JP3257539B2 - Reaction product removal device in exhaust duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaction product removing device in an exhaust duct for removing a reaction product of an exhaust gas emitted from a production apparatus of a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing plant, various types of chemicals and special gases are used in production equipment for each semiconductor device manufacturing process. In order to collectively process the exhaust gas generated for each production device, each production device and the gas processing device are connected by an exhaust duct, and the exhaust gas emitted to each production device is sent to the exhaust gas processing device. .

[0003]

Therefore, in the exhaust duct connected to each production device, several types of gas contained in the exhaust gas of each production device may be mixed,
For this reason, there is a problem that a reaction occurs in each part of the exhaust duct and a reaction product is generated, and this product is deposited in the exhaust duct, particularly in a portion having a large flow resistance, for example, an elbow portion or a T-shaped portion of the duct. .

[0004] In addition, the concentration of the exhaust component of each production device changes depending on the operation status of each production device, so that the load of the exhaust gas treatment device connected downstream of the exhaust duct fluctuates. There is a problem that the stable operation of the device is hindered.

Japanese Patent Application Laid-Open No. 10-125607 (exhaust system) (Prior art 1) discloses that in a vapor phase growth apparatus, by-products are generated along with film formation by a chemical reaction, By-products accumulate in vacuum pipes and traps, causing problems such as clogging of pipes, pumps, and traps with accumulated by-products.To solve such problems, supply solutions to trap fins. Proposes an exhaust system that constantly flushes by-products adhering to the fins during operation of the dry pump.

In the first prior art, by using such an exhaust system, by-products adhering to the fins of the cleaning trap are always removed, so that the cleaning step is not required and the semiconductor device manufacturing apparatus is not stopped. The effect of being able to do so is emphasized.

The prior example 1 is intended to treat by-products contained in the exhaust gas generated from the vapor phase growth apparatus, but the exhaust gas discharged from the production apparatus contains components not captured by the fins. The system is not directly applicable to a production apparatus that emits inorganic exhaust gas components.

[0008] In a production apparatus for discharging inorganic components,
The acidic gas component and the alkaline gas component in the exhaust gas react with each other to produce a reaction product (salt) in the exhaust duct only after the reaction product is deposited in the exhaust duct. A problem arises.

SUMMARY OF THE INVENTION An object of the present invention is to prevent the accumulation of reaction products due to the reaction between an acidic gas component and an alkaline gas component in an exhaust gas generated in the exhaust duct, and also suppress a variation in exhaust load. To provide a reaction product removal device.

[0010]

According to the present invention, there is provided a reaction product removing apparatus in an exhaust duct having a nozzle, the apparatus comprising: The nozzles commonly receive the exhaust gas discharged from two or more production devices. The nozzle sends and sprays the solvent into the exhaust duct, and mixes the acidic gas component in the exhaust gas emitted from each production device with the solvent. It decomposes or flushes out reaction products that accumulate in the exhaust duct due to the reaction with the alkaline gas component.

Further, the exhaust duct has a drain pipe, and the drain pipe, together with the solvent, removes the reaction product in the exhaust gas that has been decomposed or washed out by the sending and spraying of the solvent.
It is discharged from the exhaust duct.

The nozzle sprays a solvent into the exhaust duct, brings the exhaust gas into contact with the solvent in a gas-liquid manner, performs a pretreatment for purifying the exhaust gas, and provides an exhaust gas treatment device connected to the latter stage of the exhaust duct. It is intended to suppress the fluctuation of the load.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, in a semiconductor device manufacturing factory, a production device 1 is provided for each semiconductor device manufacturing process.
1. There are several production devices 1, 1
.. As a set of a plurality of production equipment sets 1A, 1B,.
.., The production equipment of each set is connected to a common branch exhaust duct 2a, 2a,... For each set, and the branch exhaust ducts 2a, 2a,. Are connected to one trunk exhaust duct 2b.

The exhaust gas emitted from each of the production apparatuses 1, 1,... Is sucked by the exhaust fan 4 connected to the downstream of the main exhaust duct 2b, and first flows into the branch exhaust duct 2a.
The exhaust gas of each production device 1 first joins in the branch exhaust duct 2a, and further, each set of branch exhaust ducts 2a, 2a,.
The exhaust gas emitted from all the production apparatuses 1 merges with the gas in the main exhaust duct 2b, and the exhaust gas passes through the exhaust gas treatment apparatus 3 connected to the subsequent stage of the main exhaust duct 2b. After being purified, the treated gas is released into the outside air.

Therefore, when the exhaust gas emitted from each of the production apparatuses 1, 1,... Is an inorganic exhaust gas,
The exhaust gas discharged from the production device that emits the acidic gas component and the exhaust gas discharged from the production device that emits the alkaline gas component merge in the branch exhaust duct 2a or the main exhaust duct 2b, and the acid in the exhaust gas The gas component reacts with the alkaline gas component, and a salt as a reaction product accumulates in the exhaust duct 2a or 2b.

