TWM545002U - Shell mold sintering device - Google Patents

Description

Shell mold sintering device

The present invention relates to a precision casting process, and more particularly to a shell mold sintering device.

Precision casting is a casting method relative to conventional casting processes that achieves relatively accurate shape and high casting accuracy. The process of precision casting is: first, a wax mold is produced, which is consistent with the size and shape of the product to be cast; then, a ceramic shell is formed on the surface of the prepared wax mold; and then, the ceramic shell is dewaxed. Treatment (after melting the wax mold inside thereof); after that, the ceramic shell is sintered at a high temperature; finally, the metal material is cast into the sintered ceramic shell, and after the metal material is cooled and solidified, the ceramic shell is crushed and removed to obtain The casting is the desired product.

In the above process, the production of ceramic shell is very important, and its quality determines the pros and cons of the casting. At present, the commonly used method for making ceramic shells is: shell moulding method, in particular, water-soluble cerium sol shelling method is often used. In the method of making ceramic shell, refractory material is used to prepare different slurry and sand, and one layer of pulp is layered. The sand is gradually layered on the surface of the wax mold to form a ceramic shell of the desired thickness. Then, the obtained ceramic shell is dried, dewaxed, and placed in a sintering furnace at a high temperature sintering at 900 to 1400 °C. Since sintering is an indispensable step in the production of shell molds, the quality of the shell directly affects the quality of the shell mold and the quality of the final casting.

The inventor's prior application Chinese Patent No. CN105903898A discloses a shell mold sintering method and a sintering apparatus using the same, which adopts a segmented heating method to divide the shell mold sintering process into a wax burning stage and a sintering stage, and the wax burning stage ensures In the sintering environment, sufficient oxygen and wax are fully combusted, so that there is almost no residual carbon formed in the shell mold due to carbonization of the residual wax, thereby avoiding the occurrence of The problem of molten steel splashing during casting and the problem of penetrating pores in the casting. At the same time, the oxygen concentration in the sintering environment is reduced as much as possible in the sintering stage, and the carbon powder in the shell mold is completely burned out in the sintering stage, so that the mold wall reaction phenomenon occurs when the shell mold is poured into the molten steel.

In the course of further research, the inventors found that the prior application still has the following problems to a certain extent: 1. In the wax burning stage (requiring high oxygen low temperature), it maintains sufficient oxygen content in the sintering furnace (ie, high oxygen). ), the furnace temperature is 600 ° C ~ 800 ° C (relative to the sintering temperature is low temperature), the maintenance time is 5 ~ 20min, under this condition, due to sufficient oxygen content, high furnace temperature and long maintenance time, Therefore, the carbon powder added in the shell mold may still be partially consumed by combustion, thereby weakening the protective effect of the carbon powder on the shell mold, and the mold wall reaction still occurs to some extent; 2. In the sintering stage (requiring hypoxia) High temperature), which controls the low-oxygen or oxygen-free environment in the sintering furnace by closing the air blowing device and the exhaust flue. However, at the end of the wax burning stage, the oxygen content in the sintering furnace is still at a high level. These residual oxygen will continue to consume the carbon powder added in the shell mold during the sintering stage, further weakening the protective effect of the carbon powder on the shell mold and increasing the probability of occurrence of the mold wall reaction.

In addition, in the continuous production of the shell mold, after the first shell mold is taken out from the sintering furnace, the temperature in the furnace is about 900 ° C. When the second shell mold is placed, the temperature in the furnace is still high. When the second shell mold is waxed, once the temperature of the shell mold increases, in the high oxygen environment, the carbon powder added in the shell mold may start to be burned successively, so it is necessary to shorten the wax burning stage. Time (shortening the time of high oxygen), and as far as possible, the high-oxygen to low-oxygen or oxygen-free environment in the sintering furnace after the end of the wax-burning stage is used to reduce the consumption of the carbon powder added in the shell mold.

The technical problem to be solved by the present invention is to provide a shell mold sintering device which can greatly shorten the time of the wax burning stage and make the low-oxygen or oxygen-free environment in the sintering furnace as soon as possible after the end of the wax burning stage, reducing The consumption of toner added to the shell mold.

