Waste heat utilization device for preparing zinc oxide by dry method

Abstract

The invention relates to the technical field of zinc oxide preparation, and particularly discloses a waste heat utilization device for preparing zinc oxide by a dry method, the waste heat utilization device comprises a thermal insulation outer cylinder and a settling cylinder, the lower end of the settling cylinder is connected with a V-shaped connecting pipe, and the other end of the connecting pipe is connected with a vertically upward settling pipe; a plurality of fan-shaped columnar heat storage boxes are rotationally arranged on the outer wall of the settling cylinder in the heat preservation outer cylinder, each heat storage box is filled with a phase change heat storage material, and a plurality of heat exchange pipes vertically penetrate through the heat storage boxes; compared with traditional waste heat recovery equipment, the device has the advantages that high-temperature flue gas is recovered on line and can be released and utilized at any time, zinc oxide powder in the high-temperature flue gas can be settled through the two vertical flue gas movement processes of the heat exchange pipe and the settling barrel, and the zinc oxide powder in the high-temperature flue gas can be recycled at any time. The problems of waste heat recovery and powder sedimentation of existing zinc oxide high-temperature flue gas are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of zinc oxide preparation, and in particular discloses a waste heat utilization device for preparing zinc oxide by dry method. Background Art

[0002] The dry process of preparing zinc oxide is to convert zinc-containing materials into zinc oxide by high-temperature roasting. That is, a zinc block is placed in a calcining furnace to heat, melt and evaporate. During the evaporation process, it comes into contact with the external low-temperature air, thereby oxidizing the zinc vapor into zinc oxide, and heating the low-temperature air to a high temperature, ultimately forming zinc oxide powder and high-temperature flue gas. The high-temperature flue gas is then transported along a pipeline for cooling, and finally sent to a bag collection device for filtration and collection.

[0003] In the process of dry preparation of zinc oxide, the waste heat of its high-temperature flue gas is usually dissipated into the air through a long pipe, which not only leads to serious waste of heat energy, but also requires a long pipe for the whole set of equipment to cool down the high-temperature flue gas during transportation. During the cooling process, some powder will also settle in the pipe and cannot be effectively cleaned. In addition, the high-temperature zinc oxide powder with poor cooling effect will directly interact with the bag collector, which will also affect its service life.

[0004] The utility model patent with application number 202323402385.8 discloses a waste heat recovery system for calcining rotary kiln for zinc oxide production, including a first heat exchanger, a flash tank and a waste heat recovery pipe. The tail gas of the calcining rotary kiln enters the first heat exchange pipe through the waste heat recovery pipe. The tail gas in the first heat exchange pipe can be heated by natural gas and sent to the flash tank, which is used as a heat source to flash dry the basic zinc carbonate in the flash tank. The dried basic zinc carbonate and tail gas enter the cyclone separator for separation, and the separated basic zinc carbonate enters the calcining rotary kiln. The separated gas can be discharged through the outlet pipe. Although this patent realizes the recovery and utilization of the waste heat of the tail gas of the calcining rotary kiln and improves the heat source utilization rate of natural gas, the waste heat recovery pipe in the technical solution is used in the high-temperature flue gas transportation process. On the one hand, the precipitated zinc oxide powder cannot be collected, and on the other hand, the waste heat utilization can only be used online and cannot be stored for use at a specific time, resulting in a small scope. Therefore, in view of the problems existing in the utilization of waste heat from high-temperature flue gas in the existing dry process for preparing zinc oxide, the present application proposes a waste heat utilization device for preparing zinc oxide by dry process that can effectively solve the above technical problems. Summary of the invention

[0005] The present invention aims to provide a waste heat utilization device for dry preparation of zinc oxide, so as to solve the problems that the existing waste heat recovery and utilization system of the calcining rotary kiln for zinc oxide production cannot perform online sedimentation of zinc oxide powder and cannot store the heat of high-temperature flue gas for use when utilizing waste heat.

