Roller kiln waste heat recovery system

Abstract

The utility model discloses a roller kiln waste heat recovery system which comprises a first air inlet main pipe, a second air inlet main pipe, a first exhaust pipe, a second exhaust pipe and a heat exchanger, one end of the first air inlet main pipe is connected with an air supply device, the other end of the first air inlet main pipe is connected with the heat exchanger, and one end of the second air inlet main pipe is communicated with the first air inlet main pipe through the heat exchanger. One end of the first air inlet main pipe is connected with an inlet of the roller kiln, the other end of the first air inlet main pipe is connected with an inlet of the roller kiln, the second air inlet main pipe is provided with a three-way proportional valve, the first air inlet main pipe is connected with an air inlet bypass pipe in parallel, an outlet of the air inlet bypass pipe is connected with the three-way proportional valve, any air inlet main pipe is provided with a first air blower, and the air inlet bypass pipe is provided with a second air blower; one end of the first exhaust pipe is connected with an exhaust port of the roller kiln, the other end of the first exhaust pipe is connected with the heat exchanger, the inlet end of the second exhaust pipe is communicated with the first exhaust pipe through the heat exchanger, and an induced draft fan is arranged on any exhaust pipe. According to the scheme, air entering the kiln is preheated through efficient utilization of high-temperature waste gas, drying of materials in the kiln is completed, and energy is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste heat recovery in the new energy industry, and specifically relates to a waste heat recovery system for a roller hearth kiln. Background Art

[0002] At present, the combustion heating cost of the roller hearth kiln remains high. With the energy shortage and fierce market competition, how to effectively reduce the heating cost and emissions has become the focus of attention of each enterprise. Since the atomic diffusion energy during the sintering process is positively correlated with the temperature, the tail gas temperature discharged from the kiln furnace is relatively high in most process productions. If this part of energy is not reasonably utilized, it will not only be a waste of energy but also have an impact on the environment. In actual production, how to maximize the utilization efficiency of this part of energy is the key to reducing production costs.

[0003] In the production processes of new energy industries such as lithium manganate, due to the particularity of battery materials, downstream manufacturers require a raw material quality traceability period of up to ten years, which further deepens the manufacturers' pursuit of product quality. The existing waste heat recovery and utilization devices for kiln furnaces do not regulate the temperature. Since the lithium manganate production process has relatively high requirements for the sintering temperature, preheating and drying are required before firing in the kiln furnace. If the high-temperature tail gas discharged from the kiln furnace is directly used to preheat the incoming furnace gas through heat conversion without regulation, when the high-temperature tail gas temperature is insufficient, it will affect the preheating and drying effect of the incoming furnace gas on the materials, and when the high-temperature tail gas temperature is too high, it will damage the materials when the incoming furnace gas preheats and dries the materials. Content of the Utility Model

[0004] The purpose of the utility model is to provide a waste heat recovery system for a roller hearth kiln to solve at least one of the problems and defects mentioned in the above background art.

[0005] A waste heat recovery system for a roller hearth kiln includes a first intake main pipe, a second intake main pipe, a first exhaust pipe, a second exhaust pipe, and a heat exchanger. One end of the first intake main pipe is connected to a gas supply device, and the other end is connected to the heat exchanger. One end of the second intake main pipe is connected to the first intake main pipe through the heat exchanger, and the other end is connected to the roller hearth kiln inlet. A three-way proportional valve is provided on the second intake main pipe. An intake bypass pipe is connected in parallel to the first intake main pipe, and the outlet of the intake bypass pipe is connected to the three-way proportional valve. A first blower is provided on the first intake main pipe or the second intake main pipe, and a second blower is provided on the intake bypass pipe;

[0006] One end of the first exhaust pipe is connected to the roller hearth kiln exhaust port, and the other end is connected to the heat exchanger. The inlet end of the second exhaust pipe is connected to the first exhaust pipe through the heat exchanger. An induced draft fan is provided on the first exhaust pipe or the second exhaust pipe.

[0007] Furthermore, a temperature sensor is provided on the second intake main pipe, and the temperature sensor is arranged between the three-way proportional valve and the roller hearth kiln inlet.

