High-temperature suspension roasting atmosphere furnace device

Abstract

The invention discloses a high-temperature suspension roasting atmosphere furnace device, and belongs to the field of material engineering. A shell of a suspension roasting atmosphere furnace of the device is arranged on a furnace body in a sleeving manner; the heat preservation layer is arranged on the furnace body in a surrounding mode and arranged in the shell, and a closed first annular cavity is formed between the inner wall of the heat preservation layer and the outer wall of the furnace body. An inflation pipe is arranged at the lower end of the first annular cavity, an air outlet pipe is arranged at the upper end of the first annular cavity, and the cavity is filled with first gas; the plurality of first heating elements are arranged around the furnace body; the gas preheater is sleeved on the reaction gas input pipe; the output end of the reaction gas input pipe is communicated with the input end of the furnace body; one end of the material particle input pipe is communicated with the quantitative feeder, and the other end of the material particle input pipe is communicated with the reaction gas input pipe between the gas preheater and the input end of the furnace body; the input end of the output pipe is communicated with the output end of the furnace body; and the cooler is sleeved on the output pipe. Under the high-temperature working condition, temperature control is more accurate, materials are heated more evenly, and the heat insulation performance is improved.

Description

Technical Field

[0001] This application relates to the field of materials engineering technology, and in particular to a high-temperature suspension roasting atmosphere furnace device. Background Art

[0002] The suspension technology is a highly innovative thermal processing method in current industrial production. The core of this technology lies in using air flow or other power methods to keep the materials in a suspended state, increasing the contact area between the material particles and the heat medium, thus significantly improving the heat transfer and mass transfer efficiency. Compared with traditional thermal processing methods, the suspension technology can complete the thermal processing process in a shorter time, bringing higher efficiency and benefits to industrial production. As the key equipment to realize the suspension technology, the suspension calciner usually consists of multiple parts such as a furnace body, a combustion system, a feeding system, a discharging system, and a control system. Its working principle is to send the material particles into the furnace body through the feeding system, and under the action of air flow or other power, the material particles are in a suspended state. The high-temperature heat medium generated by the combustion system conducts sufficient heat exchange with the suspended material particles, enabling the material particles to complete the calcination process in a short time.

[0003] Although the suspension calciner used in the existing suspension roasting technology can improve the heat transfer efficiency by suspending the material particles with air flow, there are still problems in high-temperature working conditions, such as inaccurate temperature control, large axial and circumferential temperature differences in the furnace, resulting in uneven heating of the materials, and over-burning or under-burning in some areas. In addition, there is also the problem of insufficient heat insulation performance and serious heat loss, resulting in high energy consumption. Summary of the Invention

[0004] The embodiments of this application provide a high-temperature suspension roasting atmosphere furnace device, which can solve the problems of uneven heating of materials caused by inaccurate temperature control of the existing suspension calciner and serious heat loss caused by insufficient heat insulation performance.

[0005] To achieve the above object, the technical solution of the embodiments of the present invention is as follows:

[0006] An embodiment of the present invention provides a high-temperature suspension roasting atmosphere furnace device, which includes a gas preheater, a reaction gas input pipe, a metering feeder, a material particle input pipe, a suspension roasting atmosphere furnace, an output pipe, and a cooler; the suspension roasting atmosphere furnace includes a furnace body, a housing, a heat insulation layer, and a first heating element; the housing is a columnar body with a hollow interior and first annular surfaces at both ends, and is sleeved on the furnace body; the heat insulation layer is arranged around the furnace body and is arranged inside the housing, and a closed first annular cavity is formed between the inner wall of the heat insulation layer and the outer wall of the furnace body; an inflation pipe is arranged at the lower end of the first annular cavity, and an exhaust pipe is arranged at the upper end, and the cavity is used to fill a first gas; the first heating element includes a plurality of them, and the plurality of first heating elements are arranged around the furnace body, and the length extension direction is parallel to the axial direction of the furnace body, and is used to heat the furnace body so that the temperature is stabilized at 1200°C to 1600°C; the gas preheater is sleeved on the reaction gas input pipe to preheat the reaction gas input from the reaction gas input pipe to 800°C to 1200°C; the output end of the reaction gas input pipe is communicated with the input end of the furnace body; one end of the material particle input pipe is communicated with the metering feeder, and the other end is communicated with the position of the reaction gas input pipe between the gas preheater and the input end of the furnace body; the input end of the output pipe is communicated with the output end of the furnace body; the cooler is sleeved on the output pipe.

[0007] In a possible implementation manner, each of the first heating elements includes 3 to 5 sections of first heating sub-elements arranged along the axial direction of the furnace body; the heat insulation layer includes 3 to 5 sections of heat insulation sub-layers arranged along the axial direction of the furnace body; the housing includes 3 to 5 sub-housings arranged along the axial direction of the furnace body; the number of sections of the heat insulation sub-layer and the sub-housing is the same as the number of sections of the first heating sub-element; the adjacent two sections of the heat insulation sub-layers are fixedly connected; both ends of the heat insulation sub-layer extend inward to form extension rings; both ends of the first heating sub-element are fixedly arranged on the extension rings at corresponding positions.

