JPH0776720A - Device and method for executing flame treatment of metallic rod - Google Patents

Abstract

PURPOSE:To stabilize flame condition at the time of burning at high temp. and to improve annealing and degassing efficiency by controlling the oxygen concn. in fuel gas mixed with air. CONSTITUTION:A device provided with a means which measure the oxygen concn. in the fuel gas mixed with primary air to be supplied to a burner and feeds back the measured value to adjust the oxygen quantity in the fuel gas in used. Then, the max. temp. of combustion flame and the flame length at the time of annealing and degreasing are stabilized. As the fuel gas mixed with air, propan incorporating 19.5-20.5vol% oxygen, desirably 20.10-20.50vol% oxygen, is used. By this method, the degreasing efficiency per fuel calory is improved and the uniformity of metal surface characteristics can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for annealing and degreasing a metal strip after rolling (in the present invention, a metal strip means a metal foil or plate having a thickness of 5 μm to 3 mm). In order to improve the flame stability and the degreasing efficiency of the flame for the frame treatment with high productivity, the wettability of the strip in the width direction and the length direction is high, and the surface properties such as the oxide film are highly uniform.
TECHNICAL FIELD The present invention relates to a flame processing apparatus and a processing method thereof that can control combustion capacity easily and reliably.

[0002]

2. Description of the Related Art Many metals are relatively inexpensive and have excellent mechanical suitability for their price. Therefore, they are inexpensive conductive materials and, in the case of precious metals, have excellent chemical corrosion resistance and decorative properties. Therefore, it is widely used as an industrial material and an electric material.

Especially in the fields of packaging materials, electrical materials, daily necessities, ornaments, industrial materials, etc., a large amount of metal foil (about 5 μm to 200 μm) or metal thin plate (about 200 μm to 3 mm) is used for this purpose. Being produced.

These metal strips are generally slab-shaped metal that is rolled using a roll, but the surface after rolling is covered with rolling oil used during rolling, and the metal strips for printing, lamination, etc. Often an obstacle to secondary processing. For this reason, it is usual to anneal the rolled metal strips for degreasing (removal of rolling oil). Usually, it is often done with the metal strip wound in a coil, but it was not without frame treatment.

In this case, when the material of the metal strip is a metal having a relatively high melting point such as iron, it does not matter so much, but when it is a metal having a relatively low melting point such as aluminum, copper or alloys thereof, degreasing is performed. In some cases, softening of the material due to annealing and annealing progresses at the same time, and degreasing may cause excessive softening of the metal.

Especially in the frame processing, the number of metal strips is 1.
Since degreasing and annealing are performed by contact with a flame at a temperature of 500 ° C or higher for an extremely short time, even if the running speed of a metal strip is constant, control of the heating capacity of the burner can be performed with a slight error. This may cause problems such as insufficient or excessive annealing. For this reason, in the case of aluminum strips, etc., so-called batch annealing, in which annealing is performed while wound in a coil shape, which has problems such as non-uniformity in the width direction of degreasing and requiring a long time, becomes the mainstream, and the width direction and the length direction Despite some excellent features such as uniformity of surface characteristics and high productivity, it seems that this was the reason why annealing degreasing by flame treatment was rarely carried out except for special cases.

However, although various measures have been taken for the nonuniformity of the metal strip surface characteristics in the width direction and the low productivity due to the batch annealing, this problem is a basic one, and its solution is solved. Is extremely difficult.

In the flame treatment, which has the advantages of uniform surface characteristics and high productivity, the degreasing efficiency is improved by raising the flame temperature, and the flame combustion state is stabilized to stabilize the metal. It is known that the surface characteristics of the strip can be made uniform.

[0009]

DISCLOSURE OF THE INVENTION According to the present invention, a metal strip is annealed and degreased by a frame treatment to obtain a metal strip having a constant quality. Therefore, the frame temperature is kept as high as possible to improve the degreasing efficiency. In addition, it is an object of the present invention to develop a flame treatment device for metal strips and a flame treatment method for metal strips, which is provided with an appropriate control means capable of stabilizing the combustion state of the flame and controlling degreasing and annealing.

