A sintering plant silo steam preheating line

Abstract

The utility model belongs to sintering workshop storehouse technical field relates to a sintering workshop storehouse steam preheating pipeline, apply to storehouse, the storehouse is connected with a mixing machine, a mixing machine outlet is connected to two mixing machines, two mixing machine outlets are connected to the sintering machine, and one end of the sintering machine is connected with the ring cooling machine, and the other end is connected to the main exhaust room through the air supply pipeline, and an electric dust collector is arranged on the air supply pipeline, and the main exhaust room is connected with the chimney, a main steam input pipe is arranged on one side of the storehouse, a plurality of distribution branch pipes are communicated with the main steam input pipe, and a temperature detection device is arranged in the storehouse. The utility model preheats the steam by precisely spraying the steam into the material in the storehouse, uses the sintering waste heat steam, saves the energy and reduces the consumption, improves the mixing uniformity and the air permeability before sintering, improves the sintering efficiency and the quality, and effectively prevents the material from caking.

Description

Technical Field

[0001] This utility model belongs to the technical field of sintering workshop material silos, specifically relating to a steam preheating pipeline for sintering workshop material silos. Background Technology

[0002] Sintering is a raw material pretreatment process in the iron and steel smelting process. It involves mixing iron ore powder, flux, fuel and return ore in a certain proportion, and then igniting and venting the mixture to partially melt and bind it into sinter with sufficient strength.

[0003] Currently, most sintering plants in China generally adopt the "cold material sintering" mode, where raw materials at ambient temperature are directly conveyed into the mixer via belt conveyor. Inside the mixer, hot water or steam is sprayed to wet the mixture and form pellets. However, the contact between cold material and hot water causes a large amount of steam to condense, resulting in a limited temperature rise in the mixture, typically reaching around 40-50℃, which does not reach the ideal preheating temperature of 70℃. Moreover, after the low-temperature mixture enters the sintering machine trolley, it undergoes intense heat exchange with the high-temperature exhaust gas drawn in from the bottom of the material layer, producing a large amount of condensate. This condensate re-wets the already formed pellets, leading to excessive moisture in the lower part of the material layer and severely deteriorating its permeability.

[0004] To overcome the problem of excessively wetted layers and improve air permeability, a commonly used and effective technical approach in the industry is to preheat the mixture. The most common preheating method in existing technologies is to introduce low-pressure steam into the primary or secondary mixer. However, steam cannot fully and evenly contact all materials within the mixer, resulting in heating blind spots. Some steam escapes directly into the environment without heat exchange with the materials, leading to low thermal efficiency and wasted steam energy.

[0005] Existing equipment lacks real-time online monitoring and feedback of material temperature. Operators cannot accurately grasp the material temperature and can only operate based on experience, which easily leads to a mismatch between steam supply and actual demand. Insufficient supply results in poor preheating effect; excessive supply causes the material to become too wet, resulting in "clumping" and "caking," which in turn blocks the voids in the material layer and severely damages permeability. Introducing excessive steam into the primary mixer will over-wet the material, destroying the already formed mother pellets, which is not conducive to effective snowballing growth in the secondary mixer, ultimately affecting the particle size distribution and uniformity of the sintered material layer.

[0006] Therefore, a steam preheating pipeline for the sintering workshop silo is proposed to increase the temperature of the mixed material before it enters the furnace. Utility Model Content

[0007] The purpose of this utility model is to provide a steam preheating pipeline for sintering workshop silos, which has the advantages of uniform preheating and precise temperature control, and solves the problems of low thermal efficiency, energy waste and uneven heating that easily lead to material agglomeration in the existing technology of direct steam heating of mixtures.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a steam preheating pipeline for a sintering workshop silo, which is applied to the silo. The silo is connected to a mixer, the outlet of which is connected to a second mixer, and the outlet of the second mixer is connected to a sintering machine. One end of the sintering machine is connected to an annular cooler, and the other end is connected to the main exhaust room through an air supply pipe. An electrostatic precipitator is installed on the air supply pipe, and the main exhaust room is connected to a chimney. A main steam input pipe is provided on one side of the silo, and multiple distribution branch pipes are connected to the main steam input pipe. The distribution branch pipes are connected to the silo, and a temperature detection device is installed inside the silo.

