CN106914609B - A kind of aluminium alloy melt heating heat preserving method - Google Patents

Abstract

The invention discloses a kind of aluminium alloy melt heating heat preserving methods, include the steps that heating and thermal insulation aluminium alloy melt, heating and thermal insulation is carried out to melt using aluminium alloy melt heating and heat-insulating device in the step, aluminium alloy melt heating and heat-insulating device includes furnace body, electrical heating elements, temperature controller and temperature sensor；The inside of furnace body has cavity, and cavity constitutes melt temperature adjustment furnace chamber；Temperature sensor is mounted on furnace body；It is characterized in that: the step of heating and thermal insulation aluminium alloy melt further includes the steps that indirect heating, the step of indirect heating, forms heating surface including the use of the medial surface of the furnace lining of furnace body, and heating surface is for heating the indoor aluminium alloy melt of melt conditioning oven.Aluminium alloy melt heating heat preserving method of the invention has implementation simple and convenient, and molten bath is heated and uniformity of temperature profile, is easily installed, replaces electrical heating elements, and molten bath slag is facilitated to remove operation, safe and reliable advantage.

Description

A kind of aluminum alloy melt heating and heat preservation method

technical field

The invention belongs to the field of aluminum alloy smelting methods, and particularly relates to a heating and heat preservation method for aluminum alloy melt.

Background technique

Before aluminum alloy casting is formed, it is necessary to first heat and melt the alloy charge into an alloy melt. The obtained melt is purified and then transferred to a temperature-adjusting molten pool or a holding furnace, and the temperature is adjusted to meet the requirements of the subsequent casting process. Then use manual or pouring machinery to quantitatively supply casting and forming equipment. In practical industrial production, in order to obtain products with stable configuration, it is necessary to strictly control the temperature of the cast aluminum alloy melt. In order to meet this requirement, it is necessary to adjust the temperature of the aluminum alloy melt with the required purity in the heating and temperature-adjusting melting chamber of the smelting equipment or in an independent heating and holding furnace before pouring.

At present, there are two main types of electric heating and temperature regulation methods for metal melts used in industrial production: one is the top resistance heating temperature regulation method (which is widely used in heating and temperature regulation furnaces and furnaces at home and abroad); the other is the Immersion bottom heating method (used in many new baths). The above two types of methods each have the following advantages and disadvantages:

When using the top-type electric heating temperature adjustment method (see Figure 1 for the specific schematic diagram), the resistance heating element is installed above the heating temperature adjustment melting chamber and the molten pool of the furnace, and the molten pool is heated and temperature adjusted by resistance heat radiation. Although this method has the advantages that the resistance heating element is easy to maintain and replace, and the resistance heating element does not hinder the removal of the molten pool slag, but this method is because the heat source is located above the molten pool, and the heat can only be transferred to the bottom of the molten pool through the melt, resulting in There is a significant temperature difference between the top and bottom of the molten pool (that is, there is a certain temperature gradient on the height of the molten pool), which not only causes the temperature of the externally supplied melt to change with the decrease of the molten pool level, but also occurs due to the temperature difference. The high temperature elements crystallize and settle at the low temperature part of the molten pool. While changing the composition of the melt alloy, bottom slag is formed at the bottom of the molten pool, which increases the workload of slag removal.

The immersion bottom heating and temperature regulation method (see Figure 2 for the specific schematic diagram) is a newly proposed method for heating and temperature regulation of the molten pool for the problems faced by the top heating. Such heating and temperature regulating devices can be found in utility model patents CN201620543247.2, CN201520893819.5, etc. In this method, the resistance heating element is placed in a protective tube inserted into the bottom of the molten pool, and the temperature of the melt is heated and adjusted from the bottom of the molten pool through the protective tube. Although this method can obtain uniform molten pool temperature from top to bottom, high heating efficiency and energy efficiency, it needs to use a protective tube inserted through the furnace lining and inserted into the bottom of the molten pool to provide isolation protection for the heating element. The protective tube not only hinders the removal of bottom slag from the molten pool, but once damaged, in addition to the potential risk of melt leakage, it needs to be shut down for a long time for maintenance and replacement, which affects the continuity and stability of production.

