Roller hearth kiln system resistant to corrosion and plugging

Abstract

The utility model relates to a kind of anticorrosion and jamming's roller kiln system, it includes roller kiln, incinerator, waste heat recovery component and pretreatment component;The air inlet end of the incinerator is connected with the exhaust end of the roller kiln and communicates;The pretreatment component includes cyclone dust collector and calcium injection tower, the air inlet end of the cyclone dust collector is connected with the exhaust end of the incinerator and communicates, the exhaust end of the cyclone dust collector is connected with the air inlet end of the waste heat recovery component via the calcium injection tower and communicates;After incineration in incinerator, the waste gas led out by roller kiln, can remove organic volatile matter (VOCs), then via cyclone dust collector dust removal, can remove ≥5 μm particulate matter in waste gas, reduce heat exchanger jamming risk, finally via calcium injection tower injection nano Ca (OH) 2 Powder can neutralize HF, protect heat exchanger from acidic corrosion.

Description

Technical Field

[0001] This utility model relates to the field of roller kiln technology, and in particular to a roller kiln system that is resistant to corrosion and clogging. Background Technology

[0002] Roller kilns are divided into three functional zones according to the process flow: preheating zone, firing zone, and cooling zone. This ensures that the heat generated by the combustion of gas is evenly transferred to the surface of the product. During operation, roller kilns inevitably generate a large amount of waste gas.

[0003] For example, in the sintering process of lithium battery cathode materials (such as ternary materials and lithium iron phosphate), roller kilns generate a large amount of high-temperature waste gas (typically between 300 and 800°C). During the treatment of this waste gas, waste heat recovery is carried out simultaneously to avoid wasting the large amount of heat energy contained in the waste gas.

[0004] However, the exhaust gas contains volatile organic compounds (VOCs) and acidic gases (such as HF), and direct heat exchange can easily lead to corrosion and blockage of the heat exchanger. Utility Model Content

[0005] In view of this, it is necessary to provide a corrosion-resistant and clogging-resistant roller kiln system to solve the problem that direct heat exchange can easily lead to corrosion and clogging of heat exchangers when the exhaust gas contains volatile organic compounds (VOCs) and acidic gases (such as HF).

[0006] This utility model provides a corrosion-resistant and clogging-resistant roller kiln system, including a roller kiln, an incinerator, a waste heat recovery component, and a pretreatment component; the inlet end of the incinerator is connected to the exhaust end of the roller kiln; the pretreatment component includes a cyclone dust collector and a calcium spraying deacidification tower, the inlet end of the cyclone dust collector is connected to the exhaust end of the incinerator, and the exhaust end of the cyclone dust collector is connected to the inlet end of the waste heat recovery component via the calcium spraying deacidification tower.

[0007] Furthermore, the spray calcium deacidification tower includes a tower body and a spray element installed inside the tower body. An air inlet is formed on the side wall of the tower body, which is connected to the exhaust end of the cyclone dust collector, and an exhaust end is formed on the top of the tower body, which is connected to the air inlet end of the pretreatment component.

[0008] Furthermore, the waste heat recovery assembly includes a first heat exchanger, a second heat exchanger, and a waste heat boiler connected in sequence.

[0009] Furthermore, the first heat exchanger includes a first chamber and a second chamber spaced apart, the air inlet of the first chamber is connected to the exhaust end of the calcium spraying deacidification tower, and the exhaust end of the first chamber is connected to the second heat exchanger.

[0010] Furthermore, it also includes a nitrogen heating pipeline, which passes through the second cavity and its nitrogen supply end is connected to the roller kiln.

[0011] Furthermore, the nitrogen heating pipeline includes a first nitrogen conduit, a first pressure stabilizing tank, and a second nitrogen conduit. One end of the first nitrogen conduit is connected to a nitrogen source, and the other end of the first nitrogen conduit is connected to one side of the second cavity of the first heat exchanger. One end of the second nitrogen conduit is connected to the other side of the second cavity of the first heat exchanger via the first pressure stabilizing tank, and the other end of the second nitrogen conduit is connected to the roller kiln.