[0009] Preferably, the temperature detection device is arranged in the silo to monitor the preheating temperature of the monitoring area, and the temperature detection device consists of multiple thermocouple temperature sensors.

[0010] Preferably, a flow control valve is provided on the main steam input pipe.

[0011] Preferably, the distribution branch pipe is a high-temperature resistant stainless steel pipe with a high-temperature resistant ceramic lining on the inner wall.

[0012] Preferably, the mixer is equipped with an atomizing water supply device.

[0013] Preferably, the device also includes a control unit, and the temperature detection device and flow control valve are all electrically connected to the control unit.

[0014] Preferably, the control device is a PLC controller or a DCS control system.

[0015] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0016] 1. This utility model uses distributed branch pipes to precisely inject steam into the material in the silo for preheating, utilizing the waste heat steam from sintering to save energy and reduce consumption, improve the uniformity and permeability of the mixing before sintering, improve sintering efficiency and quality, and effectively prevent material agglomeration.

[0017] 2. This utility model has the advantages of uniform preheating and precise temperature control, and solves the problems of low thermal efficiency, energy waste and uneven heating that easily lead to material agglomeration in the existing technology of direct steam heating of mixtures. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of the structure of a steam preheating pipeline in a sintering workshop silo, according to one embodiment.

[0020] In the above diagram, 1. silo, 2. primary mixer, 3. secondary mixer, 4. sintering machine, 5. annular cooler, 6. air supply duct, 7. main exhaust room, 8. electrostatic precipitator, 9. chimney, 10. main steam input pipe, 11. distribution branch pipe, 12. temperature detection device, 13. flow control valve, 14. atomizing water supply device, and 15. control device. Detailed Implementation

[0021] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein, and therefore the present invention is not limited to the specific embodiments disclosed in the following specification.

[0023] Example 1, as Figure 1 As shown, a steam preheating pipeline for a sintering workshop silo 1 is used to store pre-sintering mixtures, such as iron ore powder, flux, and return ore. Serving as a steam preheating reactor, the steam exchanges heat fully and evenly with the cold materials, preheating the entire material to the target temperature. The bottom of silo 1 is preferably designed with a conical structure to facilitate the concentrated falling of materials under gravity, preventing bridging and material accumulation. The outer wall of silo 1 is covered with an insulation layer, such as rock wool or aluminosilicate fiber felt, to reduce heat loss, improve thermal efficiency, and ensure stable preheating performance.

[0024] The silo 1 is connected to a primary mixer 2, the outlet of which is connected to a secondary mixer 3, and the outlet of the secondary mixer 3 is connected to a sintering machine 4. The primary mixer 2 receives material from the preheated silo 1 and its main function is wetting and preliminary mixing. Through rotational stirring, water, mineral powder, flux, fuel, etc., are initially mixed evenly, and small granule mother balls begin to form. Since the material has been preheated to a high temperature in the silo 1, the primary mixer 2 requires little or no steam heating. The secondary mixer 3 receives the preliminary mixture from the primary mixer 2 and its function is to enhance pelletizing. Through longer rolling and kneading, the small mother balls gradually form qualified small balls with a certain strength and particle size. The material from the primary mixer 2 has a suitable temperature and uniform moisture content, resulting in small balls with uniform particle size and high strength, providing a highly permeable material layer for the sintering machine 4.

[0025] One end of the sintering machine 4 is connected to the annular cooler 5, and the other end is connected to the main exhaust room 7 through the air supply duct 6. An electrostatic precipitator 8 is installed on the air supply duct 6, and the main exhaust room 7 is connected to the chimney 9. The annular cooler 5 cools the red-hot sinter discharged from the sintering machine 4 to a transportable temperature through the blower. While cooling the sinter, the blown-in cold air is heated into high-temperature exhaust gas, which is used to generate steam through the waste heat boiler as a steam source. The waste heat of the sintering process itself is used to preheat the raw materials, which in turn promotes the sintering process and achieves energy saving and consumption reduction.