[0008] In a possible implementation manner, along the direction from the side wall of the housing to the side wall of the furnace body, the heat insulation sub-layer is sequentially arranged as an outer layer, an intermediate layer, and an inner layer; the outer layer is a circular cylinder, and is embedded in the inner wall of the housing with a calcium carbonate plate, and the thickness is 20 mm to 40 mm; the intermediate layer is embedded around the outer layer, and multiple layers of nano-porous heat insulation felts are laid and the extension rings are arranged, and the thickness is 30 mm to 50 mm; the inner layer is laid on the inner surface of the intermediate layer, and is formed by vibration casting with a light refractory material, and the thickness is 50 mm to 100 mm; the closed first annular cavity is formed between the inner wall and the outer wall of the furnace body; a plurality of anchor bolts are evenly distributed on the outer layer, and both ends anchor the outer layer and the housing respectively; the adjacent two sections of the intermediate layer and the adjacent two sections of the inner layer are fixedly connected.

[0009] In a possible implementation, a first extension column is further included above the intermediate layer; a second extension column is provided at a position corresponding to the first extension column on the inner layer; the air outlet pipe penetrates through the first extension column and the second extension column to communicate the first annular cavity with the outside.

[0010] In a possible implementation, the gas preheater includes a sleeve, an isolation cylinder, and a second heating element; the sleeve is a columnar body with a hollow interior and second annular surfaces at both ends, and is sleeved on the reaction gas input pipe so that a closed second annular cavity is formed between the outer wall of the sleeve and the outer wall of the reaction gas input pipe; the isolation cylinder is sleeved on the reaction gas input pipe and is clamped in the sleeve to divide the second annular cavity into a first sub-annular cavity and a second sub-annular cavity; the first sub-annular cavity is close to the reaction gas input pipe and is filled with a second gas; the second heating elements are uniformly distributed in the second sub-annular cavity.

[0011] In a possible implementation, the gas preheater further includes a partition ring; there are a plurality of partition rings, and the plurality of partition rings are clamped in the second sub-annular cavity to axially divide the second sub-annular cavity into a plurality of independent sub-cavities; the second heating elements in each sub-cavity are independently temperature-controlled.

[0012] In a possible implementation, the reaction gas input pipe includes a reduced-diameter section; the reduced-diameter section includes a first reduced-diameter sub-section, a second reduced-diameter sub-section, and a third reduced-diameter sub-section arranged in sequence; along the flow direction of the reaction gas, the diameter gradually decreases from the first end to the second end of the first reduced-diameter sub-section; the diameter of the second reduced-diameter sub-section remains unchanged and is the same as the diameter of the second end of the first reduced-diameter sub-section; the diameter gradually increases from the first end to the second end of the third reduced-diameter sub-section; the other end of the material particle input pipe is communicated with a position between the second end of the third reduced-diameter sub-section and the input end of the furnace body.

[0013] In a possible implementation, the cooler includes a liquid cooling sleeve and heat dissipation fins; the liquid cooling sleeve is sleeved on the output pipe; the heat dissipation fins are spirally wound around the liquid cooling sleeve.

[0014] In a possible implementation, an explosion-proof pressure relief valve is provided at the top of the first annular cavity.

[0015] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0016] The high-temperature suspension roasting atmosphere furnace device provided by the embodiment of the present invention is provided with a gas preheater, a reaction gas input pipe, a metering feeder, a material particle input pipe, a suspension roasting atmosphere furnace, an output pipe and a cooler. Among them, the suspension roasting atmosphere furnace includes a furnace body, a shell, a heat preservation layer and a first heating element. The shell is a cylinder with a hollow interior and first annular surfaces at both ends, and is sleeved on the furnace body. The heat preservation layer is arranged around the furnace body and inside the shell, and a closed first annular cavity is formed between the inner wall of the heat preservation layer and the outer wall of the furnace body. An inflation pipe is arranged at the lower end of the first annular cavity, and an exhaust pipe is arranged at the upper end. The first gas is filled in the cavity. The first heating element includes a plurality of elements, and the plurality of first heating elements are arranged around the furnace body, and the length extension direction is parallel to the axial direction of the furnace body, and is used to heat the furnace body so that the temperature is stabilized at 1200 °C to 1600 °C. The output end of the reaction gas input pipe is communicated with the input end of the furnace body. One end of the material particle input pipe is communicated with the metering feeder, and the other end is communicated with the position between the gas preheater and the input end of the furnace body of the reaction gas input pipe. The input end of the output pipe is communicated with the output end of the furnace body. The cooler is sleeved on the output pipe. Through the close cooperation and optimized design among the components, the overall coordinated operation of the device is realized. At the same time, the first gas is filled in the first annular cavity, so that the temperature control of the high-temperature suspension roasting atmosphere furnace device is more accurate under high-temperature working conditions, the axial and circumferential temperature differences in the furnace become smaller, the temperature fluctuation is small, the heat distribution is uniformized, the material is heated more uniformly, the material has good dispersibility, and the phenomenon of overburning or underburning in some areas of the material is prevented. In addition, the setting of the heat preservation layer and the first annular cavity also improves the heat insulation performance of the high-temperature suspension roasting atmosphere furnace device, with less heat loss, high thermal efficiency, reduced energy consumption, significantly shortened roasting time, and excellent safety performance, providing a reliable safety guarantee for the roasting process. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments of the present invention. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic cross-sectional structure diagram of the high-temperature suspension roasting atmosphere furnace device provided by the embodiment of the present application;

