Aluminum alloy nitrogen atmosphere protection annealing furnace and annealing process

Abstract

The invention relates to the technical field of aluminum alloy nitrogen annealing, in particular to an aluminum alloy nitrogen atmosphere protection annealing furnace and an annealing process. The aluminum alloy nitrogen atmosphere protection annealing furnace is provided with a furnace body, an opening is formed in the front side of the furnace body, the opening position is closed through a furnace door, a support is arranged at the bottom in the furnace body, and at least two circulating fans are installed at the top of the furnace body; a machine body of the circulating fan is fixed on the outer side of the furnace body, a circulating fan of the circulating fan extends into the furnace body, a nitrogen conveying pipeline is arranged above the furnace body and connected with a nitrogen tank, at least two nitrogen inlet pipes are arranged on the nitrogen conveying pipeline, one end of each nitrogen inlet pipe is connected with the nitrogen conveying pipeline, and the other end of each nitrogen inlet pipe is connected with the circulating fan. The other end of the nitrogen inlet pipe penetrates through the upper portion of the furnace body and extends into the furnace body, an oxygen analyzer is arranged on the side face of the furnace body, the induction end of the oxygen analyzer extends into the furnace body, and a negative pressure air pipe is installed at the top of the furnace body. The aluminum alloy annealing furnace has the advantages that the structure is simple, air can be fully isolated, the oxygen content in the furnace can be controlled to be 1000 ppm or below during annealing, and aluminum alloy material coils are prevented from being polluted.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy nitrogen annealing, and in particular to an aluminum alloy nitrogen atmosphere protection annealing furnace and annealing process which have a simple structure, can fully isolate the air, can control the oxygen content in the furnace to be below 1000ppm during annealing, and can prevent pollution of aluminum alloy coils. Background Art

[0002] As we all know, aluminum annealing furnace is the most widely used equipment for aluminum alloy heat treatment. To ensure high-quality annealing of aluminum, the atmosphere in the annealing furnace has high requirements, because aluminum is easily oxidized in the heated state, thus forming an aluminum oxide film on the surface. In addition, the rolling oil on the aluminum will be oxidized before volatilization from the aluminum, which will also leave yellow spots on the aluminum, affecting the performance and quality of the aluminum. To ensure that the aluminum is not oxidized during the entire annealing process, nitrogen needs to be filled into the annealing furnace. Nitrogen is a neutral gas and can be used as a protective gas in the heating process in an inactive state to prevent the oxidation of aluminum.

[0003] In the prior art, the annealing furnace is filled with nitrogen as a protective gas. In a common alloy coil annealing furnace, there is no nitrogen for annealing, and oxygen enters the furnace and annealing oxidation occurs, thereby contaminating the aluminum alloy coil. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned deficiencies in the prior art and to provide an aluminum alloy nitrogen atmosphere protection annealing furnace and annealing process which has a simple structure, can fully isolate the air, can control the oxygen content in the furnace below 1000ppm during annealing, and prevent pollution of the aluminum alloy coil.

[0005] The technical solution adopted by the present invention to solve its technical problem is: A nitrogen atmosphere protection annealing furnace for aluminum alloy is provided with a furnace body, an opening is provided on the front side of the furnace body, and the opening position is closed by a furnace door, characterized in that a bracket is provided at the bottom of the furnace body, a material coil is placed on the bracket, at least two circulation fans are installed on the top of the furnace body, the body of the circulation fan is fixed on the outside of the furnace body, and the circulation fan of the circulation fan extends into the furnace body, a nitrogen delivery pipeline is provided above the furnace body, the nitrogen delivery pipeline is connected to the nitrogen tank, at least two nitrogen inlet pipes are provided on the nitrogen delivery pipeline, one end of the nitrogen inlet pipe is connected to the nitrogen delivery pipeline, and the other end of the nitrogen inlet pipe passes through the top of the furnace body and extends into the furnace body, an oxygen analyzer is provided on the side of the furnace body, the oxygen analyzer is fixed on the side of the furnace body, and the sensing end of the oxygen analyzer extends into the furnace body, a negative pressure air duct is installed on the top of the furnace body, one end of the negative pressure air duct extends into the furnace body, a negative pressure fan is installed on the other end of the negative pressure air duct, and a negative pressure control valve is installed on the negative pressure air duct extending out of the furnace body.

