JPH0634814Y2 - Exhaust gas treatment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an exhaust gas treatment device.

(Prior Art) Conventionally, an exhaust gas treating apparatus is generally provided with a honeycomb-shaped oxidation or reduction catalyst inside a tubular body, and the catalyst and the exhaust gas are brought into contact with each other to remove harmful substances ( It converts carbon dioxide, hydrocarbons, etc.) into harmless substances. In this type of exhaust gas treating apparatus, when dust or the like adheres to the catalyst and poisons it, the catalyst performance is restored by washing with water (for example, JP-A-60-11).
4329, JP-A-63-13735).

(Problems to be solved by the invention) However, if the exhaust gas is, for example, an exhaust gas generated from an asphalt regenerating furnace, the exhaust gas contains components such as carbon and pitch in addition to the malodorous substances. Since it adheres strongly to the catalyst, it cannot be completely removed by washing with water as described above, and as a result, the performance of the catalyst deteriorates and the life of the catalyst becomes short.

Therefore, an object of the present invention is to provide an exhaust gas treatment device capable of extending the life of the catalyst by completely removing carbon, pitch, etc. attached to the catalyst.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides an exhaust gas treatment device, in which an oxidation catalyst layer made of an impregnated ceramic honeycomb body is provided in a rigid cylinder, and above this catalyst layer. A water spray nozzle and a hot air supply nozzle are provided below, and an exhaust pipe is attached to the upper part of the cylinder, an exhaust gas supply pipe is attached to the lower part, and a drain pipe is attached to the bottom part.

(Example) Next, an exhaust gas treatment apparatus according to the present invention will be described with reference to the accompanying drawings.

In the figure, oxidation catalyst layers 2 and 3 are provided in an upper portion and a lower portion inside a cylindrical body 1. For the catalyst layers 2 and 3, what is called an impregnation type in which a porous ceramic honeycomb body is impregnated with a catalytic metal is used.

Then, above the catalyst layers 2 and 3, water spray nozzles 9a and 9b,
Hot air supply nozzles 10a and 10b are disposed below, and the sprinkling nozzles 9a and 9b and the hot air supply nozzles 10a and 10b are in communication with each other so that cleaning water is supplied to the former and hot air is supplied to the latter. It has become.

An exhaust gas supply pipe 1a is attached to the lower portion of the cylindrical body 1, an exhaust pipe 1b is attached to the upper portion, and a drain pipe 1c is attached to the bottom portion.

An exhaust pipe of an asphalt regenerating furnace (not shown) is connected to the exhaust gas supply pipe 1a via a preheating chamber 8. on the other hand,
A temperature sensor 4 is provided inside the cylindrical body 1, and an odor sensor 6 is provided at the exhaust pipe 1b. The temperature sensor 4 detects the ambient temperature inside the cylinder 1, and the odor sensor 6 detects odorous substances contained in the exhaust gas passing through the exhaust pipe 1b.

The amount of fuel and air supplied to the burner provided in the preheating chamber 8 is controlled by the temperature controller based on the detection signal sent from the temperature sensor 4 and the detection signal sent from the odor sensor 6 via the temperature setter 7. Adjusted to a predetermined amount with 5,
The temperature of the exhaust gas supplied into the cylinder 1 is adjusted to the optimum reaction temperature (300 to 400 ° C.) of the oxidation catalyst.

In the exhaust gas treating apparatus having the above structure, the exhaust gas (temperature of 200 to 250
(° C) is heated to 300 to 400 ° C in the preheating chamber 8 and then supplied into the cylindrical body 1 from the exhaust gas supply pipe 1a. Then, the exhaust gas rises in the cylindrical body 1 and sequentially passes through the oxidation catalyst layers 2 and 3 so that the malodorous substances and the like in the exhaust gas are harmless substances (carbon dioxide,
The exhaust pipe 1b provided on the upper part of the cylinder 1,
It is exhausted to the outside through the exhaust fan 11.

Then, when the catalyst performance is deteriorated by poisoning the catalyst layers 2 and 3 by the exhaust gas treatment, the supply of the exhaust gas is stopped, and first,
Cleaning water is sprayed from the water spray nozzles 9a and 9b provided above the catalyst layers 2 and 3 for a predetermined time to wash dust and the like adhering to the catalyst layers 2 and 3 with water. The wash water that has been washed with water is discharged to the outside from the drain pipe 1c at the bottom of the cylinder 1.

Next, hot air supply nozzles 10a, 10b provided below the catalyst layers 2, 3
The hot air of 500-700 ℃ is supplied for a predetermined time, and the catalyst layers 2, 3
Burn out (burn off) residual combustibles (carbon, pitch, etc.) adhering to the. Since the catalyst layers 2 and 3 are of impregnated type, there is no problem of peeling of the catalytic metal due to the above washing or burnout unlike the so-called coating type in which the catalytic metal is adhered to the surface of the carrier (ceramics). , The catalytic function does not deteriorate.

In this embodiment, two catalyst layers were provided in series in the exhaust gas flow passage, but a single layer may be provided, and the exhaust gas treatment devices may be arranged in parallel to perform exhaust gas treatment on the one hand and catalyst regeneration on the other hand. May be.

(Effect of the Invention) As is clear from the above description, in the exhaust gas treating apparatus of the present invention, first, the poisoned catalyst is removed by washing with water,
After that, burn out (burn off) combustible substances (carbon, pitch, etc.) that cannot be removed by washing with hot air.
As a result, the catalyst can be sufficiently activated as compared with the conventional case, and the life of the catalyst layers 2 and 3 can be extended from 3 years or more to less than 1 year if the conventional cleaning was performed only with water. It is possible to extend the life of the.

Further, since the impregnated type is used for the catalyst layer, the catalytic function is not deteriorated at the time of activation by washing with water or burnout as compared with the case where the catalyst metal is coated on the surface of the carrier (ceramics).

[Brief description of drawings]

FIG. 1 is a block diagram of an exhaust gas treating apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Cylindrical body, 1a ... Exhaust gas supply pipe, 1b ... Exhaust pipe, 1c ... Drain pipe, 2,3 ... First and second oxidation catalyst layers, 8 ... Preheating chamber, 9a, 9b water spray nozzle, 10a, 10b ... Hot air Supply nozzle.

Claims (1)

[Scope of utility model registration request] 1. An oxidation catalyst layer made of an impregnated ceramic honeycomb body is provided in a rigid cylinder, a water spray nozzle is provided above the catalyst layer, and a hot air supply nozzle is provided below the catalyst layer.
An exhaust gas treatment device, wherein an exhaust pipe is attached to an upper portion of the cylindrical body, an exhaust gas supply pipe is attached to a lower portion thereof, and a drain pipe is attached to a bottom portion thereof.