High-temperature roasting product cascade cooling waste heat boiler

Abstract

The utility model relates to a high-temperature roasting product cascade cooling waste heat boiler which comprises a fluidized bed heat exchanger, the top of the fluidized bed heat exchanger is connected with an inlet of a cyclone separator of a nitrogen circulation system or a water vapor circulation system, and the cyclone separator is connected with a tail flue and the fluidized bed heat exchanger. The tail flue is connected with one end of the nitrogen circulating system or the water vapor circulating system, and the other end is connected with the bottom of the fluidized bed heat exchanger to form circulation; the nitrogen circulation system or the water vapor circulation system further comprises a booster fan and a bag-type dust collector, and an outlet of the booster fan is connected with a fluidizing air device at the bottom of the fluidized bed heat exchanger to achieve closed-loop circulation. The fluidized bed heat exchanger, the steam pocket and the deaerator are connected with the sewage discharge system, the steam pocket and the deaerator are connected with the dosing device, the deaerator is connected with the steam pocket, the steam pocket is connected with the fluidized bed heat exchanger, and a top outlet of the fluidized bed heat exchanger is connected with the steam pocket. Nitrogen or water vapor is adopted as a circulating medium, and non-oxidation cooling and waste heat recovery of high-temperature roasting products can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of mineral processing, and in particular relates to a high-temperature roasting product step-cooling waste heat boiler. Background Art

[0002] More than 97% of my country's iron ore is complex and difficult to select iron ore, which is characterized by low iron grade, fine particle size of useful minerals, and complex mineral composition. Reduction roasting-magnetic separation is an effective method for the efficient development and utilization of complex and difficult to select iron ore. During the reduction roasting process, hematite (α-Fe2O3), limonite (Fe2O3·nH2O) and siderite (FeCO3) are converted into highly magnetic magnetite (Fe3O4) or magnetic hematite (γ-Fe2O3). However, the roasting temperature is generally above 500°C, while magnetic separation is carried out at room temperature, so the cooling process of high-temperature roasted products is crucial. The cooling process needs to protect the magnetite from being oxidized to hematite, while recovering the waste heat of the cooling process to reduce process energy consumption.

[0003] The traditional cooling method is water jacket heat exchange cooling, and the cooling process is one-stage cooling. This method has low cooling efficiency, the generated heat is not effectively utilized, and even high-quality waste heat is converted into low-quality waste heat, resulting in low energy efficiency and a large amount of energy waste. Therefore, there is an urgent need for an efficient high-temperature roasting product cooling device and method. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a high-temperature roasting product cascade cooling waste heat boiler, which adopts nitrogen or steam as the circulating medium, can achieve oxidation-free cooling and waste heat recovery of the high-temperature roasting product, and the cascade cooling can significantly improve the cooling efficiency.

[0005] A high-temperature roasting product step-cooling waste heat boiler comprises a fluidized bed heat exchanger, a steam drum, a deaerator, a dosing device and a sewage discharge system. The top of the fluidized bed heat exchanger is connected to the inlet of a cyclone separator of a nitrogen circulation system or a steam circulation system, the gas outlet of the cyclone separator is connected to a tail flue, and the solid outlet at the lower end of the cyclone separator is connected to the fluidized bed heat exchanger; the tail flue is connected to one end of the nitrogen circulation system or the steam circulation system, and the other end of the nitrogen circulation system or the steam circulation system is connected to the bottom of the fluidized bed heat exchanger to form a circulation;

[0006] The nitrogen circulation system or steam circulation system also includes a pressurized fan and a bag dust collector, the tail flue is connected to the bag dust collector, and the air outlet of the pressurized fan is connected to the fluidized bed heat exchanger through a safety valve II; a solenoid valve and a safety valve I are sequentially arranged between the pressurized fan and the bag dust collector; if a nitrogen circulation system is adopted, the nitrogen generator is connected between the solenoid valve and the safety valve I; if a steam circulation system is adopted, the steam generator is connected between the solenoid valve and the safety valve I; the outlet of the pressurized fan is connected to the fluidized air device at the bottom of the fluidized bed heat exchanger, and a closed-loop circulation is formed;

[0007] The fluidized bed heat exchanger, steam drum, deaerator are connected to the inlet of the sewage system, the steam drum and deaerator are connected to the dosing device, the deaerator is connected to the steam drum, the steam drum outlet is connected to the fluidized bed heat exchanger, and the top outlet of the fluidized bed heat exchanger is connected to the steam drum inlet.