[0006] An oil removal pipe is installed above the furnace body of the present invention, one end of the oil removal pipe extends into the furnace body, the other end of the oil removal pipe extends out of the furnace body and is connected to the oil removal fan, and an oil removal control valve is installed on the oil removal pipe extending out of the furnace body.

[0007] Heaters are respectively installed above the left and right sides of the furnace body of the present invention. The heaters are fixed above the inside of the furnace body, and the gas in the furnace body is heated by the heaters.

[0008] A cooling mechanism is provided on the rear side of the furnace body described in the present invention, and the cooling mechanism includes a cooling air inlet pipe, a cooling air outlet pipe, a condenser, and a cooling fan. The cooling air inlet pipe is installed at an upper position of the furnace body and is connected to the furnace body, and the cooling air outlet pipe is installed at a lower position of the furnace body and is connected to the furnace body. The condenser and the cooling fan are connected between the cooling air inlet pipe and the cooling air outlet pipe. The hot air extracted by the cooling fan is cooled by the condenser, thereby cooling the material coils in the furnace body.

[0009] The circulating fan of the circulating fan of the present invention is provided with a guide cover on the outside of the circulating fan. The guide cover is closed at the lower end and has air guide ports on the left and right sides, and the air guide ports face the direction of the heater.

[0010] The furnace body below the heater of the present invention is provided with an air guide component, and the air guide component comprises an upper closing plate, a lower closing plate, a left closing plate, a right closing plate, a front closing plate, a rear closing plate and an air guide plate, and the upper closing plate, the lower closing plate, the left closing plate, the right closing plate and the rear closing plate are connected to each other to form a closed box, the front closing plate is in a Chinese-Hui shape, the outer end of the front closing plate is fixedly connected to the open outer end of the furnace body, the inner ends of the front closing plate are respectively connected to the front ends of the upper closing plate, the lower closing plate, the left closing plate and the right closing plate, the closed box is fixed in the furnace body, and an air guide chamber is formed between the outer end of the closed box and the furnace body, the circulating fan and the heater are both arranged in the air guide chamber, the nitrogen inlet pipe extends into the closed box, the bracket is fixed on the lower closing plate of the closed box, the lower closing plate of the closed box is fixedly connected to the bottom of the furnace body via the supporting frame, and the lower closing plate, the left closing plate, the right closing plate and the rear closing plate are respectively provided with air guide ports, the air guide ports are respectively connected to the air guide plates, and the air guide plates face the material coil position in the closed box.

[0011] A nitrogen inlet valve and a flow meter are respectively installed on the nitrogen delivery pipeline of the present invention.

[0012] The negative pressure air duct described in the present invention is respectively connected to the nitrogen recovery pipe and the exhaust air duct, the exhaust air duct is equipped with an exhaust valve, the nitrogen recovery pipe is equipped with a recovery valve, and the nitrogen recovery pipe is connected to the nitrogen tank.

[0013] An annealing process of an aluminum alloy nitrogen atmosphere protection annealing furnace, characterized in that the annealing process steps are as follows: First, start the annealing furnace cleaning operation, first close the furnace door, open the nitrogen inlet valve on the nitrogen delivery pipeline, start the oil removal fan, oil removal control valve, negative pressure control valve, negative pressure fan, exhaust valve, so that the oxygen content in the furnace drops below 1000ppm, then close the oil removal fan, negative pressure fan, oil removal control valve, negative pressure control valve, exhaust valve, turn on the heater and circulating fan for circulating heating; use the oxygen analyzer to monitor the oxygen content in the furnace and feed back to the nitrogen inlet valve and flowmeter to adjust the nitrogen atmosphere in the furnace; after annealing is completed, start the condenser and cooling fan to cool down, and the coil temperature drops to 100° before it is taken out of the furnace.

[0014] In the annealing process step of the present invention, the coil temperature drops to 100° and then nitrogen is recovered before being discharged from the furnace. The nitrogen recovery method is to close the nitrogen inlet valve on the nitrogen delivery pipeline, open the nitrogen recovery pipe, the negative pressure fan, and the recovery valve, and recover the nitrogen in the furnace body into the nitrogen tank. After the nitrogen is recovered, the furnace door is opened to discharge the material.

