JPS6329137Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a catalytic converter that recovers waste heat such as engine exhaust heat and reaction heat during its purification process.

Recently, stationary gas engines that run on city gas or natural gas have been used for heating and cooling facilities such as offices and large stores to save electricity.
This operates the compressor to perform air conditioning and heating, but from the perspective of pollution control, just like in vehicles.
A catalytic converter is installed in the exhaust pipe from the engine to the muffler, oxidizing and reducing harmful components in the exhaust such as CO, HC, and NOx, rendering them harmless and releasing them to the outside.

Figures 1A and 1B show the catalytic converter used therein, and inside a metal container 1' which has a double peripheral wall 1a' and a bottom wall 1b' to form a water jacket 5', A honeycomb body 3' in which a metal catalyst such as platinum or palladium is coated on the surface of a lattice body made of ceramic is placed in a hood-shaped holding cylinder 4'.
(This is formed by a pair of parts facing each other.) The upper end of the holding cylinder 4' is connected to the lower surface of the lid body 2' which connects the exhaust inlet pipe 2a' and the outlet pipe 2b'. It is fixed to the center of the container 1', and the engine exhaust flowing into the center of the container 1' from the exhaust inlet pipe 2a' is purified by passing through the honeycomb body 3', and the purified exhaust is passed from the bottom side to the side. The water is turned over so that it flows out from the outlet pipe 2b', and the water is passed through the water jacket 5' to exchange heat with the exhaust heat and the reaction heat accompanying the purification action to produce hot water, which is then used for hot water supply, washing, etc. I have to.

By the way, in this conventional converter, the exhaust gas is directly cooled by the water in the water jacket 5' as it passes through the honeycomb catalyst 3' and rises around the holding cylinder 4', so the temperature decreases. This affects the honeycomb body 3', prevents the temperature of the catalyst from increasing, and reduces the exhaust gas purification efficiency.
This idea was devised to improve the above-mentioned problems.It prevents the temperature of the catalyst from dropping, promotes its warm-up and maintains it at the desired temperature, increases the purification efficiency of exhaust gas, and also helps muffle noise. A catalytic converter is provided, in which a honeycomb body whose surface is covered with a metal catalyst is enclosed and housed in a metal container disposed in the middle of an exhaust pipe by a hood-like holding cylinder. In the waste heat recovery type catalytic converter in which the circumferential wall and the bottom wall of the container are doubled to form a water jacket, a partition box surrounding the holding cylinder is disposed outside the holding cylinder, and the upper edge of the partition box is disposed outside the holding cylinder. is fixed to the lower surface of the lid to form a narrow gap between it and the container, and the upper end of the wall of the partition box on the water supply pipe side is provided with a plurality of window holes, and the exhaust outlet pipe located on the opposite side is provided with a plurality of window holes. It is characterized in that the lower end portion is located close to the inner bottom wall of the container.

Describing the embodiment with reference to FIGS. 2 and 3, reference numeral 1 denotes the metal container of the catalytic converter disposed in the middle of the exhaust pipe of the engine as described above, and the exhaust outlet when viewed from above. The pipe side has a constricted shape, and the peripheral wall 1a and the bottom wall 1b are doubled to form a water jacket 5,
A water supply pipe 1c is provided at the bottom of one side, and an outflow pipe 1d is provided at the top of the other side, and a lid body 2 connecting an exhaust inlet pipe 2a and an exhaust outlet pipe 2b is detachably attached to the upper opening. ing.

An exhaust inlet pipe 2 is provided at the center of the lower surface of the lid body 2.
The upper end of a holding cylinder 4 (which may also be circular), which is elliptical when viewed from above, is fixed so as to surround the inlet of a, and this holding cylinder 4 has an upper conical part 4a and a lower straight cylinder part 4b. It has a hood shape and is formed by abutting a pair of parts, and a first
A honeycomb body 3 having a metal catalyst such as platinum or palladium coated on the surface of a lattice-like body made of ceramic as shown in FIG.

Furthermore, a partition box 6 with an open top is disposed on the outside of the holding cylinder 4 so as to wrap around the entire holding cylinder 4, and its upper edge is fixed to the lower surface of the lid body 2. A narrow gap 7 is formed between the partition box 6 and the bottom wall 1b, and a plurality of relatively large window holes 6a are provided at the upper end of the wall surface of the partition box 6 facing the water supply pipe 1c.