[0008] Further, a heater is provided on the second intake main pipe, and the heater is arranged between the temperature sensor and the inlet of the roller hearth kiln.

[0009] Further, a filtering device is connected to the outlet end of the second exhaust pipe.

[0010] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0011] 1. In this solution, the high-temperature waste gas of the roller hearth kiln is discharged through the exhaust pipe, and the temperature of the high-temperature waste gas in the exhaust pipe is transferred to the gas in the intake main pipe through the heat exchanger. The gas in the intake main pipe enters the roller hearth kiln after being preheated by the heat exchanger, and after non-contact drying of the material in the preheating chamber of the roller hearth kiln, it enters the combustion chamber to participate in combustion. This solution preheats the gas entering the kiln through the waste heat of the high-temperature waste gas, thereby reducing the heat required for heating the original room-temperature air, and finally realizing waste heat recovery. It has strong applicability to any industry, and avoids the problems of low heat conduction efficiency, few actual application scenarios, and low economic benefits caused by the traditional use of the waste heat of the kiln for heat exchange.

[0012] 2. In this solution, a heater, a temperature sensor and a three-way proportional valve are arranged on the second intake main pipe, and an intake bypass pipe is connected in parallel on the first intake main pipe. The outlet of the intake bypass pipe is connected to the three-way proportional valve. All devices in this solution are regulated by an external control system. When the temperature sensor detects that the temperature of the gas in the second intake main pipe is not sufficient to dry the material in the roller hearth kiln after being preheated by the heat exchanger, the heater will start for further heating, so as to ensure that the temperature of the gas output to the roller hearth kiln is sufficient to dry the material. When it is detected that the temperature of the gas in the second intake main pipe is too high after being preheated by the heat exchanger, the unheated gas in the first intake main pipe is introduced through the intake bypass pipe and regulated by the three-way proportional valve, so as to ensure that the temperature of the gas entering the roller hearth kiln for drying the material is kept within a certain range. This solution can keep the temperature of the intake port of the kiln constant through system self-regulation, and reduces the product quality fluctuation caused by the change of the intake air temperature at the intake port due to seasonal changes. By adjusting the stable high-temperature waste gas and the unstable intake air volume of the kiln by the system, it can ensure that the air at the intake port is in a constant temperature state, so that the product quality remains stable during the sintering process. Description of the Drawings

[0013] For the convenience of understanding by those skilled in the art, the present utility model will be further described below with reference to the drawings.

[0014] Figure 1 It is a schematic diagram of the overall structure of the present utility model.

[0015] In the figure: 1, roller hearth kiln; 2, heat exchanger; 301, first intake main pipe; 302, intake bypass pipe; 303, second intake main pipe; 304, three-way proportional valve; 305, temperature sensor; 306, heater; 307, first blower; 308, second blower; 401, induced draft fan; 402, first exhaust pipe; 403, second exhaust pipe; 5, filtering device. Detailed implementation manners

[0016] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model, that is, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Usually, the components of the embodiments of the present utility model described and shown in the accompanying drawings herein can be arranged and designed in various different configurations.

[0017] Therefore, the detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the present utility model to be protected, but only represents the selected embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present utility model.

[0018] Please refer to Figure 1 As shown, in the embodiment of the present utility model, a roller hearth kiln waste heat recovery system includes a heat exchanger 2, a first exhaust pipe 402 and a second exhaust pipe 403. An induced draft fan 401 is provided on the first exhaust pipe 402 or the second exhaust pipe 403. One end of the first exhaust pipe 402 is connected to the exhaust port of the roller hearth kiln 1, and the other end is connected to the heat exchanger 2. The inlet end of the second exhaust pipe 403 is communicated with the first exhaust pipe 402 through the heat exchanger 2. The outlet end of the second exhaust pipe 403 is connected to the filtering device 5. The high-temperature waste gas discharged from the roller hearth kiln 1 is attracted by the induced draft fan 401, enters through the first exhaust pipe 402, undergoes heat conversion in the heat exchanger 2 to recover waste heat, and then the waste gas will be discharged into the filtering device 5 from the outlet end of the second exhaust pipe 403 and discharged to the outside after being filtered by the filtering device 5.