[0008] The fluidized bed heat exchanger includes nine modules, namely, empty bed A, evaporator A, high-temperature superheater, low-temperature superheater, evaporator B, empty bed B, evaporator C, evaporator D, and high-temperature economizer, as well as a low-temperature economizer and a low-temperature economizer. The empty bed A is located at one end of the fluidized bed heat exchanger, corresponding to the feed port; the evaporator A, high-temperature superheater, low-temperature superheater, evaporator B, empty bed B, evaporator C, evaporator D, and high-temperature economizer are arranged in sequence near the empty bed A; the discharge port is arranged on one side of the high-temperature economizer; the tops of the nine modules of the fluidized bed heat exchanger are connected to the inlet of the cyclone separator of the nitrogen circulation system or the steam circulation system through a recovery main pipe; the low-temperature economizer and the low-temperature economizer are placed in the tail flue, and the low-temperature economizer is arranged near one side of the cyclone separator; the side of the tail flue close to the low-temperature economizer is connected to one end of the nitrogen circulation system or the steam circulation system.

[0009] The cyclone separator is a volute type cyclone separator.

[0010] The high-temperature economizer adopts a serial structure, which contains three circuits and is arranged in series; the high-temperature economizer is arranged at the outlet of the fluidized bed heat exchanger; the low-temperature economizer adopts a staggered structure, forming a two-stage arrangement with the high-temperature economizer; a sonic soot blower is provided inside to prevent ash accumulation; the low-temperature economizer is arranged in the tail flue to absorb part of the heat carried away by the nitrogen; the low-temperature economizer adopts a staggered structure, divided into three groups, and is arranged in series countercurrent in the tail flue, with a sonic soot blower arranged inside.

[0011] The nitrogen generator is a nitrogen making machine, and the generated high-pressure nitrogen enters the nitrogen pipeline.

[0012] The inlet of the pressurized fan is connected to the outlet of the solenoid valve, which is used to transport nitrogen to the nitrogen pipeline; the nitrogen pipeline also includes a pipeline connecting the nitrogen generator, the pressurized fan, the fluidized bed heat exchanger, the cyclone separator, the tail heating surface of the tail flue and the bag filter, which is used to transport nitrogen; a metal compensator is provided at the connection or bend of the pipeline; and a bracket is provided on the pipeline; the outlet of the nitrogen generator, the outlet of the pressurized fan, the inlet of each air distribution plate, and the inlet of the pipeline for nitrogen recovery arranged between the top outlet of the fluidized bed heat exchanger and the inlet of the pressurized fan are all provided with pipeline valves; the outside of the nitrogen pipeline is provided with an insulation layer, and temperature sensors and pressure sensors are installed at the outlet of the nitrogen generator, the outlet of the pressurized fan, the inlet of each air distribution pipe, and the inlet of each nitrogen recovery pipeline;

[0013] The high-pressure nitrogen process is as follows: nitrogen supplement → pressurization by booster fan → air distribution plates and bell-shaped air caps of each module of fluidized bed heat exchanger → material mixing and fluidization heat exchange → high-temperature nitrogen exits each module and enters the recovery main pipe → cyclone separator dust removal → tail heating surface of tail flue cools down to 50℃ to 100℃ → bag dust removal → returns to the inlet of booster fan;

[0014] The steam generator is a water tube boiler, and the generated high-pressure steam enters the steam pipeline;

[0015] The high-pressure steam process is: supplementary steam → pressurization by booster fan → air distribution plates and bell-type hoods of each module of fluidized bed heat exchanger → material mixing and fluidization heat exchange → high-temperature steam exits each module and enters the recovery main pipe → cyclone separator for dust removal → the tail heating surface of the tail flue is cooled to 110℃ to 150℃ → bag dust collector for dust removal → back to the inlet of the booster fan.

[0016] The feed temperature of the fluidized bed heat exchanger is 500-600°C, and the discharge temperature is 120-200°C; the particle size of the high-temperature roasted material is -200 mesh, accounting for 65% to 90%, and the particle size of the material returned to the fluidized bed heat exchanger from the cyclone separator is -400 mesh, not less than 80%;

[0017] The high-temperature roasting material flow is: empty bed A→evaporator A→high-temperature superheater→low-temperature superheater→evaporator B→empty bed B→evaporator C→evaporator D→high-temperature economizer→discharge port. The high-temperature roasting material undergoes heat exchange layer by layer, and the final temperature reaches the process requirement of ≤200℃, and then enters the next process.

[0018] The utility model has the following beneficial effects: two empty beds are arranged in the fluidized bed heat exchanger of the utility model, which are two cooling stages. By adopting this step cooling technology, a more efficient heat exchange efficiency between high-temperature roasting materials and cooling medium can be achieved compared with the traditional cooling method. Step cooling rapidly cools the high-temperature materials to the target temperature through multi-stage temperature regulation, thereby effectively controlling the heat release of the materials and protecting the equipment, and avoiding damage to the equipment caused by a sudden drop in temperature. In addition, the utility model can use nitrogen or steam as a cooling medium, and has a wider scope of application. The use of nitrogen cooling can accurately control the temperature of the cooling product by adjusting the pressure and flow rate as needed. When nitrogen cooling is used, the dryness of the cooling product can be guaranteed. When steam cooling is used, steam has higher thermal conductivity and specific heat capacity, and can absorb and transfer heat more effectively, thereby improving the cooling efficiency. Under the same volume or mass conditions, steam can absorb more heat, which helps to maintain the stability of the system temperature; steam is more convenient to obtain, the preparation cost is lower, and it has more significant economic benefits. Therefore, in actual use, nitrogen or steam can be selected as a cooling medium as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the connection of a waste heat boiler for step cooling of high temperature roasting products provided in Example 5 of the utility model;

