JPS589940A - Controlling method for internal pressure of preheating furnace in sintering machine - Google Patents

Abstract

PURPOSE:To manufacture a high quality product inexpensively and efficiently with a sintering furnace provided with preheating furnaces before and behind the igniting furnace by regulating the internal pressure of each of the preheating furnaces to a suitable plus range and keeping it higher than the internal pressure of the igniting furnace. CONSTITUTION:The internal pressure of a preheating furnace 5 is detected with a pressure detecting terminal 10, and the detected value is fed back to a controller 12. The controller 12 regulates the opening of a valve 13 and/or the opening of a damper 16 so as to regulate the detected value of the internal pressure of the furnace 5 to +0.5- +2.0mm.H2O. The internal pressure of an igniting furnace 6 is detected with a pressure detecting terminal 11, and the detected value is fed back to the controller 12. The controller 12 regulates the opening of a valve 14 and/or the opening of a damper 17 so as to make the detected value of the internal pressure of the furnaces 0-3mm.H2O higher than that of the furnace 6 at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION This article relates to a method for controlling the pressure inside a preheating furnace in casting #IIK.

Dwight a-type sintering @ * K is I Aichi, and
In some cases, when 1 ignition ≧ medium heat retention furnace is operated, - quite a bit of O cooling - is discharged ◆ #II gas! 1IiIIj The technique of heating the cotton while introducing hot gas into the heat retention device during ignition is known.

In the modern sintered ore production method, controlling the pressure inside the ignition furnace and heat retention furnace is important, and much research is being conducted on the ignition furnace. Publication No. 55-9444 discloses a technique in which high-temperature exhaust gas discharged from the cooler of the sintering machine is introduced into the ignition furnace to maintain the pressure inside the furnace at positive pressure at all times.
Publication No. 28306 discloses a technology in which air for adjusting the furnace internal pressure is supplied into the ignition furnace in addition to the combustion air to control the furnace internal pressure to a predetermined negative pressure. There are research reports and reports that the pressure inside the furnace should be kept close to atmospheric pressure, and based on these findings and the experience of the H4 industry, we considered the pressure inside the ignition furnace. Mi1
The optimum value of the furnace pressure (%) cannot be determined in a simple manner as it varies depending on the sintering raw materials, composition, operating conditions of the 1wa sintering machine, etc., and there are many technical issues to be solved. look.

Also, regarding the internal pressure control fjlK of a heat retention furnace,
Publication No. 20926, Ks furnace is injected with lI & A technology has been disclosed that heats and sinters the ignition while controlling the temperature within the range.

Since 1991, a proposal has been made regarding the operation of the sintering furnace Ota* in the ignition furnace. It wasn't.

However, recently, for example, special plan 1972-24682
As described in the above publication, a technology has been invented, in which a preheating furnace is provided in front of the ignition furnace to preheat the surface layer of the raw material before ignition, and then ignited and sintered, and is being put into practical use. This technology eliminates the shortcomings of the Dwight Lloyd method of producing sintered ore in that it requires a drying and preheating chamber on the upper layer of the raw material on the pallet before ignition, and improves the quality of I11 ore.

The effect of shortening the open time during sintering and reducing energy in the fuel section can be obtained.

However, the preheating furnace installed before the ignition furnace is not installed in a different position from the conventional heat retention furnace, but because the machine #XR is all < Preheating furnace operation tKIi's operating technology for heat retention furnace and ignition furnace [
It is not possible to use it.

Since the preheating furnace is installed upstream of the ignition furnace, preferably adjacent to it, not only the operating conditions of the preheating furnace alone but also the operation of the preheating device affect the ignition furnace. Since the pressure is affected by the influence tube, how to operate the preheating furnace was a technical problem faced by manufacturers.

The present invention was made in view of this situation.
In a sintering machine with a preheating furnace 1 installed upstream of the ignition furnace, the pressure inside the preheating furnace is set within the range of 100, s to +2.0 ■HsO, and the pressure inside the ignition furnace is kept within the range of , 63m*1 (, 0 or less) is considered to be a good mold.

The present invention will be explained below based on the drawings.

Fig. 1 is a schematic diagram illustrating a sintering machine according to the present invention, and Fig. 211 is an explanatory diagram showing an embodiment of the present invention.

The sintering machine according to the present invention has the following features:
'The sintering raw material is transferred from the raw material feeder 1 to the lut 3 of the sintering machine 2.
Continuously cut the material into the soil, turn it around at a low speed of Nupro 4V, preheat the surface layer of the hooked raw material on the armlet 3 by blowing hot air from the preheating furnace 5, and transfer it to the surface of the preheated raw material in the ignition furnace. At step 6, a flame tube is injected into the mold and the coke powder mixed in the □ gate □ section. This is a device that sinters over the gold layer and continuously produces @ feed ore tlI4, and this device itself is made of, for example, II # Kinsho 54-24682.
Publication K14 Indicated L Deutroid type casting machine 0
Kai JL! 1' is a knowledgeable thing.

