CN203790936U - Multifunctional microwave heating vacuum oven - Google Patents

Abstract

The utility model discloses a multifunctional microwave heating vacuum furnace, which is composed of a metal shell, an intermediate insulation layer and an inner tank; the inner tank is a vacuum cavity, and a heating tube is arranged on the upper part of the heating tube, and a thermocouple and a heating tube are inserted respectively. The ventilation pipe and the thermocouple are connected with the programmable logic controller PLC, and the ventilation pipe is respectively connected with the tail gas treatment device and the vacuum device through the three-way pipe, and the vacuum device is connected with the PLC; the heating pipe is set on the precision electronic balance, and the electronic balance and The PLC is connected; the inner tank has a small hole connected to the protective gas blowing device; the microwave generating device is installed in the middle insulation layer and connected to the PLC; the PLC is connected to the computer. The utility model is used to realize the automatic control and online monitoring of parameters such as temperature, vacuum degree, quality, heating time and tail gas recovery in the process of material synthesis and cracking in a microwave field under vacuum conditions. It is an environmentally friendly and efficient microwave oven that can be used for scientific research and production.

Description

Multifunctional Microwave Heating Vacuum Furnace

technical field

The utility model relates to a multi-functional microwave heating vacuum furnace, which is used for realizing automatic control and online monitoring of parameters such as temperature, vacuum degree, quality, heating time and tail gas recovery in the process of material synthesis and cracking in a microwave field under vacuum conditions.

Background technique

As an unconventional heating method, microwave heating has the advantages of fast heating speed, uniform heating, high heating efficiency, selective heating, and real-time control because it is "body heating". It is widely used in food, medicine, chemical industry, metallurgy and fields such as mining.

In the microwave field, physical and chemical changes occur between the heated substances. Under the action of an alternating magnetic field with a frequency of billions of Hz, the polar molecules rotate rapidly, and the electrical energy is quickly converted into heat energy in the form of dielectric loss. When the temperature rises, the microwave chemical reaction is accelerated in the reaction time and reaction time. The sequence, product composition, etc. are different from chemical reactions under conventional heating.

The interaction between microwave and matter has also become the focus of research in recent years. In the microwave field, as the temperature increases, the electromagnetic parameters of the substance change, which in turn promotes the interaction between the microwave and the substance.

At present, the mechanism of microwave heating has not been able to be further developed, largely due to the lag in the research and development of microwave equipment, especially the microwave heating equipment that involves process control and online monitoring has certain defects in the design and manufacturing process; and the use process The environmental pollution problems caused by it are also not considered.

Therefore, it is necessary to develop a multifunctional microwave heating furnace. While using various controllable parameters to study the reaction mechanism of microwave heating materials, it is necessary to broaden the application field of microwave heating and gradually realize its industrial application.

Utility model content

The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a multifunctional microwave heating vacuum furnace, which can be used to realize automatic control and temperature, On-line monitoring of vacuum degree, quality, heating time and other parameters and tail gas recovery.

In order to solve the above problems, the utility model adopts the following technical solutions:

The utility model provides a multifunctional microwave heating vacuum furnace. The multifunctional microwave heating vacuum furnace is composed of a metal shell, an intermediate insulation layer and an inner container; the inner container is a cylindrical structure plus a sealing flange and a lower sealing The fully enclosed system composed of flanges is fixed on the supporting frame of the metal outer body. The interior of the inner tank is a vacuum chamber, and a heating tube is arranged in the vacuum chamber. The heating tube is placed on the claw-shaped bracket; Shield the microwave heat insulation board, a precision electronic balance is installed on the lower sealing flange under the microwave shielding heat insulation board, the upper part of the heating tube is an insulation cover, and there are two small holes on the insulation cover, respectively inserting the thermocouple and the ventilation pipe , where one end of the thermocouple is inserted into the material in the heating tube, the other end passes through the sealing hole on the side wall of the inner tank and is connected to the programmable logic controller PLC, one end of the ventilation tube is placed above the material in the heating tube, and the other end passes through the inner tank Another sealing hole on the side wall is connected to the tee pipe, and the other two ends of the tee pipe are respectively connected to the exhaust gas treatment device and the vacuuming device, and a valve is provided on the pipeline of the vacuuming device, and the vacuuming device is connected to the PLC; The type bracket is set on the precision electronic balance through the small hole on the shielding microwave heat insulation board, and the precision electronic balance is connected to the PLC; there is a small hole connected to the protective gas blowing device on the lower side wall of the inner tank; the microwave generating device is installed in the middle insulation Layer, and connected to PLC to control microwave power; PLC is connected to computer and power supply at the same time; all openings of multi-functional microwave heating vacuum furnace are equipped with microwave suppression shielding tubes to prevent microwave leakage.