[0020] in,

[0021] 1-feed port, 2-fluidized bed heat exchanger, 2.1-empty bed A, 2.2-evaporator A, 2.3-high temperature superheater, 2.4-low temperature superheater, 2.5-evaporator B, 2.6-empty bed B, 2.7-evaporator C, 2.8-evaporator D, 2.9-high temperature economizer, 2.10-fluidized air device, 2.11-low temperature economizer, 2.12-low temperature economizer, 3-discharge port, 4-cyclone separator, 5-bag dust collector, 6-ash hopper, 7-safety valve I, 8-solenoid valve, 9-pressurized fan, 10-safety valve II, 11-steam generator, 12-periodic sewage expansion device, 13-steam drum, 14-dosing pump, 15-dosing tank, 16-boiler feed pump, 17-deaerator. DETAILED DESCRIPTION

[0022] In order to better explain the present invention and facilitate understanding, the technical scheme and effects of the present invention are described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0023] Example 1

[0024] A high-temperature roasting product step-cooling waste heat boiler comprises a fluidized bed heat exchanger 2, a steam circulation system, a steam drum 13, a deaerator 17, a dosing device and a sewage discharge system.

[0025] The fluidized bed heat exchanger 2 includes nine modules, namely, an empty bed A2.1, an evaporator A2.2, a high-temperature superheater 2.3, a low-temperature superheater 2.4, an evaporator B2.5, an empty bed B2.6, an evaporator C2.7, an evaporator D2.8, and a high-temperature economizer 2.9, as well as a low-temperature economizer 2.11 and a low-temperature economizer 2.12. The empty bed A2.1 is located at one end of the fluidized bed heat exchanger 2, corresponding to the feed port 1, and the high-temperature roasting material is fed into the fluidized bed heat exchanger 2 through the feed port 1. The evaporator A2.2, the high-temperature superheater 2.3, the low-temperature superheater 2.4, the evaporator B2.5, the empty bed B2.6, the evaporator C2.7, the evaporator D2.8, and the high-temperature economizer 2.9 are arranged in sequence near the empty bed A2.1; and the discharge port 3 is arranged at one side of the high-temperature economizer 2.9. The tops of the nine modules of the fluidized bed heat exchanger 2 are connected to the inlet of the cyclone separator 4 of the steam circulation system through the recovery main pipe, the gas outlet of the cyclone separator 4 is connected to the tail flue, and the solid outlet at the lower end of the cyclone separator 4 is connected to the fluidized bed heat exchanger 2. The cyclone separator 4 is a volute type cyclone separator 4. The low-temperature economizer 2.11 and the low-temperature economizer 2.12 are placed in the tail flue to absorb the heat brought out by the high-pressure steam, and do not participate in the heat absorption of the hot mineral powder. The low-temperature economizer 2.11 is arranged close to one side of the cyclone separator 4. The side of the tail flue close to the low-temperature economizer 2.12 is connected to one end of the steam circulation system, and the other end of the steam circulation system is connected to the bottom of the fluidized bed heat exchanger 2 to form a circulation.

[0026] The evaporator A2.2, evaporator B2.5, evaporator C2.7, and evaporator D2.8 have the same structure, using existing commercial products, including 4 modules, and adopting a light pipe layout. Each module is equipped with an independent inlet and outlet header, and is connected to the steam drum 13 through an ascending pipe and a downcomer to ensure that the water circulation of each heating surface is safe and reliable. The high-temperature superheater 2.3 and the low-temperature superheater 2.4 use existing commercial products and adopt a light pipe layout. The temperature adjustment of superheated nitrogen or steam is achieved by a water spray cooler. The water spray point is set at the outlet of the low-temperature superheater 2.4. The water spray cooler adopts a pipeline layout and adopts a multi-hole nozzle type water spray cooler. The high-temperature economizer 2.9 adopts a serial structure, which contains three circuits and adopts a series layout. The high-temperature economizer 2.9 is arranged at the outlet of the fluidized bed heat exchanger 2, and is mainly involved in the heat exchange process of the mineral powder; the low-temperature economizer 2.11 and the low-temperature economizer 2.12 adopt existing commercially available products, and the low-temperature economizer 2.11 adopts a staggered structure to form a two-stage arrangement with the high-temperature economizer 2.9; a sonic soot blower is provided inside to prevent ash accumulation; the low-temperature economizer 2.11 is arranged in the tail flue, and is mainly used to absorb part of the heat taken away by the steam; the low-temperature economizer 2.12 adopts a staggered structure, divided into three groups, and is arranged in series countercurrent in the tail flue, and is provided with a sonic soot blower inside.