[0019] Figure 2 It is a schematic structure diagram of the high-temperature suspension roasting atmosphere furnace device provided by the embodiment of the present application;

[0020] Figure 3 It is a schematic cross-sectional view of a part of the structure of the suspension roasting atmosphere furnace provided by the embodiment of the present application.

[0021] Icons: 1 - Gas preheater; 11 - Sleeve; 12 - Isolation cylinder; 13 - Second heating element; 14 - Partition ring; 2 - Reaction gas input pipe; 21 - Reducing section; 211 - First reducing sub - section; 212 - Second reducing sub - section; 213 - Third reducing sub - section; 3 - Quantitative feeder; 4 - Material particle input pipe; 5 - Suspended roasting atmosphere furnace; 51 - Furnace body; 52 - Shell; 53 - Thermal insulation layer; 531 - Outer layer; 532 - Intermediate layer; 532a - First extension column; 533 - Inner layer; 533a - Second extension column; 54 - First heating element; 541 - First heating sub - element; 55 - First annular cavity; 56 - Gas filling pipe; 57 - Outlet pipe; 58 - Thermocouple; 6 - Output pipe; 7 - Cooler; 71 - Liquid cooling sleeve; 72 - Heat sink. Detailed implementation mode

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. The terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0024] Please refer to Figures 1 to 3 As shown, the embodiments of the present invention provide a high - temperature suspended roasting atmosphere furnace device, including a gas preheater 1, a reaction gas input pipe 2, a quantitative feeder 3, a material particle input pipe 4, a suspended roasting atmosphere furnace 5, an output pipe 6, and a cooler 7.

[0025] The suspended roasting atmosphere furnace 5 includes a furnace body 51, a shell 52, a thermal insulation layer 53, and a first heating element 54.

[0026] The furnace body 51 is a vertical corundum tube with an inner diameter of 50 mm to 300 mm and a wall thickness of 10 mm to 30 mm.

[0027] The shell 52 is a cylinder with a hollow interior and two ends being first annular surfaces, and is sleeved on the furnace body 51. That is, the furnace body 51 is clamped in the inner hole of the first annular surface. The shell 52 is made of metal, such as made of heat-resistant stainless steel.

[0028] The heat insulation layer 53 is disposed around the furnace body 51 and is arranged inside the shell 52, and a closed first annular cavity 55 is formed between the inner wall of the heat insulation layer 53 and the outer wall of the furnace body 51. An inflation pipe 56 is provided at the lower end of the first annular cavity 55, and an exhaust pipe 57 is provided at the upper end, and the cavity is used to fill with a first gas.

[0029] In practice, a first gas such as an inert gas is filled into the first annular cavity 55 through an air pump, the flow rate of the first gas introduced is 5 L / min to 20 L / min, and the pressure is 0.1 MPa to 0.3 MPa, so that the first gas filled in the first annular cavity 55 forms a dynamic heat insulation barrier.

[0030] It is possible to block the inflation pipe 56 and the exhaust pipe 57 after the first annular cavity 55 is filled with the first gas. It is also possible to dynamically and continuously fill the first gas during the heating process of the furnace body 51. During the normal operation stage, the flow rate of the first gas is automatically adjusted according to the furnace temperature (5 L / min to 20 L / min); when the furnace temperature reaches the set value and the fluctuation ≤ 10%, it is switched to the pulse intake mode (intake for 2 min / intermittent for 1 min); during the emergency cooling stage, the gas flow rate is increased to 30 L / min to 50 L / min, and it is switched to rapid heat dissipation with cold gas.

[0031] The first heating element 54 can be a carbon silicon rod.

[0032] An explosion-proof pressure relief valve is provided at the top of the first annular cavity 55 to ensure the safety of the entire device.

[0033] There are multiple first heating elements 54. The multiple first heating elements 54 are disposed around the furnace body 51, and the length extension direction is parallel to the axial direction of the furnace body 51, and are used to heat the furnace body 51 to make the temperature stable at 1200 °C to 1600 °C.