[0006] The present invention is achieved through the following technical solutions: A waste heat utilization device for preparing zinc oxide by dry process, comprising a heat-insulating outer cylinder and a settling cylinder arranged concentrically, wherein the lower end of the settling cylinder extending out of the heat-insulating outer cylinder is connected to a V-shaped connecting pipe, the other end of the connecting pipe is connected to a vertically upward settling pipe, and a discharge pipe is arranged at the bottom of the connecting pipe; A plurality of fan-shaped columnar heat storage boxes are rotatably arranged on the outer wall of the settling cylinder located in the heat-insulating outer cylinder, and the annular inner cavities of the heat-insulating outer cylinder above and below the heat storage boxes are divided into an air outlet area and an air inlet area corresponding to each heat storage box by a plurality of partitions, and a gear ring is commonly connected to the upper ends of the plurality of heat storage boxes, and a power assembly for driving the gear ring to rotate is arranged on the heat-insulating outer cylinder, each of the heat storage boxes is filled with phase-change heat storage material, and a plurality of heat exchange tubes are vertically penetrated in the heat storage box, an air inlet pipe is connected to the outer wall of one of the air inlet areas, a connecting port corresponding to the air inlet pipe is opened at the upper end of the settling cylinder, and a plurality of groups of heat exchange medium inlet pipes and heat exchange medium outlet pipes are connected to the outer walls of the other air inlet areas and air outlet areas; A dust collecting hopper is connected to the bottom wall of the air inlet area corresponding to the air inlet pipe, and an auger feeder is connected to the lower end of the dust collecting hopper.

[0007] As a further configuration of the above scheme, an airflow pressurization guide cover is arranged in the settling cylinder located below the connecting port, and the airflow pressurization guide cover is arranged to be wide at the top and narrow at the bottom.

[0008] As a further configuration of the above solution, the side ends of a plurality of the heat storage tanks are sequentially connected and configured to form a ring column surrounding the outer wall of the settling cylinder.

[0009] As a further configuration of the above scheme, the power assembly includes a driving motor arranged on the outer wall of the heat-insulating outer cylinder, and a gear meshing with the gear ring is arranged on the motor shaft of the driving motor.

[0010] As a further configuration of the above solution, a plurality of heat exchange fin rings in contact with the phase change heat storage material are arranged at intervals on the outer wall of the heat exchange tube in the heat storage tank.

[0011] As a further configuration of the above scheme, the partition includes an upper radial partition and a lower radial partition arranged at the upper and lower ends of the heat-insulating outer cylinder, and the upper radial partition is connected to one side end of the corresponding heat storage box.

[0012] As a further configuration of the above scheme, the upper end of the heat exchange tube in each of the heat storage boxes is extended to a certain length, and an air outlet facing the sedimentation cylinder is opened at the upper end of the heat exchange tube extending out of the heat storage box, and a vertical rotating rod is concentrically arranged in each of the heat exchange tubes, and a guide spiral blade is arranged on the outer circular surface of the vertical rotating rod, and a transmission mechanism for driving all the vertical rotating rods to rotate is arranged at the upper end of the insulation outer cylinder corresponding to the air inlet connecting pipe area.

[0013] As a further configuration of the above scheme, the transmission mechanism includes a cylinder arranged on the heat-insulating outer cylinder, the lower end of the cylinder is connected to a transmission box, the lower surface of the transmission box is rotatably provided with a second toothed wheel, and the transmission box is provided with a rotating motor that drives the second toothed wheel to rotate, and the upper end of the vertical rotating rod extending out of the heat exchange tube is provided with a first toothed wheel that acts on the second toothed wheel.

[0014] During the operation of the waste heat utilization device for preparing zinc oxide by dry method disclosed in the present invention, high-temperature flue gas of zinc oxide is introduced through the air inlet pipe, and the introduced high-temperature flue gas will flow upward along the heat exchange tube. In the process of the high-temperature flue gas flowing along the heat exchange tube, it will be absorbed by the phase change heat storage material in the heat storage box, so that the heat is stored in the heat storage box, and then enters the air outlet area above the heat storage box after cooling.