[0012] Furthermore, the second heat exchanger includes a third chamber and a fourth chamber spaced apart, the air inlet of the third chamber being connected to the second heat exchanger, and the exhaust end of the third chamber being connected to the waste heat boiler.

[0013] Furthermore, it also includes an air heating pipe that passes through the fourth cavity.

[0014] Furthermore, the air heating pipeline includes a first air duct, a second pressure stabilizing tank, and a second air duct. One end of the first air duct is connected to an external air source, and the other end of the first air duct is connected to one side of the fourth cavity of the second heat exchanger. One end of the second air duct is connected to the other side of the fourth cavity of the second heat exchanger via the second pressure stabilizing tank, and the other end of the second air duct is connected to the roller kiln.

[0015] Furthermore, it also includes a solenoid valve and a controller installed on the waste heat recovery assembly. The controller has a flow detection end, which is installed at the exhaust end of the incinerator for detecting the waste gas flow rate. The controller is electrically connected to the solenoid valve and is used to control the opening and closing degree of the solenoid valve according to the waste gas flow rate.

[0016] Compared with existing technologies, the exhaust gas from the roller kiln can be incinerated in the incinerator to remove volatile organic compounds (VOCs), and then dusted by a cyclone dust collector to remove particles ≥5μm from the exhaust gas, reducing the risk of heat exchanger blockage. Finally, nano-Ca(OH)2 powder is sprayed out by the calcium spraying deacidification tower to neutralize HF and protect the heat exchanger from acid corrosion. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of the anti-corrosion and anti-clogging roller kiln system provided in this embodiment of the utility model. Detailed Implementation

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] like Figure 1 As shown, the present invention provides a corrosion-resistant and clogging-resistant roller kiln system, including a roller kiln 100, an incinerator 200, a waste heat recovery component 300, and a pretreatment component 400; the air inlet of the incinerator 200 is connected to the exhaust end of the roller kiln 100; the pretreatment component 400 includes a cyclone dust collector 410 and a calcium spraying deacidification tower 420, the air inlet of the cyclone dust collector 410 is connected to the exhaust end of the incinerator 200, and the exhaust end of the cyclone dust collector 410 is connected to the air inlet of the waste heat recovery component 300 via the calcium spraying deacidification tower 420.

[0020] During implementation, the exhaust gas from the roller kiln 100 is incinerated in the incinerator 200 to remove volatile organic compounds (VOCs). Then, it is dusted by the cyclone dust collector 410 to remove particles ≥5μm from the exhaust gas, reducing the risk of heat exchanger blockage. Finally, nano-Ca(OH)2 powder is sprayed out by the calcium spraying deacidification tower 420 to neutralize HF and protect the heat exchanger from acid corrosion.

[0021] The roller kiln 100 in this embodiment can be used to fire lithium battery cathode materials. It is a conventional structure that those skilled in the art can conceive of, and will not be elaborated or explained in detail.

[0022] The incinerator 200 in this embodiment is used to incinerate the waste gas generated by the roller kiln 100, and can remove the volatile organic compounds contained in the waste gas.

[0023] The waste heat recovery component 300 in this embodiment is used to recover the heat energy in the waste gas after it has been treated by the incinerator 200 and the pretreatment component 400.

[0024] In one embodiment, the waste heat recovery assembly 300 includes a first heat exchanger 310, a second heat exchanger 320, and a waste heat boiler 330 connected in sequence. A fan is installed at the exhaust end of the waste heat boiler 330 to drive the flow of waste gas. This configuration enables three-stage waste heat recovery and utilization of the waste gas.

[0025] In this embodiment, the first heat exchanger 310 includes a first cavity and a second cavity arranged at intervals. The air inlet of the first cavity is connected to the exhaust end of the calcium spraying deacidification tower 420, and the exhaust end of the first cavity is connected to the second heat exchanger 320.

[0026] Nitrogen protection is required during the sintering of the cathode material, and the injected nitrogen needs to be preheated. Nitrogen has a low specific heat capacity, resulting in high preheating energy consumption. In order to make reasonable use of the recovered waste heat, this embodiment also includes a nitrogen heating pipeline 500. The nitrogen heating pipeline 500 passes through the second cavity and its nitrogen supply end is connected to the roller kiln 100.