[0034] The suspended roasting atmosphere furnace 5 further includes a plurality of thermocouples 58. The plurality of thermocouples 58 are evenly distributed on the shell 52, and the measuring ends extend into the first annular cavity 55.

[0035] The gas preheater 1 is sleeved on the reaction gas input pipe 2 to preheat the reaction gas input from the reaction gas input pipe 2 to 800 °C to 1200 °C.

[0036] The output end of the reaction gas input pipe 2 is communicated with the input end of the furnace body 51. The reaction gas input pipe 2 is in an L shape, which can facilitate the installation of the gas preheater 1 and the connection with the metering feeder 3 more conveniently.

[0037] One end of the material particle input pipe 4 is communicated with the metering feeder 3, and the other end is communicated with the position of the reaction gas input pipe 2 between the gas preheater 1 and the input end of the furnace body 51.

[0038] Among them, the metering feeder 3 includes a screw feeding mechanism, a weighing sensor and a pneumatic seal valve. In practice, the feeding accuracy of the material particles is low, and it is easy to be blocked or agglomerated, which affects the gas-solid mixing uniformity. The feeding amount of the metering feeder 3 adjusts the rotation speed of the screw feeding mechanism through a frequency conversion motor, so that the feeding speed is 0.1 kg / h to 10 kg / h, and the accuracy error ≤ 1%. The output end of the screw feeding mechanism is communicated with the first end of the material particle input pipe 4, so that the material particles enter the suspension roasting furnace 5 through the material particle input pipe 4 and the reaction gas input pipe 2.

[0039] The input end of the output pipe 6 is communicated with the output end of the furnace body 51. The cooler 7 is sleeved on the output pipe 6.

[0040] The output pipe 6 includes a first to a fourth sub-pipe connected in sequence. The input end of the first sub-pipe is communicated with the output end of the furnace body 51. The second sub-pipe is perpendicular to the first sub-pipe. The third sub-pipe is perpendicular to the second sub-pipe. The fourth sub-pipe is perpendicular to the third sub-pipe. The cooler 7 is sleeved on the output pipe 6. The shape of the output pipe 6 provided by the embodiment of the present invention is convenient for connecting with the furnace body 51 and at the same time convenient for arranging the cooler 7, which helps to cool the material.

[0041] Among them, the components are hermetically connected.

[0042] The high-temperature suspension roasting atmosphere furnace device provided by the embodiment of the present invention includes a gas preheater 1, a reaction gas input pipe 2, a metering feeder 3, a material particle input pipe 4, a suspension roasting atmosphere furnace 5, an output pipe 6, and a cooler 7. Among them, the suspension roasting atmosphere furnace 5 includes a furnace body 51, a housing 52, a heat insulation layer 53, and a first heating element 54. The housing 52 is a columnar body with a hollow interior and first annular surfaces at both ends, and is sleeved on the furnace body 51. The heat insulation layer 53 is disposed around the furnace body 51 and within the housing 52, and a closed first annular cavity 55 is formed between the inner wall of the heat insulation layer 53 and the outer wall of the furnace body 51. An inflation pipe 56 is provided at the lower end of the first annular cavity 55, and an exhaust pipe 57 is provided at the upper end. The cavity is used to fill a first gas. The first heating element 54 includes a plurality of elements, and the plurality of first heating elements 54 are disposed around the furnace body 51, and the length extension direction is parallel to the axial direction of the furnace body 51, and is used to heat the furnace body 51 to make the temperature stable at 1200°C to 1600°C. The output end of the reaction gas input pipe 2 is communicated with the input end of the furnace body 51. One end of the material particle input pipe 4 is communicated with the metering feeder 3, and the other end is communicated with the position of the reaction gas input pipe 2 between the gas preheater 1 and the input end of the furnace body 51. The input end of the output pipe 6 is communicated with the output end of the furnace body 51. The cooler 7 is sleeved on the output pipe 6. Through the close cooperation and optimized design among the components, the overall coordinated operation of the device is realized. At the same time, the first gas is filled into the first annular cavity 55, so that the temperature control of the high-temperature suspension roasting atmosphere furnace device is more accurate under high-temperature working conditions, the axial and circumferential temperature differences in the furnace become smaller, the temperature fluctuation is small, the heat distribution is uniformized, the material is heated more uniformly, the material has good dispersibility, and the phenomenon of over-burning or under-burning in some areas of the material is prevented. In addition, the setting of the heat insulation layer 53 and the first annular cavity 55 also improves the heat insulation performance of the high-temperature suspension roasting atmosphere furnace device, reduces heat loss, has high thermal efficiency, reduces energy consumption, significantly shortens the roasting time, and has excellent safety performance, providing reliable safety protection for the roasting process.