In the utility model, both the metal shell and the inner tank are made of Cr-containing stainless steel; the middle insulation layer is made of heat-resistant aluminum, magnesium and silicate heat-preservation materials or heat-insulation materials.

In the utility model, all vent pipes in the multifunctional microwave heating vacuum furnace are made of ceramic or quartz material.

In the utility model, the heating tube is a quartz tube or a corundum tube.

In the utility model, the protective gas generated by the protective gas blowing device is Ar or N ₂ .

In the utility model, the vacuum device can control the vacuum degree in the vacuum chamber, and the maximum vacuum degree is -40Pa.

In the utility model, the thermocouple adopts an armored thermocouple or an infrared sensor with different temperature ranges, and its measurement accuracy is ±5°C.

In the utility model, the claw-shaped bracket is welded by stainless steel, and has a smooth surface.

In the utility model, the minimum weighing unit of the precision electronic balance is 0.01g, and its mass measurement range is 0-5Kg.

In the utility model, the gas recovered by the tail gas treatment device is one or more of SO ₂ , SO ₃ , CO ₂ , Cl ₂ , NH ₃ , HCl or HF.

The utility model is equipped with a microwave suppression shielding tube to prevent microwave leakage at the openings on the top and bottom of the microwave oven, and the unit leakage test conforms to the national safety standard. The vacuum chamber is completely sealed, and the outlet pipe is connected to the exhaust gas treatment device, which is safe and environmentally friendly. When the sample in the heating tube is heated by microwaves, the programmable controller PLC can realize the functions of vacuum degree control, power adjustment, temperature setting and heat preservation, and it is connected with the computer to automatically collect time, temperature, quality and vacuum degree change data. and displayed on the computer screen.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Example 1

Referring to Fig. 1, the utility model provides a kind of multifunctional microwave heating vacuum furnace, and described multifunctional microwave heating vacuum furnace is made of metal shell 18, middle insulating layer 13 and inner container 3; The upper sealing flange 20 and the lower sealing flange 8 constitute a fully enclosed system, and are fixed on the supporting frame 2 of the metal outer body. The interior of the inner tank is a vacuum chamber, and a quartz tube 16 is arranged in the vacuum chamber, and the quartz tube 16 Placed on the stainless steel claw-shaped bracket 14; the upper part of the quartz tube 16 is an insulating cover 19, and there are two holes on the insulating cover 19, respectively inserting the thermocouple 17 and the vent pipe connected to the exhaust gas treatment device 1, wherein one end of the thermocouple 17 is inserted into the quartz The material in the tube is 15 miles, and the other end passes through the sealing hole on the side wall of the vacuum chamber to connect with the programmable logic controller (PLC) 10; and one end of the ventilation pipe is placed above the material in the quartz tube, and the other end passes through the side wall of the vacuum chamber The other sealing hole of the valve is connected with a three-way pipe, which is connected with the tail gas treatment device 1 and the vacuum device 9 respectively, and a valve 6 is set on the pipeline of the vacuum device 9, and the vacuum device is connected with the PLC; The hole on the heat shield 12 is placed on the precision electronic balance 11 below the microwave oven, and the electronic balance 11 is connected to the PLC; The microwave generating device 4 is installed in the middle insulating layer between the inner tank and the metal shell, and is connected with the PLC to control the microwave power. The PLC is connected to the computer 5 again, and is connected to the power supply at the same time. All openings of the multifunctional microwave heating vacuum furnace are provided with microwave suppression shielding tubes to prevent microwave leakage. The thermocouple 7 adopts armored thermocouples or infrared sensors of different temperature sections.

The quartz tube 16 can also be replaced by a corundum tube.

Claw support 14 is welded by stainless steel, and surface is smooth.

Both the metal shell and the inner tank are made of Cr-containing stainless steel, and the middle insulation layer 13 is made of high-temperature-resistant aluminum and magnesium heat-insulating materials.

