Apparatus for cooling overheated gas in engine room

1. An apparatus for cooling overheated gas generated from a diesel particulate filter which is connected between a diesel engine and an exhaust pipe of the diesel engine, the apparatus comprising:

a tail pipe for discharging outwardly the overheated gas discharged from the diesel particulate filter;

a cooling fan, provided at one side of an engine room, for generating an air stream by sucking ambient air; and

a diffuser enclosing an outer circumference of the tail pipe in such a way a space is formed between the diffuser and the tail pipe to prevent the diffuser from directly contacting the tail pipe;

wherein the engine room is provided with a through-hole penetrating one side of the engine room; and

wherein the tail pipe has one end connected to the diesel particulate filter, and the other end extended outwardly from the engine room through the through-hole;

wherein the tail pipe comprises guide means for smoothly guiding the air stream generated by the cooling fan into the tail pipe and for preventing the overheated gas from flowing back into the engine room, and

wherein the diffuser comprises means for mixing the air stream generated by the cooling fan with the overheated gas discharged from the tail pipe or for guiding the air stream into the tail pipe such that the diffuser is adapted to lower a temperature of the overheated gas.

2. The apparatus as claimed in claim 1 , wherein the diffuser includes a sealing portion at a position in which the diffuser is engaged to the through-hole to completely seal a gap between the diffuser and the through-hole.

3. The apparatus as claimed in claim 1 , wherein the guide means comprises a plurality of guides inwardly embossed on a circumference of a portion of the tail pipe that extends outwardly from the engine room through the through-hole.

4. The apparatus as claimed in claim 3 , wherein the diffuser completely encloses the portion of the tail pipe that extends outwardly from the engine room through the through-hole.

5. The apparatus as claimed in claim 4 , wherein the diffuser has a cross-section that gradually widens so as to reduce velocity of fluid flowing through the diffuser.

6. An apparatus comprising:

(a) an engine room comprising a through-hole penetrating one side of the engine room;

(b) a diesel engine disposed in the engine room;

(c) an exhaust pipe for the diesel engine disposed in the engine room;

(d) a diesel particulate filter disposed in the engine room and between the diesel engine and the exhaust pipe for collecting and burning particulate matter discharged from the diesel engine;

(e) a tail pipe for discharging outwardly overheated gas discharged from the diesel particulate filter, the tail pipe having a first end connected to the diesel particulate filter and a second end extending outwardly from the engine room through the through-hole;

(f) a cooling fan disposed in the engine room for generating an air stream by sucking ambient air; and

(g) diffuser means for mixing the air stream generated by the cooling fan with the overheated gas discharged from the tail pipe or for guiding the air stream into the tail pipe so as to lower a temperature of the overheated gas;

wherein the tail pipe comprises guide means for smoothly guiding the air stream generated by the cooling fan into the tail pipe and for preventing the overheated gas from flowing back into the engine room.

7. The apparatus as claimed in claim 6 , wherein the diffuser means comprises a diffuser enclosing an outer circumference of the tail pipe, the diffuser being spaced from the outer circumference such that the diffuser does not directly contact the tail pipe.

8. The apparatus as claimed in claim 7 , wherein the guide means comprises a plurality of guides inwardly embossed on a circumference of a portion of the tail pipe that extends outwardly from the engine room through the through-hole.

9. The apparatus as claimed in claim 8 , wherein the diffuser completely encloses the portion of the tail pipe that extends outwardly from the engine room through the through-hole.

10. The apparatus as claimed in claim 9 , wherein the diffuser has a cross-section that gradually widens so as to reduce velocity of fluid flowing through the diffuser.

11. The apparatus as claimed in claim 10 , wherein the diffuser includes a sealing portion that completely seals a gap between the diffuser and the through-hole.