[0043] Each first heating element 54 includes 3 to 5 first heating sub-elements 541 arranged along the axial direction of the furnace body 51. The heat insulation layer 53 includes 3 to 5 heat insulation sub-layers arranged along the axial direction of the furnace body 51. The housing 52 includes 3 to 5 sub-housings arranged along the axial direction of the furnace body 51, and the number of segments of the heat insulation sub-layers and the sub-housings is the same as that of the first heating sub-elements 541. The heat insulation sub-layers between adjacent two segments are fixedly connected. As Figure 1 Fig. shows a schematic structural diagram including 4 first heating sub-elements 541 arranged along the axial direction of the furnace body 51.

[0044] Both ends of the heat insulation sub-layer extend inward to form extension rings. The extension rings can axially divide the first annular cavity 55 into at least two sub-air cavities.

[0045] Both ends of the first heating sub-element 541 are fixedly arranged on the extension rings at corresponding positions. The arrangement of the extension rings facilitates the stable fixation of the first heating sub-unit.

[0046] In the embodiments of the present application, the housing 52, the first heating element 54, and the heat preservation layer 53 are arranged in multiple sections, which facilitates their manufacture and installation. At the same time, it is convenient for segmented temperature measurement. According to the temperature change of each section, the power of the first heating sub-unit at the corresponding position is controlled, realizing segmented precise temperature control. By configuring the first heating sub-elements 541 with multiple independent temperature controls, and filling the first annular cavity 55 with the first gas to form a heat insulation barrier, the temperature in the furnace can be stabilized at 1200°C to 1600°C, and the temperature difference ≤ ±15°C.

[0047] For example, the first heating sub-element 541 is a silicon carbide rod. The power of each section is 10kw to 30kw, and 6 to 18 silicon carbide rods are evenly distributed circumferentially around the furnace body 51 (the arc interval between each is 20°C to 60°C). In the embodiments of the present application, 18 silicon carbide rods are evenly distributed circumferentially around the furnace body 51 to optimize the spacing through thermal field simulation.

[0048] As Figure 1 and Figure 3 As shown, the inner walls at the same plane in the middle of each sub-section of the furnace body 51 are symmetrically embedded with thermocouples 58 at 120°, directly contacting the material gas flow. The thermocouples 58 are electrically connected to the control system. According to the feedback data of the thermocouples 58, the control system can adjust the power of the first heating sub-elements 541 in each section in real time through the PID algorithm. When the temperature of a certain section exceeds the limit, the power of the first heating sub-element 541 in this section is automatically reduced and the power of the first heating sub-elements 541 in the adjacent areas is synchronously increased to form heat compensation. The power of the first heating sub-elements 541 in each section is independently adjusted, and the power of the inlet section is higher than that of the outlet section to compensate for the heat loss during the heating process of the material.

[0049] The gas flow rate input through the reaction gas input pipe 2 is dynamically correlated with the heating power. When the flow rate is high, the power is automatically increased to prevent temperature fluctuations. The temperature difference between sections ≤ 10°C, the temperature uniformity difference of the axial temperature in the furnace ≤ 15°C, and the circumferential deviation ≤ ±10°C. Ensure that the gas preheating temperature is stabilized at 800°C to 1200°C.

[0050] An infrared thermal imager is installed on the top of the furnace body 51 to scan the temperature distribution on the inner surface of the furnace body 51 and automatically correct the cold and hot spots, introducing thermal imaging feedback to ensure the temperature uniformity in the furnace.

[0051] Furthermore, an electromagnetic induction coil (frequency 1kHz to 10kHz) is wound outside the first heating sub-element 541 (such as a silicon carbide rod), and the eddy current effect is used to assist heating, increasing the surface heating rate of the furnace body 51 by 20% to 30%.

[0052] As Figure 1 andFigure 3 As shown, along the direction from the side wall of the housing 52 to the side wall of the furnace body 51, the heat-insulating sub-layers are sequentially arranged as an outer layer 531, an intermediate layer 532, and an inner layer 533. The layers are overlapped with staggered joints, and high-temperature adhesive is applied at the joints. When installing the nano felt, a pre-compression amount of 5% - 10% is applied to avoid voids caused by expansion at high temperatures.

[0053] The outer layer 531 is a circular ring column, and a calcium carbonate board is embedded in the inner wall of the housing 52, with a thickness of 20 mm - 40 mm.

[0054] The intermediate layer 532 is embedded around the outer layer 531, and multiple layers of nano-porous heat-insulating felt are laid and an extension ring is provided, with a thickness of 30 mm - 50 mm.

[0055] The inner layer 533 is laid on the inner surface of the intermediate layer 532 and is formed by vibration casting of lightweight refractory material, with a thickness of 50 mm - 100 mm. A closed first annular cavity 55 is formed between the inner wall of the inner layer 533 and the outer wall of the furnace body 51.