[0015] The present invention has the advantages of simple structure, sufficient air isolation, control of oxygen content in the furnace below 1000ppm during annealing, and prevention of pollution of aluminum alloy coils due to the adoption of the above structure and process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention.

[0017] Figure 2 yes Figure 1 Side view of.

[0018] Figure 3 This is a diagram of the connection between the negative pressure fan, the nitrogen recovery pipe, and the exhaust tank. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings: As shown in the accompanying drawings, an aluminum alloy nitrogen atmosphere protection annealing furnace is provided with a furnace body 1, an opening is provided on the front side of the furnace body 1, and the opening position is closed by a furnace door 2, characterized in that a bracket 3 is provided at the bottom of the furnace body 1, a material coil 4 is placed on the bracket 3, at least two circulation fans 5 are installed on the top of the furnace body 1, the body of the circulation fan 5 is fixed on the outside of the furnace body 1, and the circulation fan of the circulation fan 5 extends into the furnace body 1, and a nitrogen delivery pipeline 6 is provided above the furnace body 1, and the nitrogen delivery pipeline 6 is connected to the nitrogen tank 7, and at least two A nitrogen inlet pipe 8, one end of which is connected to the nitrogen delivery pipeline 6, and the other end of the nitrogen inlet pipe 8 passes through the top of the furnace body 1 and extends into the interior of the furnace body 1. An oxygen analyzer 9 is provided on the side of the furnace body 1, and the oxygen analyzer 9 is fixed on the side of the furnace body 1. The sensing end of the oxygen analyzer 9 extends into the interior of the furnace body 1. A negative pressure air duct 10 is installed on the top of the furnace body 1, and one end of the negative pressure air duct 10 extends into the interior of the furnace body 1. A negative pressure fan 11 is installed on the other end of the negative pressure air duct 10, and a negative pressure control valve 12 is installed on the negative pressure air duct 10 extending out of the furnace body 1.

[0020] Furthermore, an oil removal pipe is installed above the furnace body 1, one end of the oil removal pipe extends into the furnace body 1, and the other end of the oil removal pipe extends out of the furnace body 1 and is connected to the oil removal fan 34, and an oil removal control valve 13 is installed on the oil removal pipe extending out of the furnace body 1.

[0021] Furthermore, heaters 14 are installed above the left and right sides of the furnace body 1 , respectively. The heaters 14 are fixed above the inside of the furnace body 1 , and the gas in the furnace body 1 is heated by the heaters 14 .

[0022] Furthermore, a cooling mechanism is provided on the rear side of the furnace body 1, and the cooling mechanism includes a cooling air inlet pipe 15, a cooling air outlet pipe 16, a condenser 17, and a cooling fan 18. The cooling air inlet pipe 15 is installed at the upper position of the furnace body 1 and is connected to the furnace body 1, and the cooling air outlet pipe 16 is installed at the lower position of the furnace body 1 and is connected to the furnace body 1. The condenser 17 and the cooling fan 18 are connected between the cooling air inlet pipe 15 and the cooling air outlet pipe 16. The hot air extracted by the cooling fan 18 is cooled by the condenser 17, thereby cooling the material coil 4 in the furnace body 1.

[0023] Furthermore, a deflector 19 is provided on the outside of the circulation fan of the circulation fan 5 . The deflector 19 covers the outside of the circulation fan. The lower end of the deflector 19 is closed, and air guide ports 20 are opened on the left and right sides. The air guide ports 20 face the direction of the heater 14 .