In order to solve the above technical problems, the present invention provides the technical solution as follows: On the one hand, a shell mold sintering device is provided, comprising a sintering inner cavity, wherein the sintering inner cavity is provided with a shell mold placing platform and a heating device, and the sintering inner cavity One end of the sintering chamber is provided with a smoke outlet, and the other end of the sintering chamber is provided with a flue gas outlet, wherein the shell mold sintering device is an electric furnace, and the shell mold placement platform The upper surface is provided with a plurality of rows of grooves extending along the length of the sintering cavity, the width of the grooves being smaller than the diameter of the pouring cup of the shell mold to be sintered; the sintering chamber setting chamber An inner side of one end of the flue gas outlet is provided with a first intake pipe for supplying air at a position corresponding to the shell mold placing platform, and the first intake pipe is connected with an air blowing device, the first intake air a first nozzle oriented toward the groove is disposed on the tube; a second nozzle for providing a flammable gas or liquid is further disposed in the sintering cavity; the height of the flue gas outlet is higher than the shell mold placement Platform height

Further, the sintering inner cavity is provided with an inner side of one end of the flue gas outlet, and a second intake pipe for providing a flammable gas or liquid is further disposed at a position corresponding to the shell mold placing platform, the second A nozzle is located on the second intake pipe and faces in the direction of the groove.

Further, a plurality of windshields are uniformly disposed in a middle portion of at least one sidewall of the groove, and lengths of the windshields are sequentially lengthened from the inside to the outside along the sintering cavity.

Further, the end of the wind deflector is an arc-shaped air guiding portion.

Further, the windshield portion is inclined rearward from the inner side to the outer side of the sintering inner cavity, and the inclination angle is 1 to 10 degrees.

Further, the sintering inner cavity is provided with an inner side of one end of the closing door at a position corresponding to the shell mold placing platform, and a falling sand collecting groove is arranged along the width direction of the sintering inner cavity. extend.

Further, a secondary combustion furnace is disposed between the flue gas outlet and the exhaust flue, and the secondary combustion furnace is provided with a third nozzle for supplying air and a fourth for providing a flammable gas or liquid. a nozzle, the flue gas outlet being a contraction structure toward the secondary combustion furnace.

Further, the temperature in the secondary combustion furnace is 1200 ° C or higher, and the oxygen content of the secondary combustion furnace is 25% or more.

Further, a ceramic sponge screening program is disposed in the secondary combustion furnace at a connection with the exhaust flue.

Further, the first intake pipe is connected with a metal preheating pipeline, and the metal preheating pipeline is disposed in the secondary combustion furnace.

Further, a temperature sensing module and an oxygen concentration monitoring module are disposed in the sintering inner cavity.

In another aspect, a method for performing shell mold sintering using the above-described shell mold sintering apparatus includes: Step 1: placing a shell mold to be sintered on a shell mold placement platform in a sintered inner cavity, and closing the closed door; 2: Turn on the heating device, the air blowing device and the exhaust flue, so that there is sufficient oxygen content in the sintering inner cavity, the temperature is raised to the burning temperature of the shell mold wax, and the temperature in the sintering inner cavity is maintained until the residual in the shell mold The wax is completely burned out; Step 3: The nozzle is opened to make the sintered inner cavity a low-oxygen or oxygen-free environment, and the temperature is raised to the sintering temperature of the shell mold and the temperature in the sintered inner cavity is maintained as the sintering temperature of the shell mold until the shell mold is sintered.

Further, in the step 2, when it is detected that the oxygen content in the sintering inner cavity does not decrease within a certain time, the process proceeds to step 3.

Further, in the step 2, the heating device, the air blowing device and the air exhaust device are turned on, so that the oxygen content of the sintering inner cavity is 16-20%; in the step 3, the nozzle is opened to make the sintering inner The oxygen content of the chamber is below 5%.

Further, in the step 2, the combustion temperature of the shell mold wax is 600 ° C to 800 ° C, and the maintenance time of the temperature in the sintering furnace is maintained within 3 min; in the step 3, the shell mold is The sintering temperature is 1150 to 1400 ° C, and the maintenance time of the temperature in the sintering furnace is maintained for 10 to 30 minutes.

