A high-efficiency energy-saving rotary furnace

Abstract

The present invention provides a high-efficiency energy-saving rotary furnace, comprising an upper material bin, a furnace body, a furnace tube, a lower material bin, a first gas-filling part, a second gas-filling part, an inner tube and a heat exchange tube, the direction in which the first gas-filling part introduces gas into the furnace tube is consistent with the direction in which the upper material bin introduces powdered materials into the furnace tube; the directions in which the first gas-filling part introduces gas are opposite to the second gas-filling part, the flow rate of the gas in the first gas-filling part is greater than the flow rate of the gas in the second gas-filling part, and the gas in the first gas-filling part and the gas in the second gas-filling part form a static area in the furnace tube; the inner tube is arranged between the static area and the head of the furnace tube, and a filter is arranged at the tail of the inner tube; the heat exchange tube passes through the head of the furnace tube and is connected to the head of the inner tube, and the heat exchange tube passes through the first gas-filling part; the heating wire is arranged longitudinally inside the furnace body. The high-efficiency energy-saving rotary furnace of the present invention has the advantages of low energy consumption and high yield.

Description

Technical Field

[0001] The invention relates to the field of thermal equipment, in particular to a rotary furnace. Background Art

[0002] A rotary kiln is a thermal equipment for calcining, roasting or drying granular and powdered materials.

[0003] See also Figure 1 , Figure 1 1 is a schematic diagram of the structure of an existing common rotary furnace, which includes an upper material bin 100, a furnace tube 101, a hydrogenation unit 102, a lower material bin 103, a recovery bin 104 and a furnace body 106, wherein the furnace tube 101 passes through the furnace body 106, and a heating wire ( Figure 1 (not shown), the upper bin 100 and the lower bin 103 are respectively arranged at both ends of the furnace tube 101, the hydrogenation section 102 and the lower bin 103 are arranged on the same side of the furnace tube 101, the recovery bin 104 and the upper bin 100 are arranged on the other side of the furnace tube 101, and the furnace tube 101 is inclined, and the end of the furnace tube 101 close to the upper bin 100 is higher than the end close to the lower bin 103. Figure 1 From the direction shown, the upper bin 100 adds the powdered material to be reduced (such as tungsten trioxide) from the right end of the furnace tube 101, and the hydrogenation part 102 introduces hydrogen from the left end of the furnace tube 101. The hydrogen is heated to about 500°C by the hydrogen heater 105. The hydrogen and the powdered material undergo a reduction reaction in the furnace tube 101. The furnace tube 101 is heated to provide the temperature required for the reaction. During operation, the furnace tube 101 rotates along its axial direction, and the powdered material slides into the lower bin 103 along the furnace tube 101 after being reduced. During the operation of the rotary kiln, since the direction in which hydrogen enters the furnace tube 101 is opposite to the direction in which the powdered material enters the furnace tube 101, part of the powdered material moves to one end of the upper bin 100 under the action of the hydrogen gas flow, and then the "refluxed" powdered material is recovered through the recovery bin 104.

[0004] However, this rotary kiln has the following defects:

[0005] 1. High energy consumption. The hydrogen introduced from the hydrogenation unit 102 needs to be heated by the hydrogen heater 105 to reach the process temperature. The cold hydrogen is preheated to 500 to 600 ° C before entering the furnace tube, and then heated to the reduction process temperature by the heating wire in the furnace body. A large amount of hydrogen carries a large amount of heat energy and is discharged out of the furnace after the reaction, resulting in extremely high reduction energy consumption. This rotary furnace has a hydrogen flow rate of 400m 3 / h, and its total power consumption is about 180kw / h.

[0006] 2. The heating wire in the rotary kiln adopts the traditional "horizontal" arrangement method. The heating wire will be worn out during operation and needs to be replaced after a period of time. This reduction furnace needs to be shut down when replacing the heating wire. After the furnace body is cooled, the furnace cover is opened and the heating wire is replaced in the furnace body. The replacement is very troublesome and requires shutdown, which affects production efficiency. A lot of energy is wasted during the shutdown process, further increasing energy consumption.