[0027] The nitrogen heating pipeline 500 includes a first nitrogen conduit 510, a first pressure stabilizing tank 520, and a second nitrogen conduit 530. One end of the first nitrogen conduit 510 is connected to a nitrogen source, and the other end of the first nitrogen conduit 510 is connected to one side of the second cavity of the first heat exchanger 310. One end of the second nitrogen conduit 530 is connected to the other side of the second cavity of the first heat exchanger 310 via the first pressure stabilizing tank 520, and the other end of the second nitrogen conduit 530 is connected to the roller kiln 100.

[0028] In this embodiment, the second heat exchanger 320 includes a third chamber and a fourth chamber spaced apart. The air inlet of the third chamber is connected to the second heat exchanger 320, and the exhaust of the third chamber is connected to the waste heat boiler 330.

[0029] To further utilize the aforementioned waste heat, this embodiment also includes an air heating pipe 600, which passes through the fourth cavity.

[0030] The air heating pipeline 600 includes a first air duct 610, a second pressure stabilizing tank 620, and a second air duct 630. One end of the first air duct 610 is connected to an external air source, and the other end of the first air duct 610 is connected to one side of the fourth cavity of the second heat exchanger 320. One end of the second air duct 630 is connected to the other side of the fourth cavity of the second heat exchanger 320 via the second pressure stabilizing tank 620, and the other end of the second air duct 630 is connected to the roller kiln 100.

[0031] The first heat exchanger 310 can be a high-temperature ceramic heat exchanger made of corrosion-resistant silicon carbide material, which cools the 800℃ waste gas to 400℃ and preheats the nitrogen to 300℃. The second heat exchanger 320 can be a plate gas-to-gas heat exchanger, which uses the 400℃ waste gas to further preheat the air to 250℃, and the waste gas outlet temperature drops to 150℃. The waste heat boiler 330 recovers the waste heat of the 150℃ waste gas to generate low-pressure steam for the precursor drying process.

[0032] The pretreatment component 400 in this embodiment is used to pretreat the exhaust gas that is about to enter the waste heat recovery component 300, thereby reducing the risk of blockage in the waste heat recovery component 300.

[0033] In one embodiment, the calcium spray deacidification tower 420 includes a tower body and a spray element installed inside the tower body. An air inlet is formed on the side wall of the tower body, communicating with the exhaust end of the cyclone dust collector 410, and an exhaust end is formed on the top of the tower body, communicating with the air inlet of the pretreatment component 400. The spray element can spray nano-Ca(OH)2 powder into the tower body to neutralize acidic substances such as HF in the waste gas.

[0034] This embodiment also includes a solenoid valve and a controller 700 installed on the waste heat recovery assembly 300. The controller 700 has a flow detection terminal installed at the exhaust end of the incinerator 200 to detect the waste gas flow rate. The controller 700 is electrically connected to the solenoid valve and is used to control the opening degree of the solenoid valve according to the waste gas flow rate. When the output of the roller kiln 100 increases, resulting in an increase in the waste gas flow rate, the control system increases the opening degree of the solenoid valve to improve the heat exchange efficiency and ensure the stability of the preheated air temperature.

[0035] It is understandable that the controller 700 mentioned above can be a multivariable collaborative controller 700, which has multiple functions such as detecting the temperature inside the roller kiln 100 and the incinerator 200, detecting the composition of the exhaust gas, and the nitrogen demand, and is used to dynamically adjust the opening of the heat exchanger valves and the speed of the fan.

[0036] Workflow:

[0037] The high-temperature exhaust gas (800℃) first enters the first heat exchanger 310, where it exchanges heat with nitrogen at 25℃, reducing the exhaust gas temperature to 400℃, while the cold air is preheated to 300℃. The exhaust gas then enters the second heat exchanger 320, where it exchanges heat with air at 20℃, reducing the exhaust gas temperature to 150℃ and raising the air temperature to 250℃. The exhaust gas then passes through a waste heat boiler 330, where waste heat is transferred to heat pipes to absorb heat from the exhaust gas. This heat is then transferred to the water in the steam drum, heating and vaporizing the water to generate 0.5MPa low-pressure steam, meeting the requirements of subsequent processes. Finally, the exhaust gas temperature is reduced to below 80℃ before discharge, achieving a multi-stage coupled preheating function. The preheated nitrogen / air / 0.5MPa low-pressure steam is then transported via a pressure stabilizing tank to the inlet of the roller kiln 100 / spray dryer / precursor dryer.