This creation has the following beneficial effects:

The present invention adjusts the direction of the groove on the shell mold placing platform, and reasonably arranges the position of the first nozzle for supplying air, so that a circulating air flow can be formed in the sintering inner cavity, the heating efficiency is improved, and the position of the first nozzle is The design can drive the airflow inside the shell mold, and can bring enough oxygen to the wax burning during the wax burning stage, so that the wax can be burned more quickly, which can greatly shorten the time of the wax burning stage; the creation is also in the sintering cavity The nozzle is disposed in the nozzle, and after the wax burning phase is finished, the nozzle can spray a flammable gas or a liquid, and consumes oxygen in the sintered inner cavity by combustion, thereby achieving the purpose of rapidly reducing the oxygen content in the sintered inner cavity, so that the wax is burned. After the end of the stage, the furnace is changed from high oxygen to low oxygen or oxygen-free environment as soon as possible. Even in the continuous production of the shell mold, the creation ensures that the carbon powder added to the shell mold is not consumed by combustion, ensuring the quality of the shell mold, thereby improving the quality of the casting. The creation can produce castings with high enough precision, so that the required casting precision can be achieved without or with less finishing, which reduces the defective product and the scrap rate, improves the production efficiency, and greatly reduces the production cost.

1‧‧‧Sintered cavity

10‧‧‧Secondary burner

11‧‧‧ third nozzle

12‧‧‧four nozzle

13‧‧‧Ceramic Sponge Screening Program

2‧‧‧Shell placement platform

21‧‧‧ Groove

22‧‧‧wind shield

221‧‧‧Arc-shaped draft

24‧‧‧Semicircular depression

3‧‧‧Closed door

4‧‧‧Smoke gas export

5‧‧‧Exhaust flue

6‧‧‧First intake pipe

61‧‧‧First nozzle

7‧‧‧Second intake manifold

71‧‧‧second nozzle

8‧‧‧Tour Cup

9‧‧‧Land sand collection tank

1 is a schematic structural view of an embodiment of a shell mold sintering apparatus according to the present invention; [FIG. 2] is a schematic cross-sectional view of the shell mold placement platform AA of FIG. 1; [FIG. 3] is a shell mold placement platform of FIG. A schematic plan view of a structure of a groove; [Fig. 4] is a schematic plan view of another structure of a groove of the shell mold placement platform of Fig. 1; [Fig. 5] is the groove shown in Fig. 3. A schematic view of the front side structure of the side wall with the windshield; [Fig. 6] is a schematic structural view of another embodiment of the shell mold sintering apparatus of the present invention; [Fig. 7] is a schematic flow chart of the shell mold sintering method of the present invention.

In order to make the technical problems, technical solutions and advantages of the present invention more clear, the following detailed description will be made with reference to the accompanying drawings and specific embodiments.

In one aspect, the present invention provides a shell mold sintering apparatus, as shown in FIGS. 1 to 5, including a sintered inner chamber 1 in which a shell mold placing platform 2 and a heating device (not shown) are provided, and the inner cavity is sintered. 1 is provided with a closing door 3, the other end of the sintering chamber 1 is provided with a flue gas outlet 4, and the flue gas outlet 4 is connected with an exhaust flue 5, wherein: the shell mold sintering device is an electric heating furnace, and the shell mold placing platform 2 The upper surface is provided with a plurality of rows of grooves 21 extending along the length direction of the sintered inner cavity 1 (i.e., the left-right direction in Fig. 1), and the width of the groove 21 is smaller than the diameter of the pouring cup 8 of the shell mold to be sintered. The sintering inner chamber 1 is provided with an inner side of one end of the flue gas outlet 4 at a position corresponding to the shell mold placing platform 2, and a first intake pipe 6 for supplying air is provided, and the first intake pipe 6 is connected with an air blowing device (not The first intake pipe 6 is provided with a first nozzle 61 oriented in the direction of the groove 21; The sintering chamber 1 is further provided with a second nozzle 71 for providing a flammable gas or liquid (such as gas, alcohol, etc.); the height of the flue gas outlet 4 is higher than the height of the shell mold placing platform 2, generally the height difference can be For the 5~20cm, the person skilled in the art can also flexibly adjust according to the actual situation.