[0007] 3. The direct yield is low. The yield of the rotary kiln is generally around 80-90%. This is because the flow direction of hydrogen is opposite to that of the powdered material. The large flow of hydrogen will bring the flying powder out of the furnace tube, resulting in a low direct yield.

[0008] 4. The exhausted hydrogen carries a large amount of powder, which needs to be recovered by a multi-stage dust removal device, which increases the burden on the equipment and makes the operation complicated. Summary of the invention

[0009] The purpose of the invention is to provide a rotary kiln with low energy consumption, high yield and easy replacement of heating wires.

[0010] In order to achieve the above-mentioned purpose, the present invention provides a high-efficiency energy-saving rotary furnace, including an upper bin, a furnace body, a furnace tube and a lower bin, the furnace tube passes through the furnace body, a heating wire for heating the furnace tube is arranged inside the furnace body, the upper bin is arranged at the head of the furnace tube, and the lower bin is arranged at the tail of the furnace tube, and also includes: a first gas-filling part, the first gas-filling part is arranged at the head of the furnace tube, and the direction in which the first gas-filling part introduces gas into the furnace tube is consistent with the direction in which the upper bin introduces gas into the furnace tube; a second gas-filling part, the second gas-filling part is arranged at the tail of the furnace tube, and the direction in which the first gas-filling part introduces gas into the furnace tube is consistent with the direction in which the second gas-filling part introduces gas into the furnace tube The direction is opposite to that of the first gas filling part, the flow rate of the gas in the first gas filling part is greater than the flow rate of the gas in the second gas filling part, and the gas introduced into the furnace tube by the first gas filling part and the gas introduced into the furnace tube by the second gas filling part form a static area in the furnace tube; the inner tube is arranged in the furnace tube, the inner tube is arranged between the static area and the head of the furnace tube, and a filter is arranged at the tail of the inner tube; the heat exchange tube, the heat exchange tube passes through the head of the furnace tube and is connected with the head of the inner tube, the heat exchange tube passes through the first gas filling part, and the gas in the first gas filling part enters the furnace tube after heat exchange with the heat exchange tube; wherein, multiple temperature zones are arranged inside the furnace body; the heating wire is longitudinally arranged inside the furnace body.

[0011] It can be seen from the above technical scheme that since the gas introduced into the first gasifying part and the second gasifying part is in opposite directions, a static area is formed in the furnace tube, so that the floating metal powder is deposited in the static area and slides along the inner wall of the furnace tube. Since a filter screen is arranged at the tail of the inner tube, the metal powder is prevented from being taken out of the furnace tube, which greatly improves the output. The direct yield of the rotary kiln product of the present invention can be increased by more than 10%; the gas in the first gasifying part enters the furnace tube after heat exchange with the heat exchange tube, which increases the gas temperature of the first gasifying part, and no additional gas heater is required. At the same time, the heat taken out by the gas discharged from the furnace tube is reduced, which greatly reduces the energy consumption. Under the same conditions, the energy consumption of the rotary kiln using the present invention is only 79kw / h, which is less than half of the energy consumption of the existing rotary kiln; since only a very small amount of metal powder is taken out of the furnace tube, there is no need to set up a dust removal device for recovery, which simplifies the equipment; the heating wire is arranged longitudinally inside the furnace body and can be directly taken out from the top of the furnace body, which is very convenient to replace and does not require shutdown operation, thereby improving production efficiency.

