal performance.

The measurement conditions were an inlet concentration of 1.0 to 1.2 ppm, a temperature of 30°C, and a relative humidity of 52%.

FIG. 7 is a characteristic diagram showing how the NO□ removal performance of a granulated product obtained by extruding and granulating the above composition to a diameter of 3 mm changes depending on the space velocity.

These series of compositions oppose and scavenge N02 as described below.

(1) 6N02+ to 2CO3+2Ca(OH)2→KN
O3+Ca(NO3)2+KNO2+Ca(NO2)2
+2H20+C02 (2) 2N203+ to 2C03+Ca(OH)2→2K
NO2+Ca(NO2)2+H20+C02 Also, this composition simultaneously acts as an alkali and acidic gas (SO2...
etc.) and removes them.

(3) 2SO2+ to 2C03+Ca(OH)2→2S
O3+CaSO3+H20+C02(4)2S02+0
20 to 2C03+Ca(OH)2→to2 S 04 +
Through reactions such as Ca S 04 + H20 + C02, environmental concentration of NO2 etc. is removed at a high removal rate,
Moreover, since the reaction is an absorption reaction, it has a long life and N
This is unprecedented in that it does not have the ability to reduce O2 to NO.

Regarding the above composition, alkali is the main component of the absorption reaction, and carbonates of alkali metals or hydroxides of alkali metals or alkaline earth metals are preferable in terms of reaction rate, removal life, etc.

Furthermore, powdered activated carbon is blended as a catalyst in order to allow the above absorption reaction to proceed at a high reaction rate.

As a cement agent, it is an aggregate to form a porous hardened body, but due to the stability of the composition and its fine dispersibility, calcium sulfate (calcined gypsum), lime aluminate (alumina cement), etc. ) etc. are desirable.

Furthermore, in order to put this remover into practical use, it is necessary to add carboxymethyl cellulose ((J, M, C) sudo) for the purpose of improving strength under high temperature and high humidity conditions.

In addition, the present inventors have developed a method for purifying CO at an environmental concentration level at room temperature by using a catalyst in which noble metals are supported on a hardened composition containing three main components: alkali, powdered activated carbon, and cement. It was found that it has excellent performance and durability under coexisting general atmospheric conditions.

This catalyst consists of a kneaded composition consisting of 1 part of potassium carbonate, 3 parts of powdered activated carbon, and 6 parts of lime aluminate (all by weight), and platinum and palladium each added at 0.3% by weight of the carrier. The performance is shown in Fig. 8.

The conditions for evaluating the activity of the catalyst are a constant absolute water content at saturation at 15°C, and a space velocity of S -50000 (h
-1), the inlet CO concentration is set to 1001) pm.

Figure 8 shows the temperature and C when the catalyst packed bed temperature is changed.
The relationship with O conversion rate is shown.

Although the catalyst of the present invention was tested with a particle size of 6 to 10 meshes, the reaction rate of the catalyst was completely dominated by external mass transfer, and the activity of the catalyst itself was extremely excellent.

Further, to explain the method for preparing the catalyst, first, a carrier composition is kneaded and then granulated by, for example, extrusion molding.

This is made into a predetermined particle size, impregnated in an aqueous solution of chloroplatinic acid and palladium chloride, and adsorbed on the surface as chloride.
After reduction, it is dried.

Catalyst powder activated carbon, potassium carbonate, whose performance is shown in Figure 8.
Lime aluminate was used so that the amount of precious metals supported in the reduced state was 0.3%, and sodium borohydride was used to add 10 times the reduction equivalent in mole.

As seen in Figure 8, this catalyst has an extremely high C
Shows O conversion performance.

Catalysts with high activity at such low temperatures are completely unprecedented.

Potassium carbonate, when partially eluted into an aqueous solution, realizes the reduction of precious metals from the hydroxide state, contributing not only to high activation and an increase in specific surface area, but also to other examples. This contributes to the activation of activated carbon, which is presumed to have a promoter effect.

On the other hand, as a cement agent, it plays a role as a stable binder for each component, and is also related to the pore physical properties of a porous hardened material. An effect can be obtained in which the catalytic effect contributes to the reactivity of the catalyst in the coexistence of water vapor.