The inventors found in the research process that the sintering furnaces in the prior art are mainly divided into two types. The first one is an electric heating furnace, and the disadvantages are as follows: 1. Heating by electric heating pipes arranged on three sides in the furnace, only heat radiation heating, heat Uneven, low efficiency; 2, the electric furnace is mostly closed, no ventilation, no convection, insufficient oxygen content, it is difficult to provide the high oxygen environment required for the wax burning stage; the second is the gas / oil furnace, its shortcomings It is: 1. Although there is ventilation and convection, but it relies on gas/fuel to heat and consume most of the oxygen, so there are often defects in the oxygen content in the wax burning stage; 2. If the oxygen supply is increased, then In the sintering stage, it is easy to cause the carbon powder added in the shell mold to be consumed by combustion.

The beneficial effects of this creation are:

1. On the basis of the existing electric furnace, and in combination with the inventor's prior application, the direction of the groove 21 on the shell mold placing platform 2 is adjusted, and the position of the first nozzle 61 for supplying air is reasonably arranged, so that The circulating gas flow can be formed in the sintering inner cavity 1 to improve the heating efficiency. The specific description is as follows: an air blowing device is introduced on the electric heating furnace, which can stir the air in the furnace, and solves the disadvantage that the electric heating furnace only has heat radiation and has poor efficiency. The air in the furnace stirs the air to create the best heat transfer conditions for heat convection, heat conduction and heat radiation, and fully transfers the heat of the electric heating tube to the shell mold quickly, increasing the heating efficiency, saving energy and shortening the time required for sintering. Increase production efficiency; the arrows in each figure indicate the direction of airflow. The direction of the circulating airflow formed in this creation is shown in Fig. 1. Compared with the prior application of the inventor, the creation of the airflow direction is more reasonable and the heating efficiency is higher.

Moreover, the groove 21 extends along the length of the sintering cavity 1, and this arrangement is advantageous for cleaning out the falling sand generated during the sintering process (both for artificial sand cleaning and for automatic sand cleaning by the inlet air flow).

2. In the present creation, the first intake pipe 6 for supplying air is provided with a first nozzle 61 oriented toward the groove 21, and the shell mold to be sintered is placed on the shell mold placing platform 2, which is located just below The upper side of the groove 21, so that the flow of the intake air flow of the first nozzle 61 will drive the airflow inside the shell mold, and the advantage is that: in the wax burning stage, sufficient oxygen can be brought to the wax combustion, so that the wax It can burn more quickly, and the other is to reduce the internal and external temperature difference of the shell mold during the sintering stage (the inner and outer temperature difference of the shell mold can be as low as 5 °C in this creation), so as to avoid the inside and outside of the shell mold during the sintering process due to the internal and external temperature difference. Different expansion amounts will cause fine cracks on the shell mold, thereby avoiding the problem that the surface of the casting has outwardly protruding burrs or convex water/concave water marks;

3. The width of the groove 21 is smaller than the diameter of the gate cup 8 of the shell mold to be sintered, so that the shell mold can be smoothly placed on the shell mold placing platform 2 without slipping/falling in the groove 21, so that Adhere to the falling sand falling during the sintering process to ensure that the casting does not produce sand holes;

4. The sintering inner chamber 1 is provided with a second nozzle 71 for supplying a flammable gas or liquid. After the wax burning phase is finished, the second nozzle 71 can eject a combustible gas or liquid, and consumes the sintered inner cavity 1 by combustion. Oxygen, thereby achieving the purpose of rapidly reducing the oxygen content in the sintered cavity 1.

In summary, the present invention adjusts the direction of the groove on the shell mold placement platform, and rationally arranges the position of the first nozzle for providing air, so that a circulating air flow can be formed in the sintered inner cavity, the heating efficiency is improved, and the first The position of the nozzle is designed to drive the airflow inside the shell mold, which can bring enough oxygen to the wax burning during the wax burning stage, so that the wax can be burned more quickly, which can greatly shorten the time of the wax burning stage; a nozzle is arranged in the sintering cavity, and after the wax burning phase is finished, the spraying The mouth can eject a flammable gas or liquid, and consumes oxygen in the sintered inner cavity by combustion, thereby achieving the purpose of rapidly reducing the oxygen content in the sintered inner cavity, so that the sintering furnace is changed from high oxygen to low as soon as possible after the wax burning phase ends. Oxygen or anaerobic environment. Even in the continuous production of the shell mold, the creation ensures that the carbon powder added to the shell mold is not consumed by combustion, ensuring the quality of the shell mold, thereby improving the quality of the casting. The creation can produce castings with high enough precision, so that the required casting precision can be achieved without or with less finishing, reducing the defective product, the reject rate, improving the production efficiency and greatly reducing the production cost.