[0010]

The present invention is a means for measuring the oxygen concentration in a fuel gas mixed with primary air supplied to a burner, and feeding back the measured value to adjust the oxygen concentration in the fuel gas. A frame treatment device for metal strips, which is provided with a means, and when degreasing the metal strips by flame treatment, the oxygen concentration in the mixed gas mixed with primary air is 19.5 to 20.5% by volume, It is preferably 20.00 to 20.35% by volume, more preferably 20.
The above object was achieved by developing a flame treatment method for metal strips, characterized in that 10 to 20.25% by volume of propane is used as fuel.

The metal strip to which the present invention is applied is a soft, low-melting metal such as aluminum, copper or an alloy thereof; a noble metal such as gold, silver or platinum; a relatively hard or high metal such as iron or stainless steel. Rolled metal foil (5 to 200 μm or so) of melting point metal, thin metal plate (200 μm)
-3 mm). Particularly, it is preferably used for a metal strip of a soft low melting point metal or a noble metal.

The present invention will be described below by taking an aluminum strip as a representative, but the aluminum strip may be pure aluminum for general industry (including electrolytic aluminum and ordinary pure aluminum) or an aluminum alloy, particularly There is no limit. Although the thickness of the aluminum strip is not particularly limited, it is generally about 5 μm to 3 mm.

The frame treatment is a separator in the rolling process,
Where a single aluminum strip such as a slitter is running (especially when two thin foils are rolled and rolled), or during the process from the separator, slitter, etc. to the aluminum strip winder Can be performed by a frame processing device provided in any of the lines, or a coiled aluminum strip wound after passing through a separator, a slitter, etc. can be performed in a process of installing an offline frame processing device different from the line. . Ease of operation,
When considering productivity, it is easier to use the inline method at once.

FIG. 2 shows an example of a flow sheet of the apparatus of the present invention.

The frame processing apparatus of the present invention is, for example, as shown in FIG. 2 (for single-sided processing) when the rolled aluminum strip is separated and the material wound on the roll is subjected to the frame processing.

The aluminum strip (1) wound into a roll is supplied to a bridle roll (4) provided with a burner (3) via a dancer roll (2). The bridle roll (4) is a motor (not shown).
The aluminum strip is wound around more than about half of the circumference of the roll with the help of other tension reels. The roll is cooled by circulating cooling water or the like.

The burner (3) is a bridle roll (4)
Slightly away from, the aluminum strips (8) on the roll surface are provided to blow the frame. Here, the aluminum strip whose surface has been heated and oil has been burned is cooled by the cooling roll in contact therewith, and is also cooled after leaving the frame, so that excessive annealing of the aluminum strip is prevented. Next, the aluminum strip (8) from which oil has been removed is wound into a roll by a winder (9) via auxiliary rolls such as a rubber roll (5) for preventing wrinkles, a bridle roll (6) and a tension roll (7). Taken.

In the present invention, the higher the flame temperature is, the better the degreasing property is, the better the degreasing efficiency per unit calorie of the fuel is, and the higher the flame temperature is to maintain stable combustion, It is based on the finding that it can be achieved by controlling the oxygen concentration in the mixed gas of the fuel gas and the primary air in an appropriate range.

That is, as the fuel, a gas fuel, for example, a gas fuel such as natural gas, methane, propane or LPG can be used. Particularly, propane is preferable from the viewpoint of easy handling and availability.