In the present invention, the pressure inside the ignition furnace 6 and the preheating furnace 5 installed at the front stage of the ignition furnace 6 are determined by the relationship t*g
t, the furnace pressure of the ToL preheating furnace 5 is controlled to be within the range of f + 0-5- +2-OM Hs00 by an optimal control method, and the furnace pressure of the ignition furnace is controlled to be within the range of f + 0-5- +2-OM Hs00. The goal is to maintain it within the following range.

The internal pressure of the preheating furnace is 0.5 to +2; OwxQ range is 1 point large - the crystallizing material - the value must be 1I11 for uniform preheating, + 0.5 m )! *O
, 1 Fcell O, there is a problem that the pressure fluctuation in the heating furnace 5 is large due to the influence of the pressure inside the ignition furnace 6), and the large flame in the ignition furnace flows into the preheating furnace 5. If the lower end of the partition 1118 that separates the preheating furnace 5 from the 1st ignition melts, and the pressure in the preheating furnace becomes lower than the atmospheric pressure 1], the lower end of the partition 1118 that separates the preheating furnace 5 and This makes it impossible to uniformly preheat the surface layer of the raw material fed into the cold air pipe machine, and there is a great risk that the preheating function will be reduced. If the pressure inside the three-way furnace exceeds +2-OwHg0k, the hot air from inside the preheating furnace will not blow out properly (a dangerous situation will occur), and furthermore, preheated air will enter the ignition furnace from the preheating furnace, preventing normal ignition in the ignition furnace. A problem arises in which the number of keys is lost.

On the other hand, the furnace internal pressure of the preheating furnace and the ignition furnace O furnace internal pressure L9 are always 0.
The reason why the value is set higher than HIO and less than 3-Om HmO is because when the pressure inside the preheating furnace gets too low, the flame in the ignition furnace flows toward the preheating furnace. There is a problem of melting and damage in the two-ignition furnace.
As a result, the strength of the sintered ore is greatly reduced and the product yield of the sintered ore is deteriorated.

In addition, if the pressure difference in the furnace exceeds 3 mm H*O, the flame of the ignition furnace will be opposite to that of the preheating furnace. In this case, uniform ignition to the surface layer of the raw material becomes impossible, and the product yield, energy consumption rate, and product quality deteriorate. If the preheating furnace oyJ is operated so that the internal pressure difference is in the range of 0 to 31UH10 and the preheating furnace oyJ is always high, the internal pressure between the preheating furnace and the ignition furnace will be well balanced, the preheating furnace can function normally for Km, and even the ignition furnace will The flame is not blown away and the flame is stable and uniform ignition is possible.

Next, a method k for controlling the internal pressure of a preheating furnace and an ignition furnace according to the present invention.
Delight based on g211.

As shown in FIG. 2, a pressure expansion force outlet end 10 is provided in the preheating furnace 5, and a pressure detection end lit is also provided in the ignition furnace 6, and the 8E force detection ends 10 and 11 are connected to the control device 12 to detect the pressure. )

Hot air 11 is sent from the control device 12 into the preheating furnace 5 and into the ignition furnace 6.
It is designed to issue valve opening/closing commands to the hot air flow rate adjustment valves 13 and 14 provided in branch pipes 9 and 9B, respectively. [Wind leg 15A, 15 to connect
B [Dunno opening/closing commands are issued to the installed flow rate adjustment dampers 16 and 17. In the figure, 9 is a main pipe for blowing hot air.

The control device ft12 according to the present invention determines whether the furnace pressure value in the preheating furnace 5 is within the range of +0.5 to +2.0 H,O, and determines whether the furnace pressure value is within the range of +0.5 to +2.0. If so, the valve 13 and damper 160 opening/closing commands are not issued. Next, the pressure in the ignition furnace 6 is compared with the pressure in the preheating furnace 5, and the pressure in the preheating furnace 50 and the pressure in the ignition furnace 6 are higher within the range of 3 mH10. . If the result of this determination is within the range, the opening/closing command for the valve 14 and damper 17 will not be issued. However, if the pressure inside the preheating furnace 5 is higher than the pressure inside the ignition furnace 6,
Or, if the internal pressure of the preheating furnace HOP is lower than the pressure inside the ignition furnace 6, the valve 14 or the valve 14 installed on the branch pipe 9B that blows the hot air into the ignition furnace 6 or the quintile/arm-170mfm can be used to close the furnace inside the ignition P6. Adjusting the internal pressure The difference in internal pressure between the KLp preheating furnace 5, the ignition furnace 6, and the O furnace is set to a predetermined value, that is, the preheating rsO is 0.
The pressure in the 0 ignition furnace 6, which maintains KM to a high value within the range of 0 to 3, is set to a value as close to atmospheric pressure as possible. -b If I am able to attend, I will hold the next 15 meeting.

