Coal powder conveying and preheating device
Patent Information
- Application Number
- CN202521753407.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-18
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-08-18
AI Technical Summary
但是，煤粉气力输送多为稀相气力输送，最多也就是170kg/t，因此在气力输送管道中的大部分实际是气相，在管道外部设置的换热装置或加热装置实际上也是对气体进行加热，而后再由气相传热给固相才能实现对煤粉的加热，因此，加热效果并不好
[0012]本实用新型提供的煤粉输送预热装置，能实现对煤粉直接加热，并能保证在气力输送过程中煤粉的温度，能够提升对于气力输送的煤粉的加热效果，提升煤粉在高炉中的燃烧率。
Smart Images
Figure CN224787168U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of blast furnace smelting technology, and in particular to a pulverized coal conveying and preheating device. Background Technology
[0002] Blast furnace pulverized coal injection technology involves directly injecting finely ground pulverized coal into the blast furnace to replace scarce and expensive metallurgical coke, acting as both a heating agent and a reducing agent, thereby reducing the coke ratio and pig iron costs. However, as the injection rate increases, the pulverized coal injection ratio reaches a certain limit, after which the injected pulverized coal cannot be completely burned before the tuyeres. Unburned pulverized coal is carried out of the vortex zone by the rising gas and adheres to the slag in the slag formation zone, increasing the viscosity of the initial slag, worsening the permeability of the blast furnace charge, hindering smooth blast furnace operation, and even causing some carbon particles to be carried out of the furnace and wasted. Therefore, improving the combustion rate of pulverized coal before the tuyeres becomes crucial for further increasing the pulverized coal injection ratio.
[0003] Currently, pulverized coal injection in blast furnaces commonly uses pneumatic conveying. Pneumatic conveying involves injecting pulverized coal directly into the blast furnace through pipelines. The injected pulverized coal encounters the hot blast (temperatures above 1100℃) within the blast furnace, undergoing a heating process until ignition. Therefore, higher pulverized coal temperatures are more conducive to complete combustion. Thus, pulverized coal preheating is a crucial step.
[0004] Currently, many documents disclose preheating devices for pulverized coal pneumatic conveying. Generally, heat exchangers or heating devices are installed near the pneumatic conveying pipeline to preheat the pulverized coal during pneumatic conveying. However, pulverized coal pneumatic conveying is mostly dilute-phase pneumatic conveying, with a maximum flow rate of only 170 kg / t. Therefore, the majority of the gas in the pneumatic conveying pipeline is actually gas. The heat exchangers or heating devices installed outside the pipeline actually heat the gas, and then the gas phase transfers heat to the solid phase to heat the pulverized coal. Therefore, the heating effect is not good. Furthermore, during pneumatic conveying, the gas in the pipeline is also in a high-speed flow state, which cannot be effectively heated, thus further impairing the heating effect.
[0005] This invention aims to provide a pulverized coal conveying preheating device to improve the heating effect of pneumatically conveyed pulverized coal and increase the combustion rate of pulverized coal in the blast furnace. Utility Model Content
[0006] This invention provides a pulverized coal conveying preheating device to improve the heating effect of pneumatically conveyed pulverized coal and increase the combustion rate of pulverized coal in the blast furnace.
[0007] This utility model provides a pulverized coal conveying and preheating device, comprising: a pneumatic conveying pipeline leading to a blast furnace; a hot air source connected to the pneumatic conveying pipeline; an air pump installed on the pneumatic conveying pipeline and positioned between the hot air source and the blast furnace; a screw feeder with its outlet connected to the pneumatic conveying pipeline and positioned between the air pump and the blast furnace, its inlet connected to a pulverized coal silo, and a heat exchange module or heating module externally mounted on the screw feeder.
[0008] Furthermore, a heat exchanger is provided outside the screw feeder, and hot air or blast furnace exhaust gas is circulated inside the heat exchanger.
[0009] Furthermore, an electric heater is provided on the outside of the screw feeder.
[0010] Furthermore, an insulation material layer is provided on the outside of the pneumatic conveying pipeline.
[0011] Furthermore, a heat exchanger or electric heater is installed outside the pneumatic conveying pipeline.
[0012] The pulverized coal conveying preheating device provided by this utility model can directly heat pulverized coal and ensure the temperature of pulverized coal during pneumatic conveying, thereby improving the heating effect of pneumatically conveyed pulverized coal and increasing the combustion rate of pulverized coal in the blast furnace. Attached Figure Description
[0013] Figure 1 The diagram shown is a structural schematic of the pulverized coal conveying and preheating device according to the first embodiment of this utility model.
[0014] Figure 2 The diagram shown is a structural schematic of the pulverized coal conveying and preheating device according to the second embodiment of this utility model.
[0015] Figure 3 The diagram shown is a structural schematic of a pneumatic conveying pipeline in another embodiment of this utility model.