[0038] Compared with existing technologies: the exhaust gas from the roller kiln 100 is incinerated in the incinerator 200 to remove volatile organic compounds (VOCs), and then dusted by the cyclone dust collector 410 to remove ≥5μm particles from the exhaust gas, reducing the risk of heat exchanger blockage. Finally, nano-Ca(OH)2 powder is sprayed out by the calcium spraying deacidification tower 420 to neutralize HF and protect the heat exchanger from acid corrosion.

[0039] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A corrosion- and blockage-resistant roller kiln system, characterized in that, include: Roller kiln; The incinerator has its air inlet connected to the exhaust outlet of the roller kiln. Waste heat recovery components; The pretreatment component includes a cyclone dust collector and a calcium spraying deacidification tower. The inlet of the cyclone dust collector is connected to the exhaust of the incinerator, and the exhaust of the cyclone dust collector is connected to the inlet of the waste heat recovery component via the calcium spraying deacidification tower.

2. The anti-corrosion and anti-clogging roller kiln system according to claim 1, characterized in that, The calcium spray deacidification tower includes a tower body and a spray unit installed inside the tower body. An air inlet is formed on the side wall of the tower body, which is connected to the exhaust end of the cyclone dust collector. An exhaust end is formed on the top of the tower body, which is connected to the air inlet end of the pretreatment component.

3. The anti-corrosion and anti-clogging roller kiln system according to claim 1, characterized in that, The waste heat recovery assembly includes a first heat exchanger, a second heat exchanger, and a waste heat boiler connected in sequence.

4. The anti-corrosion and anti-clogging roller kiln system according to claim 3, characterized in that, The first heat exchanger includes a first chamber and a second chamber arranged at intervals. The air inlet of the first chamber is connected to the exhaust end of the calcium spraying deacidification tower, and the exhaust end of the first chamber is connected to the second heat exchanger.

5. The anti-corrosion and anti-clogging roller kiln system according to claim 4, characterized in that, It also includes a nitrogen heating pipeline, which passes through the second cavity and whose nitrogen supply end is connected to the roller kiln.

6. The anti-corrosion and anti-clogging roller kiln system according to claim 5, characterized in that, The nitrogen heating pipeline includes a first nitrogen conduit, a first pressure stabilizing tank, and a second nitrogen conduit. One end of the first nitrogen conduit is connected to a nitrogen source, and the other end of the first nitrogen conduit is connected to one side of the second cavity of the first heat exchanger. One end of the second nitrogen conduit is connected to the other side of the second cavity of the first heat exchanger via the first pressure stabilizing tank, and the other end of the second nitrogen conduit is connected to the roller kiln.

7. The anti-corrosion and anti-clogging roller kiln system according to claim 3, characterized in that, The second heat exchanger includes a third chamber and a fourth chamber spaced apart. The air inlet of the third chamber is connected to the second heat exchanger, and the exhaust of the third chamber is connected to the waste heat boiler.

8. The anti-corrosion and anti-clogging roller kiln system according to claim 7, characterized in that, It also includes an air heating pipe that passes through the fourth cavity.

9. The anti-corrosion and anti-clogging roller kiln system according to claim 8, characterized in that, The air heating pipeline includes a first air duct, a second pressure stabilizing tank, and a second air duct. One end of the first air duct is connected to an external air source, and the other end of the first air duct is connected to one side of the fourth cavity of the second heat exchanger. One end of the second air duct is connected to the other side of the fourth cavity of the second heat exchanger via the second pressure stabilizing tank, and the other end of the second air duct is connected to the roller kiln.

10. The anti-corrosion and anti-clogging roller kiln system according to claim 1, characterized in that, It also includes a solenoid valve and a controller installed on the waste heat recovery assembly. The controller has a flow detection end installed at the exhaust end of the incinerator for detecting the waste gas flow. The controller is electrically connected to the solenoid valve for controlling the opening and closing degree of the solenoid valve according to the waste gas flow.

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