[0056] A plurality of anchor bolts are evenly distributed on the outer layer 531, and the two ends are respectively anchored to the outer layer 531 and the housing 52. The intermediate layer 532 between adjacent two sections and the inner layer 533 between adjacent two sections are fixedly connected.

[0057] The calcium carbonate board can serve as a rigid support for the entire heat-insulating layer 53 and is fixed to the housing 52 through stainless steel anchor bolts (the distance between each anchor bolt is 200 nm - 300 nm).

[0058] Continue to refer to Figure 1 and Figure 3 As shown, the upper part of the intermediate layer 532 further includes a first extension column 532a. A second extension column 533a is provided at the position corresponding to the first extension column 532a on the inner layer 533. The gas outlet pipe 57 penetrates through the first extension column 532a and the second extension column 533a to connect the first annular cavity 55 and the outside. The materials of the inner layer 533 and the intermediate layer 532 are easy to process, so as to facilitate the setting of installation holes for installing the gas outlet pipe 57.

[0059] Refer to Figure 1 and Figure 2 As shown, the gas preheater 1 includes a sleeve 11, an isolation cylinder 12, and a second heating element 13. The sleeve 11 is a hollow column with two ends being second annular surfaces, and is sleeved on the reaction gas input pipe 2 so that a closed second annular cavity is formed between the outer wall of the sleeve 11 and the outer wall of the reaction gas input pipe 2. The isolation cylinder 12 is sleeved on the reaction gas input pipe 2 and is clamped on the sleeve 11 to divide the second annular cavity into a first sub-annular cavity and a second sub-annular cavity. The first sub-annular cavity is close to the reaction gas input pipe 2 and is filled with a second gas. The second gas can be an inert gas or a protective gas. The second heating elements 13 are evenly distributed in the second sub-annular cavity.

[0060] The gas preheater 1 of the embodiment of the present application adopts a coaxial double-layer temperature-controlled sleeve 11 structure, which can preheat the gas input into the reaction gas input pipe 2 to 800°C - 1200°C, and uses a thermocouple 58 to measure the gas temperature. The second heating element 13 and the thermocouple 58 are both electrically connected to the control mechanism, and the control mechanism dynamically adjusts the heating power of the second heating element 13 and the gas flow rate of the gas input into the reaction gas input pipe 2 through the PID algorithm. Through the double heating of the input gas by the gas preheater 1 and the suspension roasting atmosphere furnace 5, faster and more stable heating and dynamic temperature adjustment are achieved.

[0061] Furthermore, the gas preheater 1 further includes a dividing ring 14. There are multiple dividing rings 14, and the multiple dividing rings 14 are clamped in the second sub-ring cavity to axially divide the second sub-ring cavity into multiple independent sub-cavities. The second heating element 13 in each sub-cavity is independently temperature-controlled.

[0062] For example, the dividing ring 14 includes 3 - 5, and the 3 - 5 dividing rings 14 are clamped in the second sub-ring cavity to axially divide the second sub-ring cavity into 4 - 6 independent sub-cavities. The second heating element 13 in each sub-cavity is independently temperature-controlled, with each power being 2kw - 8kw, and the temperature difference between adjacent two sub-cavities ≤ ±10°C. The power of each second heating unit is adjusted in real time through the PID algorithm.

[0063] K-type thermocouples are respectively arranged at the positions of the reaction gas input pipe 2 corresponding to each sub-cavity to feedback the temperature to the control mechanism in real time. The control mechanism adjusts the power of the second heating element 13 in each sub-cavity through the PID algorithm in real time to ensure that the preheating temperature of the gas input into the reaction gas input pipe 2 is 800°C - 1200°C; the gas flow rate (5 - 30m 3 / h) is dynamically correlated with the heating power of the second heating element 13. When the flow rate is high, the power is automatically increased to ensure that the gas preheating temperature is stably maintained at 800°C - 1200°C, and the temperature difference between sections ≤ 10°C, preventing temperature fluctuations.

[0064] As Figure 1 shown, the reaction gas input pipe 2 includes a reduced-diameter section 21. The reduced-diameter section 21 includes a first reduced-diameter sub-section 211, a second reduced-diameter sub-section 212, and a third reduced-diameter sub-section 213 arranged in sequence. Along the direction of the reaction gas flow, the diameter of the first end to the second end of the first reduced-diameter sub-section 211 gradually decreases.

[0065] The diameter of the second reduced-diameter sub-section 212 remains unchanged and is the same as the diameter of the second end of the first reduced-diameter sub-section 211, and it is different from the diameter of other parts of the reaction gas input pipe 2, so it is also a reduced-diameter. The diameter of the first end to the second end of the third reduced-diameter sub-section 213 gradually increases. The other end of the material particle input pipe 4 communicates with the position between the second end of the third reduced-diameter sub-section 213 and the input end of the furnace body 51.