As shown in FIG. 1, preferably, the sintering inner chamber 1 is provided with an inner side of one end of the flue gas outlet 4 at a position corresponding to the shell mold placing platform 2, and a second intake pipe 7 for supplying a flammable gas or liquid is further disposed. The second nozzle 71 is located on the second intake pipe 7 and faces in the direction of the groove 21.

The position design of the second nozzle 71 (direction toward the groove 21) enables the groove 21 to become a fire channel, so that it can quickly consume oxygen outside the shell mold, and can directly consume oxygen inside the shell mold. , further increasing the speed of oxygen removal. Moreover, if the residual carbon formed by carbonization of the wax which is not completely removed in the high temperature and low oxygen environment remains in the shell mold, the position design of the second nozzle 71 can also blow away the residual carbon, thereby improving the shell mold. Quality.

In the present invention, the groove 21 on the shell mold placing platform 2 may have various shapes such as a U shape, a trapezoidal shape, a triangular shape, etc., and the embodiment shown in FIG. 2 is a triangular groove. In this embodiment, in order to increase the accommodation of the falling sand. The semi-circular recess 24 is also added to the bottom of the groove.

As shown in FIGS. 2 to 3, the middle portion of at least one side wall of the recess 21 is preferably evenly provided with a plurality of wind deflectors 22, and the length of each wind deflector 22 is lengthened along the direction from the inside to the outside of the sintered inner chamber 1 in the As can be seen in Fig. 3, the closer to the left side (the direction of the closed door 3 of the sintered inner chamber 1), the longer the length of the wind deflector. The advantage of this is that when the intake air flows through, the wind deflector can block a part of the wind and lead it to Located in the pouring cup of the shell mold above, the air flow in the shell mold is increased. In order to improve the air intake effect, as shown in FIG. 3, the end of the wind deflector 22 may be an arc-shaped air guiding portion 221.

It should be noted that the wind deflector 22 is disposed at the middle of the side wall of the groove 21, and the lower end does not extend downward, so that the intake air flow can still flow under the entire groove, so that the falling sand falling during the sintering process can be blown out to Close the door side. As shown in FIG. 2, the heights of the windshields may be the same, and only the lengths may be different. Alternatively, the wind deflector can be designed either on one side wall of the recess (as shown in Figure 3) or on both side walls of the recess (as shown in Figure 4). It can be understood that the specific parameters, such as the size and the number of the groove and the wind deflector, can be flexibly set according to actual needs, and will not be further described herein.

As shown in FIG. 5, preferably, the upper portion of the windshield 22 is inclined rearward from the inside to the outside of the sintering inner cavity 1. The angle of inclination (ie, the angle between the wind deflector and the vertical direction) α may be 1 to 10 degrees. . In this way, more wind will be drawn into the interior of the shell mold, further increasing the air flow within the shell mold.

In the present creation, the sintering inner chamber 1 is provided with an inner side of one end of the closing door 3 at a position corresponding to the shell mold placing platform 2, preferably provided with a falling sand collecting groove 9, which extends in the width direction of the sintering inner chamber 1. In order to collect the falling sand regularly. When the sintering device is stopped, the air can be blown through the first air inlet pipe and the first nozzle by means of the air blowing device, and the sand falling in the groove can be blown into the falling sand collecting groove to facilitate centralized cleaning.

As a further improvement of the present invention, as shown in FIG. 6, a secondary combustion furnace 10 is disposed between the flue gas outlet 4 and the exhaust flue 5, and a third nozzle 11 for supplying air is disposed in the secondary combustion furnace 10 and A fourth nozzle 12 for supplying a flammable gas or liquid, the flue gas outlet 4 being a contraction structure toward the secondary combustion furnace 10.

