JPH0694378A - Recovering method for waste heat of cupola - Google Patents

Abstract

PURPOSE:To improve a utilizing efficiency of waste gas energy by burning CO in waste gas to be discharged from a cupola, introducing the gas into a heat exchanger, and driving a refrigerator with vapor due to waste heat of the waste gas to cool to dehumidify blown air of the cupola. CONSTITUTION:Waste gas to be discharged from a cupola 1 is introduced into a combustion chamber 2 to burn CO in the gas. The gas is also introduced into a heat exchanger 4 to heat blown air to the cupola 1. Further, the gas is introduced into a waste heat boiler 5 to recover the waste heat of the gas as vapor, and then a refrigerator 10 is driven with the vapor as a driving heat source. On the other hand, refrigerant having cold to be obtained by the refrigerator 10 is introduced into an air cooler 11 to cool to dehumidify blown air. The dehumidified air is introduced into the exchanger 4. Thus, the waste heat of the cupola 1 is effectively utilized to heat the air without inputting energy from the exterior and to cool to dehumidify it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cupola waste heat recovery method for recovering waste heat discharged from a cupola to improve energy utilization efficiency.

[0002]

2. Description of the Related Art Conventionally, in a foundry or the like, waste air discharged from a cupola is used to heat air blown to the cupola. This blown air is used for combustion and requires dehumidification in advance so that it is dehumidified by an air cooling device. Conventionally, the air cooling device is driven by energy separately input from outside the system.

For example, in the case of applying cogeneration, waste gas of a gas engine for driving a generator is used to heat air blown to a cupola, and waste heat of cooling water of the gas engine is used. Then, the absorption refrigeration machine and the adsorption refrigeration machine are driven, and dehumidification is performed by cooling the blown air using the cold heat obtained in this refrigeration machine.

[0004]

However, in the above-mentioned conventional structure, the energy for dehumidifying the blown air is taken in from the outside, and the waste heat discharged from the cupola is not sufficiently effectively utilized. . In addition, there is a problem in that the heat quantity of the waste gas varies and stable heating cannot be performed.

The present invention is intended to solve the above problems, and it is an object of the present invention to improve the utilization efficiency of energy required for operating a cupola.

[0006]

In order to solve the above-mentioned problems, the method for recovering waste heat of a cupola according to the present invention introduces the waste gas discharged from the cupola into a combustion chamber and removes CO in the waste gas in the combustion chamber. After burning, guide the waste gas to the heat exchanger,
After the blast air to the cupola is heated with waste gas in the heat exchanger, the waste gas that has passed through the heat exchanger is guided to the waste heat boiler, and the waste heat of the waste gas is recovered as steam in the waste heat boiler, and the recovered steam Drive the refrigerator with the driving heat source as the driving heat source, and guide the refrigerant with cold heat obtained in the refrigerator to the air cooler,
In the air cooler, the blown air is cooled and dehumidified, and the dehumidified blown air is guided to the heat exchanger.

[0007]

With the above structure, after the CO in the waste gas is burned in the combustion chamber, the waste gas is guided to the heat exchanger, so that the heat energy recoverable in the heat exchanger is added to the waste heat of the waste gas. Since the heat of combustion of the unburned gas is included, the amount of heat returning to the cupola via the blown air increases, and the fuel supplied to the cupola can be reduced.

Further, since the cold heat of the air cooler for dehumidifying the blown air is obtained by driving the refrigerator using the steam of the waste heat boiler as a driving heat source, it is necessary to drive the air cooler as in the conventional case. It is not necessary to separately supply energy from the outside of the system, and it is possible to dehumidify the blown air using the energy generated by the cupola itself, and it is possible to improve the energy utilization efficiency.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the furnace top waste gas discharged from the cupola 1 is guided to the combustion chamber 2, and CO in the waste gas is burned in the combustion chamber 2 to raise the temperature of the waste gas. At this time, when the exhaust gas temperature fluctuates due to variations in the operating temperature of the cupola 1, the waste gas in the combustion chamber 2 is appropriately supplemented by a burner 3 provided in the combustion chamber 2 using city gas or the like as fuel. To do.