[0012] A further solution is that a mounting hole is opened on the top of the furnace body, an insulating magnetic gasket is arranged on the top of the mounting hole, a fixing hole and a first threading hole and a second threading hole are arranged on the insulating magnetic gasket, the two ends of the heating wire are respectively connected to the positive electrode terminal rod and the negative electrode terminal rod, the upper end of the heating wire is connected to a fixing rod, the fixing rod passes through the fixing hole and is connected to the fixing nut outside the insulating magnetic gasket, the positive electrode terminal rod passes through the first threading hole and is connected to the first terminal nut outside the insulating magnetic gasket, and the negative electrode terminal rod passes through the second threading hole and is connected to the second terminal nut outside the insulating magnetic gasket.

[0013] It can be seen that by providing the insulating magnetic gasket, not only the heat loss is reduced, and the energy consumption is further reduced, but also when replacing the heating wire, only the insulating magnetic gasket needs to be taken out and the heating wire can be taken out together, which is simple to operate.

[0014] A further solution is that the insulating magnetic gasket is cylindrical, and an annular step portion is provided at the bottom of the insulating magnetic gasket, the top surface of the annular step portion abuts against the top surface of the furnace body, an external thread is provided on the side surface of the annular step portion, and an internal thread is provided on the upper end peripheral wall of the mounting hole, and the external thread on the side surface cooperates with the internal thread of the mounting hole.

[0015] It can be seen that by providing the annular step portion, not only the installation stability of the insulating magnetic gasket is improved, but also the installation is facilitated.

[0016] A further solution is that the fixing hole is arranged on the axis of the insulating magnetic gasket, and the first threading hole and the second threading hole are symmetrically arranged on both sides of the second fixing hole.

[0017] It can be seen that symmetrically arranging the first fixing hole and the third fixing hole on both sides of the second fixing hole can improve the stability of the heating wire installed on the insulating magnetic gasket.

[0018] A further solution is that the multi-level temperate zones include one temperature zone, two temperature zones, three temperature zones, four temperature zones, five temperature zones and six temperature zones in sequence.

[0019] A further solution is that a heat insulating portion is provided between adjacent temperature zones, and a gap is left between the heat insulating portion and the outer wall of the furnace tube.

[0020] It can be seen that by providing the heat insulation part, the heat conduction between adjacent temperature zones is reduced, which is beneficial to maintaining the temperature stability in each temperature zone.

[0021] A further solution is that the static area is located at the junction of the four-zone temperature zone and the five-zone temperature zone.

[0022] A further solution is that the first gas adding part is a shell-and-tube heat exchanger. The shell-and-tube heat exchanger can improve the heat exchange efficiency.

[0023] A further solution is that the flow rate of gas introduced into the first gasification section is 200-600m 3 / h, the flow rate of gas introduced into the second gasification part is 30-100m 3 / h.

[0024] A further solution is that the flow rate of the gas introduced into the first gas adding part is 0.1-0.5 m / s, and the flow rate of the gas introduced into the second gas adding part is 0.03-0.1 m / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an existing ordinary rotary kiln.

[0026] Figure 2 It is a schematic structural diagram of an embodiment of a high-efficiency energy-saving rotary kiln of the present invention.

[0027] Figure 3 yes Figure 2 A magnified view of the structure of part A.

[0028] Figure 4 yes Figure 2 Cross-sectional view along the BB direction.

[0029] Figure 5 yes Figure 4 A magnified view of the structure of part D.

[0030] Figure 6 It is a top view of the insulating magnetic gasket of the high-efficiency energy-saving rotary furnace embodiment of the present invention.

[0031] Figure 7 It is a front view of the insulating magnetic gasket of the high-efficiency energy-saving rotary furnace embodiment of the present invention.

[0032] Figure 8It is a top view of the furnace body of the high-efficiency energy-saving rotary furnace embodiment of the present invention.

[0033] Fig. 9 yes Figure 2 Cross-sectional view along CC direction.