[0019] It further includes a first intake main pipe 301 and a second intake main pipe 303. One end of the first intake main pipe 301 is connected to a gas supply device, and the other end is connected to a heat exchanger 2. One end of the second intake main pipe 303 is communicated with the first intake main pipe 301 through the heat exchanger 2, and the other end is connected to the inlet of the roller hearth kiln 1. A three-way proportional valve 304 is provided on the second intake main pipe 303. An intake bypass pipe 302 is connected in parallel to the first intake main pipe 301, and the outlet of the intake bypass pipe 302 is connected to the three-way proportional valve 304. A temperature sensor 305 and a heater 306 are also provided on the second intake main pipe 303. The temperature sensor 305 is arranged between the three-way proportional valve 304 and the inlet of the roller hearth kiln 1, and the heater 306 is arranged between the temperature sensor 305 and the inlet of the roller hearth kiln 1. A first blower 307 is provided on the first intake main pipe 301 or the second intake main pipe 303, and a second blower 308 is provided on the intake bypass pipe 302.

[0020] It should be noted that all the devices in this solution are regulated by an external control system. When the devices are started, the external gas supply system starts to supply gas. Under the operation of the first blower 307, the normal-temperature gas enters through the first intake main pipe 301, undergoes heat conversion in the heat exchanger 2 to complete preheating, and then enters the roller hearth kiln 1 through the second intake main pipe 303 to dry the materials in the preheating chamber. The temperature sensor 305 can detect the gas temperature in the second intake main pipe 303. When it is detected that the gas temperature in the second intake main pipe 303 is still not sufficient to fully dry the materials after preheating, the heater 306 will be started to further heat the gas in the second intake main pipe 303, so as to ensure that the gas temperature output to the roller hearth kiln 1 is sufficient to complete the drying of the materials. When it is detected that the gas temperature in the second intake main pipe 303 is too high after heat conversion, the external control system will regulate the three-way proportional valve 304 and start the second blower 308 to introduce the normal-temperature hot gas in the first intake main pipe 301 through the intake bypass pipe 302 and mix it with the preheated gas. By regulating the three-way proportional valve 304, the gas temperature output to the roller hearth kiln 1 is controlled to maintain the gas temperature within a certain range, while ensuring the quality of material preheating and drying and avoiding affecting the material quality and wasting energy.

[0021] The above content is only an example and description of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them. As long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should all fall within the protection scope of the present invention.

Claims

1. A roller kiln waste heat recovery system, characterized in that: It comprises a first air intake main pipe, a second air intake main pipe, a first exhaust pipe, a second exhaust pipe and a heat exchanger, wherein one end of the first air intake main pipe is connected to an air supply device and the other end is connected to a heat exchanger, one end of the second air intake main pipe is connected to the first air intake main pipe through a heat exchanger, and the other end is connected to an inlet of a roller kiln, a three-way proportional valve is arranged on the second air intake main pipe, an air intake bypass pipe is connected in parallel to the first air intake main pipe, an outlet of the air intake bypass pipe is connected to a three-way proportional valve, a first blower is arranged on the first air intake main pipe or the second air intake main pipe, and a second blower is arranged on the air intake bypass pipe; One end of the first exhaust pipe is connected to the roller kiln exhaust port, and the other end is connected to the heat exchanger. The inlet end of the second exhaust pipe is connected to the first exhaust pipe through the heat exchanger. The first exhaust pipe or the second exhaust pipe is provided with an induced draft fan.

2. A roller kiln waste heat recovery system according to claim 1, characterized in that: The second air inlet main pipe is provided with a temperature sensor, and the temperature sensor is arranged between the three-way proportional valve and the roller kiln entrance.

3. The roller kiln waste heat recovery system according to claim 1, characterized in that: The second air inlet main pipe is provided with a heater, and the heater is arranged between the temperature sensor and the roller kiln entrance.

4. The roller kiln waste heat recovery system according to claim 1, characterized in that: The outlet end of the second exhaust pipe is connected with a filtering device.

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