Energy-saving system for car bottom type roasting furnace

Abstract

The utility model discloses a kind of car bottom type roasting furnace energy-saving systems, and the system includes multiple car bottom furnaces, intercommunication flue unit, oxygen supplement unit and oxygen content monitoring control unit.The intercommunication flue unit is conveyed to another target car bottom furnace hearth in high-temperature roasting stage by high-concentration volatile flue gas generated by one source car bottom furnace in low-temperature roasting stage through exhaust fume auxiliary flue, intercommunication flue and volatile fraction supplementary flue.The oxygen content monitoring control unit monitors target hearth oxygen content in real time, and accurately supplements oxygen by controller instruction oxygen supplement unit, ensures volatile stable, sufficient combustion.The utility model realizes the cascade and cross-furnace utilization of volatile chemical latent heat, significantly reduces the external fuel consumption of high-temperature furnace, achieves the purpose of energy saving and emission reduction, and the system has high integration, is safe and controllable, and is particularly suitable for carbon enterprise of multiple car bottom furnaces parallel production.

Description

Technical Field

[0001] This utility model relates to the technical field of car-bottom roasting furnaces, specifically to an energy-saving system for car-bottom roasting furnaces. Background Technology

[0002] Bottom-mounted calcining furnaces are key equipment for producing high-end carbon products (such as graphite electrodes and special graphite), and are widely used due to their advantages such as precise furnace temperature control, high product quality, and high production flexibility. However, their biggest disadvantage is their extremely high energy consumption; the energy consumption per ton of product can be more than twice that of traditional ring-type calcining furnaces, which seriously restricts their widespread application.

[0003] The main reason for the high energy consumption lies in its process characteristics: during the low-temperature heating stage of carbon products (300 to 500°C), a large amount of high-calorific-value combustible volatiles (mainly composed of pitch soot) are released. However, because the furnace is in a protective atmosphere that isolates oxygen during this stage, the volatiles cannot be burned. The traditional practice is to directly discharge the combustible volatiles and send them to a dedicated incinerator for treatment. This not only wastes the chemical energy it contains but also requires additional energy consumption for incineration. In the high-temperature heating stage above 700°C, the amount of volatiles released by the product itself is extremely small, and a large amount of external fuel needs to be burned to maintain rapid heating, resulting in concentrated energy consumption.

[0004] While existing technologies have attempted to utilize volatiles within a single furnace, the varying atmosphere and temperature requirements at different roasting stages make it difficult to achieve efficient, stable, and complete combustion of volatiles within a single furnace. For example, in the low-temperature stage where volatiles are generated in large quantities, the furnace temperature is already low, lacking the high-temperature environment and sufficient oxygen to ignite and sustain combustion. Forcibly adding a large amount of air to aid combustion may over-cool the furnace chamber, disrupting the roasting process curve. Therefore, there is an urgent need for a system capable of collaboratively utilizing energy across furnace chambers and stages to address these issues. Utility Model Content

[0005] This invention aims to solve the problem of excessive energy consumption in existing car-bottom roasting furnaces, particularly how to safely, efficiently, and directly utilize the high concentration of volatiles released from the products themselves as fuel within the furnace to replace some of the external energy consumption, while ensuring product quality and production safety.

[0006] To achieve the above technical objectives, the following technical solutions were adopted: This utility model provides an energy-saving system for a car-bottom type roasting furnace, including multiple car-bottom furnaces, a connecting flue unit, an oxygen supply unit, and an oxygen content monitoring and control unit. The connecting flue unit includes an auxiliary flue for exhaust gas installed on each car bottom furnace, a connecting flue for connecting different car bottom furnaces, and a volatile matter supplement flue installed on each car bottom furnace; the inlet of the auxiliary flue for exhaust gas is connected to the furnace chamber of the car bottom furnace, and its outlet is connected to the inlet of the connecting flue through a flue gas exhaust regulating valve; the inlet of the volatile matter supplement flue is connected to the outlet of the connecting flue, and its outlet is connected to the furnace chamber of the car bottom furnace; a volatile matter supplement regulating valve is installed on the volatile matter supplement flue. The oxygen supply unit includes an oxygen supply fan, an oxygen supply collection pipe connecting different car bottom furnaces, and an oxygen supply pipe installed on each car bottom furnace; the outlet of the oxygen supply fan is connected to the inlet of the oxygen supply collection pipe, the inlet of the oxygen supply pipe is connected to the outlet of the oxygen supply collection pipe, and its outlet is connected to the furnace of the car bottom furnace; an oxygen supply regulating valve is installed on the oxygen supply pipe. The oxygen content monitoring and control unit is installed on each car bottom furnace, including an oxygen content detection instrument, a sampling fan, and a controller; the inlet of the sampling fan is connected to the furnace chamber of the car bottom furnace through a sampling pipe, and a sampling switch valve is installed on the sampling pipe; the outlet of the sampling fan is connected to the oxygen content detection instrument; the signal input terminal of the controller is electrically connected to the oxygen content detection instrument, and its control output terminal is electrically connected to the oxygen replenishment regulating valve on the car bottom furnace.