[0026] Air supply duct 6 connects the air boxes of the four sintering machines and the main exhaust fan, serving as the collection and transport channel for high-temperature exhaust gases during the sintering process. The main exhaust chamber 7 provides the exhaust power source for the entire sintering process, generating a huge negative pressure that allows air to penetrate the sintering material layer from top to bottom, supplying the oxygen required for combustion and carrying away the exhaust gases. An electrostatic precipitator 8 is installed on the air supply duct 6 to remove particulate matter from the sintering flue gas. The purified flue gas is then discharged at high altitude through the chimney 9.

[0027] A main steam inlet pipe 10 is installed on one side of the silo 1. Multiple distribution branch pipes 11 are connected to the main steam inlet pipe 10 and are connected to the silo 1. A temperature detection device 12 is installed inside the silo 1. The main steam inlet pipe 10 introduces external steam, preferably from a waste heat boiler or power plant waste heat. The distribution branch pipes 11 evenly distribute the steam from the main steam inlet pipe 10 across the entire cross-section of the silo 1. Steam nozzles on the distribution branch pipes 11 inject steam into the material at a certain speed and direction. The distribution branch pipes 11 can be evenly distributed above the silo 1 in a ring, comb, or S-shape to ensure steam coverage of all areas. The temperature detection device 12 monitors the material temperature inside the silo 1 in real time, serving as a basis for controlling the steam flow rate.

[0028] Sintering machine 4 is the equipment for performing sintering. A trolley carrying the mixed material moves on sintering machine 4. After passing the ignition furnace, the exhaust system causes the material layer to undergo combustion and consolidation reactions from top to bottom, ultimately turning the mixture into sinter. The preheated hot material eliminates the "overly wet layer" in the trolley's material layer, significantly reducing airflow resistance. Improved permeability allows for increased exhaust negative pressure or faster trolley speed, directly increasing the output of sintering machine 4. Higher material temperature means less additional heat is needed for ignition and sintering. The sintering process is more uniform and complete, resulting in higher strength sinter and a lower return rate.

[0029] The specific design of the aforementioned key components will be discussed in detail below:

[0030] The temperature detection device 12 is arranged within the silo 1 to monitor the preheating temperature of the monitoring area. The temperature detection device 12 consists of multiple thermocouple temperature sensors. To accurately reflect the overall temperature gradient of the material within the silo 1 and avoid monitoring blind spots, the multiple thermocouple temperature sensors are arranged in a three-dimensional grid. Specifically, three monitoring layers—upper, middle, and lower—are set in the vertical direction of the silo 1; in the horizontal direction of each layer, at least a center point and 2-4 monitoring points near the silo wall are set. The temperature value of the lower monitoring point serves as the core feedback signal for the control system.

[0031] The thermocouples are armored K-type or S-type thermocouples, with protective sheaths made of wear-resistant and high-temperature-resistant 310S stainless steel. The thermocouple temperature sensors are installed on the silo wall 1 by oblique or vertical insertion, constructing a complete temperature field monitoring network to provide a real-time and reliable data foundation for the closed-loop control system.

[0032] The main steam inlet pipe 10 is equipped with a flow control valve 13. The flow control valve 13 is preferably an electric or pneumatic regulating valve. The valve body material matches the steam pipeline, and the valve core and seat of the valve internals are made of stainless steel SS304 to improve cavitation resistance and corrosion resistance. The flow control valve 13 has an equal percentage flow characteristic, achieving fine adjustment at small openings and rapid response at large openings, accurately regulating the steam flow rate, thereby controlling the total heat input to the silo 1.

