Method and device for heating object to be heated

Patent metadata

Field	Value
Publication number	US-11534823-B2
Application number	US-201716493056-A
Country	US
Kind code	B2
Filing date	Dec 28, 2017
Priority date	Mar 13, 2017
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A method and device heat an object to be heated by a flame which is produced by supplying a fuel fluid and a combustion supporting gas to a burner as a heat, source. A temperature rising rate is increased by gradually increasing an oxygen concentration in the combustion supporting gas supplied to the burner and a device for heating an object to be heated including a burner for heating the object to be heated. A flow rate control unit controls a flow rate of a fuel fluid and a combustion supporting gas. A calculation unit transmits combustion information of the burner to the flow rate control unit, and the flow rate control unit increases a temperature rising rate of the object to be heated by increasing the oxygen concentration in the combustion supporting gas supplied to the burner.

First claim

The invention claimed is:

1. A method for heating an object to be heated, the method comprising:
measuring a temperature of the object to be heated;
supplying a fuel fluid and a combustion supporting gas to a burner to produce a flame that heats the object to be heated; and
adjusting an oxygen concentration in the combustion supporting gas supplied to the burner based on the measured temperature of the object to be heated,
wherein the oxygen concentration in the combustion supporting gas is increased as the temperature of the object to be heated increases to prevent a heat transfer efficiency between the flame and the object to be heated from decreasing as the temperature of the object to be heated increases.

2. The method for heating an object to be heated according to claim 1 , wherein a combustion state of the burner is a periodic oscillation state by gradually increasing the oxygen concentration in the combustion supporting gas supplied to the burner with periodical changes, periodically changing at least one of a flow rate of the fuel fluid and a flow rate of the combustion supporting gas, periodically changing an equivalent ratio obtained by dividing a total amount of oxygen supplied to the burner by an amount of theoretical oxygen required to combust the fuel fluid completely, and providing a phase difference between the periodic change of the oxygen concentration and the periodic change of the equivalent ratio.

3. The method for heating an object to be heated according to claim 2 , wherein a phase difference is provided between a periodic change of the flow rate of the fuel fluid and a periodic change of the oxygen concentration and the equivalent ratio.

4. The method for heating an object to be heated according to claim 1 , wherein the object to be heated is a ladle or a tundish used in a steel manufacturing process.

5. A device configured to heat an object to be heated, the device comprising:
a burner configured to combust a fuel fluid and a combustion supporting gas to heat the object to be heated, the burner comprising:
a center supply pipe disposed along a central axis of the burner and configured to supply the fuel fluid and a primary oxygen gas, the center supply pipe comprising:
a primary fuel supply pipe which is disposed on the central axis of the burner:
a secondary fuel supply pipe which is disposed to surround the primary fuel supply pipe; and
a primary oxygen gas supply pipe which is disposed to surround the secondary fuel supply pipe; and

at least one combustion supporting gas supply pipe which is concentrically arranged around the center supply pipe and is configured to supply combustion supporting gas;

a flow rate control unit configured to control a flow rate of the fuel fluid, a flow rate of the combustion supporting gas, and a flow rate of oxygen gas supplied to the burner;
a temperature measuring unit installed in the object to be heated; and
a calculation unit configured to perform arithmetic processing based on a temperature measured by the temperature measuring unit to generate combustion information and transmit the combustion information to the flow rate control unit,
wherein the flow rate control unit is configured to:
selectively increase or decrease a flow rate of the fuel fluid and the combustion supporting gas based on the combustion information input from the calculation unit, to increase a temperature of the object to be heated, and
maintain or increase a heat transfer efficiency between the flame and the object to be heated as the temperature of the object to be heated increases by selectively increasing or decreasing the flow rate of the fuel fluid and the combustion supporting gas to increase an oxygen concentration in the combustion supporting gas supplied to the burner based on the temperature measured by the temperature measuring unit so that the oxygen concentration in the combustion supporting gas increases with an increase in the temperature of the object to be heated.

6. The device of claim 5 , wherein the flow rate control unit is configured to control a combustion state of the burner to be a periodic oscillation state by gradually increasing the oxygen concentration in the combustion supporting gas supplied to the burner while periodically changing at least one of the flow rate of the fuel fluid and the flow rate of the combustion supporting gas, periodically changing an equivalence ratio, which is obtained by dividing a total amount of oxygen supplied to the burner by an amount of theoretical oxygen necessary to completely combust the fuel fluid, and providing a phase difference between a periodic change of the oxygen concentration and a periodic change of the equivalence ratio.

7. The device of claim 5 , wherein the flow rate control unit is configured so that when supplying the fuel fluid to the burner as a primary fuel and a secondary fuel, the flow rate control unit controls supply of the primary fuel to the primary fuel supply pipe at a constant flow rate, and supply of the secondary fuel to the secondary fuel supply pipe such that the flow rate of the secondary fuel is increased.

8. The device of claim 5 , wherein the flow rate control unit is configured so that when supplying the fuel fluid to the burner as a primary fuel and a secondary fuel, the flow rate control unit controls supply of the secondary fuel to the secondary fuel supply pipe at a constant flow rate, and supply of the primary fuel to the primary fuel supply pipe such that the flow rate of the primary fuel is increased.

9. The device of claim 5 , wherein an outlet of the primary oxygen gas supply pipe is disposed at a position projecting in a flame ejection direction from an outlet of the primary fuel supply pipe and the secondary fuel supply pipe of the center supply pipe in the burner.

10. The device of claim 5 , wherein the at least one combustion supporting gas supply pipe in the burner is configured receive air and a secondary oxygen as the combustion supporting gas.

Assignees

• Taiyo Nippon Sanso Corp

Inventors

• Hagihara Yoshiyuki
• Matsumura Takayuki
• SEINO Naoki

Classifications

• F23M5/025

  specially adapted for burner openings · CPC title

• B22D41/015 Primary

  with external heating, i.e. the heat source not being a part of the ladle · CPC title

• F23D14/22

  with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other · CPC title

• F23M2900/05021

  Wall blocks adapted for burner openings · CPC title

• F23D2200/00

  Burners for fluid fuel · CPC title