[0034] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0035] See also Figure 2 , Figure 2 : is a structural schematic diagram of an embodiment of a high-efficiency energy-saving rotary kiln of the present invention. In this embodiment, the rotary kiln includes an upper bin 1, a furnace body 2, a furnace tube 3, a lower bin 4, a first gas-filling part 5, a second gas-filling part 6, an inner tube 7 and a heat exchange tube 8. This embodiment is specifically described by taking the rotary kiln reducing the powdered material WO3 as an example. The powdered material WO3 is placed in the upper bin 1, and the powdered material WO3 is added from the upper bin 1 to the furnace tube 3, and after reduction, it enters the lower bin 4 for collection. The upper bin 1 is arranged at the head of the furnace tube 3, and the lower bin 4 is arranged at the tail of the furnace tube 3. In the present invention, the end close to the feed is the head of the furnace tube 3, and the end close to the discharge is the tail of the furnace tube 3. The furnace tube 3 is inclined, the head of the furnace tube 3 is higher than the tail of the furnace tube 3, and the inclination angle of the furnace tube 3 is 2° to 5°. The furnace tube 3 rotates along its axial direction during operation, so that the powdered material WO3 slides from the head of the furnace body 2 to the tail of the furnace body 2.

[0036] The furnace tube 3 passes through the furnace body 2, and a heating wire for heating the furnace tube is arranged inside the furnace body 2. A premixing zone 30 is formed between the head of the furnace tube 3 and the furnace body 2, and a material discharge zone 31 is formed between the tail of the furnace tube 3 and the furnace body 2. A reduction zone 32 is formed between the premixing zone 30 and the material discharge zone 31. The hydrogen added to the furnace tube 3 by the first gas adding part 5 and the powdered material WO3 added to the furnace tube 3 by the upper material bin 1 are premixed in the premixing zone 30, and then enter the reduction zone 32 for reduction, and then enter the material discharge zone 31 to discharge from the material discharge bin 4.

[0037] The furnace body 2 includes a first temperature zone 21, a second temperature zone 22, a third temperature zone 23, a fourth temperature zone 24, a fifth temperature zone 25 and a sixth temperature zone 26 from the head to the tail, and the first temperature zone 21, the second temperature zone 22, the third temperature zone 23, the fourth temperature zone 24, the fifth temperature zone 25 and the sixth temperature zone 26 form a multi-level temperature zone. In this embodiment, the temperature of the first temperature zone 21 is 630°C, the temperature of the second temperature zone 22 is 650°C, the temperature of the third temperature zone 23 is 700°C, the temperature of the fourth temperature zone 24 is 750°C, the temperature of the fifth temperature zone 25 is 960°C, and the temperature of the sixth temperature zone 26 is 1000°C.

[0038] The inner tube 7 is arranged in the furnace tube 3 , and the inner tube 7 extends from the fourth temperature zone 24 to the premixing zone 30 .

[0039] The heat exchange tube 8 passes through the head of the furnace tube 3 and is connected to the head of the inner tube 7 . The heat exchange tube 7 passes through the first gas filling part 5 . The hydrogen introduced into the first gas filling part 5 exchanges heat with the heat exchange tube 8 and then enters the furnace tube 3 .

[0040] In this embodiment, the flow rate of hydrogen introduced into the first gas filling part 5 is 350m 3 / h, the gas flow rate is 0.3m / s, the initial temperature of the gas is 20°C, and the temperature of the heat exchanged gas through the heat exchange tube 8 can reach 400-500°C. The flow rate of hydrogen introduced into the second gasification part 6 is 60m 3 / h, the gas flow rate is 0.06m / s, and the initial temperature of the gas is 20°C. In other embodiments, the flow rate and flow rate of hydrogen introduced into the first gasification part 5 and the second gasification part 6 can also be adjusted. Generally, the flow rate of the gas introduced into the first gasification part is controlled to be 200-600m 3 / h, the gas flow rate is 0.1-0.5m / s; the gas flow rate of the second gas adding part is 30-100m 3 / h, the gas flow rate is 0.03-0.1m / s.

[0041] See also below Figure 2 and Figure 3 Describe the working principle of the rotary kiln of the present invention in detail, Figure 3 yes Figure 2 A magnified view of the structure of part A.