Primary air is mixed with this fuel gas in order to improve the combustibility. In this case, the oxygen concentration in the fuel mixed gas is changed due to changes in temperature, changes in humidity in the air, variations in the amount of air supplied, etc. Changes. This change can continue the combustion phenomenon itself due to excessive secondary air (atmosphere), but changes in the flame state (changes in the maximum temperature and the length of the oxidation flame that reaches the maximum temperature) are unavoidable, It is difficult to always continue the process with the optimum frame. For example, when the oxygen concentration is low, the oxidation flame becomes long, on the contrary, the excess oxygen concentration shortens it, and when the oxygen concentration is high, detonation is formed and the flame goes backward into the burner. Normally, primary air operates at a relatively safe small mixing ratio, avoiding the explosion limit, but it is still inevitable that the state of the frame will change due to variations in atmospheric temperature, humidity, and air supply as described above. Absent.

In the present invention, means for measuring the oxygen concentration in the fuel gas mixed with the primary air supplied to the burner, and the measured value measured by the means are fed back to make the oxygen concentration in the fuel gas appropriate. The problem was solved by developing a processing device for a metal strip frame with means for adjusting to various ranges.

An example of this processing apparatus is shown in FIG. Fuel 12 and air 13 are supplied to the ribbon burner 11.
The air 13 is pressurized by a blower 15 via a filter 14, and is passed through a oximeter 17 and a motor valve 16 controlled by a controller 19 to the mixer 1.
8 are supplied. The fuel 12 is also supplied to the mixer 18 via another motor valve 16 controlled by the controller 19, where they are mixed. As a result, oxygen in the fuel mixture gas is adjusted to an appropriate range that differs depending on the type of fuel gas without being affected by changes in air temperature and atmospheric humidity, and always shows a stable maximum temperature. The frame makes it possible to process metal strips.

When propane is used as the fuel gas,
The oxygen concentration in the mixed gas can be 18 to 22% by volume, but 1 is effective from the flame temperature and flame properties.
9.5 to 20.5% by volume, preferably 20.00 to 2
0.35% by volume, more preferably 20.10 to 20.2
It is to be 5% by volume.

In the above description, a single-sided processing device was shown, but if another set of temperature-adjustable bridle rolls and frame burners is provided so that the other side of the aluminum strip can be processed, double-sided frame processing is possible. Can be done all at once.

Although the bridle roll (4) has been described as being cooled, it should be a device that can produce a semi-hard or soft aluminum strip in one pass when it is used as a heating roll such as circulating heating oil or enclosing an electric heater. You can

In the above description, the aluminum strip which has been separated and wound up has been described. However, the frame processing device is incorporated in a separator or a slitter, or installed in a line between the separator and the slitter and the winder. Of course, continuous processing may be performed.

In the flame treatment of the present invention, the type of metal, the calorific value of the burner, the thickness of the aluminum strip, the type of rolling oil and the amount of residual oil, the target contact angle of the product aluminum strip with pure water are used. Generally, high-speed processing of about 100 to 1000 m / min is possible, though it depends on whether it is in-line or offline.

Prior to the frame treatment, the type of rolling oil adhering to the aluminum strip, the amount of rolling oil deposited, the aluminum material of the target product aluminum strip, the mechanical strength, the strip thickness, the target aluminum strip. Since the energy supplied per area changes depending on properties such as the contact angle with water, it is preferable to measure it experimentally. A small amount of degreasing may be required when sufficient annealing is performed in another annealing step. Separately, when an aluminum strip with high mechanical strength is required, sufficient rolling oil removal is required only by flame treatment. Because.

Generally, the aluminum strip after frame treatment has a contact angle with water of 40 ° or less, preferably 30 °.
If it is less than the following, it will be an aluminum strip that does not hinder normal use, so it is necessary to perform frame processing within this numerical range as a target.

The amount of heat supplied as a frame also varies depending on various conditions, but in general applications it is about 0.1-10.
kcal / m ² (one side), which is slightly higher than this value, especially when it is desired to increase the degreasing degree.

The temperature of the cooling roll is also a target product. The rigidity of the aluminum strip, the burner capacity, the aluminum strip thickness,
It varies depending on the traveling speed and the like, but is not limited to about 40 ° C or less for a rigid strip, about 180 to 300 ° C for semi-rigid,
When it is soft, it is about 250 to 600 ° C. If the obtained aluminum strip is harder than the target rigidity, the roll temperature may be raised, and if it is soft, the roll temperature may be lowered.