In particular, reaction products tend to accumulate downstream of the portion where the exhaust gas is mixed as shown in FIG. Therefore, in the present invention, as shown in FIG. 3, the solvent is sent to a position in the main exhaust duct 2b and / or the branch exhaust duct 2a where an acid gas component, an alkaline gas component, and a reaction product are easily generated. The reaction product is decomposed or washed away to remove or remove the reaction product from the exhaust duct, and the exhaust gas is pre-processed at the same time, thereby suppressing the fluctuation of the load of the exhaust treatment device.

In the following description, an example in which the present invention is applied to a main exhaust duct is shown. However, the same applies to a branch exhaust duct. Further, the relationship between the branch exhaust duct and the main exhaust duct is not limited to the example shown in the figure, but may be a tree-shaped branch at two or more stages. In FIG. 3, the main exhaust duct 2b and / or the branch exhaust duct 2a
An example in which the present invention is applied to the exhaust duct 2 will be described.

In FIG. 3, a large number of nozzles 8 are mounted in an exhaust duct 2, and each of the nozzles 8, 8,... Is connected by a solvent supply pipe 7, and a solvent is supplied from a solvent tank 5 to a pump 6 , And water is supplied to each of the nozzles 8, 8,... Through the solvent supply pipe 7.

A drain pipe 9 is attached to the exhaust duct 2, and the solvent sprayed from each nozzle 8 and the decomposition or the reaction product washed out by the solvent pass through the drain pipe 9 to the outside of the exhaust duct 2. Drain.

The nozzle 8 does not need to be disposed on the entire exhaust duct. As described above, a location where reaction products are likely to accumulate, such as an elbow or a T-shaped portion of the exhaust duct, is selected and specified. , And the reaction products decomposed or washed away in a specific section in the exhaust duct 2 can be removed from the drain pipe 9 and processed independently of the other exhaust duct parts.

The shape of the nozzle 8 used in the present invention is not particularly limited. However, as shown in FIG. 4, the nozzle 8 has a large number of fine jets 10, 10,. A gas that can be sprayed and that can make sufficient gas-liquid contact with the exhaust gas flowing in the exhaust duct 2 is used.

In the present invention, the reaction product of the acidic gas component and the alkaline gas component discharged from each production device 1 is dissolved by spraying or sending the solvent into the exhaust duct 2 to remove the reaction product from the duct. Along with removal, primary purification processing of exhaust gas will be performed in the exhaust duct,
The load on the exhaust treatment device 3 that performs the exhaust gas purification process in the subsequent stage is reduced.

[0023]

As described above, according to the present invention, the solvent is sprayed into the exhaust duct, and the reaction between the acidic gas component in the exhaust gas and the alkaline gas component in the exhaust gas discharged from the production equipment is performed. Since the substance is decomposed or washed away, no reaction product is accumulated in the exhaust duct, and therefore, the inside of the exhaust duct is not blocked by the reaction product.

Further, the primary processing of the exhaust gas is performed in the exhaust duct, so that the load on the exhaust gas processing device at the subsequent stage is reduced, the load on the exhaust gas processing device is stabilized, and the environmental load can be reduced. Has an effect.

[Brief description of the drawings]

FIG. 1 is an exhaust gas flow diagram of a semiconductor factory to which the present invention is applied.

FIG. 2 is an enlarged detail view of a portion A in FIG.

FIG. 3 is an enlarged detail view of a portion B in FIG. 2;

FIG. 4 is a front view of a nozzle.

[Explanation of symbols]

 1. Production equipment 2. Exhaust duct 3. Exhaust gas treatment device 4. Exhaust fan 5. Solvent tank 6. Solvent feed pump 7. 7. solvent supply piping Nozzle 9. Drainage pipe 10 Nozzle opening

Claims (3)

(57) [Claims] 1. A device for removing a reaction product in an exhaust duct having a nozzle, wherein the exhaust duct commonly receives exhaust gas discharged from two or more production devices, and the nozzle removes a solvent. Liquids are sprayed and sprayed into the exhaust duct to decompose or wash away the reaction products deposited in the exhaust duct due to the reaction between the acidic gas component and the alkaline gas component in the exhaust gas emitted from each production device. A reaction product removal device in an exhaust duct, characterized in that: 2. The exhaust duct has a drain pipe, and the drain pipe discharges a reaction product in the exhaust gas that has been decomposed or washed out by solvent feeding and spraying together with the solvent from the exhaust duct. 2. The reaction product removal device in an exhaust duct according to claim 1, wherein the reaction product is removed. 3. An exhaust gas treatment device connected to a downstream portion of the exhaust duct, wherein the nozzle sprays the solvent into the exhaust duct, brings the exhaust gas into contact with the solvent in gas-liquid contact, performs pretreatment of exhaust gas purification, The apparatus for removing reaction products in an exhaust duct according to claim 1, wherein the fluctuation of the load of the reaction is suppressed.