Based on this, the applicant considers to design a safe and reliable heating and heat preservation method for aluminum alloy melt, which is simple and reasonable in structure, convenient for molten pool slag removal operation.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is: how to provide a safe and reliable aluminum alloy molten pool heating and heat preservation device with simple and reasonable structure, convenient for molten pool slag removal operation.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A method for heating and insulating an aluminum alloy melt, comprising the steps of heating and insulating an aluminum alloy melt;

In the step of heating and insulating the aluminum alloy melt, an aluminum alloy melt heating and insulating device is used to heat and heat the melt, and the aluminum alloy melt heating and insulating device includes a furnace body, an electric heating element, a temperature controller and a temperature sensor. The inside of the furnace body has a cavity, and the cavity constitutes a melt tempering furnace chamber; the electric heating element is fixedly installed on the furnace body and is used for heating the melt in the melt tempering furnace ; The output end of the temperature controller is connected with the interface of the electric heating element through a cable, and the signal input end of the temperature controller is connected with the output interface of the temperature sensor through a cable; the temperature sensor is installed in the on the furnace body and for detecting the melt temperature in the melt tempering furnace;

It is characterized in that: the step of heating and insulating the aluminum alloy melt further includes the step of indirect heating, and the step of indirect heating includes using the inner side surface of the furnace lining of the furnace body to form a heating surface, and the heating surface is used for the heating surface. The aluminum alloy melt in the melt tempering furnace is heated.

In this technical solution, the furnace lining refers to the furnace wall of the furnace body.

The aluminum alloy melt heating and heat preservation method of the present invention is in use:

First, the molten aluminum alloy metal melt is transferred into the melt tempering furnace chamber.

Then, set the required heat preservation temperature of the aluminum alloy metal through the thermostat, and start the electric heating element to heat and adjust the temperature. The temperature sensor detects the temperature of the aluminum alloy metal melt. When the actual temperature of the aluminum alloy metal melt is higher than the set temperature, the electric heating element stops heating; and when the actual temperature of the aluminum alloy metal melt is lower than the set temperature, the electric heating The elements are heated to ensure that the aluminum alloy metal melt in the melt tempering furnace is at the temperature set by the system. It can be seen that the aluminum alloy melt heating and heat preservation method of the present invention can precisely control the melt temperature.

In addition, because the heating and heat preservation method of the aluminum alloy melt of the present invention adopts the step of indirect heating, the step of indirect heating is to indirectly heat the aluminum alloy melt by using the inner side of the furnace lining of the furnace body. The volume of the melt tempering furnace chamber can be enlarged, and there is no electric heating element in the melt tempering furnace chamber to block the slag removal operation, thereby facilitating the slag removal operation and improving the slag removal efficiency.

Preferably, the furnace lining of the furnace body can conduct heat, and a heating element installation chamber is arranged inside the furnace lining, and the electric heating element is installed in the heating element installation chamber, so that the inner side surface of the furnace lining can form a heating surface .

By adopting the above preferred solution, the step of indirect heating can be realized most simply.

Because the electric heating element is not arranged in the melt tempering furnace chamber, the electric heating element can be easily installed and replaced, and there is no risk of melt leakage caused by damage to the furnace lining. At the same time, because the electric heating element is not arranged in the melt tempering furnace chamber, the electric heating element will not constitute any obstruction to the melt tempering furnace chamber, thereby facilitating the removal of molten pool slag.

Preferably, the melt tempering furnace chamber has a funnel-shaped structure as a whole.

After the above preferred solution is adopted, even the bottom of the melt tempering furnace chamber can gather the slag, so that the slag can be cleaned quickly and the slag removal operation is more efficient and convenient.

Preferably, the electric heating element is a resistance heating element.

The resistance heating element has the advantages of convenient procurement, low cost, uniform heating, and high temperature control precision, which can help the aluminum alloy melt heating and heat preservation method of the present invention to obtain a more accurate heating and heat preservation effect.

Preferably, the resistance heating element is an elongated structure as a whole;

The overall shape of the furnace body is a cone-shaped structure with a large top and a small bottom; a strip hole extending from top to bottom is arranged inside the furnace lining of the furnace body, and the upper end of the strip hole is for the insertion of resistance heating elements. The open end of the furnace body, and the strip-shaped holes are arranged at intervals along the circumferential direction of the furnace body, and each strip-shaped hole constitutes the heating element installation chamber, and the heating element installation chamber is inserted into the The resistive heating element is installed.