[0027] The bottom of the fluidized bed heat exchanger 2 is a fluidizing air device 2.10, including a wind chamber corresponding to each module and an air distribution plate (carbon steel) and a bell-shaped wind hood in the wind chamber, and the air volume is adjusted by a solenoid valve 8. The bell-shaped wind hood is arranged separately from the air duct, and the bell-shaped wind hood is welded to the top of the air duct for easy maintenance and replacement; the material of the bell-shaped wind hood is wear-resistant cast steel. The air distribution plate is located on the side of the fluidized bed and a slag discharge pipe is arranged near the bottom. Large pieces of slag that are locally compacted can be discharged through the slag discharge pipe for convenient operation.

[0028] The steam circulation system also includes a booster fan 9 and a bag filter 5 connected by a steam pipeline, and an ash hopper 6 is arranged at the bottom of the bag filter 5; the tail flue is connected to the bag filter 5, and the air outlet of the booster fan 9 is connected to the fluidized bed heat exchanger 2 through a safety valve II10; a solenoid valve 8 and a safety valve I7 are arranged between the booster fan 9 and the bag filter 5 in sequence, and a steam generator 11 is connected between the solenoid valve 8 and the safety valve I7, and steam is used as a circulating cooling medium. The outlet of the booster fan 9 is connected to the fluidizing air device 2.10 at the bottom of the fluidized bed heat exchanger 2.

[0029] The steam generator 11 is a water tube boiler, and the generated high-temperature and high-pressure steam enters the steam pipeline. The inlet of the water tube boiler is connected to the outlet of the solenoid valve 8, which is used to transport the steam to the steam pipeline; the steam pipeline also includes a pipeline connecting the water tube boiler, the booster fan 9, the fluidized bed heat exchanger 2, the cyclone separator 4, the tail heating surface of the tail flue and the bag filter 5, which is used to transport steam; a metal compensator is provided at the connection or bend of the pipeline to adjust the thermal expansion and contraction of the pipeline, prevent the pipeline from generating stress due to temperature changes, and protect the stability of the pipeline system; and a bracket is provided on the pipeline, Used to support and fix the pipeline system to ensure safe operation of the pipeline and maintain good arrangement; pipeline valves, temperature sensors and pressure sensors are installed at the outlet of the water tube boiler, the outlet of the booster fan 9, the inlet of each air distribution plate, and the inlet of the pipeline for steam recovery between the top outlet of the fluidized bed heat exchanger 2 and the inlet of the booster fan 9. The pipeline valve is used to control the flow of air flow and adjust the pressure and flow of the system. The temperature sensor and pressure sensor are used to monitor the temperature and pressure of nitrogen in real time to ensure that the entire equipment operates in a safe and stable state, and to make necessary adjustments and controls. An insulation layer is provided on the outside of the steam pipeline to reduce heat loss. The steam is fed into the fluidized bed heat exchanger 2 by the booster fan 9, and the steam after heat exchange enters the volute cyclone separator 4 for gas-solid separation, and the steam further enters the bag filter 5 for purification and recovery.

[0030] The high-pressure steam process is: replenish steam → pressurizing fan 9 → air distribution plates and bell-shaped hoods of each module of fluidized bed heat exchanger 2 → material mixing and fluidizing heat exchange → high-temperature steam exits each module and enters the recovery main pipe → cyclone separator 4 dust removal → tail heating surface of tail flue cools to 110℃ to 150℃ → bag filter 5 dust removal → returns to the inlet of pressurizing fan 9. After a cycle is completed, pressurizing fan 9 pressurizes and participates in the cycle again, and the whole system is basically closed. According to the oxygen content prompt in the instrument of steam generator 11, a small amount of steam is added.

[0031] The fluidized bed heat exchanger 2 is connected to the inlet of a sewage system through a sewage pipe, and the sewage system includes a periodic sewage expander 12.

[0032] The drum 13 is connected to the dosing device through a dosing pump 14, and the deaerator 17 is connected to the dosing device through a boiler feed water pump 16, and the dosing device is a dosing tank 15. The drum 13 is connected to the inlet of the sewage system through a sewage pipe. The outlet of the drum 13 is connected to the inlet of the evaporator A2.2, evaporator B2.5, evaporator C2.7, and evaporator D2.8 at the bottom of the fluidized bed heat exchanger 2 through a downcomer, and the outlet of the drum 13 is connected to the inlet of the high-temperature superheater 2.3 and the low-temperature superheater 2.4 through a lead-out pipe, and the top outlet of the fluidized bed heat exchanger 2 is connected to the inlet of the drum 13 through a riser.

