JPS60144516A - Heating method by on/off burning of plural burners - Google Patents

Abstract

PURPOSE:To obtain the excellent burning efficiency even under low burning time by a method wherein the firing sequence and firing time for burners are set previously, then the variation of burning quantity is controlled in stages by the number of firing burners. CONSTITUTION:Whole number sequential firing for plural number of burners 1, 2,...,8 faced toward the inside of a furnace is repeated periodically according to the desired timing interval X and previously designated sequence. The one firing time (t) is made constant, and the desired firing timing interval X is varied according to the required amount of heat. Further, the burning of each burner is made to keep the constant air/fuel ratio under the maximum air blow-off quantity and fuel injecting quantity. Thereby, the excellent burning efficiency can be achieved even under the low burning time.

Description

[Detailed Description of the Invention] This invention relates to a furnace heating method that efficiently heats a heat treatment furnace for iron, steel, etc. by turning on and off multiple burners, and more precisely equalizes the temperature inside the furnace. .

In the case of a batch-type heating furnace, the amount of combustion is at its maximum at the beginning of heating, and a large amount of combustion gas circulates in the furnace, but after that the amount of combustion gradually decreases, and during soaking heating, the amount of combustion gas is at its maximum during initial heating. /
Only 10 to 1/100 of the amount of heat is required. As a method for reducing the amount of heat, an electro-air/fuel ratio combustion system that throttles both air and fuel has already been used, but as the amount of combustion decreases, problems arise in maintaining temperature uniformity. Furthermore, constant air combustion systems have already been used in which the amount of air is fixed at the maximum combustion level and only the amount of combustion is reduced, but this system has poor combustion efficiency during uniform heating. Furthermore, an impulse combustion system in which all burners are turned on (combustion) and off (non-combustion) at the same time is already in use, but the off-time of the burners during uniform heating is long, and during this off-time, the circulation of gas in the furnace is limited. Since this is not carried out, it is difficult to equalize the temperature inside the furnace.

Furthermore, a special system that uses a special nozzle and combines an electro-air combustion system and an electro-air ratio combustion system is known, but the structure is complicated and the combustion efficiency at low combustion times is still insufficient. This invention was made to solve these problems, and will be described in detail below with reference to the drawings.

Figure 1 shows a plan view of the furnace. Burners 1, 2..., 7°8 are arranged on the left and right side walls 10. These burners are designed to perform electro-air fuel ratio combustion at maximum air and fuel injection amounts during combustion in the on state, and in the on state, both air and fuel are It is designed to prevent it from gushing out. and,
Each burner is 1, 2.3...8, 1, 2.・
... 8.1. (The burner ignition order is set during the test run and remains constant thereafter.)

Figures 2, 3, and 4 show the operating states of the burner when the required amount of heat is small (sometimes one ignition), medium (4 ignitions), and large (5 ignitions), respectively. where,
T each indicates one cycle which is variable depending on the combustion time.

This invention comprises a plurality of burners 1.2.
. . . , 8 maintains the desired ignition timing interval X and periodically repeats ignition one by one in accordance with a predetermined order, and one ignition time t remains unchanged and the desired ignition timing interval X is changed according to the required amount of heat, and the combustion of each burner is performed by electro-air combustion at the maximum amount of air and fuel.

That is, in this invention, the ignition order and ignition time of the burners are set in advance, and changes in the combustion amount can be controlled in stages according to the number of burners ignited.In other words, as the combustion amount increases, the ignition timing interval X and period T become smaller. Become,
In other words, the ignition timing interval X is changed so that the number of burners ignited (the number of burners ignited at the same time) increases, that is, the ignition timing interval X changes as the combustion amount changes.
It has excellent combustion efficiency even at low combustion times.

Note that it is convenient to calculate the required amount of heat based on the temperature difference between a predetermined furnace atmosphere setting temperature and a temperature measured at a furnace control point.

1

[Brief explanation of the drawing]

The drawings are for explaining this invention. Fig. 1 is a perspective plan schematic diagram of the furnace, and Figs. 2 is a graph showing the operating state of the burner in FIG. 1 to 8 Burner 9 Furnace 10.11 Left and right side walls of the furnace t Ignition time T Period , Indication of the case Japanese Patent Application No. 58-247734 2, Title of the invention Furnace heating method by on-off combustion of multiple burners 3, Person making the amendment Relationship with the case Patent applicant Sanken Sangyo Co., Ltd. 4, Agent ■730 5. Date of amendment order Voluntary action 6. The detailed description of the invention, which is increased by the amendment, is amended as follows. (b) Amend the claims as shown in the attached sheet. (B) On page 4, line 4, on line 9 of page 4, and on line 12 of page 12, each "xJ is corrected to rXJ." (C) On page 4, line 15, "fire combustion" Correct "fire" to "ratio". (d) Page 4, line 20, page 5, line 3, page 6, line 1
Correct each row rXJ to rXJ. Scope of claims 1. Multiple burners facing into the furnace (1, 2°...
..., 8) maintains the desired ignition timing interval (5) and periodically repeats all ignitions sequentially according to a predetermined order, and the one ignition time (t) remains unchanged and the desired ignition timing interval (5) is maintained and The ignition timing interval (on) is changed according to the required amount of heat, and the combustion of each burner is performed at the electro-air fuel ratio combustion at the maximum air injection amount and fuel injection amount. Furnace heating method by off-combustion. 2. Turning on/off multiple burners as set forth in claim 1, wherein the required heat amount is calculated based on the temperature difference between a predetermined furnace atmosphere setting temperature and a temperature measured at a furnace control point. Method of heating the furnace by combustion.

Claims (1)

[Claims] 1. A plurality of burners facing into the furnace (1, 2°...
..., 8) maintains the desired ignition timing interval (X) and periodically repeats all ignitions sequentially according to a predetermined order, and the one ignition time (t) remains unchanged, and the desired ignition timing interval (X) The ignition timing interval (X) is changed according to the required amount of heat, and the combustion of each burner is performed by electro-air fuel ratio combustion at the maximum air injection amount and fuel injection amount.On-off combustion of multiple burners. Furnace heating method. 2. On-off combustion of multiple burners according to claim 1, wherein the required amount of heat is calculated based on the temperature difference between a predetermined furnace atmosphere setting temperature and a temperature measured at a furnace control point. Furnace heating method.