[0015] Subsequently, the high-temperature flue gas after cooling will enter the settling tube through the connecting port and flow downward from the upper end of the settling tube. At the same time, due to the design of the airflow booster guide cover, the high-temperature flue gas entering from the side will gather and speed up toward the center. After passing through the airflow booster guide cover, it will diffuse to the surroundings and slow down. After deceleration, part of the zinc oxide powder in the high-temperature flue gas will settle and eventually enter the connecting pipe and be discharged through the discharge pipe at the bottom of the connecting pipe. At the same time, when the high-temperature flue gas flows upward along the heat exchange tube, some large particles of zinc oxide powder will settle locally and fall directly into the dust hopper and be sent out by the auger feeder.

[0016] When the phase change heat storage material in the heat storage box is close to saturation, the power assembly is directly started to rotate all the heat storage boxes around the outer wall of the settling tube at a certain angle, so that the new heat storage box is cut into the heat absorption station to absorb the waste heat of the high-temperature flue gas. At the same time, when the heat in the heat storage box needs to be utilized, the heat storage box can be rotated and switched to the station with the heat exchange medium inlet pipe and the heat exchange medium outlet pipe, and then the heat exchange medium is introduced to absorb the heat in the phase change heat storage material and heat it up, thereby completing the heat release process and realizing the use of heat at any time.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The waste heat utilization device for preparing zinc oxide by dry method disclosed in the present invention adopts a heat storage box with a rotary design, and is provided with heat exchange tubes vertically penetrating up and down in the heat storage box. In the process of utilizing the waste heat of high-temperature flue gas of zinc oxide, the heat storage box can be quickly switched to absorb the high-temperature flue gas, and then it can be quickly switched out for use at any time when heat is needed. Compared with traditional waste heat recovery equipment, it has the advantages of online recovery of high-temperature flue gas and can be released for utilization at any time.

[0018] In addition, in the process of recovering the waste heat of high-temperature flue gas, the vertical flue gas movement process of the heat exchange tube and the sedimentation tube can allow the zinc oxide powder in the high-temperature flue gas to settle. In particular, the specially designed airflow booster guide cover in the sedimentation tube can effectively settle the high-temperature flue gas entering from the side, avoiding the problem of pipeline blockage caused by the sedimentation of high-temperature flue gas when flowing in the horizontal section of the pipeline. It effectively solves the existing problems of zinc oxide high-temperature flue gas waste heat recovery and powder sedimentation.

[0019] The present invention further provides guide spiral blades in the heat exchange tube, so that the high-pressure flue gas that originally flows vertically upward flows upward in a spiral flow trajectory, thereby increasing the contact time between the high-temperature flue gas and the phase change heat storage material in the heat storage box. In addition, the vertical rotating rod drives the guide spiral blades to flow in the opposite direction of the high-temperature flue gas, which can further increase the waste heat recovery contact time of the high-temperature flue gas, so that the heat in the high-temperature flue gas can be repeatedly absorbed, avoiding the high-temperature flue gas directly entering the bag collector due to excessive temperature and affecting the service life of the bag. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure of the heat-insulating outer cylinder, the sedimentation cylinder, etc. in the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the components inside the heat-insulating outer cylinder of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure inside the heat-insulating outer cylinder of the present invention; Figure 5 It is a three-dimensional structural schematic diagram of the heat storage box and the gear ring in the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure inside the sedimentation cylinder of the present invention; Figure 7 Schematic diagram of the three-dimensional structure of the heat storage box and the transmission box in Example 2 of the present invention Figure 8 It is a schematic diagram of the three-dimensional structure inside the heat exchange tube in Example 2 of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Figures 1 to 8 , and describes the application in detail with reference to embodiments. Example 1