[0033] The deaerator 17 is connected to the drum 13 through a water supply pipe, and the deaerator 17 is connected to the inlet of the sewage system through a low-pressure saturated steam pipe, and the outlet of the sewage system is connected to the deaerator 17. The sewage system is set at the lowest header in each circulation loop. The lowest header is the lowest water collector in the entire system, located at the bottom of the system, and is used to collect sewage or wastewater in the system and discharge it. The lowest header, economizer, drum 13 and lower header of the deaerator 17 are all equipped with sewage systems (not shown in the figure), and sewage is discharged regularly according to the water quality test results.

[0034] These locations play an important role in the boiler system. They are used to collect and discharge wastewater and sewage in the system to maintain the normal operation of the system and ensure good water quality. Regular sewage discharge based on water quality test results is to maintain the stability and safety of the system water quality.

[0035] The feed temperature of the fluidized bed heat exchanger 2 is 500-600° C., and the discharge temperature is 120-200° C. The particle size of the high-temperature roasted material is -200 mesh, accounting for 65% to 90%, and the particle size of the material returned to the fluidized bed heat exchanger 2 from the cyclone separator 4 is -400 mesh, not less than 80%.

[0036] The high-temperature roasting material flow is: empty bed A2.1→evaporator A2.2→high-temperature superheater 2.3→low-temperature superheater 2.4→evaporator B2.5→empty bed B2.6→evaporator C2.7→evaporator D2.8→high-temperature economizer 2.9→discharge port 3. The high-temperature roasting material undergoes heat exchange layer by layer, and the final temperature reaches the process requirement of ≤200℃, and then enters the next process.

[0037] Steam-water process: make-up water is fed into the deaerator 17 for deoxygenation, and then fed into the dosing tank 15 through the boiler feed water pump 16, and then fed into the steam drum 13 through the dosing pump 14 after being mixed with phosphate. The saturated water in the steam drum 13 is introduced into the evaporator A2.2, evaporator B2.5, evaporator C2.7, and evaporator D2.8 of the fluidized bed heat exchanger 2 through the downcomer. After heat exchange, the steam-water mixture is collected and ascended, and is introduced into the steam drum 13 again through the ascending pipe to complete the steam-water separation through the steam-water separator. The steam is introduced into the high-temperature superheater 2.3 and the low-temperature superheater 2.4 from the outlet pipe to continue absorbing heat, thus completing the steam-water process.

[0038] A method for using a waste heat boiler for step cooling of high temperature roasting products is as follows:

[0039] The feed port 1 is initially opened to supply high-temperature roasting materials into the fluidized bed heat exchanger 2; the 600°C high-temperature roasting materials with a particle size of -200 mesh accounting for 65% are fed into the empty bed A2.1 of the fluidized bed heat exchanger 2 through the feed port 1. In the fluidized bed heat exchanger 2, the high-temperature and high-pressure steam fluidizing air generated by the booster fan 9 is sent into the fluidized bed heat exchanger 2 through the air distribution plate to mix with the high-temperature roasting materials, so that the powder is fluidized and disturbed up and down, and passes through in turn in the form of "up and down" movement. After passing through evaporator A2.2, high-temperature superheater 2.3, low-temperature superheater 2.4, evaporator B2.5, empty bed B2.6, evaporator C2.7, evaporator D2.8, high-temperature economizer 2.9, the booster fan 9 is started immediately after the feed port 1 is opened, generating high-temperature and high-pressure steam fluidized air, which is sent to the fluidized bed heat exchanger 2 to mix with the high-temperature roasting material. The fluidized bed heat exchanger 2 is kept in operation throughout the process to complete the heat exchange and heat exchange of the material. Finally, the high-temperature roasting material is cooled to 130°C and discharged through the discharge port 3 as needed to enter the next process. The steam after heat exchange with the high-temperature roasting material in the fluidized bed heat exchanger 2 enters the cyclone separator 4 from the pipe at the top of the fluidized bed heat exchanger 2. The pipe at the top of the fluidized bed heat exchanger 2 is always kept open, so that the steam enters the cyclone separator 4 for further heat exchange. After the steam enters the cyclone separator 4, it further exchanges heat on the tail heating surface of the tail pipe, cools down to 120°C and enters the bag filter 5. The bag filter 5 is always kept in operation to remove particulate matter in the steam and return it to the inlet of the booster fan 9.

[0040] The particle size of the material returned from the cyclone separator 4 to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 80%. The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 1.

[0041] Table 1 Material temperature in fluidized bed heat exchanger

[0042]

[0043]

[0044] Example 2

[0045] The remaining structure of the device in this embodiment is the same as that in embodiment 1, the circulating cooling medium is steam, and the method is the same as that in embodiment 1, except that:

[0046] (1) The high temperature calcination product temperature is 550°C, and the particle size is -200 mesh, accounting for 75%.

[0047] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger is -400 mesh, accounting for 85%.

[0048] (3) The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 6.