[0007] Furthermore, the auxiliary flue is connected in parallel with the original main flue on the car bottom furnace, and the main flue is equipped with a main flue flue regulating valve; the outlet of the main flue is connected to a flue gas collection pipe, which is connected in sequence to the flue gas combustion equipment, the flue gas fan and the chimney.

[0008] Furthermore, each car bottom furnace is equipped with multiple volatile matter replenishment flues, the inlet of each of the volatile matter replenishment flues is connected to the outlet of the connecting flue, and the outlets are respectively connected to different positions in the furnace chamber of the car bottom furnace.

[0009] Furthermore, each car bottom furnace is equipped with multiple oxygen supply pipes, the inlet of each oxygen supply pipe is connected to the outlet of the oxygen supply main pipe, and the outlets are respectively connected to different positions in the furnace chamber of the car bottom furnace.

[0010] Furthermore, a cold air duct and a hot air duct are connected in parallel at the inlet of the oxygen supplement fan. A cold air switch valve is installed on the cold air duct, and a hot air switch valve is installed on the hot air duct.

[0011] Furthermore, the oxygen content detection instrument and sampling fan are designed to be externally mounted.

[0012] Compared with existing technologies, this utility model provides an energy-saving system for a car-bottom type roasting furnace. It has the following significant advantages: 1. Significant energy saving and consumption reduction: By directly introducing the volatile matter generated in the low-temperature furnace chamber into the high-temperature furnace chamber for combustion, the chemical energy of the volatile matter is efficiently recovered and utilized, and the external fuel consumption in the high-temperature stage is greatly reduced.

[0013] 2. High system integration and easy modification: This system can be built in conjunction with the existing car bottom furnace. It can be achieved by adding a connecting flue, oxygen supply and monitoring system, and the investment is relatively low.

[0014] 3. Safe and controllable: Through oxygen content monitoring and feedback control, the oxygen supplementation is precisely and dynamically adjusted, ensuring stable and complete combustion of volatiles in the furnace. At the same time, the oxygen concentration in the furnace is strictly controlled within a safe range, completely avoiding the risks of product oxidation, temperature runaway or deflagration.

[0015] 4. Easy maintenance: The oxygen content monitoring system is external and equipped with a valve to control the sampling timing, which effectively avoids the contamination and damage of precision instruments by tar generated at low temperatures, and improves the long-term reliability of the system. Attached Figure Description

[0016] The present invention will now be described in conjunction with the accompanying drawings.

[0017] Figure 1 This is a process flow diagram of the system of this utility model.

[0018] In the diagram: 1-Main flue exhaust regulating valve; 2-Auxiliary flue exhaust; 3-Auxiliary flue exhaust regulating valve; 4-Connecting flue; 5-Volatile matter replenishment flue; 6-Volatile matter replenishment regulating valve; 7-Sampling switch valve; 8-Oxygen content detection instrument; 9-Sampling fan; 10-Oxygen replenishment regulating valve; 11-Oxygen replenishment pipeline; 12-Oxygen replenishment collection pipeline; 13-Oxygen replenishment fan; 14-Cold air switch valve; 15-Hot air switch valve. Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. The described embodiments are merely some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] like Figure 1 As shown, the energy-saving system of the car-bottom type roasting furnace of this utility model mainly consists of multiple car-bottom furnaces (numbered 1#, 2#, 3#, ...#), a connecting flue unit, an oxygen supplementation unit, and an oxygen content monitoring and control unit; The original flue gas system is retained, including: each car bottom furnace is equipped with its own main flue gas duct, on which a main flue gas exhaust regulating valve 1 is installed. The main flue gas ducts of all car bottom furnaces eventually converge into a flue gas collection pipe. This flue gas collection pipe connects in sequence to the flue gas combustion equipment, the exhaust fan, and the chimney, forming a standard flue gas treatment and emission path.