[0024] Example 1 discloses a waste heat utilization device for preparing zinc oxide by dry method, Figure 1-3 The main body of the device includes a frame 1, on which an insulating outer cylinder 2 is arranged, and a settling cylinder 3 is fixedly arranged concentrically inside the insulating outer cylinder 2, and the lower end of the settling cylinder 3 is connected to a V-shaped connecting pipe 4, and the other end of the connecting pipe 4 is connected to a vertically upward settling pipe 5, and a discharge pipe 6 with a discharge valve is arranged at the bottom of the connecting pipe 4. During operation, the other end of the settling pipe 5 is connected to the feed end of the bag collector (not shown in the figure), and the other end of the bag collector is connected to the exhaust fan, so that under the action of the exhaust fan, the interior of the settling cylinder 3 can form a downward airflow and make the interior of the settling cylinder 3 in a negative pressure state.

[0025] On the outer circumference of the settling tube 3 in the heat-insulating outer tube 2, 4-8 heat storage tanks 7 are arranged in a circular array. In this figure, there are a total of six heat storage tanks 7, and each heat storage tank 7 is in the shape of a fan-shaped column with equal angles, and a large amount of phase-change heat storage material is filled inside. At the same time, the side ends of all heat storage tanks 7 are connected in sequence to form a ring column and are rotatably arranged on the outer circumference of the settling tube 3. A gear ring 8 is fixedly arranged at the outer edge of the upper end of all heat storage tanks 7, and then a driving motor 9 is arranged at the upper end of the outer wall of the heat-insulating outer tube 2. A gear 10 meshing with the gear ring 8 is arranged on the motor shaft of the driving motor 9, so that all heat storage tanks 7 can be synchronously rotated around the outer wall of the settling tube 3 at a fixed angle under the action of the driving motor 9. In addition, a plurality of heat exchange tubes 11 vertically penetrated from top to bottom are arranged in each heat storage tank 7, and a plurality of heat exchange fin rings 12 in contact with the phase-change heat storage material inside the heat storage tank 7 are arranged at intervals on the outer wall of the heat exchange tube 11.

[0026] Reference Figure 3 and attached Figure 4The upper and lower ends of the inner cavity of the heat-insulating outer cylinder 2 are provided with upper radial baffles 201 and lower radial baffles 202 in an annular array, the number of which is equal to the number of the heat storage tanks 7, and the lower end of the upper radial baffle 201 is in contact with the upper surface of the heat storage tank 7, and the upper end of the lower radial baffle 202 is in contact with the lower surface of the heat storage tank 7, so that the annular inner cavity at the upper and lower ends of the heat-insulating outer cylinder 2 is divided into an air outlet area and an air inlet area corresponding to each heat storage tank 7 by the upper radial baffle 201 and the lower radial baffle 202. An air inlet pipe 203 is provided at the lower end of the outer wall of the heat-insulating outer cylinder 2 corresponding to one of the air inlet areas, and a connecting port 301 is provided on the outer circumferential surface of the upper end of the settling cylinder 3 directly above the corresponding air inlet pipe 203. During operation, the zinc oxide high-temperature flue gas enters the air inlet area through the air inlet pipe 203, then flows vertically upward along the heat exchange tube 11, and during the flow, the heat is transferred to the phase change heat storage material through the heat exchange tube 11 and the heat exchange fin ring 12, then flows to the air inlet area and enters the settling tube 3 through the connecting port 301, and finally flows downward along the settling tube 3.

[0027] Reference Figure 2 , Attachment Figure 4 and attached Figure 5 , a dust hopper 13 is connected to the bottom of the air inlet area corresponding to the air inlet pipe 203, and an auger feeder 14 is connected to the lower end of the dust hopper 13. An airflow booster guide hood 15 with a wide top and a narrow bottom is provided in the settling tube 3 below the connecting port 501. Through the above design, when the zinc oxide high-temperature flue gas flows upward along the heat exchange tube 11, some large particles of zinc oxide particles will settle downward and fall directly into the dust hopper 13, and then be discharged in a direction by the auger feeder 14, and at the same time, the particles inside the auger conveyor 14 play a material sealing role. When the high-temperature flue gas flows downward along the inner cavity of the settling tube 3, the high-temperature flue gas entering from the side first gathers to the middle and speeds up through the airflow booster guide hood 15, and then diffuses to the surroundings and flows downward after passing through the airflow booster guide hood 15. At this time, the flow speed of the high-temperature flue gas is reduced, so that the small particles of zinc oxide powder can settle at this stage, and finally enter the connecting pipe 4 and be discharged by the discharge pipe 6.

