JPH07119902A - Exhaust gas economizer with soot fire extinguisher - Google Patents

Abstract

PURPOSE:To reduce damage of a heat exchange tube due to a soot fire by pouring fire extinguishing water in a furnace, closing an inlet of an exhaust gas introducing tube with the water, and sealing inert gas in an exhaust gas economizer. CONSTITUTION:When a soot fire occurs in a heat exchanger tube 5, a diesel main engine is stopped, a water supply piston valve 3 is opened, and a large quantity of fire extinguishing water is scattered on the tube 5 through a fire extinguishing nozzle 2. An exhaust gas introducing tube 31 is closed by the water poured in a furnace of an exhaust gas economizer 30, and the air from the tube 31 is shut OFF to expedite fire extinguishing of the fire. After the tube 31 is closed, when a carbon dioxide gas piston valve 4 is opened, carbon dioxide gas is injected from the nozzle 3 into the furnace. Since the gas has large specific weight it fully fills the furnace down to the closed part of the tube 31 to entirely extinguish the fire. Thus, the fire in the furnace can be entirely extinguished in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas economizer attached to, for example, a land or marine diesel engine, and more particularly to an exhaust gas economizer provided with a fire extinguishing device when a suitfire occurs in the furnace.

[0002]

2. Description of the Related Art As an exhaust gas economizer attached to a land or marine diesel engine, one shown in FIG. 5 is known, and an exhaust gas economizer 30 has a heat exchange tube 5 mounted therein and The exhaust gas introduction pipe 34 is connected to the lower portion, and the exhaust gas discharge pipe 32 is further connected to the upper portion. Exhaust gas from diesel engine
After being introduced into the exhaust gas economizer 30 from below at 34 and performing heat exchange with the heat exchange tube 5, it is discharged from the upper part of the exhaust gas economizer 30 through the exhaust gas discharge pipe 32 to a stack (not shown). And at this time, the heat exchange tube 5
The soot attached to is removed by the soot removing device 6.

If the soot that is strongly deposited on the heat exchange tube 5 is ignited for some reason without being removed, soot fire occurs. Conventionally, when a suitfire occurs, the fire is extinguished by waiting until the fire is extinguished, opening the manhole 1 when the fire is down, and discharging water from the manhole to the heat exchange tube 5.

[0004]

By the way, when a suitfire occurs in the heat exchange tube in the exhaust gas economizer, if the manhole is opened to extinguish the fire, oxygen in the air is supplied from the manhole to further increase the firepower. Will result. It is also said that when a small amount of water is poured to extinguish a fire when the firepower of Suitfire is intense, hydrogen burning occurs, which in turn promotes Suitfire. (The reason why only a small amount of water can be injected is that there is concern that the injected water will flow into the exhaust gas passage on the diesel engine side via the exhaust gas introduction pipe when a large amount of water is injected.) Therefore, a suitfire occurred. As a fire extinguishing method at this time, first, stop the diesel engine, wait for the suitfire to go down to some extent, inject water from the manhole, while opening the drain valve 10 of the exhaust gas introduction pipe while draining. The fire has been extinguished.

However, in many cases, tubes producing suitfire are dissolved in a wide area by high heat, and internal pressure causes local high temperature creep destruction and rupture.
As a result, large-scale replacement is required for its repair and restoration.

The present invention is intended to solve such problems, and when a suitfire occurs in the exhaust gas economizer, the diesel engine is stopped and at the same time, fire extinguishing water is injected into the furnace to extinguish the fire. Along with the operation, an exhaust gas economizer with a suitfire fire extinguisher was designed to block the inlet (smoke path) of the exhaust gas introduction pipe with fire extinguishing water, and to enclose inert gas such as carbon dioxide in the exhaust gas economizer to extinguish fire. The purpose is to provide.

[0007]

In order to achieve the above object, an exhaust gas economizer with a suitfire extinguisher of the present invention is an exhaust gas economizer, which is connected to a heat exchange tube mounted inside the exhaust gas economizer and an upper part thereof. Equipped with an exhaust gas exhaust pipe and an exhaust gas introduction pipe connected to the lower part, a fire extinguishing nozzle is provided above the heat exchange tube inside the exhaust gas economizer, and a water supply pipe and an inert gas introducing pipe are connected to the fire extinguishing nozzle. The smoke passage portion of the exhaust gas introducing pipe is formed in a U-shape or a structure similar to this, and the drain valve capable of discharging the accumulated water in the smoke passage portion and the drain valve are opened and closed. Further, a float switch capable of holding the accumulated water in the smoke passage portion at a predetermined water level is provided.

[0008]

In the exhaust gas economizer with the suitfire fire extinguisher device of the present invention described above, when a suitfire occurs in the exhaust gas economizer, a large amount of fire extinguishing water is injected into the furnace of the exhaust gas economizer to extinguish the fire, or a U-shape Fire extinguishing water is stored in the smoke passage of the exhaust gas introducing pipe having a similar structure, and the accumulated water completely blocks the inlet of the exhaust gas introducing pipe to interrupt the supply of oxygen from the exhaust gas introducing pipe. After the exhaust gas introduction pipe is closed, if the inert gas is filled in the furnace of the exhaust gas economizer, the inert gas becomes more serious. Therefore, the downstream side of the closed portion of the exhaust gas introduction pipe is filled with the inert gas and the suitfire is completely extinguished. After the fire is extinguished, the accumulated water in the smoke passage of the exhaust gas introduction pipe is drained from the drain valve and restored.