Regarding the application of the above harmful gas remover 14 to a total heat exchanger, it is molded into a plate shape, and the plate-shaped molded body is bonded with an adhesive.
As shown in FIG. 3, it is attached to the total heat exchange wall 4, or as shown in FIG. 6, a molded body formed into a honeycomb shape is placed between two total heat exchange walls.

All of the harmful gas removers 14. Since it contains a cement agent as its main component, it can be applied to any molding method such as dry pressing, semi-dry pressing, and wet casting.

However, when considering mass production and other considerations, a semi-dry press method is preferable.

When a plurality of harmful gas removers 14 are arranged as shown in FIG. 4, it is desirable to arrange some NO2 removers upstream and then arrange some CO purification catalysts.

The reason for this is that CO purification catalysts tend to be temporarily poisoned due to NO2 adsorption, resulting in a slight decline in CO purification performance. This is to prevent the effects of temporary poisoning mentioned above.

Other means for applying the harmful gas remover 14 are to wrap the harmful gas remover 14 in a nonwoven fabric such as polypropylene and attach the nonwoven fabric itself to the total heat exchange wall using an adhesive, or to attach it to the total heat exchange wall using a thread, etc. You can also use it to sew it onto the total heat exchange wall.

In this case, there is an advantage that even if the harmful gas remover 14 is damaged, there is no fear that its dust will contaminate the air.

In addition, by arranging the harmful gas removing agent inside the total heat exchanger in this manner, the effect of generating turbulent flow within the system and improving the total heat exchange efficiency is also expected.

As described above, the total heat exchanger of the present invention completely solves the problem of indoor contamination due to inhalation of contaminated gas when performing ventilation, and has excellent effects in terms of energy saving and non-pollution. be.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view of a total heat exchanger according to an embodiment of the present invention, Fig. 2 is a sectional view of the total heat exchanger when installed, Fig. 3 is a side view of the harmful gas remover, and Fig. 4 The figure is a partial top view of the total heat exchange wall seen from the circumferential cross section in Figure 1, Figure 5 is a side view of the total heat exchange wall, and Figure 6 is a side view showing how the harmful gas remover is installed. Figure 7 is a characteristic diagram showing the relationship between the space velocity, which is one of the basic performances of NO2 absorbent, and the NO2 removal rate, and Figure 8 is a characteristic diagram showing the relationship between the catalyst layer temperature and the CO conversion rate for the CO purification catalyst. It is a characteristic diagram showing a relationship. 1... Total heat exchanger, 4... Total heat exchange wall, 14... Harmful gas remover.

Claims (1)

[Scope of Claims] 1. In a total heat exchanger that performs total heat exchange by alternately forming countercurrents, a harmful gas remover is used in a total heat exchanger such that each of the alternating countercurrents passes through contact with the harmful gas remover. A total heat exchanger characterized by having a layer of 2. The harmful gas remover is: i. Composition 11 containing powdered activated carbon, alkali and cementing agent as main components; One or more platinum metal elements supported on a hardened body containing powdered activated carbon, alkali and cementing agent as main components. The total heat exchanger according to claim 1, characterized in that the total heat exchanger is composed of at least one substance of groups 1 and 11 of catalysts. 3. As a harmful gas remover, the alkali consists of an alkali metal hydroxide or carbonate, and the cement agent is selected from the group of alkaline earth metal hydroxides, aluminates, or sulfates. 3. The total heat exchanger according to claim 1 or 2, wherein the total heat exchanger is a harmful gas removing agent consisting of more than one species. 4 As a harmful gas remover: 1 Composition consisting of potassium carbonate: 3 parts, calcium hydroxide: 3 parts, powdered activated carbon: 2 parts, calcium sulfate: 2 parts (all by weight) 11 Powdered activated carbon: 3 parts, aluminium The entire method according to claim 1 or 2, characterized in that a catalyst comprising platinum and palladium supported on a carrier consisting of 6 parts of acid lime and 1 part of potassium carbonate is used. Heat exchanger. 5. The total heat exchanger according to claim 2 or 4, characterized in that 51 components are arranged upstream and 11 catalysts are arranged downstream.