[0049] Table 6 Material temperature in fluidized bed heat exchanger

[0050] name Inlet material temperature / ℃ Outlet material temperature / ℃ Empty bed A 550 530 Evaporator A 530 400 High temperature superheater 400 380 Low temperature superheater 380 350 Evaporator B 350 280 Empty bed B 280 250 Evaporator C 250 200 Evaporator D 200 160 High temperature economizer 160 120 Low temperature economizer 330(Steam) 180(Steam) Low and low temperature economizer 180(Steam) 110(Steam)

[0051] Example 3

[0052] The structure of the device in this embodiment is the same as that in embodiment 1, the circulating cooling medium is steam, and the method is the same as that in embodiment 1, except that:

[0053] (1) The temperature of the high temperature calcined product is 500°C, and the particle size is -200 mesh, accounting for 85%.

[0054] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 90%. (3) The temperature of the material in each module in the fluidized bed heat exchanger 2 is shown in Table 3.

[0055] Table 3 Material temperature in fluidized bed heat exchanger

[0056] name Inlet material temperature / ℃ Outlet material temperature / ℃ Empty bed A 500 470 Evaporator A 470 360 High temperature superheater 360 340 Low temperature superheater 340 310 Evaporator B 310 260 Empty bed B 260 240 Evaporator C 240 180 Evaporator D 180 150 High temperature economizer 150 120 Low temperature economizer 300(Steam) 160(Steam) Low and low temperature economizer 160(Steam) 110(Steam)

[0057] Example 4

[0058] The device structure is the same as in Example 1, the circulating cooling medium is steam, and the method is the same as in Example 1, except that:

[0059] (1) The temperature of the high temperature calcined product is 530°C, and the particle size is -200 mesh, accounting for 90%.

[0060] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 95%. (3) The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 4.

[0061] Table 4 Material temperature in fluidized bed heat exchanger

[0062]

[0063]

[0064] Example 5

[0065] like Figure 1 As shown, in this embodiment, a nitrogen circulation system is used to replace the steam circulation system in Embodiment 1. The difference between the nitrogen circulation system and the steam circulation system is only that a nitrogen generator is used to replace the steam generator 11, and the connection method of the nitrogen generator in the nitrogen circulation system is the same as the connection method of the steam generator 11 in the steam circulation system.

[0066] The nitrogen circulation system also includes a pressurized fan 9 and a bag filter 5 connected by a nitrogen pipeline, and an ash hopper 6 is arranged at the bottom of the bag filter 5; the tail flue is connected to the bag filter 5, and the air outlet of the pressurized fan 9 is connected to the fluidized bed heat exchanger 2 through a safety valve II10; a solenoid valve 8 and a safety valve I7 are arranged between the pressurized fan 9 and the bag filter 5 in sequence, and a nitrogen generator is connected between the solenoid valve 8 and the safety valve I7, and nitrogen is used as a circulating cooling medium. The outlet of the pressurized fan 9 is connected to the fluidizing air device 2.10 at the bottom of the fluidized bed heat exchanger 2. The fluidized bed heat exchanger 2 relies on high-pressure nitrogen to provide fluidizing air, and a closed-loop cycle. The nitrogen generator is a nitrogen generator, and the high-temperature and high-pressure nitrogen generated by the nitrogen generator enters the nitrogen pipeline. The inlet of the booster fan 9 is connected to the outlet of the solenoid valve 8, which is used to transport nitrogen to the nitrogen pipeline; the nitrogen pipeline also includes a pipeline connecting the nitrogen generator, the booster fan 9, the fluidized bed heat exchanger 2, the cyclone separator 4, the tail heating surface of the tail flue and the bag filter 5, which is used to transport nitrogen; a metal compensator is provided at the connection or bend of the pipeline to adjust the thermal expansion and contraction of the pipeline, prevent the pipeline from generating stress due to temperature changes, and protect the stability of the pipeline system; and a bracket is provided on the pipeline to support and fix the pipeline system to ensure the safe operation of the pipeline and maintain a good arrangement; the outlet of the nitrogen generator, the outlet of the booster fan 9, the inlet of each air distribution duct, and the inlet of the pipeline for nitrogen recovery set between the top outlet of the fluidized bed heat exchanger 2 and the inlet of the booster fan 9 are all provided with pipeline valves, which are used to control the flow of airflow and adjust the pressure and flow of the system. An insulation layer is provided on the outside of the nitrogen pipeline to reduce heat loss. Nitrogen is fed into the fluidized bed heat exchanger 2 by the pressure fan 9. After heat exchange, the nitrogen enters the volute cyclone separator 4 for gas-solid separation. The nitrogen further enters the bag filter 5 through the tail flue for purification and recovery.

[0067] The high-pressure nitrogen process is: nitrogen replenishment → pressurization by booster fan 9 → air distribution plates and bell-shaped hoods of each module of fluidized bed heat exchanger 2 → material mixing and fluidization heat exchange → high-temperature nitrogen exits each module and enters the recovery main pipe → cyclone separator 4 dust removal → tail heating surface of tail flue cools to 50℃ to 100℃ → bag filter 5 dust removal → returns to the inlet of booster fan 9. After a cycle is completed, booster fan 9 pressurizes and participates in the cycle again, and the entire system is closed. Nitrogen is replenished according to the oxygen content prompt in the instrument of the nitrogen generator.