Further, in this case, the float switch provided in the exhaust gas introducing pipe acts so that the water level of the accumulated water in the smoke path does not exceed a certain level, so that even if a large amount of fire extinguishing water is injected, the diesel main engine is injected. Extinguishing water does not flow back into the exhaust gas passage on the side.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An exhaust gas economizer with a suitfire extinguishing system according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view during normal operation, FIG. 2 is a side view during water injection, and FIG. , 4 are side views of the modified example during normal operation and during water injection.

The exhaust gas economizer 30 of this embodiment is also attached to a land or marine diesel engine, and the heat exchange tube 5 is mounted inside the exhaust gas economizer 30. A fire extinguishing nozzle 2 is installed in the upper part of the furnace of the exhaust gas economizer 30, and a carbon dioxide gas cylinder 7 is connected to the fire extinguishing nozzle 2 via a water supply piston valve 3 and a carbon dioxide gas piston valve 4. There is.

When suitfire occurs in the heat exchange tube 5, first the diesel main engine is stopped, the water supply piston valve 3 is "opened", and a large amount of fire extinguishing water is passed through the fire extinguishing nozzle 2 onto the heat exchange tube 5. It is scattered. While extinguishing the fire, the fire extinguishing water is dropped under the exhaust gas economizer 30 and flows out into the exhaust gas introducing pipe 31. The flue portion of the exhaust gas introducing pipe 31 is formed in a U-shaped structure as shown in FIGS. Therefore, the fire extinguishing water dripping inside the exhaust gas economizer 30 collects in the U-shaped pipe portion 31a and closes the exhaust gas introducing pipe 31.

On the other hand, the float switch 8 is provided at the bottom of the U-shaped pipe portion 31a so that the water level of the accumulated water does not exceed a certain level.
It is equipped with a drain valve 9 that opens and closes in conjunction with the exhaust gas introduction pipe 31 that is blocked by accumulated water, but can prevent backflow of fire extinguishing water into the exhaust gas passage on the diesel engine side ( See FIG. 2).

In the above structure, the exhaust gas economizer
When the exhaust gas introducing pipe 31 is closed by the fire extinguishing water injected into the furnace of 30, the air from the exhaust gas introducing pipe 31 is blocked and the extinguishing of the suitfire is promoted. Exhaust gas introduction pipe
When the carbon dioxide piston valve 4 is "opened" after the blockage of 31, carbon dioxide is injected from the fire extinguishing nozzle 2 into the furnace. Since carbon dioxide is a serious gas, it fills up the closed part of the exhaust gas introducing pipe 31 and completely extinguishes the suitfire. The carbon dioxide gas piston valve 4 is "closed" after operating for an appropriate period of time. Further, the drain valve 9 of the exhaust gas introduction pipe 31 is "opened" after extinguishing the fire, and the accumulated water in the U-shaped pipe portion 31a is drained to restore the exhaust gas economizer 30. Instead of carbon dioxide gas, an inert gas [eg (N ₂ ) gas etc.] may be used.

In the case of the modified example shown in FIGS. 3 and 4, the smoke passage of the exhaust gas introducing pipe 31 is formed in a kite-shaped passage structure in which the central portion is divided by the partition plate 33. And this square-shaped passage 31
The same operational effect as that of the U-shaped tube portion 31a in the case of b in FIGS.

[0016]

As described in detail above, according to the exhaust gas economizer with a suitfire extinguishing device of the present invention, at the same time as the suitfire occurs in the exhaust gas economizer, the extinguishing water does not flow back to the flue of the diesel engine side. Since a large amount can be supplied and the exhaust gas introduction pipe can be completely blocked by this fire extinguishing water, oxygen that contributes to suitfire can be blocked and the fire extinguishing effect can be promoted. Further, by enclosing inert gas in the exhaust gas economizer furnace, the suitfire in the furnace can be extinguished entirely in a short time, and the effect of reducing the damage caused by the suitfire of the heat exchange tube can be obtained as much as possible.

[Brief description of drawings]

FIG. 1 is a side sectional view of an exhaust gas economizer with a suitfire fire extinguisher according to an embodiment of the present invention during normal operation.

FIG. 2 is a side sectional view at the time of water injection.

FIG. 3 is a side sectional view corresponding to FIG. 1 of the modified example.

FIG. 4 is a side sectional view of the modified example, which corresponds to FIG.

FIG. 5 is a side sectional view of a conventional exhaust gas economizer.

[Explanation of symbols]

 1 Manhole 2 Fire-extinguishing nozzle 3 Water supply piston valve 3a Water supply pipe 4 Carbon dioxide gas piston valve 5 Heat exchange tube 6 Soot removal device 7 Carbon dioxide gas cylinder 8 Float switch 9 Drain valve 10 Drain valve 30 Exhaust gas economizer 31 Exhaust gas introduction pipe 31a U-shaped pipe section 31b Sine-shaped passage 32 Exhaust gas exhaust pipe 33 Partition plate

Claims (1)

[Claims] 1. An exhaust gas economizer comprising a heat exchange tube mounted inside the exhaust gas economizer, an exhaust gas discharge pipe connected to an upper part, and an exhaust gas introduction pipe connected to a lower part, and the inside of the exhaust gas economizer. A fire extinguishing nozzle is provided above the heat exchange tube, and a water supply pipe and an inert gas introducing pipe are connected to the extinguishing nozzle, and a smoke passage part of the exhaust gas introducing pipe is formed in a U-shape or a structure similar thereto. The smoke passage portion is provided with a drain valve capable of discharging the accumulated water in the smoke passage portion and a float switch capable of opening and closing the drain valve to hold the accumulated water in the smoke passage portion at a predetermined water level. Exhaust gas economizer with a suitfire fire extinguisher.