The desired value of the pressure inside the ignition furnace is set in the control device 12 as atmospheric pressure plus or minus 1. It is necessary to input the value of oIIwHlo in advance and adjust the pressure inside the ignition furnace 6! If it is predicted that the adjusted pressure will deviate from the pre-input value, the pressure in the preheating furnace S is controlled using the furnace pressure pipe of the ignition furnace as is. By adjusting the pressure in the preheating furnace 5, the opening degree of the igt*a valve 13 or the line I damper 16, and feeding back the pressure output value in the furnace by the pressure detection terminal lO, either the valve 1'3 or the damper 16 can be adjusted. Alternatively, by adjusting both opening degrees, the pressure inside the furnace is controlled to a predetermined value within the range of +α5 to +20−H,O. or.

After the pressure in the ignition furnace 6 has been adjusted within a possible range, the pressure of the residue may be controlled in the preheating furnace 5.

The pressure detected in the preheating furnace 5 by the pressure detection end 10 is +0,
If the value falls outside the range of 5 to +20■H 0, immediately control the opening of valve 13 or Dan''-16 to maintain the predetermined pressure in the furnace, and after controlling the pressure in the ignition furnace 6. It is determined whether the difference in the pressure between In the case of 9, the pressure inside the ignition furnace 6 is controlled as described above.

Example: A Dwight Lloyd type sintering machine is used, which has a preheating furnace installed in the front stage of the ignition furnace and adjacent to the ignition furnace. Then ignition L-
# was made in the felt feed. At this time, the pressure inside the preheating furnace is in the range of 10.5 to 3.OmaHlo.

The internal pressure of the ignition furnace was varied in 8 steps within the range of -2.0 to 1.5 w H20, respectively, to determine product yield, fuel consumption, quality of feed ore, The production ratio was compared. The results are summarized in Table 1.

1 Sea urchin product yield shown in Table 1, powder mixed in raw materials) -
00G basic unit in one ignition furnace,
The drop strength, low iIR original powdering index, and raw material ratio of the obtained sintered ore were determined when the pressure inside the preheating furnace was 0.5 to 2.0 ■ H 00@
At @, [preheating furnace furnace pressure] is 0 to 3 w
r) Examples 1 to 4 in the Is 00 range showed excellent values. However, the pressure inside the preheating furnace is O-5m.
Comparative Examples 1 and 2, in which the pressure in the preheating furnace 1 and the ignition furnace 07F were lower than HtO, had inferior results compared to the examples of the present invention. 2・
Comparative example 3.4 in which wHsOkm was 1 and [preheating furnace internal pressure] exceeded 3 M 1110 vt was not inferior in any way compared to the present @ C) lil example, but was as above. The results were also inferior to Comparative Example 1.21. Comparative Examples 3 and 4 are both JIIJI! of the present invention! Requirements [Not only lacking, but also essential! It is thought that the fact that the ignition furnace O is out of the appropriate furnace internal pressure range is one of the negative effects.

According to the above-mentioned 15, according to the present invention, when manufacturing sintered ore using a Dwight Lloyd sintering machine equipped with a preheating furnace at the front stage of the ignition furnace, a high quality product can be produced at low cost and efficiently using IR.
It has the HIF effect of being able to create.

[Brief explanation of the drawing]

wXIIll is a schematic diagram illustrating a sintering machine according to the present invention. @2 Figure is an explanatory diagram showing an embodiment of the present invention. 2... Sintering machine S 5... Preheating furnace, 6... Ignition furnace. 9 people, sea lion...branch pipe, 10.11...pressure detection end. 12...Control device, 13.14...Valve, 1$A, 1
5B... Wind leg, 16.17... Damper. Agent Patent Attorney Masanobu Akizawa 2 people

Claims (1)

[Claims] (1) In the sintering machine equipped with a preheating device in the front stage of the ignition furnace O,
Furnace pressure of preheating furnace k + 0-5 ~ + 2-OmH,O
Ignition PIDf' internal pressure A j
l 3 wm 40 or less ctHts to maintain high (IIIk) t41 mold during sintering @preliminary & furnace pressure control method.