After adopting the above preferred solution, when installing the resistance heating element on the furnace body, the installation can be completed only by inserting the resistance heating element through the strip hole, so the installation and replacement of the electric heating element can be made easier.

At the same time, after adopting "the overall shape of the furnace body is a cone-shaped structure with a large upper and a small lower", it is possible to obtain a uniform temperature distribution up and down in the molten pool without inserting the resistance heating element into the bottom of the molten pool. While suppressing the condensation of high-temperature elements due to the temperature at the bottom of the molten pool being lower than the temperature above, it facilitates the removal of bottom slag in the molten pool.

Preferably, the cone-shaped structure is a square-cone-shaped structure, and the strip-shaped holes are distributed on any two opposite sides of the square-cone-shaped structure.

In this way, the structure of the furnace body with the square cone structure is simpler (compared to the conical shape), and it is more convenient to manufacture.

Preferably, the resistance heating element is sleeved with a bushing for the heating element.

After the above preferred solution is adopted, the resistance heating element can be well protected by the bushing for the heating element to prevent frictional damage of the resistance heating element during installation or removal (from the heating element installation chamber).

Preferably, the lower end of the resistance heating element is lower than the bottom position of the melt tempering furnace chamber.

After the above preferred solution is adopted, the design of obtuse angles between the furnace bodies on both sides where the resistance heating elements are placed and the bottom of the melt tempering furnace chamber can fully ensure that the melt in the melt tempering furnace chamber is heated evenly and will not be heated in the melt tempering furnace chamber. There is an obvious temperature difference in the height of the molten pool, which ensures that the temperature of the externally supplied aluminum alloy melt is consistent and stable.

Preferably, the furnace lining is made of a refractory material with a thermal conductivity greater than 1 W/m·degree.

In this way, the furnace lining has better thermal conductivity, and the heating and heat conduction efficiency of the resistance heating element is improved.

Preferably, the thermostat is PCC.

After PCC (Programmable Computer Controller) is used as the temperature controller, the advantages of PCC can be used to help the aluminum alloy melt heating and heat preservation method of the present invention to obtain the advantages of high reliability and convenient programming, and it is convenient to realize the melting temperature adjustment furnace. Indoor high-precision temperature control.

Compared with the prior art, the beneficial effects of the aluminum alloy melt heating and heat preservation method of the present invention are:

1. It can make the melt in the molten pool heated and the temperature distribution uniform. The design of the obtuse angle between the two sides of the furnace body on which the resistance heating element is placed and the bottom of the melt tempering furnace chamber can fully ensure that the melt in the melt tempering furnace is heated evenly, and there is no obvious temperature at the height of the molten pool. difference, to ensure that the temperature of the external aluminum alloy melt is consistent and stable.

2. It is convenient to remove molten pool slag. Because the aluminum alloy molten pool obtained by the present invention has no upper and lower temperature difference, the composition change caused by the crystallization of high-melting elements and the problems of slag formation at the bottom of the molten pool do not occur;

3. Easy to install and replace electric heating elements, safe and reliable. Because the resistance heating element is placed inside the furnace lining and is not inserted into the molten pool through the furnace body, it not only ensures the completeness of the inner wall of the furnace, but also effectively avoids the risk of aluminum alloy melt leakage; Provide convenience.

4. Due to the built-in resistance heating element, the furnace wall of the molten pool is complete and standardized, and the bottom area is reduced, which makes the slag removal operation more efficient and convenient.

Description of drawings

FIG. 1 is a schematic diagram of a top resistance heating temperature adjustment method in the background art.

FIG. 2 is a schematic diagram of a bottom immersion heating method in the background art.

3 is a schematic structural diagram of an embodiment of the method for heating and maintaining an aluminum alloy melt according to the present invention.

FIG. 4 is a cross-sectional view A-A in FIG. 3 .

Marked in Figure 1: 1—furnace cover, 2—resistance heating element, 3—heating and tempering melting chamber, 4—furnace body.

Marked in Figure 2: 1—resistance heating element, 2—resistance heating element protective tube, 3—heating and tempering melting chamber, 4—furnace body.

3 and 4 are marked as: 1—melt tempering furnace chamber, 2—furnace body, 3—heating element installation chamber, 4—lining for heating element, 5—resistance heating element.

Detailed ways

The present invention will be further described in detail below in conjunction with an aluminum alloy melting method adopting the present invention. Herein, descriptive terms such as up, down, left, right, etc. are used for the description to aid the reader's understanding and are not intended to be limiting.

