JPH059594A - Continuous annealing furnace - Google Patents

Abstract

PURPOSE:To anneal materials to be heated in such a manner that the rolling oil, etc., sticking to the materials to be heated as completely as possible. CONSTITUTION:A vacuum chamber 4 is provided between a preheating chamber 3 and a heating and soaking chamber 5 and the materials a which are to be heated and are preheated in the preheating chamber 3 are transferred into the vacuum chamber 4 where the materials are subjected to a pressure reduction in the preheated state to evaporate the rolling oil sticking to the materials a; thereafter, the materials a are transferred into the heating and soaking chamber 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous annealing furnace which removes rolling oil and the like adhering to a material to be heated as completely as possible and anneals it.

[0002]

2. Description of the Related Art When a material to be heated such as a metal strip is heated to a high temperature with rolling oil attached, seizure occurs and the product value is lost. Therefore, conventionally, the object to be heated is cleaned with a cleaning solution such as a solvent before heating, or the rolling oil evaporated from between the coils is purged by a purge gas.

[0003]

However, in the method of removing rolling oil by cleaning, equipment such as a cleaning tank and a drying chamber is required, so that the apparatus becomes large and there is a problem of waste liquid treatment. Further, the removal method using the purge gas has a problem that the pressure oil is not completely removed and the surface properties of the product are not good.

[0004]

The continuous annealing furnace of the present invention is intended to solve the above-mentioned problems. A vacuum chamber is provided between the preheating chamber and the heating / soaking chamber and preheated in the preheating chamber. The object to be heated is transferred to a vacuum chamber, and the rolling oil adhering to the object to be heated is vaporized by depressurizing the object in a preheated state, and then the object to be heated is transferred to a heating / soaking chamber. It is characterized by.

[0005]

[Function] Since the pressure is reduced under preheating, the pressure oil is likely to be vaporized and can be completely removed.

[0006]

An embodiment of the present invention will be described with reference to the drawings. The continuous annealing furnace shown in this drawing is intended to continuously anneal a coiled object a formed by winding a metal strip into a coil, and the coiled object a is horizontally supported on a pedestal b. It is possible to move the inside of the furnace in the direction of the arrow by means of the roller conveying means.

In the figure, 1 is a charging table, 2 is an inlet side purge chamber, 3 is a preheating chamber, 4 is a vacuum chamber, 5 is a heating / uniform temperature chamber, 6 is a cooling chamber, and 7 is an outlet side purge chamber. The respective chambers are provided in a straight line in series from the inlet side purge chamber 2 to the outlet side purge chamber 7, and the above-mentioned roller transfer means is provided on the floor thereof.

The inlet side purge chamber 2 and the outlet side purge chamber 7 are
Opening / closing lids 8, 9, 10, 11 capable of hermetically closing the pressure-resistant cylindrical container are provided at both ends of the container, and vacuum pumps are provided in the inlet-side purge chamber 2 and the outlet-side purge chamber 7, respectively. 12, 13 are connected, an air supply pipe 15 communicating with the atmosphere gas supply source 14 is provided in the inlet side purge chamber 2, and an air supply pipe 37 is provided in the outlet side purge chamber 7.

The preheating chamber 3 has a space into which three coil-shaped objects to be heated a are inserted, and heat insulating doors 16 and 17 are provided at openings at both ends thereof. An air supply pipe 18 that communicates with the atmospheric gas supply source 14 is provided. Reference numeral 19 denotes a circulation fan provided on the ceiling of the preheating chamber 3. An airtight door pocket 20 is formed between the inlet side purge chamber 2 and the preheating chamber 3 so that the opening / closing lid 8 and the heat insulating door 16 can slide upward. Further, in the preheating chamber 3, a heat source (not shown) such as a radiant tube burner for heating the atmospheric gas supplied from the air supply pipe 18 is provided.

A vacuum chamber 4 provided between the preheating chamber 3 and the heating / uniform heating chamber 5 is made of a cylindrical pressure vessel similar to the purge chambers 2 and 7, and opening / closing lids 21 and 22 are provided at both end openings thereof. It is provided so as to be airtightly closed. 23 is the heat insulation door 17
It is an airtight door pocket that holds the opening / closing lid 21. The vacuum chamber 4
A vacuum pump 24 is connected to the air supply pipe 36, and an air supply pipe 36 connected to the atmospheric gas supply source 14 is provided.

The heating / heating chamber 5 has six coil-shaped objects to be heated a.
Has a space for entering and has heat insulation doors 25 and 26 at the openings at both ends.
Is provided. 27 is the opening / closing lid 22 and the heat insulating door 25
It is an airtight door pocket that holds. An air supply pipe 28 that communicates with the atmospheric gas supply source 14 is also provided in the heating / heating chamber 5, and a circulation fan 29 is provided in the ceiling to heat the atmospheric gas in the heating / heating chamber 5. A heat source (not shown) is provided for this purpose.