[0066] The gas flow velocity above the second end of the third reduced-diameter sub-section 213 increases, and the negative pressure generated by the material particle input pipe 4 is used to suck the material particles into the reaction gas input pipe 2 for mixing with the reaction gas, resulting in more uniform mixing.

[0067] The diameter of the second reduced-diameter sub-section 212 matches the particle size of the material particles. Specifically, when the reaction gas flow velocity in the second reduced-diameter sub-section 212 ≥ 20 m / s and the particle size of the material particles ≤ 50 μm, the diameter of the second reduced-diameter sub-section 212 is designed to be 10 mm - 20 mm; when the particle size of the material particles is 50 μm - 100 μm, the diameter of the second reduced-diameter sub-section 212 is designed to be 20 mm - 30 mm, so as to ensure good gas-solid mixing effect for different particle sizes of material particles and enable the gas-solid mixed material to enter the suspension roasting atmosphere furnace 5 evenly.

[0068] As Figure 1 shown, the cooler 7 includes a liquid cooling sleeve 71 and heat dissipation fins 72. The liquid cooling sleeve 71 is sleeved on the output pipe 6. The heat dissipation fins 72 are spirally wound around the liquid cooling sleeve 71. The flow rate of the circulating cooling water in the liquid cooling sleeve 71 is 1 m 3 / h - 5 m 3 / h, the inlet water temperature ≤ 25 °C, the outlet water temperature ≤ 60 °C, the residence time of the material in the position of the output pipe 6 where the cooler 7 is located is 10 s - 30 s, and the material output temperature ≤ 100 °C.

[0069] The heat dissipation fins 72 are made of aluminum and are fixedly connected to the liquid cooling sleeve 71 by welding. The setting of the heat dissipation fins 72 can increase the heat transfer of the conveying pipe and improve the cooling effect.

[0070] In practice, the emergency temperature reduction response is slow, posing a safety hazard. The suspension roasting atmosphere furnace 5 provided by the embodiment of the present invention is provided with an emergency power-off mechanism, which automatically cuts off the power when the temperature of the furnace body 51 exceeds the limit.

[0071] The entire device is fully automatically and closed-loop controlled by an integrated control mechanism. The control mechanism includes a PLC controller, a touch screen, and a data storage module, communicates with each component sensor and actuator, realizes the full-automatic closed-loop control of temperature, pressure, flow rate, and feed rate, and supports multi-terminal process curve programming and fault alarm functions. The outlet temperature of the gas preheater 1 and the inlet temperature of the suspension roasting atmosphere furnace 5 are linked by the control mechanism. If the inlet temperature of the suspension roasting atmosphere furnace 5 is lower than the set value, the power of the second heating element 13 in the terminal sub-cavity of the gas preheater 1 is automatically increased to reduce the temperature difference impact. The control mechanism is built-in with a thermodynamic model, and automatically optimizes the power distribution of each heating section according to historical data.

[0072] The operator can perform multi-terminal process curve programming through the touch screen to set parameters such as temperature, pressure, flow rate, and feed rate. The system has a fault alarm function and will send an alarm in a timely manner when the operating parameters are abnormal. The overall device is modularly designed, facilitating the replacement of single components. When the equipment fails or needs to be upgraded, the corresponding module can be quickly replaced to reduce downtime. At the same time, the modular design also supports capacity expansion. The number of modules can be increased or adjusted according to production requirements to flexibly improve production capacity. In addition, high-quality sealing materials and sealing processes are used for sealing between each connecting pipe and component, and the sealed parts are regularly inspected and maintained to ensure no gas leakage and heat dissipation, guaranteeing the stable, safe, and efficient operation of the system.

[0073] This device is applicable to the calcination of powders such as lithium-ion battery cathode materials, silicon nitride powders, or carbide hard alloys. The product purity is ≥99.9%, and the deviation of the particle size distribution D50 is ≤±5%. It has the advantages of high thermal efficiency, safety and reliability, and modular expansion.

[0074] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0075] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. A high-temperature suspension roasting atmosphere furnace device, characterized in that, It includes a gas preheater, a reaction gas inlet pipe, a metering feeder, a material particle inlet pipe, a suspension roasting atmosphere furnace, an outlet pipe, and a cooler; The suspension roasting atmosphere furnace includes a furnace body, a shell, a heat-insulating layer, and a first heating element; The shell is a cylinder with a hollow interior and first annular surfaces at both ends, and is sleeved on the furnace body; The heat-insulating layer is disposed around the furnace body and within the shell, and a closed first annular cavity is formed between the inner wall of the heat-insulating layer and the outer wall of the furnace body; An air inlet pipe is provided at the lower end of the first annular cavity, and an air outlet pipe is provided at the upper end, and the cavity is used to fill a first gas; There are multiple first heating elements, and the multiple first heating elements are disposed around the furnace body, and the length extension direction is parallel to the axial direction of the furnace body, and is used to heat the furnace body to keep the temperature stable at 1200°C to 1600°C; The gas preheater is sleeved on the reaction gas inlet pipe to preheat the reaction gas input from the reaction gas inlet pipe to 800°C to 1200°C; The output end of the reaction gas inlet pipe is communicated with the input end of the furnace body; One end of the material particle inlet pipe is communicated with the metering feeder, and the other end is communicated with the reaction gas inlet pipe at a position between the gas preheater and the input end of the furnace body; The input end of the outlet pipe is communicated with the output end of the furnace body; The cooler is sleeved on the outlet pipe.