[0028] Finally, in order to realize the recycling of the heat in the heat storage tank 7, one or two groups of heat exchange medium inlet pipes 204 and heat exchange medium outlet pipes 205 are also arranged on the outer wall of the heat-insulating outer tube 2, and the heat exchange medium inlet pipes 204 and the heat exchange medium outlet pipes 205 are respectively connected to the upper end and the lower end of the inner cavity of the heat-insulating outer tube 2. When heat utilization is required, the heat exchange medium is introduced into the interior through the heat exchange medium inlet pipe 204, and the heat exchange medium absorbs the heat stored in the phase change heat storage material when flowing through the heat exchange tube 11 to increase its own temperature, and then is discharged from the heat exchange medium outlet pipe 205 to realize heat utilization. Example 2

[0029] Example 2 discloses a waste heat utilization device for preparing zinc oxide by dry process, which is improved based on the technical solution in Example 1. The similarities with Example 1 will not be described again.

[0030] Reference Figure 7 and attached Figure 8 In the present embodiment 2, on the one hand, all the upper radial baffles 201 are connected to one side end of the corresponding heat storage tank 7, so that the upper end of the upper radial baffle 201 fits with the top wall of the heat-insulating outer cylinder 2, and the air outlet area formed by the two upper radial baffles 201 rotates synchronously during the rotation of the heat storage tank 7. On the other hand, the upper ends of all the heat exchange tubes 11 are extended out of the heat storage tank 7 by a certain distance, and then an air outlet 111 facing the sedimentation cylinder 3 is opened at the upper end of the heat exchange tube 11 extending out of the heat storage tank 7. A vertical rotating rod 16 arranged along the central axis of the heat exchange tube 11 is rotatably connected in each heat exchange tube 11, and then a guide spiral blade 17 is arranged on the outer circumferential surface of the vertical rotating rod 16 located inside the heat exchange tube 11, and a first toothed wheel 18 is connected to the top of the vertical rotating rod 16 extending out of the heat exchange tube 11.

[0031] A storage groove is provided at the top of the heat preservation outer cylinder 2 corresponding to the air inlet pipe 203 area, and a transmission box 19 is provided in the storage groove. A cylinder 20 for driving the transmission box 19 to move downward and extend into the air outlet area is provided on the heat preservation outer cylinder 2. Finally, a second toothed wheel 21 aligned with all the first toothed wheels 18 on a heat storage tank 7 is rotatably provided on the lower surface of the transmission box 19, and a rotating motor 22 for driving all the second toothed wheels 22 to rotate is provided on the transmission box 19.

[0032] In the present embodiment 2, through the above-mentioned improved design, during the heat exchange between the heat storage box 7 and the zinc oxide high-temperature flue gas, the transmission box 19 is pushed downward by the cylinder 20, so that all the second toothed wheels 21 are pressed with the corresponding first toothed wheels 18, and then the rotating motor 22 is started to rotate all the guide spiral blades 17 in the heat storage box 7. At this time, during the upward flow of the high-temperature flue gas along the heat exchange tube 11, the direction of the guide spiral blade 17 is opposite to the movement direction of the high-temperature flue gas, which can greatly prolong the time for the high-temperature flue gas to flow through the heat exchange tube 11, so that its heat can be fully absorbed by the phase change heat storage material; at the same time, the settled zinc oxide particles can be discharged from the lower end of the heat exchange tube 11 at the guide spiral blade 17 and directly enter the dust hopper 13.