[0024] Further, an air guide assembly is provided on the furnace body 1 below the heater 14, and the air guide assembly includes an upper closing plate 21, a lower closing plate 22, a left closing plate 23, a right closing plate 24, a front closing plate, a rear closing plate 25 and an air guide plate 26. The upper closing plate 21, the lower closing plate 22, the left closing plate 23, the right closing plate 24 and the rear closing plate 25 are connected to each other to form a closed box, and the front closing plate is in a Chinese-shaped shape. The outer end of the front closing plate is fixedly connected to the open outer end of the furnace body 1, and the inner end of the front closing plate is respectively connected to the upper closing plate 21, the lower closing plate 22, the left closing plate 23, the right closing plate 24 and the rear closing plate 25. The front end of the closed box is connected to the furnace body 1, the closed box is fixed in the furnace body 1, and an air guide chamber is formed between the outer end of the closed box and the furnace body 1. The circulating fan 5 and the heater 14 are arranged in the air guide chamber. The nitrogen inlet pipe 8 extends into the closed box. The bracket 3 is fixed on the lower closed plate 22 of the closed box. The lower closed plate 22 of the closed box is fixedly connected to the bottom of the furnace body 1 through the support frame 27. The lower closed plate 22, the left closed plate 23, the right closed plate 24 and the rear closed plate 25 are respectively provided with air guide ports 20, and the air guide ports 20 are respectively connected to air guide plates 26, and the air guide plates 26 face the position of the material roll 4 in the closed box.

[0025] Furthermore, a nitrogen inlet valve 28 and a flow meter 29 are respectively installed on the nitrogen delivery pipeline 6.

[0026] Furthermore, the negative pressure air duct 10 is respectively connected to a nitrogen recovery pipe 30 and an exhaust air duct 31 , an exhaust valve 32 is installed on the exhaust air duct 31 , a recovery valve 33 is installed on the nitrogen recovery pipe 30 , and the nitrogen recovery pipe 30 is connected to a nitrogen tank 7 .

[0027] The annealing process steps of the above scheme are as follows: First, start the annealing furnace to clean the furnace, first close the furnace door 2, open the nitrogen inlet valve 28 on the nitrogen delivery pipeline 6, start the oil removal fan 34, the oil removal control valve 13, the negative pressure control valve 12, the negative pressure fan 11, and the exhaust valve 32 to reduce the oxygen content in the furnace to below 1000ppm, then close the oil removal fan 34, the negative pressure fan 11, the oil removal control valve 13, the negative pressure control valve 12, and the exhaust valve 32, and turn on the heater 14 and the circulating fan 5 for circulating heating; the oxygen analyzer 9 is used to monitor the oxygen content in the furnace and feed back to the nitrogen inlet valve 28 and the flow meter 29 to the furnace The nitrogen atmosphere in the furnace body 1 is adjusted; after the annealing is completed, the condenser 17 and the cooling fan 18 are started to cool down. After the temperature of the coil 4 drops to 100°, the nitrogen is recovered and then taken out of the furnace. The nitrogen recovery method is to close the nitrogen inlet valve 28 on the nitrogen delivery pipeline 6, open the nitrogen recovery pipe 30, the negative pressure fan 11, and the recovery valve 33, and recover the nitrogen in the furnace body 1 to the nitrogen tank 7. After the nitrogen is recovered, the furnace door 2 is opened to discharge the material. Due to the use of the above structure and process, the present invention has the advantages of simple structure, sufficient air isolation, oxygen content in the furnace can be controlled below 1000ppm during annealing, and pollution of the aluminum alloy coil 4 can be prevented.

Claims

1. An aluminum alloy nitrogen atmosphere protection annealing furnace, comprising a furnace body, an opening on the front side of the furnace body, and a furnace door closing the opening position, characterized in that A bracket is provided at the bottom of the furnace body, and a material roll is placed on the bracket. At least two circulation fans are installed on the top of the furnace body. The body of the circulation fan is fixed on the outside of the furnace body, and the circulation fan of the circulation fan extends into the furnace body. A nitrogen delivery pipeline is provided above the furnace body, and the nitrogen delivery pipeline is connected to the nitrogen tank. At least two nitrogen inlet pipes are provided on the nitrogen delivery pipeline, and one end of the nitrogen inlet pipe is connected to the nitrogen delivery pipeline, and the other end of the nitrogen inlet pipe passes through the top of the furnace body and extends into the furnace body. An oxygen analyzer is provided on the side of the furnace body, and the oxygen analyzer is fixed on the side of the furnace body. The sensing end of the oxygen analyzer extends into the furnace body. A negative pressure air duct is installed on the top of the furnace body, and one end of the negative pressure air duct extends into the furnace body. A negative pressure fan is installed on the other end of the negative pressure air duct, and a negative pressure control valve is installed on the negative pressure air duct extending out of the furnace body.

2. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that An oil removal pipe is installed above the furnace body, one end of the oil removal pipe extends into the furnace body, the other end of the oil removal pipe extends out of the furnace body and is connected to the oil removal fan, and an oil removal control valve is installed on the oil removal pipe extending out of the furnace body.

3. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that Heaters are respectively installed on the upper left and right sides of the furnace body. The heaters are fixed on the upper part of the furnace body, and the gas in the furnace body is heated by the heaters.

4. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that A cooling mechanism is provided on the rear side of the furnace body, and the cooling mechanism includes a cooling air inlet pipe, a cooling air outlet pipe, a condenser, and a cooling fan. The cooling air inlet pipe is installed at an upper position of the furnace body and is connected to the furnace body, and the cooling air outlet pipe is installed at a lower position of the furnace body and is connected to the furnace body. The condenser and the cooling fan are connected between the cooling air inlet pipe and the cooling air outlet pipe. The hot air extracted by the cooling fan is cooled by the condenser, thereby cooling the material coil in the furnace body.

5. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that The circulation fan of the circulation fan is provided with a guide cover on the outside of the circulation fan. The guide cover is covered on the outside of the circulation fan. The lower end of the guide cover is closed, and air guide ports are opened on the left and right sides, and the air guide ports face the direction of the heater.

6. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that The furnace body below the heater is provided with an air guide component, the air guide component comprises an upper closing plate, a lower closing plate, a left closing plate, a right closing plate, a front closing plate, a rear closing plate and an air guide plate, the upper closing plate, the lower closing plate, the left closing plate, the right closing plate and the rear closing plate are connected to each other to form a closed box, the front closing plate is in a Chinese-Hui shape, the outer end of the front closing plate is fixedly connected to the open outer end of the furnace body, the inner ends of the front closing plate are respectively connected to the front ends of the upper closing plate, the lower closing plate, the left closing plate and the right closing plate, the closed box is fixed in the furnace body, an air guide chamber is formed between the outer end of the closed box and the furnace body, the circulating fan and the heater are both arranged in the air guide chamber, the nitrogen inlet pipe extends into the closed box, the bracket is fixed on the lower closing plate of the closed box, the lower closing plate of the closed box is fixedly connected to the bottom of the furnace body via the supporting frame, the lower closing plate, the left closing plate, the right closing plate and the rear closing plate are respectively provided with air guide ports, the air guide ports are respectively connected to the air guide plates, and the air guide plates face the material coil position in the closed box.

7. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that A nitrogen inlet valve and a flow meter are respectively installed on the nitrogen delivery pipeline.

8. The aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 1, characterized in that The negative pressure air duct is respectively connected to the nitrogen recovery pipe and the exhaust air duct, the exhaust air duct is installed with an exhaust valve, the nitrogen recovery pipe is installed with a recovery valve, and the nitrogen recovery pipe is connected to the nitrogen tank.

9. An annealing process for an aluminum alloy nitrogen atmosphere protection annealing furnace, characterized in that The annealing process steps are as follows: First, start the annealing furnace cleaning operation, first close the furnace door, open the nitrogen inlet valve on the nitrogen delivery pipeline, start the oil removal fan, oil removal control valve, negative pressure control valve, negative pressure fan, exhaust valve, so that the oxygen content in the furnace drops below 1000ppm, then close the oil removal fan, negative pressure fan, oil removal control valve, negative pressure control valve, exhaust valve, turn on the heater and circulating fan for circulating heating; use the oxygen analyzer to monitor the oxygen content in the furnace and feed back to the nitrogen inlet valve and flowmeter to adjust the nitrogen atmosphere in the furnace; after annealing is completed, start the condenser and cooling fan to cool down, and the coil temperature drops to 100° before it is taken out of the furnace.

10. The annealing process of the aluminum alloy nitrogen atmosphere protection annealing furnace according to claim 9, characterized in that In the annealing process step, after the temperature of the coil drops to 100°, nitrogen is recovered before being discharged from the furnace. The nitrogen recovery method is to close the nitrogen inlet valve on the nitrogen delivery pipeline, open the nitrogen recovery pipe, the negative pressure fan, and the recovery valve, and recover the nitrogen in the furnace body into the nitrogen tank. After the nitrogen is recovered, the furnace door is opened to discharge the material.

Images