[0016] Figure label: 1: Pneumatic conveying pipeline; 11: Insulation material layer; 2: Air pump; 3: Screw feeder; 31: Inlet; 32: Outlet; 33: Pipe shell; 34: Spiral auger; 4: Heat exchanger; 41: Air inlet; 42: Air outlet; 5: Resistance wire heater. Detailed Implementation
[0017] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.
[0018] like Figure 1 As shown, this utility model embodiment provides a pulverized coal conveying and preheating device, including: a pneumatic conveying pipeline 1, which leads to a blast furnace; a hot air source, which is connected to the pneumatic conveying pipeline 1; an air pump 2, which is installed on the pneumatic conveying pipeline 1 and between the hot air source and the blast furnace; a screw feeder 3, whose outlet 32 is connected to the pneumatic conveying pipeline 1 and is located between the air pump 2 and the blast furnace, and whose inlet 31 is connected to the pulverized coal silo, and whose exterior is equipped with a heat exchange module or a heating module.
[0019] Powdered coal enters the screw feeder 3 from the pulverized coal silo through the feed inlet 31. The screw conveyor 34 conveys and agitates the pulverized coal. A heat exchange module or heating module outside the tube shell 33 heats the tube shell 33, thereby heating the pulverized coal and achieving direct heating. The heated pulverized coal then enters the pneumatic conveying pipeline 1 through the discharge outlet 32. An air pump 2 pumps hot air from a hot air source, which pneumatically conveys the pulverized coal. Since the hot air itself is sufficiently hot, it does not affect the temperature of the heated pulverized coal. With its temperature adequately guaranteed, the pulverized coal enters the blast furnace and achieves complete combustion.
[0020] In this embodiment of the invention, the heat exchange module or heating module directly heats the pulverized coal. Therefore, the pulverized coal can be fully preheated. During pneumatic conveying, hot air is used as the carrier. Therefore, there is no large heat transfer between the pulverized coal and the hot air, which fully protects the temperature of the pulverized coal.
[0021] Furthermore, such as Figure 1 As shown, a heat exchanger 4 is installed outside the screw feeder 3. The heat exchanger 4 can be filled with circulating hot air or blast furnace exhaust gas to achieve exhaust gas utilization. The airflow direction inside the heat exchanger 4 can be opposite to the material conveying direction in the screw feeder 3 to achieve full convective heat exchange.
[0022] Furthermore, such as Figure 2 As shown, an electric heater, such as a resistance wire heater 5, is installed outside the screw feeder 3 to fully heat the pulverized coal inside the tube shell 33. Figure 2 As shown, the resistance wire heater 5 can be protected in the heat exchanger 4, and the air that expands due to heat can also escape to the outside through the original air inlet 41 and air outlet 42.
[0023] Furthermore, such as Figure 3As shown, an insulation layer 11 is provided on the outside of the pneumatic conveying pipe 1 to reduce heat loss of the hot air during pneumatic conveying. Since the airflow velocity is very high during pneumatic conveying, the insulation layer 11 is generally sufficient to maintain the temperature of the hot air flow. Furthermore, a heat exchanger or electric heater can also be provided on the outside of the pneumatic conveying pipe 1 to heat the airflow in the pneumatic conveying pipe 1 to maintain its temperature.
[0024] The pulverized coal conveying preheating device provided by this utility model can directly heat pulverized coal and ensure the temperature of pulverized coal during pneumatic conveying, thereby improving the heating effect of pneumatically conveyed pulverized coal and increasing the combustion rate of pulverized coal in the blast furnace.
[0025] In the description of this utility model, it should be understood that the terms "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" and their orientation or positional relationships are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0026] This utility model has been described by the above-described embodiments; however, these embodiments are merely examples for implementing this utility model. It must be noted that the disclosed embodiments do not limit the scope of this utility model. Conversely, any modifications and refinements made without departing from the spirit and scope of this utility model are within the scope of patent protection of this utility model.
Claims
1. A pulverized coal conveying and preheating device, characterized in that, include: A pneumatic conveying pipeline leading to a blast furnace; A hot air source is provided, and the pneumatic conveying pipeline is connected to the hot air source. An air pump is installed on a pneumatic conveying pipeline and is located between a hot air source and a blast furnace. The screw feeder has its discharge port connected to a pneumatic conveying pipeline, with the discharge port located between the air pump and the blast furnace. The screw feeder's inlet is connected to a pulverized coal silo, and the screw feeder is equipped with a heat exchange module or heating module on its exterior.
2. The pulverized coal conveying and preheating device according to claim 1, characterized in that, A heat exchanger is installed outside the screw feeder, and hot air or blast furnace exhaust gas is circulated inside the heat exchanger.
3. The pulverized coal conveying and preheating device according to claim 1, characterized in that, An electric heater is installed on the outside of the screw feeder.
4. The pulverized coal conveying and preheating device according to claim 1, characterized in that, An insulation material layer is provided on the outside of the pneumatic conveying pipeline.
5. The pulverized coal conveying and preheating device according to claim 1, characterized in that, A heat exchanger or electric heater is installed outside the pneumatic conveying pipeline.