[0042] The loading bin 1 adds powdered material WO3 into the furnace tube 3, and the first gas adding part 5 adds hydrogen into the furnace tube 3. The metal powder WO3 and hydrogen are premixed in the premixing zone 30 and then enter the reduction zone 32. The furnace body 2 heats the furnace tube 3, and the temperature of the first temperature zone 21 is increased to 630°C, the temperature of the second temperature zone 22 is increased to 650°C, the temperature of the third temperature zone 23 is increased to 700°C, the temperature of the fourth temperature zone 24 is increased to 750°C, the temperature of the fifth temperature zone 25 is increased to 960°C, and the temperature of the sixth temperature zone 26 is increased to 1000°C. After the metal powder WO3 and hydrogen are fully reacted at different temperatures in multiple temperature zones in the reduction zone 32, a reduced product tungsten powder (the main component is WO2) is obtained. While hydrogen is introduced into the first gasification part 5, hydrogen is introduced into the second gasification part 6 from the tail end of the furnace tube 3. The hydrogen introduced into the second gasification part 6 first passes through the unloading area 31 to cool the reduced tungsten powder to prevent the tungsten powder from being oxidized at high temperature, and then enters the reduction area 32. Since the hydrogen introduced into the first gasification part 5 and the hydrogen introduced into the second gasification part 6 have opposite gas flow directions, a static area 34 is formed in the furnace tube 3. In this embodiment, the static area 34 is located at the junction of the fourth temperature zone 24 and the fifth temperature zone 25. The inner tube 7 is arranged between the static area 34 and the head of the furnace tube 3. The tail of the inner tube 7 is provided with a filter screen 70. The mixed gas of unreacted hydrogen and water vapor enters the inner tube 7 from the tail of the inner tube 7. The metal powder is blocked outside the inner tube 7 by the filter screen 70. Then the mixed gas enters the heat exchange tube 8 from the head of the inner tube 7. The mixed gas contains a large amount of heat. After heat exchange with the first gasification part 5 through the heat exchange tube 8, the hydrogen introduced into the first gasification part 5 can be heated to 400-500°C, so that the hydrogen introduced into the first gasification part 5 is converted into hot hydrogen. In order to improve the heat exchange efficiency, the first gasification part 5 can adopt a shell-and-tube heat exchanger, and its installation method can refer to the prior art, which will not be repeated here.

[0043] During the reduction process of metal powder in the high-efficiency energy-saving rotary kiln of the present invention, a static area is formed inside the furnace tube, so that the floating metal powder settles down and slides along the inner wall of the furnace tube. Since a filter screen is arranged at the tail of the inner tube, the metal powder is prevented from being taken out of the furnace tube, thereby greatly improving the output. The product yield of the rotary kiln using the present invention can reach more than 99%.

[0044] In order to improve the thermal insulation effect between adjacent temperature zones, the present invention is provided with a thermal insulation part 27 between the fourth temperature zone 24 and the fifth temperature zone 25. A gap is left between the thermal insulation part 27 and the outer wall of the furnace tube 3 to ensure that the furnace tube 3 can rotate freely. The thermal insulation part 27 limits the heat exchange between the fourth temperature zone 24 and the fifth temperature zone 25, which is beneficial to the temperature control. The present invention is provided with a thermal insulation part identical to the thermal insulation part 27 between the first temperature zone 21 and the second temperature zone 22, between the second temperature zone 22 and the third temperature zone 23, between the third temperature zone 23 and the fourth temperature zone 24, and between the fifth temperature zone 25 and the sixth temperature zone 26 to improve the thermal insulation effect between adjacent temperature zones.