[0033] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A waste heat utilization device for preparing zinc oxide by dry process, characterized in that: It comprises a concentrically arranged heat-insulating outer cylinder and a settling cylinder, wherein the lower end of the settling cylinder extending out of the heat-insulating outer cylinder is connected to a V-shaped connecting pipe, the other end of the connecting pipe is connected to a vertically upward settling pipe, and a discharge pipe is arranged at the bottom of the connecting pipe; A plurality of fan-shaped columnar heat storage boxes are rotatably arranged on the outer wall of the settling cylinder located in the heat-insulating outer cylinder, and the annular inner cavities of the heat-insulating outer cylinder above and below the heat storage boxes are divided into an air outlet area and an air inlet area corresponding to each heat storage box by a plurality of partitions, and a gear ring is commonly connected to the upper ends of the plurality of heat storage boxes, and a power assembly for driving the gear ring to rotate is arranged on the heat-insulating outer cylinder, each of the heat storage boxes is filled with phase-change heat storage materials, and a plurality of heat exchange tubes are vertically penetrated in the heat storage box, an air inlet pipe is connected to the outer wall of one of the air inlet areas, a connecting port corresponding to the air inlet pipe is opened at the upper end of the settling cylinder, and a plurality of groups of heat exchange medium inlet pipes and heat exchange medium outlet pipes are connected to the outer walls of the other air inlet areas and air outlet areas; A dust collecting hopper is connected to the bottom wall of the air inlet area corresponding to the air inlet pipe, and an auger feeder is connected to the lower end of the dust collecting hopper.

2. The waste heat utilization device for preparing zinc oxide by dry process according to claim 1, characterized in that: An airflow booster guide cover is arranged in the settling cylinder below the communicating port, and the airflow booster guide cover is arranged in a shape of being wide at the top and narrow at the bottom.

3. The waste heat utilization device for preparing zinc oxide by dry process according to claim 1, characterized in that: The side ends of the plurality of heat storage tanks are connected in sequence and form a ring column shape surrounding the outer wall of the settling cylinder.

4. The waste heat utilization device for preparing zinc oxide by dry process according to claim 1 or 3, characterized in that: The power assembly comprises a driving motor arranged on the outer wall of the heat-insulating outer cylinder, and a gear meshing with a gear ring is arranged on the motor shaft of the driving motor.

5. The waste heat utilization device for preparing zinc oxide by dry process according to claim 1, characterized in that: A plurality of heat exchange fin rings in contact with the phase change heat storage material are arranged at intervals on the outer wall of the heat exchange tube in the heat storage box.

6. The waste heat utilization device for preparing zinc oxide by dry process according to claim 1, characterized in that: The partition includes an upper radial partition and a lower radial partition arranged at the upper and lower ends of the heat-insulating outer cylinder, and the upper radial partition is connected to one side end of the corresponding heat storage box.

7. The waste heat utilization device for preparing zinc oxide by dry process according to claim 6, characterized in that: The upper end of the heat exchange tube in each of the heat storage boxes is extended to a certain length, and an air outlet facing the sedimentation cylinder is opened at the upper end of the heat exchange tube extending out of the heat storage box. A vertical rotating rod is concentrically arranged in each of the heat exchange tubes, and a guide spiral blade is arranged on the outer circular surface of the vertical rotating rod. A transmission mechanism that drives all vertical rotating rods to rotate is arranged at the upper end of the insulation outer cylinder corresponding to the air inlet pipe area.

8. The waste heat utilization device for preparing zinc oxide by dry process according to claim 7, characterized in that: The transmission mechanism includes a cylinder arranged on an insulating outer cylinder, the lower end of the cylinder is connected to a transmission box, a second toothed wheel is rotatably arranged on the lower surface of the transmission box, and a rotating motor for driving the second toothed wheel to rotate is arranged on the transmission box, and a first toothed wheel that acts on the second toothed wheel is arranged on the upper end of the vertical rotating rod extending out of the heat exchange tube.

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