The cooling chamber 6 is provided with a cooler (not shown) for cooling the atmospheric gas supplied from the atmospheric gas supply source 14 through the air supply pipe 30, and a circulation fan 31 for circulating the atmospheric gas is provided on the ceiling portion. It is provided in.
Reference numeral 32 is a door pocket formed between the heating / uniform heating chamber 5 and the cooling chamber 6 so that the heat insulating door 26 can slide. Further, 33 is a cooling chamber 6 and an outlet side purge chamber 7 so that the opening / closing lid 10 can be housed.
It is an airtight door pocket formed between.

In the continuous annealing furnace configured as described above, the coil-shaped object to be heated a, which has been transferred by the carriage 34, is transferred onto the charging table 1, the opening / closing lid 8 is opened, and the coil-shaped object to be heated is opened. a is put into the inlet side purge chamber 2, the opening / closing lids 8 and 9 are closed, the air in the inlet side purge chamber 2 is exhausted to the outside by the vacuum pump 12, and then the atmosphere gas is supplied from the air supply pipe 15 to the inlet side. The inside of the purge chamber 2 is replaced with atmospheric gas. After that, the opening / closing door 9 and the heat insulating door 16 are opened to transfer the coiled object a to the preheating chamber 3. The preheating chamber 3 is already filled with the atmospheric gas, and the coiled object a is heated to 250 ° C. to 300 ° C. on the basis of the atmospheric gas.
Preheated to a degree.

Next, the heat insulating door 17 and the opening / closing lid 21 are opened, and the coiled object a in the preheating chamber 3 is moved to the vacuum chamber 4 so that the heat insulating door 17, the open / close lids 21, 22 and the heat insulating door 25 are closed. The atmospheric gas in the vacuum chamber 4 is sucked by the vacuum pump 24 to reduce the pressure in the vacuum chamber 4. In this way, after preheating the coil-shaped object to be heated a and moving it to the vacuum chamber 4 and decompressing it, the boiling point of the pressure oil adhering to the surface of the coil-shaped object to be heated a is remarkably easily vaporized. Is obtained and the surface is cleaned.

After the atmosphere gas is supplied from the air supply pipe 36 to restore the pressure in the vacuum chamber 4, the opening / closing lid 22 and the heat insulating door 25 are opened to heat the coil-shaped object to be heated / uniform temperature chamber 5
Move to. In the heating / heating chamber 5, the coiled object to be heated a is again fed by the atmosphere gas supplied from the air supply pipe 28.
It is heated to the required annealing temperature of 0 ° C to 750 ° C and soaked. Then, the coil-shaped object to be heated a is opened by opening the heat insulating door 26 and the cooling chamber 6
And is cooled in the cooling chamber 6 by the same atmospheric gas. The coil-shaped object to be heated a cooled in this way is provided with the opening / closing lid 1
0 is opened and is moved to the purge chamber 7. In the purge chamber 7, the atmospheric gas in the purge chamber 7 is sucked by the vacuum pump 13 and then the outside air is introduced to restore the pressure to open the opening / closing lid 11 to open the coiled object a. Extract on the trolley 35.

A heat source similar to that of the preheating chamber 3 is provided also in the vacuum chamber 4, and when the staying time of the coiled object a in the vacuum chamber 4 becomes long, the coiled object is heated by this heat source. It is desirable to prevent the temperature of the coil-shaped object to be heated a from decreasing in the vacuum chamber 4 by heating a. The inlet purge chamber and the outlet purge chamber do not necessarily have to be the vacuum purge system as shown in the embodiment, and may be a normal gas replacement system.

[0017]

INDUSTRIAL APPLICABILITY As described in the above embodiments, in the continuous annealing furnace of the present invention, the preheated object is transferred to a vacuum chamber and depressurized to remove the pressure oil adhered to the object. Since it is more completely vaporized and removed, there is a beneficial effect that an annealed product having a clean surface property can be easily obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a continuous annealing furnace of the present invention.

[Explanation of symbols]

 a Heated object 2 Inlet side purge chamber 3 Preheating chamber 4 Vacuum chamber 5 Heating / equalizing chamber 6 Cooling chamber 7 Outlet side purge chamber 24 Vacuum pump

Claims (1)

Claims: 1. A vacuum chamber is provided between the preheating chamber and the heating / soaking chamber, and an object preheated in the preheating chamber is transferred to the vacuum chamber to reduce the pressure in the preheating state. The continuous annealing furnace is characterized in that after the rolling oil adhering to the object to be heated is vaporized, the object to be heated is transferred to a heating / soaking chamber.