In the process of burning wax, black smoke is easily generated, which is caused by insufficient combustion and mixed with charcoal powder in the flue gas. The secondary combustion furnace can provide a high-temperature and oxygen-rich environment to burn and consume the carbon in the inclusion. Powder, avoiding black smoke, so that the last exhausted flue gas meets environmental protection requirements. The flue gas outlet is a shrinking structure facing the secondary combustion furnace, so that the backflow of the oxygen gas in the secondary combustion furnace to the sintered inner cavity can be effectively prevented from affecting the quality of the shell mold.

Preferably, the secondary combustion furnace 10 is in a high temperature and high oxygen environment, and preferably has an internal temperature of 1200 ° C or higher and an oxygen content of 25% or more. Further, a ceramic sponge screening program 13 is disposed in the secondary combustion furnace 10 at the junction with the exhaust flue 5 to adsorb the char powder that has not been burned, because the ceramic sponge screening program 13 is located in the secondary combustion. In the furnace 10, the adsorbed char powder can be later burned into a gas discharge in the high-temperature and high-oxygen environment of the secondary combustion furnace 10.

In the present creation, since the first intake pipe 6 introduces outside air into the sintering inner cavity 1, in order to avoid the adverse effect of the outdoor air cooling, it is preferable that the first intake pipe 6 is connected with a metal preheating pipe ( Not shown), the metal preheating line may be a metal coil, which may be disposed in the secondary combustion furnace 10 to make full use of the residual heat in the furnace. In addition, a temperature sensing module and an oxygen concentration monitoring module are preferably disposed in the sintering inner chamber 1 to instantly monitor the condition of the furnace and perform corresponding control in time.

On the other hand, the present invention also provides a method for performing shell mold sintering by using the above-mentioned shell mold sintering device, as shown in FIG. 7, comprising: step S1: placing the shell mold to be sintered downside down in a shell in the sintered inner cavity On the mold placing platform, closing the closing door; step S2: turning on the heating device, the air blowing device and the exhaust flue, so that there is sufficient oxygen content in the sintering inner cavity, heating up to the burning temperature of the shell mold wax, and maintaining the sintering The temperature in the cavity until the residual wax in the shell mold is completely burned out; Since the carbon can be relatively fully burned when the oxygen content is 16.5%, it is preferred to control the air blowing device and the exhaust flue to make the oxygen content of the sintering cavity 16-20%; the burning of the shell mold wax The temperature is preferably from 600 ° C to 800 ° C, and the maintenance time of the temperature in the sintering furnace is maintained within 3 min.

Step S3: The nozzle is turned on to make the sintered inner cavity a low-oxygen or oxygen-free environment, and the temperature is raised to the sintering temperature of the shell mold and the temperature in the sintered inner cavity is maintained as the sintering temperature of the shell mold until the shell mold is sintered.

In this step, after the nozzle is opened, the nozzle sprays a flammable gas or liquid, and consumes oxygen in the sintered inner cavity by combustion, thereby achieving the purpose of rapidly reducing the oxygen content in the sintered inner cavity to realize a low-oxygen or anaerobic environment; The temperature at which the temperature is raised to the shell mold is achieved by the electric heating tube of the electric furnace itself. Compared with the prior application, the creation does not close the air blowing device and the exhaust flue (only the opening and closing sizes of the air blowing device and the exhaust flue need to be properly adjusted according to the high temperature and low oxygen environment required in the sintering stage), thereby A circulating gas flow is still formed in the sintered inner cavity, which can agitate the air in the furnace and maintain a high heating efficiency.

In this step, low oxygen means that the oxygen content of the sintered inner cavity is 5% or less. The sintering temperature of the shell mold can be 1150~1400 °C, and the maintenance time of the temperature in the sintering furnace can be 10~30 min.

Due to the circulating airflow in the sintered inner cavity of the present invention, an air flow is also formed in the pouring cup, so the present invention can completely burn the wax in a short time (within 3 minutes), and can make the sintered inner cavity in 1 minute. The oxygen content is reduced from 16 to 20% to less than 5%, and the shell mold can be sintered in a short period of time (10 to 30 minutes). For a typical shell mold, the prior art typically requires more than 45 minutes to complete the entire sintering process, and there are many defects as mentioned in the prior application and background of the present application; this creation can be completed in 20 minutes. And to ensure the quality of the shell mold, improve the quality of the casting.