The exhaust outlet pipe 2b is deeply inserted into the container 1, and the lower end thereof, which is cut obliquely toward the outflow pipe 1d, is close to the inner bottom wall 1b of the container 1.

Based on the above configuration, when in use, engine exhaust gas flows together with secondary air into the holding cylinder 4 in the converter container 1 from the exhaust inlet pipe 2a, while the required amount of water flows into the water jacket 5 through the water supply pipe 1c. Supplied.

Thus, the exhaust gas passes through the honeycomb body 3 and removes HC, CO, or NOx contained therein.
While harmful components such as the The water rises, flows out of the box through the window hole 6a provided in the wall on the water supply pipe side, flows downward through the narrow gap 7 between the inner wall of the container 1, and in the opposite direction to the window hole 6a. During that time, it enters the outlet pipe 2b while exchanging heat with the water in the jacket 5, and flows out to the muffler side.

In this case, since the entire holding cylinder 4 is surrounded by the partition box 6, the honeycomb body 3 supporting the metal catalyst is surrounded by a warm air layer heated to a high temperature by the reaction action, and the temperature increases. The desired high temperature state is maintained without dropping, and the reaction for exhaust gas purification is promoted.

In addition, a passage bent vertically and horizontally is formed in the container 1 by the holding cylinder 4 and the partition box 6 on the outside thereof, and since the exhaust outlet pipe 2b is inserted deeply into the container 1, the container 1 The exhaust gas that has entered the inside exits from the outlet pipe 2b through a long curved passage, and the noise of the exhaust gas is suppressed to that extent.

Furthermore, since the exhaust gas leaving the partition box 6 passes through the narrow gap 7 inside the container, the efficiency of heat recovery by the water in the water jacket 5 is improved.

As described above, according to this invention, as a waste heat recovery type catalytic converter, a partition box surrounding the holding cylinder that supports the honeycomb catalyst is provided outside the holding cylinder, and the upper edge of the partition box is fixed to the lid body. A narrow gap is formed between the partition box and the container, and a plurality of window holes are provided at the upper end of the wall on the water supply pipe side of the partition box, and the lower end of the exhaust outlet pipe located on the opposite side is connected to the inside of the container. Because it is placed close to the bottom wall, the honeycomb catalyst is surrounded by high-temperature warm air and is maintained at a high temperature without being affected by water in the water jacket as in the conventional case, increasing exhaust purification efficiency. In addition, a long bent passage can be formed in the container, which can be used to muffle exhaust noise, and improve the efficiency of waste heat recovery by the water jacket.

[Brief explanation of the drawing]

FIG. 1A is a sectional view of a conventional catalytic converter. Figure B is a partially cutaway perspective view of the honeycomb body portion. FIG. 2 is a sectional view of an embodiment of this invention. Figure 3 is its plan view. In the figure, 1...metal container, 1a...peripheral wall, 1b...
...Bottom wall, 1c...Water supply pipe, 1d...Outflow pipe, 2...Lid, 2a...Exhaust inlet pipe, 2b...
Exhaust outlet pipe, 3... honeycomb body, 4... holding cylinder,
5... Water jacket, 6... Partition box, 6a
...Window hole, 7...Void.

Claims (1)

[Scope of utility model registration request] A honeycomb body 3 whose surface is coated with a metal catalyst is housed inside a metal container 1 disposed in the middle of an exhaust pipe, and is surrounded by a hood-shaped holding cylinder 4, and the peripheral wall 1a of the container 1 and In a waste heat recovery type catalytic converter in which the bottom wall 1b is doubled to form a water jacket 5, a partition box 6 surrounding the holding cylinder 4 is disposed outside the holding cylinder 4, and its upper edge is It is fixed to the lower surface of the lid 2 to form a narrow gap 7 between it and the container 1, and a plurality of window holes 6a are provided at the upper end of the wall of the partition box 6 on the water supply pipe 1C side, and located on the opposite side. A waste heat recovery type catalytic converter characterized in that the lower end of the exhaust outlet pipe 2b is located close to the inner bottom wall 1b of the container 1.