The frequency of the multifunctional microwave heating vacuum furnace of the utility model is 2.45GHz, the power is adjustable, and the maximum power is 32KW. The utility model uses the sealed chamber of the inner layer of the microwave oven as the main body of the reactor, and a microwave suppression shielding tube and a sealing ring are respectively provided at the opening to prevent microwave leakage. The controller (PLC) is connected to 10, and the temperature, quality and vacuum degree of the material are measured online, and the automatic control of temperature and power is realized at the same time. The heating temperature is up to 1200°C.

When using the utility model, the upper flange 20 of the furnace body is opened, the material is put into the quartz tube 16, the thermocouple 17 is inserted, and the upper flange 20 is tightened. Start the vacuum device 9 according to the experimental requirements to ensure that the air in the vacuum chamber is exhausted, then close the vacuum valve 6, and pass the protective gas for 5 minutes with a gas flow rate of 2 L/min. Set the heating temperature, heating power, and heating time, then turn on the power, start the start button of the programmable logic controller (PLC) 10 and the computer 5, and start the exhaust gas treatment device 1 at the same time. When the material reaction reaches the set temperature, the programmable logic controller (PLC) 10 realizes automatic temperature control and heat preservation. When the reaction is complete, turn off the power. Changes in heating time, temperature, mass and vacuum degree during the whole process can be detected and recorded on the computer 5 .

The minimum weighing unit of the electronic balance 11 of the utility model is 0.01g, and the temperature measurement accuracy of the thermocouple 17 is ±5°C.

Example 2

The composition of a certain sulfur concentrate in the present embodiment is shown in Table 1.

Table 1 Chemical composition of a sulfur concentrate / (%, mass fraction)

Element S TF SiO ₂ CaO P ₂ O ₅ MgO Al ₂ O ₃ other content 16.25 60.50 4.97 1.32 0.15 1.14 0.15 15.52

The utility model adopts a multifunctional microwave heating vacuum furnace to oxidize and roast a certain sulfur concentrate. Add Ca(OH) ₂ solution in the tail gas treatment device 1, and open the tail gas treatment device 1 at the same time; put 1Kg of material into the long quartz tube container 16, set the temperature at 1000°C and power 10KW, and carry out microwave heating; reach the set Keep warm for 10 minutes at high temperature, turn off the power; cool with the furnace. The contents of TFe and S in the reaction product were detected to be 65.5% and 0.45%, respectively, and the produced SO ₂ reacted with Ca(OH) ₂ to form CaSO ₃ ·0.5H ₂ O, and a white powder was obtained after drying. The experiment took a total of 20 minutes, the reaction time is short, the desulfurization efficiency is high, the temperature, quality and time changes during the reaction process can be monitored and recorded by the programmable logic controller (PLC) 10 connected to the computer; at the same time, the release of harmful gas SO ₂ is avoided .

Example 3

The utility model uses a multifunctional microwave heating vacuum furnace to fix fluorine and roast a certain rare earth concentrate (grade: 59.21%). Add the Ca(OH) ₂ solution into the tail gas treatment device 1, and turn on the tail gas treatment device 1 at the same time; mix the ingredients according to MgO:ReO=15:1, mix well, set the temperature at 700°C, microwave power 1KW, and carry out microwave heating; When setting the temperature, keep warm for 5 minutes, turn off the power; cool down with the furnace. The contents of ReO and F in the reactants and reaction products were detected, and the rare earth decomposition rate was calculated to be 92.5%, and the fluorine fixation rate was 94.3%. The generated CO ₂ reacts with Ca(OH) ₂ to generate CaCO ₃ , and the solid CaCO ₃ powder is obtained after drying. The experiment took a total of 15 minutes, the reaction time was short, and the fluorine fixation efficiency was high. The changes in temperature, quality, and time during the reaction process can be monitored and recorded by a programmable logic controller (PLC) 10 connected to a computer; at the same time, the CO ₂ emitted during the reaction process Gas products are recovered to prevent environmental pollution.