[0068] The remaining device structures in this embodiment are the same as those in embodiment 1, the circulating cooling medium is nitrogen, and the method is the same as that in embodiment 1, except that:

[0069] (1) The high temperature roasting product temperature is 600℃, and the particle size is -200 mesh, accounting for 65%.

[0070] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 80%. (3) The temperature of the material in each module in the fluidized bed heat exchanger 2 is shown in Table 5.

[0071] Table 5 Material temperature in fluidized bed heat exchanger

[0072] name Inlet material temperature / ℃ Outlet material temperature / ℃ Empty bed A 600 550 Evaporator A 550 440 High temperature superheater 440 420 Low temperature superheater 420 390 Evaporator B 390 350 Empty bed B 350 320 Evaporator C 320 300 Evaporator D 300 280 High temperature economizer 280 250 Low temperature economizer 340(Nitrogen) 180(Nitrogen) Low and low temperature economizer 180(Nitrogen) 90(Nitrogen)

[0073] Example 6

[0074] The structure of the device in this embodiment is the same as that in embodiment 5, the circulating cooling medium is nitrogen, and the method is the same as that in embodiment 1, except that:

[0075] (1) The high temperature calcination product temperature is 550°C, and the particle size is -200 mesh, accounting for 75%.

[0076] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 85%. (3) The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 6.

[0077] Table 6 Material temperature in fluidized bed heat exchanger

[0078]

[0079]

[0080] Example 7

[0081] The structure of the device in this embodiment is the same as that in embodiment 5, the circulating cooling medium is nitrogen, and the method is the same as that in embodiment 1, except that:

[0082] (1) The temperature of the high temperature calcined product is 500°C, and the particle size is -200 mesh, accounting for 85%.

[0083] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 90%. (3) The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 7.

[0084] Table 7 Material temperature in fluidized bed heat exchanger

[0085] name Inlet material temperature / ℃ Outlet material temperature / ℃ Empty bed A 500 480 Evaporator A 480 380 High temperature superheater 380 350 Low temperature superheater 350 320 Evaporator B 320 270 Empty bed B 270 250 Evaporator C 250 185 Evaporator D 185 140 High temperature economizer 140 110 Low temperature economizer 280(Nitrogen) 140(Nitrogen) Low and low temperature economizer 140(Nitrogen) 60(Nitrogen)

[0086] Example 8

[0087] The structure of the device in this embodiment is the same as that in embodiment 5, the circulating cooling medium is nitrogen, and the method is the same as that in embodiment 1, except that:

[0088] (1) The temperature of the high temperature calcined product is 530°C, and the particle size is -200 mesh, accounting for 90%.

[0089] (2) After gas-solid separation in the cyclone separator 4, the particle size of the material returned to the fluidized bed heat exchanger 2 is -400 mesh, accounting for 95%. (3) The material temperature in each module of the fluidized bed heat exchanger 2 is shown in Table 8.

[0090] Table 8 Material temperature in fluidized bed heat exchanger

[0091]

[0092]

Claims

1. A high-temperature roasting product cascade cooling waste heat boiler, characterized in that: It includes a fluidized bed heat exchanger, a steam drum, a deaerator, a dosing device and a sewage discharge system. The top of the fluidized bed heat exchanger is connected to the inlet of the cyclone separator of the nitrogen circulation system or the steam circulation system, the gas outlet of the cyclone separator is connected to the tail flue, and the solid outlet at the lower end of the cyclone separator is connected to the fluidized bed heat exchanger; the tail flue is connected to one end of the nitrogen circulation system or the steam circulation system, and the other end of the nitrogen circulation system or the steam circulation system is connected to the bottom of the fluidized bed heat exchanger to form a circulation; The nitrogen circulation system or steam circulation system also includes a pressurized fan and a bag dust collector, the tail flue is connected to the bag dust collector, and the air outlet of the pressurized fan is connected to the fluidized bed heat exchanger through a safety valve II; a solenoid valve and a safety valve I are sequentially arranged between the pressurized fan and the bag dust collector; if a nitrogen circulation system is adopted, the nitrogen generator is connected between the solenoid valve and the safety valve I; if a steam circulation system is adopted, the steam generator is connected between the solenoid valve and the safety valve I; the outlet of the pressurized fan is connected to the fluidized air device at the bottom of the fluidized bed heat exchanger, and a closed-loop circulation is formed; The fluidized bed heat exchanger, steam drum, deaerator are connected to the inlet of the sewage system, the steam drum and deaerator are connected to the dosing device, the deaerator is connected to the steam drum, the steam drum outlet is connected to the fluidized bed heat exchanger, and the top outlet of the fluidized bed heat exchanger is connected to the steam drum inlet.