[0045] See also Figure 4 , Figure 4 yes Figure 2 A cross-sectional view along the BB direction. In order to heat the furnace tube 3, a heating wire 9 is arranged inside the furnace body 2, and the heating wire 9 is longitudinally arranged inside the furnace body 2. A mounting hole 200 is opened on the top of the furnace body 2, and the heating wire 9 passes through the mounting hole 200 and is suspended inside the furnace body 2. The upper end of the heating wire 9 is connected to a fixing rod 10, and the two ends of the heating wire 9 are respectively connected to the positive electrode connecting rod 11 and the negative electrode connecting rod 12. See also Figure 5 , Figure 6 and Figure 7 , Figure 5 yes Figure 4 The structure of the D part is enlarged. Figure 6 is a top view of an insulating magnetic gasket of a rotary kiln embodiment of the present invention, Figure 7 It is a front view of the insulating magnetic gasket of the rotary kiln embodiment of the present invention. An insulating magnetic gasket 201 is arranged at the top of the mounting hole 200. In this embodiment, the insulating magnetic gasket 201 is cylindrical, and an annular step portion is arranged at the bottom of the insulating magnetic gasket 201. The top surface 202 of the annular step portion abuts against the top surface of the furnace body 2. The side surface 203 of the annular step portion is provided with an external thread. The upper end peripheral wall of the mounting hole 200 is provided with an internal thread. The external thread of the side surface 203 cooperates with the internal thread of the mounting hole 200 to detachably install the insulating magnetic gasket 201 in the mounting hole 200. Three through holes are arranged at intervals on the insulating magnetic gasket 201: a first threading hole 204, a fixing hole 205, and a second threading hole 206. In this embodiment, the fixing hole 205 is arranged on the axis of the insulating magnetic gasket 201, and the first threading hole 204 and the second threading hole 206 are symmetrically arranged on both sides of the fixing hole 205. The positive electrode terminal rod 11 passes through the first threading hole 204 and is connected to the first terminal nut 13 arranged outside the insulating magnetic gasket 201; the fixing rod 10 passes through the fixing hole 205 and is connected to the fixing nut 14 arranged outside the insulating magnetic gasket 201; the negative electrode terminal rod 12 passes through the second threading hole 206 and is connected to the second terminal nut 15 arranged outside the insulating magnetic gasket 201, and the positive electrode terminal rod 11 and the negative electrode terminal rod 12 are respectively electrically connected to the external circuit.

[0046] The heating wire of the high-efficiency energy-saving rotary kiln of the present invention is installed by the above-mentioned method. When the heating wire 9 needs to be replaced, the insulating magnetic gasket 201 only needs to be rotated down from the top mounting hole 200 of the furnace body 2 to take out the entire heating wire 9. Compared with the existing furnace body structure in which the heating wire is installed "horizontally", it is more convenient to replace. When replacing the heating wire, the furnace body structure in which the heating wire is installed "horizontally" needs to stop the furnace body first to wait for the furnace body to cool down, then open the furnace cover, and then take out the heating wire. The replacement cycle is long. By adopting the structure of the present invention, the heating wire can be replaced in a very short time without stopping the machine, which greatly improves the production efficiency.