When implemented, as shown in Figures 3 and 4:

A method for heating and insulating an aluminum alloy melt, comprising the steps of heating and insulating an aluminum alloy melt;

In the step of heating and insulating the aluminum alloy melt, an aluminum alloy melt heating and insulating device is used to heat and heat the melt, and the aluminum alloy melt heating and insulating device includes a furnace body 2, an electric heating element, and a temperature controller (Fig. (not shown in the figure) and a temperature sensor (not shown in the figure); the furnace body 2 has a cavity inside, and the cavity constitutes the melt tempering furnace chamber 1; the electric heating element is fixedly installed in the furnace body 2 and is used to heat the melt in the melt tempering furnace; the output end of the thermostat is connected to the interface of the electric heating element through a cable, and the signal input end of the thermostat is connected through a cable. The cable is connected with the output interface of the temperature sensor; the temperature sensor is installed on the furnace body and used to detect the melt temperature in the melt tempering furnace;

The step of heating and maintaining the aluminum alloy melt further includes the step of indirect heating, and the step of indirect heating includes using the inner side surface of the furnace lining of the furnace body to form a heating surface, and the heating surface is used to adjust the temperature of the melt. The aluminum alloy melt in the furnace chamber is heated.

During implementation, the furnace body can use either a graphite crucible or an induction furnace to indirectly heat the aluminum alloy melt.

Preferably, the furnace lining of the furnace body 2 can conduct heat, and a heating element installation chamber 3 is arranged inside the furnace lining, and the electric heating element is installed in the heating element installation chamber 3, so that the inner side of the furnace lining can be constitute the heating surface.

Wherein, the melt tempering furnace chamber 1 has a funnel-shaped structure as a whole.

Wherein, the electric heating element is a resistance heating element 5 .

Wherein, the resistance heating element 5 is an elongated structure as a whole;

The overall shape of the furnace body 2 is a cone-shaped structure with a large upper and a small lower; the inside of the furnace lining of the furnace body 2 is provided with a strip hole extending from top to bottom, and the upper end of the strip hole is used for resistance heating. The open end into which the element 5 is inserted, and the strip-shaped holes are a plurality of which are arranged at intervals along the circumferential direction of the furnace body 2, and each strip-shaped hole constitutes the heating element installation chamber 3, and the heating element The resistance heating element 5 is inserted and installed in the installation chamber 3 .

Wherein, the cone-shaped structure is a square-cone-shaped structure, and the strip-shaped holes are distributed on any two opposite sides of the square-cone-shaped structure.

Wherein, the resistance heating element 5 is sleeved with a heating element bushing 4 outside.

In practice, it is preferred that the heating element bushing 4 is made of any one of silicon carbide or SIALON. In this way, the heating element bushing 4 has the advantages of high temperature resistance, high strength, good thermal conductivity, and strong impact resistance, thereby improving heat transfer and protecting the resistance heating element 5 .

Wherein, the lower end of the resistance heating element 5 is lower than the bottom position of the melt tempering furnace chamber 1 .

Wherein, the furnace lining is made of refractory materials with thermal conductivity greater than 1 W/m·degree.

During implementation, the refractory materials with thermal conductivity greater than 1 watt/m·degree can be selected from any of magnesia bricks, chrome bricks, chrome-magnesium bricks, silicon carbide bricks or high alumina bricks.

Wherein, the temperature controller is PCC.

In this technical solution, the furnace lining refers to the furnace wall of the furnace body.

The above-mentioned aluminum alloy melt heating and heat preservation method is in use:

First, the molten aluminum alloy metal melt is transferred into the melt tempering furnace chamber.

Then, set the required heat preservation temperature of the aluminum alloy metal through the thermostat, and start the electric heating element to heat and adjust the temperature. The temperature sensor detects the temperature of the aluminum alloy metal melt. When the actual temperature of the aluminum alloy metal melt is higher than the set temperature, the electric heating element stops heating; and when the actual temperature of the aluminum alloy metal melt is lower than the set temperature, the electric heating The elements are heated to ensure that the aluminum alloy metal melt in the melt tempering furnace is at the temperature set by the system. It can be seen that the aluminum alloy melt heating and heat preservation method of the present invention can precisely control the melt temperature.