Of course, it is also possible to once manufacture an aluminum strip having a rigidity higher than the target rigidity and perform annealing in combination with the conventional batch annealing (the aluminum strip is annealed while being rolled). At this time, degreasing in the flame treatment is not required to be complete, and the time required for batch annealing can be significantly shortened.

[0033]

According to the present invention, when the rolled metal strip is annealed and degreased, it is subjected to a flame treatment which is excellent in the uniformity of the surface characteristics (degreasing and oxide film formation) in the width direction and the length direction and the productivity. At this time, we learned that the higher the flame temperature, the better the degreasing property, and the higher the degreasing efficiency per calorie.In order to burn the flame in a stable state at high temperature, the oxygen concentration in the fuel gas mixed with primary air We have found that this can be achieved by adjusting.

According to the present invention, due to slight fluctuations in the oxygen concentration in the fuel gas, the nature of the flames (oxidizing and reducing) which contact the metal strip as the maximum or maximum temperature of the oxidizing flames increases or decreases. ), The temperature change can be prevented, and the frame-treated metal strip with uniform surface characteristics can be efficiently produced.

[0035]

【Example】

(Examples 1 to 8 and Comparative Example) Propane is used as a fuel gas in an aluminum foil flame processing apparatus as shown in FIG. 2 which is heated by a heating burner having a fuel supply system capable of adjusting oxygen concentration as shown in FIG. Then, the maximum temperature of the flame and the degreasing property were examined by changing the oxygen concentration in the fuel mixed with primary air.

The frame processing condition is 1N with a thickness of 25 μm.
30 aluminum foil, line speed 300m /
It was carried out at a burner calorific value of 60,000 Kcal / hr (as a propane supply amount) per 1 meter of burner at min and 200 m / min.

The degreasing property was evaluated by the contact angle between the surface of the frame-treated aluminum foil and pure water, and the contact angle was 35 °.
Hereinafter, ◎, 36 ° to 50 ° ○, 51 ° to 60 ° Δ, 61 °
More than x. The results are shown in Table 1.

[0038]

[Table 1]

[0039]

Industrial Applicability According to the present invention, by increasing the temperature of the frame and stabilizing the state of the frame, the degreasing property in the frame treatment of metal strips, the degreasing efficiency per fuel calorie, and the deionized water are increased. A frame treatment device and a treatment method capable of efficiently producing a metal strip having high uniformity of metal strip surface characteristics such as a contact angle with, a residual oil amount, and an oxide film thickness can be provided.

[Brief description of drawings]

FIG. 1 shows an example of an oxygen concentration adjusting system in a fuel supply system.

FIG. 2 shows an example of a single-sided processing device.

[Explanation of symbols]

 1 Payoff 2 Dancer roll 3 Burner 4 Bridle roll 5 Wrinkle prevention roll 6 Bridle roll 7 Tension roll 8 Metal strip (aluminum strip) 9 Winder 11 Burner 12 Fuel 13 Air 14 Filter 15 Blower 16 Motor valve 17 Oxygen concentration meter 18 Mixer 19 controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiko Watanabe, 6-224, Kaiyama-cho, Sakai-shi, Osaka Prefecture, Showa Aluminum Co., Ltd. (72) Akio Fukuda, 6-224, Kaiyama-cho, Sakai-shi, Osaka Prefecture Aluminum Showa Within the corporation

Claims (2)

[Claims] 1. A means for measuring an oxygen concentration in a fuel gas mixed with primary air supplied to a burner, and means for feeding back the measured value to adjust the oxygen concentration in the fuel gas. Frame processing equipment for metal strips. 2. When degreasing a metal strip by flame treatment, the oxygen concentration in the mixed gas mixed with primary air is 1 or less.
A flame treatment method for a metal strip, which comprises using 9.5 to 20.5% by volume of propane as a fuel.