Example 4

The utility model adopts a multifunctional microwave heating vacuum furnace to reduce and roast certain hematite. Add Ca(OH) ₂ solution to tail gas treatment device 1, and open tail gas treatment device 1 at the same time; add activated carbon to hematite (grade: 30.21%) according to the carbon content of 1%, mix well, press into tablets, and put in quartz Insert the thermocouple 17 into the tube container 16, and tighten the upper flange 20. Start the vacuum device 9 according to the experimental requirements to ensure that the air in the vacuum chamber is discharged, then close the vacuum valve 6, and pass the protective gas for 5 minutes, and the gas flow rate is 2L/min. The temperature is set at 650°C, the microwave power is 1KW, and the start button of the programmable logic controller (PLC) 10 and the computer 5 are activated. After microwave heating reaches the set temperature, keep warm for 5 min, turn off the power; cool with the furnace. It is detected that hematite in the reaction product is transformed into magnetite, and the magnetite can be separated by weak magnetic separation, and the iron grade is above 62%. The generated CO ₂ reacts with Ca(OH) ₂ to generate CaCO ₃ , and the solid CaCO ₃ powder is obtained after drying. The experiment took a total of 13 minutes, the reaction time was short, and the magnetization efficiency was high. The changes in temperature, mass, and time during the reaction process can be monitored and recorded by a programmable logic controller (PLC) 10 connected to a computer; at the same time, the CO generated during the reaction process was recovered. ₂ gas.

Finally, it should be noted that obviously, the above-mentioned embodiments are only examples for clearly illustrating the utility model, rather than limiting the implementation manner. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the protection scope of the present utility model.

Claims (10)

1. a multifunction microwave heating, vacuum stove, is characterized in that: described multifunction microwave heating, vacuum stove consists of metal shell, middle heat-insulation layer and inner bag, inner bag is for to add by tubular construction the totally-enclosed system that sealing flange and lower seal ring flange form, and is fixed on the support frame of metal ectosome, and inner bag inside is vacuum chamber, is provided with heating tube in vacuum chamber, and heating tube is placed on pawl type support, pawl type support below is provided with shield microwaves thermal insulation board, on the lower seal ring flange of shield microwaves thermal insulation board below, a precise electronic balance is installed, heating tube top is insulation cover, on insulation cover, offer two apertures, insert respectively thermocouple and breather pipe, wherein insert in the material in heating tube thermocouple one end, the other end is connected with programmable logic controller (PLC) PLC through the closed hole of side wall of inner, breather pipe one end is placed in the material top in heating tube, the other end is through another closed hole connecting tee pipe of side wall of inner, the other two ends of three-way pipe are connected with vacuum extractor with exhaust gas processing device respectively, on the pipeline of vacuum extractor, be provided with valve, and vacuum extractor is connected with PLC, pawl type support is arranged on precise electronic balance by the aperture on shield microwaves thermal insulation board, and precise electronic balance is connected with PLC, inner bag lower end sidewall offers the aperture that protective gas device is blown in a connection, heat-insulation layer, control microwave power connected in PLC in the middle of microwave generating apparatus is installed on, PLC is connected with computer again, connects power supply simultaneously, the all tappings of multifunction microwave heating, vacuum stove are equipped with and prevent that the microwave of microwave leakage from suppressing shielded-plate tube.

2. multifunction microwave heating, vacuum stove as claimed in claim 1, is characterized in that: metal shell and inner bag all adopt the stainless steel containing Cr; Middle heat-insulation layer adopts resistant to elevated temperatures aluminium matter, magnesia and phyllosilicate insulation material or heat-insulating material.

3. multifunction microwave heating, vacuum stove as claimed in claim 2, is characterized in that: in multifunction microwave heating, vacuum stove, all breather pipes all adopt pottery or quartzy material.

4. multifunction microwave heating, vacuum stove as claimed in claim 3, is characterized in that: described heating tube is quartz ampoule or alundum tube.

5. multifunction microwave heating, vacuum stove as claimed in claim 4, is characterized in that: the protective gas that blows the generation of protective gas device is Ar or N ₂.

6. multifunction microwave heating, vacuum stove as claimed in claim 5, is characterized in that: vacuum extractor can control in vacuum chamber vacuum, maximum vacuum is :-40Pa.

7. multifunction microwave heating, vacuum stove as claimed in claim 6, is characterized in that: thermocouple adopts the infrared sensor of armoured thermocouple or different temperatures section, and its certainty of measurement is ± 5 ℃.

8. multifunction microwave heating, vacuum stove as claimed in claim 7, is characterized in that: described pawl type support is welded by stainless steel, and smooth surface.

9. multifunction microwave heating, vacuum stove as claimed in claim 8, is characterized in that: the minimum weighing of described precise electronic balance unit is 0.01g, and its quality determination scope is 0 ~ 5Kg.

10. multifunction microwave heating, vacuum stove as claimed in claim 9, is characterized in that: the gas that exhaust gas processing device reclaims is SO ₂, SO ₃, CO ₂, Cl ₂, NH ₃, one or more in HCl or HF.