In addition, because the heating and heat preservation method of the aluminum alloy melt of the present invention adopts the step of indirect heating, the step of indirect heating is to indirectly heat the aluminum alloy melt by using the inner side of the furnace lining of the furnace body. The volume of the melt tempering furnace chamber can be enlarged, and there is no electric heating element in the melt tempering furnace chamber to block the slag removal operation, thereby facilitating the slag removal operation and improving the slag removal efficiency.

Compared with the prior art, the beneficial effects of the above-mentioned aluminum alloy melt heating and heat preservation method are:

1. It can make the melt in the molten pool heated and the temperature distribution uniform. The design of the obtuse angle between the two sides of the furnace body 2 on which the resistance heating element 5 is placed and the bottom of the melt tempering furnace chamber 1 can fully ensure that the melt in the melt tempering furnace chamber 1 is heated evenly and will not be at the height of the molten pool. There is an obvious temperature difference on the surface to ensure that the temperature of the externally supplied aluminum alloy melt is consistent and stable.

2. It is convenient to remove molten pool slag. Because the aluminum alloy molten pool obtained by the present invention has no upper and lower temperature difference, the composition change caused by the crystallization of high-melting elements and the problems of slag formation at the bottom of the molten pool do not occur;

3. Easy to install and replace electric heating elements, safe and reliable. Since the resistance heating element 5 is placed inside the furnace lining and is not inserted into the molten pool through the furnace body 2, it not only ensures the completeness of the inner wall of the furnace body 2, but also effectively avoids the risk of leakage of the aluminum alloy melt; The resistance heating element 5 provides convenience.

4. Due to the built-in resistance heating element 5, the furnace wall of the molten pool is complete and standardized, and the bottom area shrinks, which makes the slag removal operation more efficient and convenient.

The above are only the preferred embodiments of the present invention. It should be pointed out that, for those skilled in the art, some modifications and improvements can be made without departing from the technical solution. The technical solutions of the above-mentioned modifications and improvements should also be regarded as falling into The scope of protection claimed in this application.

Claims (4)

1. a kind of aluminium alloy melt heating heat preserving method, it is characterised in that: using the method for indirect heating；

The indirect heating carries out heating and thermal insulation to aluminium alloy melt using aluminium alloy melt heating and heat-insulating device；

The aluminium alloy melt heating and heat-insulating device includes furnace body, electrical heating elements, temperature controller and temperature sensor；The furnace body Inside there is cavity, the cavity constitutes melt temperature adjustment furnace chamber；The electrical heating elements are fixedly mounted on furnace body and are used for The indoor aluminium alloy melt of the melt conditioning oven is heated；The output end of the temperature controller passes through cable and electric heating member The interface of part is connected, and the signal input part of the temperature controller is connected by cable with the output interface of the temperature sensor It connects；The temperature sensor is mounted on the furnace body and for detecting the indoor aluminium alloy melt temperature of the melt conditioning oven Degree；The electrical heating elements are stratie；

The shape of the furnace body is integrally in up big and down small cone cylindrical structure；The cone cylindrical structure is square cone structure, described The furnace lining of furnace body is internally provided with the strip-shaped hole extended from the top down, and the upper end of the strip-shaped hole is to be inserted into for stratie Open end；The bar shaped pore size distribution is set on the opposite side of any two of the square cone structure, and the bar shaped Hole is spaced multiple；The bottom of the two sides furnace body and the melt temperature adjustment furnace chamber that are placed with stratie is in obtuse angle Design；The furnace lining is internally provided with heating element installation chamber, and each strip-shaped hole constitutes the heating element installation Chamber, grafting is equipped with the stratie in heating element installation cavity room；The stratie is generally String configuration；Heating element bushing is socketed with outside the stratie；

The indirect heating is that heating surface is formed using the medial surface of the furnace lining of furnace body, and the heating surface is used for the melt The indoor aluminium alloy melt of conditioning oven is heated.

2. aluminium alloy melt heating heat preserving method according to claim 1, it is characterised in that: the stratie Lower end is lower than the bottom position of the melt temperature adjustment furnace chamber.

3. aluminium alloy melt heating heat preserving method according to claim 1, it is characterised in that: the furnace lining uses thermally conductive system Refractory material of the number greater than 1 watt/ meter Du is made.

4. aluminium alloy melt heating heat preserving method according to claim 1, it is characterised in that: the temperature controller is PCC.