2. A high temperature roasting product step cooling waste heat boiler according to claim 1, characterized in that: The fluidized bed heat exchanger includes nine modules including empty bed A, evaporator A, high temperature superheater, low temperature superheater, evaporator B, empty bed B, evaporator C, evaporator D, high temperature economizer, and low temperature economizer and low temperature economizer. The empty bed A is located at one end of the fluidized bed heat exchanger, corresponding to the feed port; the evaporator A, high temperature superheater, low temperature superheater, evaporator B, empty bed B, evaporator C, evaporator D, and high temperature economizer are arranged in sequence near the empty bed A; the discharge port is arranged on one side of the high temperature economizer; the tops of the nine modules of the fluidized bed heat exchanger are connected to the inlet of the cyclone separator of the nitrogen circulation system or the steam circulation system through the recovery main pipe; the low temperature economizer and the low temperature economizer are placed in the tail flue, and the low temperature economizer is arranged near one side of the cyclone separator; The side of the tail flue close to the low-temperature economizer is connected to one end of the nitrogen circulation system or the steam circulation system.

3. The high-temperature roasting product step cooling waste heat boiler according to claim 1, characterized in that: The cyclone separator is a volute type cyclone separator.

4. The high-temperature roasting product step cooling waste heat boiler according to claim 2, characterized in that: The high-temperature economizer adopts a serial structure, which contains three circuits and is arranged in series; the high-temperature economizer is arranged at the outlet of the fluidized bed heat exchanger; the low-temperature economizer adopts a staggered structure, forming a two-stage arrangement with the high-temperature economizer; a sonic soot blower is provided inside to prevent ash accumulation; the low-temperature economizer is arranged in the tail flue to absorb part of the heat carried away by the nitrogen; the low-temperature economizer adopts a staggered structure, divided into three groups, and is arranged in series countercurrent in the tail flue, with a sonic soot blower arranged inside.

5. The high-temperature roasting product step cooling waste heat boiler according to claim 2, characterized in that: The nitrogen generator is a nitrogen making machine, and the generated high-pressure nitrogen enters the nitrogen pipeline.

6. The high-temperature roasting product step cooling waste heat boiler according to claim 5, characterized in that: The inlet of the pressurized fan is connected to the outlet of the solenoid valve, which is used to transport nitrogen to the nitrogen pipeline; the nitrogen pipeline also includes a pipeline connecting the nitrogen generator, the pressurized fan, the fluidized bed heat exchanger, the cyclone separator, the tail heating surface of the tail flue and the bag filter, which is used to transport nitrogen; a metal compensator is provided at the connection or bend of the pipeline; and a bracket is provided on the pipeline; the outlet of the nitrogen generator, the outlet of the pressurized fan, the inlet of each air distribution plate, and the inlet of the pipeline for nitrogen recovery arranged between the top outlet of the fluidized bed heat exchanger and the inlet of the pressurized fan are all provided with pipeline valves; the outside of the nitrogen pipeline is provided with an insulation layer, and temperature sensors and pressure sensors are installed at the outlet of the nitrogen generator, the outlet of the pressurized fan, the inlet of each air distribution pipe, and the inlet of each nitrogen recovery pipeline; The high-pressure nitrogen process is as follows: nitrogen supplement → pressurization by booster fan → air distribution plates and bell-shaped air caps of each module of fluidized bed heat exchanger → material mixing and fluidization heat exchange → high-temperature nitrogen exits each module and enters the recovery main pipe → cyclone separator dust removal → tail heating surface of tail flue cools down to 50℃ to 100℃ → bag dust removal → returns to the inlet of booster fan; The steam generator is a water tube boiler, and the generated high-pressure steam enters the steam pipeline; The high-pressure steam process is: supplementary steam → pressurization by booster fan → air distribution plates and bell-type hoods of each module of fluidized bed heat exchanger → material mixing and fluidization heat exchange → high-temperature steam exits each module and enters the recovery main pipe → cyclone separator for dust removal → the tail heating surface of the tail flue is cooled to 110℃ to 150℃ → bag dust collector for dust removal → back to the inlet of the booster fan.

7. The high-temperature roasting product step cooling waste heat boiler according to claim 2, characterized in that: The feed temperature of the fluidized bed heat exchanger is 500-600°C, and the discharge temperature is 120-200°C; the particle size of the high-temperature roasted material is -200 mesh, accounting for 65% to 90%, and the particle size of the material returned to the fluidized bed heat exchanger from the cyclone separator is -400 mesh, not less than 80%; The high-temperature roasting material flow is: empty bed A→evaporator A→high-temperature superheater→low-temperature superheater→evaporator B→empty bed B→evaporator C→evaporator D→high-temperature economizer→discharge port. The high-temperature roasting material undergoes heat exchange layer by layer, and the final temperature reaches the process requirement of ≤200℃, and then enters the next process.

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