JPS5942824B2 - Catalytic reaction test furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a simulated gas having the same composition as harmful gases such as automobile exhaust gas and exhaust gas from various combustion equipment to evaluate the reaction efficiency and reaction of a catalyst that purifies and renders harmful gases harmless. This invention relates to a catalytic reaction test furnace designed to investigate characteristics such as speed and reaction temperature.

It is generally known that good results can be obtained with this type of catalyst if the reaction is carried out at a high temperature.

However, maintaining a catalytic reactor installed in the exhaust gas path of a car at a high temperature is disadvantageous in many aspects and is also difficult in practice, so it is necessary to carry out reactions in as wide a temperature range as possible. Progress is being made in the development of catalysts that will allow this to occur satisfactorily. In addition, many catalytic reactors use a method of heating the catalyst with high-temperature gas discharged from the combustion chamber to raise the temperature to the reaction temperature range, so the temperature of the catalyst due to the heat transferred by the gas is The reaction state during the ascent process becomes a problem. Therefore, knowing the reaction initiation temperature of a catalyst has become an extremely important test subject, but it has been difficult to test the reaction initiation temperature in conventional catalytic reaction test furnaces.

That is, in order to downsize the device and avoid spontaneous reactions of the simulated gas at high temperatures, as shown in Figure 5,
The simulated gas heating furnace b and the catalytic reaction test furnace a are arranged as close as possible.

Therefore, since the distance from heating furnace b to catalyst c is short and the high-temperature simulated gas passes directly through catalyst c, the temperature of catalyst c gradually increases as shown in FIG. a
The gas temperature inside becomes almost constant at the same time as the gas is supplied,
At what point in time is the gas temperature in the catalytic reaction test furnace a, the catalyst c
It is not possible to know what will initiate the reaction. Of course, it is possible to find out the reaction start temperature of catalyst c by keeping the simulated gas at a low temperature and gradually increasing the temperature of heating furnace b, but this is not the case for many test catalysts. Repeating such a process takes time, and combined with the heat loss in the heating furnace, the testing cost becomes extremely high.

The present invention provides a catalytic reaction test furnace that can overcome these conventional drawbacks.

Embodiments of the present invention will be described below based on the drawings.

A is a catalytic reaction test furnace equipped with a cylindrical furnace wall 3 fixed to a base seedling 2 via a stay 1 that also serves as a protective cover, and a catalyst holder 4 that is separable from the furnace wall 3. , B is a heating furnace placed close to the top thereof.

While the large flow rate gas for dilution with low reactivity flows through the mixing chamber 5, it is heated by the heating furnace B to +min and its temperature is increased.
Highly reactive gases such as NO are transferred to the mixing chamber 5 through pipes 6 and 7 in order to prevent spontaneous reactions at high temperatures as much as possible.
sent near the exit. In this case, even if the distance from the feeding position of the pipes 6, 7 to the test furnace A is short, the pipes 6, . As shown in FIG. 2, the pipe 6 is installed so that the gas added by the pipe 7 and the large flow rate gas for dilution are sufficiently mixed and introduced into the test furnace A as a stable simulated gas.
, 7 are bent upward to add the reactive gas as a counterflow to the large flow gas flow in the mixing chamber 5, and a baffle plate 8 is provided near the outlet in the mixing chamber 5 for mixing. It is desirable to encourage this. The catalyst holder 4 is
The catalyst holder 4 is only pressed from below against the lower flange 3a of the furnace wall 3, and the catalyst holder 4 is pushed down from the solid line position to the imaginary line position in FIG. is descended and separated from the furnace wall 3.

10 is a metal O-ring that ensures airtightness between the lower surface of the lower flange 3a and the upper surface of the catalyst holder 4 facing it, 11 is an adjuster, 12 is a socket nut, and 13 is an elevating guide provided on the base 2. It is a hole.

Reference numeral 14 denotes a catalyst loaded in a catalyst case 15, and the inner surface of the lower end of the catalyst case 15 is formed into a conical slope 15a, while the upper surface of the catalyst holder 4 has a tapered projection 4a that tightly fits therein. is provided so that when replacing the catalyst 14, the entire catalyst case 15 can be separated from the catalyst holder 4 with a single touch operation.