[0033] The distribution branch pipe 11 is made of high-temperature resistant stainless steel pipe with a high-temperature ceramic lining on the inner wall. The base pipe of the distribution branch pipe 11 is made of high-temperature resistant stainless steel seamless pipe, material 310S, which can withstand temperatures above 1000℃ for long-term use. The inner wall is lined with a layer of corundum Cr2O3-based high-temperature resistant ceramic through a self-propagating high-temperature synthesis centrifugal casting process or thermal spraying process. The lining thickness is preferably 3-6mm, which has high hardness and excellent wear resistance and corrosion resistance. The ceramic lining greatly alleviates the erosion and corrosion of the pipe wall caused by high-temperature steam and material flow, extending the service life of the branch pipe by several times, and significantly reducing maintenance costs and downtime.

[0034] The diameter, spacing and angle of the steam jets on the distribution branch pipe 11 need to be designed by fluid calculation. The jets can be designed to be angled downwards at 45° or 60° so that the steam jet can effectively penetrate the material and promote its loosening, while avoiding direct blowing to the bin wall or causing material splashing.

[0035] In a preferred embodiment, the primary mixer 2 is equipped with an atomizing water supply device 14. The atomizing water supply device 14 mainly consists of a high-pressure water pump, water pipes, compressed air pipes, an air-water mixing atomizing spray gun, and nozzles. Water is mixed with compressed air under high pressure inside the spray gun and then sprayed out from a specially designed nozzle, forming an extremely fine water mist. This fine water mist can evenly cover the preheated material surface, greatly improving wetting efficiency and uniformity, avoiding localized overwetting, thereby forming high-strength, uniformly sized mother pellets, laying the foundation for optimized pelletizing in the secondary mixer 3.

[0036] It also includes a control device 15, a temperature detection device 12, and a flow control valve 13, all electrically connected to the control device 15. The control device 15 is a PLC controller or a DCS control system. The control device 15 forms the core, creating a complete closed-loop automatic control system. The main hardware of the system is a PLC controller or a DCS control system, and it also includes an analog input module for receiving thermocouple signals, an analog output module for controlling the regulating valve, and a human-machine interface touch screen.

[0037] The control system incorporates a PID controller. The operator sets the target temperature value for silo 1 on the human-machine interface touchscreen. The PLC collects signals from multiple thermocouples in real time, calculates a weighted average, compares it with the set value, and outputs a 4-20mA control signal to the flow control valve 13 based on the PID calculation results. This dynamically adjusts the valve's opening, achieving automatic, precise, and stable temperature control. This replaces the traditional manual operation based on worker experience and solves the problem of mismatch between steam supply and actual demand.

[0038] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0039] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A sinter plant silo steam preheating piping characterized in that, The material is used in a silo, which is connected to a mixer. The outlet of the mixer is connected to a second mixer, and the outlet of the second mixer is connected to a sintering machine. One end of the sintering machine is connected to an annular cooler, and the other end is connected to a main exhaust room through an air supply duct. An electrostatic precipitator is installed on the air supply duct, and the main exhaust room is connected to a chimney. A main steam input pipe is installed on one side of the silo, and the main steam input pipe is connected to multiple distribution branch pipes. The distribution branch pipes are connected to the silo, and a temperature detection device is installed inside the silo.

2. A sinter plant yard bin steam preheating conduit according to claim 1, characterized in that, The temperature detection device is arranged in the silo to monitor the preheating temperature of the area. The temperature detection device consists of multiple thermocouple temperature sensors.

3. A sinter plant yard bin steam preheat piping according to claim 1, characterized in that, A flow control valve is installed on the main steam input pipe.

4. A sinter plant yard bin steam preheating conduit according to claim 1, characterized in that, The distribution branch pipe is made of high-temperature resistant stainless steel pipe with a high-temperature resistant ceramic lining on the inner wall.

5. A steam preheating pipeline for a sintering workshop silo according to claim 1, characterized in that, The mixer is equipped with an atomizing water supply device.

6. A steam preheating pipeline for a sintering workshop silo according to claim 3, characterized in that, It also includes a control device, a temperature detection device, and a flow control valve, all of which are electrically connected to the control device.

7. A steam preheating pipeline for a sintering workshop silo according to claim 6, characterized in that, The control device is a PLC controller or a DCS control system.

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