[0047] See also Figure 8 , Figure 8 This is a top view of the furnace body of the energy-efficient rotary furnace of the present invention. Figure 8 The other repeated temperature zones of the furnace body are omitted, and only one temperature zone structure is retained. In this embodiment, two rows of heating wires are arranged in the furnace body 2, and the two rows of heating wires are arranged on both sides of the furnace tube 3 along the length extension direction of the furnace body 2. The top of the furnace body 2 is sequentially provided with a first insulating magnetic gasket 2011, a second insulating magnetic gasket 2012, a third insulating magnetic gasket 2013 and a fourth insulating magnetic gasket 2014, and the structures of the first insulating magnetic gasket 2011, the second insulating magnetic gasket 2012, the third insulating magnetic gasket 2013 and the fourth insulating magnetic gasket 2014 are the same as the structure of the insulating magnetic gasket 201. A first heating wire ( Figure 8 Not visible in, refer to Figure 5 A second heating wire ( Figure 8 Not visible in, refer to Figure 5 The furnace body 2 is provided with a third heating wire ( Figure 8 Not visible in, refer to Figure 5 A fourth heating wire ( Figure 8 Not visible in, refer to Figure 5The first positive electrode connecting rod 1101 of the first heating wire is electrically connected to the positive electrode of the external circuit, the first negative electrode connecting rod 1201 of the first heating wire is electrically connected to the second positive electrode connecting rod 1102 of the second heating wire, the second negative electrode connecting rod 1202 of the second heating wire is electrically connected to the third positive electrode connecting rod 1103 of the third heating wire, the third negative electrode connecting rod 1203 of the third connecting rod is electrically connected to the fourth positive electrode connecting rod 1104 of the fourth heating wire, and the fourth negative electrode connecting rod 1204 of the fourth heating wire is electrically connected to the negative electrode of the external circuit. The first heating wire, the second heating wire, the third heating wire and the fourth heating wire are connected in series through the above wiring method. When the external circuit is turned on, the first heating wire, the second heating wire, the third heating wire and the fourth heating wire are heated after passing the current, thereby heating the furnace tube 2.

[0048] See also Fig. 9 , Fig. 9 yes Figure 2 Sectional view in CC direction. See also Figure 2 The rotary kiln of the present invention is further provided with a heat insulation board 16 in the furnace tube 3. The heat insulation board 16 is coaxially arranged with the furnace tube 3. The cross section of the heat insulation board 16 is circular. The diameter of the heat insulation board 16 is smaller than the inner diameter of the furnace tube 3, and a gap is formed between the heat insulation board 16 and the furnace tube 3. The heat insulation board 16 is fixed at the junction of the unloading zone 31 and the reduction zone 32 by a support column 17. Preferably, the number of the support columns 14 is four, and the four support columns 14 are arranged between the heat insulation board 16 and the furnace tube 3 along the circumferential direction of the heat insulation board 16 at intervals.

[0049] The heat insulation plate 16 is provided to effectively block the heat in the reduction zone 32 from transferring to the feeding zone 31 , which not only reduces the heat loss in the reduction zone 32 , but also reduces the temperature in the feeding zone 31 , which is beneficial for cooling the reduction product through the feeding zone 31 .