[0021] The connecting flue unit consists of: each car bottom furnace has a secondary flue 2 connected to its furnace chamber, with a secondary flue flue regulating valve 3 installed at its outlet. All secondary flues 2 are connected to a common connecting flue 4. Additionally, each car bottom furnace has two volatile matter supplementary flues 5, with their inlets connected to the connecting flue 4 and their outlets leading to different locations within the furnace chamber. Each volatile matter supplementary flue 5 is equipped with a volatile matter supplementary regulating valve 6. The original main flue and secondary flues 2 are connected in parallel.

[0022] The oxygen supply unit consists of a shared oxygen supply fan 13, with its outlet connected to an oxygen supply manifold 12. Each car bottom furnace is connected to the oxygen supply manifold 12 via two oxygen supply pipes 11, the outlets of which lead to the furnace and are equipped with oxygen supply regulating valves 10. A cold air pipe and a hot air pipe are connected in parallel before the inlet of the oxygen supply fan 13, controlled by a cold air switch valve 14 and a hot air switch valve 15, respectively. This design aims to maximize fuel savings. The hot air comes from the waste heat recovery system of the flue gas incinerator or recovered waste heat from other process sections. By opening the hot air switch valve 15 and closing the cold air switch valve 14, high-temperature hot air can be supplied to the furnace as combustion air, further reducing the external fuel consumption required to maintain the furnace temperature. When the waste heat system is unavailable or under maintenance, the system can be switched to cold air mode by closing the hot air switch valve 15 and opening the cold air switch valve 14, ensuring the reliability and flexibility of the system under different operating conditions.

[0023] The oxygen content monitoring and control unit is independently equipped for each car bottom furnace. It includes an oxygen content detector 8, a sampling fan 9, a sampling switch valve 7, and a controller (not shown in the figure). The oxygen content detector 8 and the sampling fan 9 are externally mounted and connected to the furnace via a flue gas sampling pipe. The sampling fan 9 extracts furnace gas and sends it to the oxygen content detector 8 for analysis. The controller receives the oxygen content signal and outputs control commands to the oxygen supplementation regulating valve 10 on the car bottom furnace, forming a closed-loop control.

[0024] The working process of this utility model is as follows: Assuming that car bottom furnace #1 is in the low-temperature roasting stage at 400℃ and is generating a large amount of volatiles, it is identified as the source car bottom furnace. Car bottom furnace #3 is in the high-temperature roasting stage at 800℃ and requires a large amount of fuel, so it is identified as the target car bottom furnace.

[0025] 1. Establishing the volatile matter transport path: Open the auxiliary flue gas exhaust regulating valve 3 of the source car bottom furnace and appropriately close its main flue gas exhaust regulating valve 1. Simultaneously, open the two volatile matter supplement regulating valves 6 of the target car bottom furnace. At this time, the volatile matter flue gas generated by the source car bottom furnace, under the action of its own furnace negative pressure, enters the connecting flue 4 through the auxiliary flue gas exhaust duct 2, and is transported to the furnace of the target car bottom furnace through the two volatile matter supplement flue ducts 5.

[0026] 2. Monitoring and control: Open the sampling switch valve 7 of the target car bottom furnace, start the sampling fan 9 and oxygen content detection instrument 8, and monitor the oxygen content in the furnace in real time.

[0027] 3. Oxygen Supplementation Combustion: Start the oxygen supplementation fan 13, preferentially introducing hot air recovered from waste heat as the oxygen supplementation source, and open the hot air switch valve 15. The controller compares the monitored real-time oxygen content data with the set target oxygen content value. If the oxygen content is too high, the opening of the oxygen supplementation regulating valve 10 is reduced; if the oxygen content is too low, the opening is increased. Through this dynamic adjustment, the oxygen content in the target hearth furnace is precisely stabilized within the range of 0.5%-1.0%, ensuring that the volatiles are ignited and continuously burned, releasing heat, while avoiding excessive combustion that could lead to excessively high local temperatures or excessive oxygen consumption, thus affecting the product process.