Then, the waste gas discharged from the combustion chamber 2 is guided to the heat exchanger 4, and the air blown to the cupola 1 is heated by the waste gas. This blown air becomes the tuyere burning air of the cupola 1. Further, the waste gas passing through the heat exchanger 4 is guided to the waste heat boiler 5, and the waste heat of the waste gas is recovered as steam in the waste heat boiler 5. The waste gas that has passed through the waste heat boiler 5 is sent to a dust collector 7 by a fan 6 to remove dust, and then treated by a desulfurization and denitration device 8 and released to the atmosphere.

Further, the steam obtained in the waste heat boiler 5 is supplied to the cement lining equipment and the coating equipment as a heat source, and is also sent to the steam compressor 9 to be used as an air power source. Further, the steam is supplied to the refrigerator 10 as a driving heat source, and the refrigerant water having the cold heat obtained in the refrigerator 10 is guided to the air cooler 11. The refrigerator 10 includes an adsorption refrigerator and an absorption refrigerator. On the other hand, the blower 12 sends the blown air to the air cooler 11. The blower air is cooled and dehumidified in the air cooler 11, and then the blown air is guided to the heat exchanger 4.

Therefore, according to this embodiment, the combustion chamber 2
After the CO in the waste gas is burned in, the waste gas is guided to the heat exchanger 4. Therefore, the heat energy recoverable in the heat exchanger 4 includes the waste heat of the waste gas and the combustion heat of the unburned gas. As a result, the amount of heat returning to the cupola 1 via the blown air increases, and the fuel coke supplied to the cupola 1 can be reduced.

Further, the cold heat of the air cooler 11 for dehumidifying the blown air is obtained by driving the refrigerator 10 by using the steam of the waste heat boiler 5 as a driving heat source, and the cold heat of the air cooler 11 as in the conventional case. It is not necessary to separately supply the energy required for driving from the outside of the system, and it is possible to dehumidify the blown air using the energy generated by the cupola itself, and it is possible to improve the energy utilization efficiency.

When the operating temperature of the cupola 1 varies and the waste gas temperature or the CO concentration detected by the sensor 13 fluctuates, the city gas or the like is used as a fuel to burn the burner 3 provided in the combustion chamber 2 as appropriate. The waste gas in the chamber 2 can be supplementarily heated to stabilize the amount of heat supplied to the heat exchanger 4.

[0015]

As described above, according to the present invention, the heat energy recoverable in the heat exchanger becomes the waste heat of the waste gas and the combustion heat of the unburned gas, and the amount of heat returned to the cupola via the blast air is reduced. By increasing the number, it is possible to reduce the fuel supplied to the cupola.

Further, the blown air can be dehumidified by utilizing the energy generated by the cupola itself, and the energy utilization efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the concept of a waste heat recovery method for a cupola showing an embodiment of the present invention.

[Explanation of symbols]

 1 Cupola 2 Combustion Chamber 4 Heat Exchanger 5 Waste Heat Boiler 10 Refrigerator 11 Air Cooler

Claims (1)

[Claims] 1. A waste gas discharged from a cupola is introduced into a combustion chamber, CO in the waste gas is burned in the combustion chamber, and then the waste gas is introduced into a heat exchanger, and the waste gas is introduced into the cupola in the heat exchanger. After heating the blast air, guide the waste gas that passed through the heat exchanger to the waste heat boiler, recover the waste heat of the waste gas as steam in the waste heat boiler, and drive the refrigerator using the recovered steam as the driving heat source. Waste heat of a cupola, characterized in that it introduces a refrigerant with cold heat obtained in a refrigerator to an air cooler, cools the blast air in the air cooler to dehumidify, and introduces the dehumidified blast air to the heat exchanger. Recovery method.