[0050] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. For example, when the rotary kiln is used to dry materials, nitrogen is introduced into the furnace tube through the first aeration section and the second aeration section. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-efficiency energy-saving rotary furnace, comprising an upper bin, a furnace body, a furnace tube and a lower bin, wherein the furnace tube passes through the furnace body, a heating wire for heating the furnace tube is arranged inside the furnace body, the upper bin is arranged at the head of the furnace tube, and the lower bin is arranged at the tail of the furnace tube, characterized in that: Also includes: A first gas adding part, wherein the first gas adding part is arranged at the head of the furnace tube, and the direction in which the first gas adding part introduces gas into the furnace tube is consistent with the direction in which the upper bin introduces powdered material into the furnace tube; a second gas-filling part, wherein the second gas-filling part is arranged at the tail end of the furnace tube, the direction in which the first gas-filling part introduces gas into the furnace tube is opposite to the direction in which the second gas-filling part introduces gas into the furnace tube, the flow rate of the gas in the first gas-filling part is greater than the flow rate of the gas in the second gas-filling part, and the gas introduced into the furnace tube by the first gas-filling part and the gas introduced into the furnace tube by the second gas-filling part form a static area in the furnace tube; An inner tube, the inner tube is arranged in the furnace tube, the inner tube is arranged between the static area and the head of the furnace tube, and a filter screen is arranged at the tail of the inner tube; A heat exchange tube, the heat exchange tube passes through the head of the furnace tube and is connected to the head of the inner tube, the heat exchange tube passes through the first gas adding part, and the gas in the first gas adding part enters the furnace tube after heat exchange with the heat exchange tube; Wherein, multiple temperature zones are arranged inside the furnace body; The heating wire is longitudinally arranged inside the furnace body; A mounting hole is provided on the top of the furnace body, an insulating magnetic gasket is provided on the top of the mounting hole, a fixing hole and a first threading hole and a second threading hole are provided on the insulating magnetic gasket, two ends of the heating wire are respectively connected to the positive electrode connecting rod and the negative electrode connecting rod, the upper end of the heating wire is connected to a fixing rod, the fixing rod is connected to the fixing nut outside the insulating magnetic gasket after passing through the fixing hole, the positive electrode connecting rod is connected to the first connecting nut outside the insulating magnetic gasket after passing through the first threading hole, and the negative electrode connecting rod is connected to the second connecting nut outside the insulating magnetic gasket after passing through the second threading hole; The top of the furnace body is provided with a first insulating magnetic gasket, a second insulating magnetic gasket, a third insulating magnetic gasket and a fourth insulating magnetic gasket in sequence, and the structures of the first insulating magnetic gasket, the second insulating magnetic gasket, the third insulating magnetic gasket and the fourth insulating magnetic gasket are the same as the structure of the insulating magnetic gasket; A first heating wire is installed in the furnace body through the first insulating magnetic gasket, a second heating wire is installed in the furnace body through the second insulating magnetic gasket, a third heating wire is installed in the furnace body through the third insulating magnetic gasket, and a fourth heating wire is installed in the furnace body through the fourth insulating magnetic gasket; a first positive electrode connecting rod of the first heating wire is electrically connected to the positive electrode of the external circuit, a first negative electrode connecting rod of the first heating wire is electrically connected to the second positive electrode connecting rod of the second heating wire, a second negative electrode connecting rod of the second heating wire is electrically connected to the third positive electrode connecting rod of the third heating wire, a third negative electrode connecting rod of the third heating wire is electrically connected to the fourth positive electrode connecting rod of the fourth heating wire, and a fourth negative electrode connecting rod of the fourth heating wire is electrically connected to the negative electrode of the external circuit; the first heating wire, the second heating wire, the third heating wire and the fourth heating wire are connected in series through wiring; when the external circuit is turned on, the first heating wire, the second heating wire, the third heating wire and the fourth heating wire generate heat after passing current, thereby heating the furnace tube.

2. The rotary kiln according to claim 1, characterized in that: The insulating magnetic gasket is cylindrical, and an annular step portion is provided at the bottom of the insulating magnetic gasket. The top surface of the annular step portion abuts against the top surface of the furnace body, and an external thread is provided on the side surface of the annular step portion. An internal thread is provided on the upper end peripheral wall of the mounting hole, and the external thread on the side surface cooperates with the internal thread of the mounting hole.

3. The rotary kiln according to claim 1, characterized in that: The fixing hole is arranged on the axis of the insulating magnetic gasket, and the first threading hole and the second threading hole are symmetrically arranged on both sides of the second fixing hole.

4. The rotary kiln according to any one of claims 1 to 3, characterized in that: The multi-level temperature zones include one temperature zone, two temperature zones, three temperature zones, four temperature zones, five temperature zones and six temperature zones in sequence.

5. The rotary kiln according to claim 4, characterized in that: A heat insulating part is arranged between adjacent temperature zones, and a gap is left between the heat insulating part and the outer wall of the furnace tube.

6. The rotary kiln according to claim 5, characterized in that: The static area is located at the junction of the four-zone temperature zone and the five-zone temperature zone.

7. The rotary kiln according to claim 1, characterized in that: The first gas adding part is a shell and tube heat exchanger.

8. The rotary kiln according to claim 1, characterized in that: The flow rate of gas introduced into the first gasification part is 200-600m 3 / h, the flow rate of gas introduced into the second gas adding part is 30-100m 3 / h.

9. The rotary kiln according to claim 8, characterized in that: The flow rate of the gas introduced into the first gas adding part is 0.1-0.5 m / s, and the flow rate of the gas introduced into the second gas adding part is 0.03-0.1 m / s.

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