[0028] 4. Switching and Cycling: After several hours, when the source furnace #1 finishes its low-temperature phase and its volatile matter production decreases, its auxiliary flue gas exhaust regulating valve 3 is closed, and the main flue gas exhaust is restored. Simultaneously, the volatile matter replenishment regulating valve 6 and sampling switch valve 7 of the target furnace #3 are closed. At this point, another furnace in the low-temperature phase can be selected from the system as a new source furnace, and another high-temperature furnace can be selected as a new target furnace. The above process is repeated to achieve continuous energy recycling for the entire furnace group.

[0029] Other aspects of this utility model that are not detailed herein are all conventional techniques known to those skilled in the art.

[0030] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0031] The scope of protection of this utility model is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this utility model shall fall within the scope of protection of this utility model.

Claims

1. An energy-saving system for a car-bottom type roasting furnace, comprising multiple car-bottom furnaces; characterized in that: It also includes a flue gas connection unit, an oxygen supply unit, and an oxygen content monitoring and control unit; The connecting flue unit includes a secondary flue (2) installed on each car bottom furnace, a connecting flue (4) connecting different car bottom furnaces, and a volatile matter supplement flue (5) installed on each car bottom furnace; the inlet of the secondary flue (2) is connected to the furnace chamber of the car bottom furnace, and its outlet is connected to the inlet of the connecting flue (4) through a secondary flue flue exhaust regulating valve (3); the inlet of the volatile matter supplement flue (5) is connected to the outlet of the connecting flue (4), and its outlet is connected to the furnace chamber of the car bottom furnace; a volatile matter supplement regulating valve (6) is installed on the volatile matter supplement flue (5). The oxygen replenishment unit includes an oxygen replenishment fan (13), an oxygen replenishment collection pipe (12) connecting different car bottom furnaces, and an oxygen replenishment pipe (11) installed on each car bottom furnace; the outlet of the oxygen replenishment fan (13) is connected to the inlet of the oxygen replenishment collection pipe (12), the inlet of the oxygen replenishment pipe (11) is connected to the outlet of the oxygen replenishment collection pipe (12), and its outlet is connected to the furnace of the car bottom furnace; an oxygen replenishment regulating valve (10) is installed on the oxygen replenishment pipe (11). The oxygen content monitoring and control unit is installed on each car bottom furnace, including an oxygen content detection instrument (8), a sampling fan (9) and a controller; the inlet of the sampling fan (9) is connected to the furnace chamber of the car bottom furnace through a sampling pipe, and a sampling switch valve (7) is installed on the sampling pipe; the outlet of the sampling fan (9) is connected to the oxygen content detection instrument (8); the signal input terminal of the controller is electrically connected to the oxygen content detection instrument (8), and its control output terminal is electrically connected to the oxygen supplementation regulating valve (10) on the car bottom furnace.

2. The energy-saving system for a car-bottom type roasting furnace according to claim 1, characterized in that: The auxiliary flue is connected in parallel with the original main flue on the car bottom furnace. The main flue is equipped with a main flue flue flue regulating valve (1). The outlet of the main flue is connected to a flue gas collection pipe, which is connected in sequence to the flue gas combustion equipment, the flue gas fan and the chimney.

3. The energy-saving system for a car-bottom type roasting furnace according to claim 1, characterized in that: Multiple volatile matter replenishment flues (5) are provided on each car bottom furnace. The inlet of each volatile matter replenishment flue (5) is connected to the outlet of the connecting flue (4), and the outlet is connected to different positions in the furnace chamber of the car bottom furnace.

4. The energy-saving system for a car-bottom type roasting furnace according to claim 1, characterized in that: Multiple oxygen supply pipes (11) are provided on each car bottom furnace. The inlet of each oxygen supply pipe (11) is connected to the outlet of the oxygen supply collection pipe (12), and the outlet is connected to different positions in the furnace chamber of the car bottom furnace.

5. The energy-saving system for a car-bottom type roasting furnace according to claim 1, characterized in that: The oxygen supplement fan (13) has a cold air pipe and a hot air pipe connected in parallel at the inlet front end. A cold air switch valve (14) is installed on the cold air pipe, and a hot air switch valve (15) is installed on the hot air pipe.

6. The energy-saving system for a car-bottom type roasting furnace according to claim 1, characterized in that: The oxygen content detection instrument (8) and the sampling fan (9) are externally mounted.

Images