2. The high-temperature suspension roasting atmosphere furnace device according to claim 1, characterized in that, Each of the first heating elements includes 3 to 5 first heating sub-elements arranged along the axial direction of the furnace body; The heat-insulating layer includes 3 to 5 heat-insulating sub-layers arranged along the axial direction of the furnace body; The shell includes 3 to 5 sub-shells arranged along the axial direction of the furnace body; The number of segments of the heat-insulating sub-layer and the sub-shell is the same as the number of segments of the first heating sub-element; The adjacent heat-insulating sub-layers are fixedly connected between two adjacent segments; Both ends of the heat-insulating sub-layer extend inward to form extension rings; Both ends of the first heating sub-element are fixedly arranged on the extension rings at corresponding positions.

3. The high-temperature suspension roasting atmosphere furnace device according to claim 2, wherein, Along the direction from the side wall of the shell to the side wall of the furnace body, the heat-insulating sub-layer is sequentially arranged as an outer layer, a middle layer, and an inner layer; The outer layer is a circular cylinder, and a calcium carbonate plate is embedded in the inner wall of the shell, with a thickness of 20 mm to 40 mm; The middle layer is embedded around the outer layer, and multiple layers of nano-porous heat-insulating felts are laid and the extension rings are provided, with a thickness of 30 mm to 50 mm; The inner layer is laid on the inner surface of the middle layer, and is formed by vibration casting of a lightweight refractory material, with a thickness of 50 mm to 100 mm; a closed first annular cavity is formed between the inner wall and the outer wall of the furnace body; Multiple anchor bolts are evenly distributed on the outer layer, and both ends anchor the outer layer and the shell respectively; The adjacent middle layers between two adjacent segments and the adjacent inner layers between two adjacent segments are fixedly connected.

4. The high-temperature suspension roasting atmosphere furnace device according to claim 3, characterized in that, The upper part of the middle layer further includes a first extension column; A second extension column is provided at a position corresponding to the first extension column on the inner layer; The air outlet pipe penetrates through the first extension column and the second extension column to communicate the first annular cavity and the outside.

5. The high-temperature suspension roasting atmosphere furnace device according to claim 1, characterized in that The gas preheater includes a sleeve, an isolation cylinder, and a second heating element; The sleeve is a hollow cylinder with second annular surfaces at both ends, and is sleeved on the reaction gas input pipe so that a closed second annular cavity is formed between the outer wall of the sleeve and the outer wall of the reaction gas input pipe; The isolation cylinder is sleeved on the reaction gas input pipe and clamped on the sleeve to divide the second annular cavity into a first sub-annular cavity and a second sub-annular cavity; The first sub-annular cavity is close to the reaction gas input pipe and is filled with a second gas; The second heating elements are evenly distributed in the second sub-annular cavity.

6. The high-temperature suspension roasting atmosphere furnace device according to claim 5, wherein, The gas preheater further includes a separating ring; There are multiple separating rings, and the multiple separating rings are clamped in the second sub-annular cavity to axially divide the second sub-annular cavity into multiple independent sub-cavities; The second heating elements in each sub-cavity are independently temperature-controlled.

7. The high-temperature suspension roasting atmosphere furnace device according to claim 1, characterized in that, The reaction gas input pipe includes a reduced-diameter section; The reduced-diameter section includes a first reduced-diameter sub-section, a second reduced-diameter sub-section, and a third reduced-diameter sub-section arranged in sequence; Along the flowing direction of the reaction gas, the diameter gradually decreases from the first end to the second end of the first reduced-diameter sub-section; The diameter of the second reduced-diameter sub-section remains unchanged and is the same as the diameter of the second end of the first reduced-diameter sub-section; The diameter gradually increases from the first end to the second end of the third reduced-diameter sub-section; The other end of the material particle input pipe communicates with a position between the second end of the third reduced-diameter sub-section and the furnace body input end.

8. The high-temperature suspension roasting atmosphere furnace device according to claim 1, characterized in that, The cooler includes a liquid cooling sleeve and heat dissipation fins; The liquid cooling sleeve is sleeved on the output pipe; The heat dissipation fins are spirally wound around the liquid cooling sleeve.

9. The high-temperature suspension roasting atmosphere furnace device according to claim 1, characterized in that, An explosion-proof pressure relief valve is provided at the top of the first annular cavity.

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