Furthermore, the slope 15a and the tapered protrusion 4a on the inner surface of the lower end of the catalyst case 15 are designed to prevent leakage through precise machining or grinding, and the catalyst case 15 is aligned with the center axis of the test reactor A. It also serves as a positioning tool to be attached together. The illustrated catalyst holder 4 is divided into an upper half having a tapered protrusion 4a and a lower half having a gas outlet 23 for ease of processing, and these are integrally connected by bolts 24. However, it may be formed as a single piece. A bypass line 18 equipped with a suction device (for example, a suction pump) 17 having a suction capacity greater than the amount of simulated gas supplied to the furnace A is provided in the flow path 16 connecting the mixing chamber 5 and the test furnace A. On the other hand, the stay 1 is provided with a 0N. 0F
A micro switch 20 that is operated by F is provided to separate the catalyst holder 4 from the furnace wall 3, so that the micro switch 20 is turned ON and the suction device 17 is activated.

211, 2, and 3 are temperature sensors, and 22 is a differential pressure measuring tube.

Note that in order to adjust the distance between the upper surface of the catalyst 14 and the temperature sensor 212, a structure may be used in which the position of the catalyst 14 can be changed and adjusted (for example, by replacing the catalyst holder 4). In this embodiment, in the above-described configuration, a flow of simulated gas to be fed to the furnace A is applied to the inner surface of the furnace wall 3 inside the catalytic reaction test furnace A and at a position upstream of the catalyst 14. A cooler 25 is provided to reflect the simulated gas, and after the simulated gas is cooled to below the catalytic reaction starting temperature, the temperature is gradually raised.

According to the above embodiment, when high-temperature simulated gas is fed into the furnace A with the catalyst 14 set in the furnace A, the high-temperature simulated gas is First, it collides with the cooler 25 and the heat is taken away directly by the cooler 25, and then the heat is taken away by the furnace wall 3.

Therefore, the gas temperature immediately before the catalyst 14 rapidly decreases to below the reaction initiation temperature of the catalyst 14 due to the above-mentioned cooling effect; however, due to the heat exchange with the high-temperature simulated gas, As the temperature gradually increases, the gas temperature begins to increase at a rate close to the temperature increase of the catalyst 14,
When replacing the catalyst 14, which gradually rises to a preset temperature after reaching the catalytic reaction starting temperature (see Figure 4), operate the lever 9 to lower the catalyst holder 4, and the micro switch will be activated. 20 is turned ON and the suction device 17 is activated, as shown in FIG. ) is sucked in and flows into the bypass line 18, and while the catalyst 14 is being replaced, the cooler 25 and furnace wall 3 are cooled in preparation for the next test.

Therefore, by replacing the catalyst 14 with the heating furnace B operating and continuously generating the simulated gas, and analyzing the gas taken out from the outlet 23, it is possible to know the reaction start temperature of each catalyst. . Note that if the degree of cooling by the cooler 25 is required to be small, the cooler 25 has a small heat capacity and is of a type that reflects the high-temperature gas flow toward the furnace wall 3.
If you want to increase the degree of cooling, use a SUS thread filter, ceramic, etc. as the cooler 25.
It is sufficient to use a material that does not have a catalytic action and has a large heat capacity. In addition, in this way, several types of coolers 25 with different heat capacities are prepared and an appropriate one is selected and used, and the reflective type cooler 25 is made hollow,
If necessary, the heat capacity may be changed by filling an arbitrary amount of SUS, granular ceramic, etc. inside the structure. The present invention has the above-mentioned configuration, and is provided with a cooler inside the catalytic reaction test furnace and at a position upstream of the catalyst to temporarily cool the simulated gas in a high temperature state fed to the furnace. Since the temperature was gradually raised after cooling to below the catalytic reaction starting temperature, it is possible to check the reaction starting temperature of the catalyst while keeping the temperature of the heating furnace constant.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is an overall vertical sectional view, Fig. 2 is an enlarged view of the main parts, Fig. 3 is an action diagram, and Fig. 4 is the relationship between gas temperature and catalyst temperature. Diagram showing 5th
The figure is a longitudinal sectional view showing a conventional example, and FIG. 6 is a diagram showing the relationship between gas temperature and catalyst temperature in the conventional example. A...Catalytic reaction test furnace, 14...Catalyst, 25...Cooler.

Claims (1)

[Claims] 1. A cooler is provided inside the catalytic reaction test furnace and at a position upstream of the catalyst to cool the simulated gas fed to the furnace to below the catalytic reaction starting temperature, and then gradually raise the temperature. A catalytic reaction test furnace characterized by being configured to heat the catalyst.