The inventor further discovered in the research process that since the sintering process is divided into a wax burning stage and a sintering stage, the wax burning stage maintains low temperature and high oxygen, and the sintering stage maintains high temperature and low oxygen, and the two stages are accurate and fast. Switching ensures the quality of the final shell mold, so the timing of the switch is very important. In this regard, the inventors have found that, in step 2, when it is detected that the oxygen content in the sintered inner cavity does not decrease within a certain period of time (for example, within 3 to 5 seconds), it is indicated that the residual wax in the shell mold has burned. After completion, the oxygen in the sintered inner cavity is no longer consumed, and the process proceeds to step 3 to start the sintering phase. The switching is accurate and there is no misjudgment. The above description is a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. These improvements and retouchings are also It should be considered as the scope of protection of this creation.

1‧‧‧Sintered cavity

2‧‧‧Shell placement platform

3‧‧‧Closed door

4‧‧‧Smoke gas export

5‧‧‧Exhaust flue

6‧‧‧First intake pipe

61‧‧‧First nozzle

7‧‧‧Second intake manifold

71‧‧‧second nozzle

9‧‧‧Land sand collection tank

Claims (10)

A shell mold sintering device comprises a sintering inner cavity, a shell mold placing platform and a heating device are arranged in the sintering inner cavity, one end of the sintering inner cavity is provided with a closing door, and the other end of the sintering inner cavity is provided with a smoke a gas outlet, the flue gas outlet is connected to the exhaust flue, wherein the shell mold sintering device is an electric heating furnace, and the upper surface of the shell mold placing platform is provided with a plurality of rows of grooves, and the groove along the groove Extending the length direction of the sintering cavity, the width of the groove being smaller than the diameter of the pouring cup of the shell mold to be sintered; the sintering inner cavity is disposed at an inner side of the flue gas outlet and is placed on the platform with the shell mold a corresponding position is provided with a first intake pipe for supplying air, the first intake pipe is connected with an air blowing device, and the first intake pipe is provided with a first nozzle oriented toward the groove, A second nozzle for providing a flammable gas or liquid is further disposed in the sintering cavity; the height of the flue gas outlet is higher than the height of the shell mold placement platform. The shell mold sintering apparatus according to claim 1, wherein the sintered inner chamber is provided with an inner side of the flue gas outlet at a position corresponding to the shell mold placement platform for providing flammability. a second intake pipe of gas or liquid, the second nozzle being located on the second intake pipe and oriented toward the groove. The shell mold sintering apparatus according to claim 1, wherein a middle portion of at least one side wall of the groove is uniformly provided with a plurality of wind deflectors, and the length of each wind shield is along the sintering inner cavity from inside to The outer direction becomes longer in turn. The shell mold sintering apparatus according to claim 3, wherein the end of the wind deflector is an arc-shaped air guiding portion. The shell mold sintering apparatus of claim 4, wherein the sintering is performed along the sintering The cavity is inclined rearward from the inside to the outside in the direction of the windshield, and the angle of inclination is 1~10°. The shell mold sintering apparatus according to claim 1, wherein the sintering inner chamber is provided with an inner side of one end of the closing door, and a sand collecting collecting groove is disposed at a position corresponding to the shell mold placing platform. The falling sand collecting groove extends in the width direction of the sintering inner cavity. The shell mold sintering apparatus according to any one of claims 1 to 6, wherein a secondary combustion furnace is disposed between the flue gas outlet and the exhaust flue, and the secondary combustion furnace is provided with useful And a fourth nozzle for supplying air and a fourth nozzle for supplying a combustible gas or liquid, the flue gas outlet being a contraction structure toward the secondary combustion furnace. The shell mold sintering apparatus according to claim 7, wherein the temperature in the secondary combustion furnace is 1200 ° C or higher, and the oxygen content of the secondary combustion furnace is 25% or more. The shell mold sintering apparatus according to claim 7, wherein a ceramic sponge type screening program is disposed in the secondary combustion furnace at a junction with the exhaust flue. The shell mold sintering apparatus according to claim 7, wherein the first intake pipe is connected to a metal preheating pipe, and the metal preheating pipe is disposed in the secondary combustion furnace.