Scrap Preheating EAF System Project of Tongling Fuxin Iron and Steel Co., Ltd.

Project Basic Information

• Project Name: Scrap Preheating EAF System Project of Tongling Fuxin Iron and Steel Co., Ltd.
• Release Date: 2023.6.23
• Processed Material: Scrap Steel
• Core Requirements: Improve scrap steel addition ratio, increase preheating temperature, match converter production rhythm
• Equipment Model: QSFZL2200*48000 Converter Scrap Preheating Vibrating Conveyor System
• Key Parameters: Heating and conveying capacity ≥150t/h, preheating temperature 700-800℃, scrap steel addition ratio increased to about 40%

I. Customer Background and Challenges

As a key regional iron and steel production enterprise, Tongling Fuxin Iron and Steel Co., Ltd. faced core pain points of low scrap steel utilization rate and limited production capacity in its converter steelmaking section. In the traditional steelmaking mode, the scrap steel preheating technology had obvious shortcomings: insufficient preheating temperature (mostly below 500℃), failing to break through the converter heat balance limit; the conveying speed did not match the converter production rhythm, leading to loss of scrap steel temperature when entering the furnace; the scrap steel addition ratio could only be maintained at about 20%, relying heavily on molten iron, which not only increased production costs but also restricted production capacity improvement.

At the same time, the customer’s on-site coal gas resources were not fully utilized, the thermal energy utilization rate of the traditional process was low, and the flue gas emission needed to be compatible with the existing dust removal system, putting forward strict requirements on the energy conservation, environmental protection and site adaptability of the equipment. The customer urgently needed a scrap steel preheating system that could actively control temperature and discharge volume, adapt to the existing site, and efficiently utilize energy to break through production bottlenecks, reduce production costs, and achieve clean production.

II. Our Solution

Based on its domestically pioneering advantages in scrap steel preheating technology and combined with the customer’s working conditions (coal gas calorific value 4300kJ/Nm³, industrial circulating water 350m³/h, etc.), Henan Quanshun Vibration Equipment Co., Ltd. tailor-made the QSFZL2200*48000 scrap preheating EAF system for the customer, realizing the whole-process coordination of “heating-conveying-insulation-discharging” and perfectly matching the converter production rhythm.

Core Advantages and Targeted Design of the System:

1. Three major technological breakthroughs, breaking industry limits: Breaking through the preheating temperature bottleneck, the scrap steel discharge temperature is stably maintained at 700-800℃; breaking through the discharge speed limit, accurately matching the converter operation to ensure the temperature of scrap steel entering the furnace; breaking through the heat balance limit, the scrap steel addition ratio is increased to about 40%, which is a domestic initiative.
2. High efficiency and energy saving, full utilization of resources: Burning blast furnace gas (natural gas optional) as the heat source, directly heating scrap steel during transportation, with thermal energy utilization rate exceeding 80%; supporting high-efficiency gas-gas heat exchanger to recover flue gas waste heat for combustion air preheating, further reducing energy consumption and meeting energy conservation and environmental protection requirements.
3. Stable and reliable, adapting to on-site working conditions: Adopting frequency conversion speed-regulating exciter (motor power 160kW), the conveyor vibration frequency adjustment range is 5-50Hz, and the horizontal amplitude is 20-28mm, ensuring uniform conveying of scrap steel; the total equipment layout length is 48m, and the internal cross-sectional size of the conveyor is 2200×800mm, accurately adapting to the customer’s site size and elevation requirements.
4. Safe and sealed, meeting environmental protection standards: Equipped with dynamic sealing device to form an air curtain to prevent flue gas overflow and air infiltration, the negative pressure at the interface is 267Pa, and the air volume is about 30000Nm³/min; the flue gas is connected to the existing dust removal system after preheating air, meeting environmental emission requirements.
5. Intelligent control, adapting to unattended operation: Adopting Siemens PLC automatic control system, integrating temperature, pressure, flow detection, video monitoring and CO detection alarm system, which can realize automatic/manual adjustment of the combustion system and conveying system, supporting unattended operation.

III. Core Equipment Parameters (QSFZL2200*48000)

IV. Implementation Effects and Customer Value

After the QSFZL2200*48000 scrap preheating EAF system was put into operation, it quickly became the core energy-saving and production-increasing equipment in the converter steelmaking section of Tongling Fuxin Iron and Steel, creating significant value for the customer:

1. Significant production capacity improvement: The scrap steel addition ratio increased from 20% to 40%, and under the same molten iron consumption, the converter steelmaking production capacity was significantly improved, meeting the customer’s capacity expansion needs.
2. Reduction of production costs: Reduced reliance on molten iron, significantly lowering the per-ton steel iron consumption cost; made full use of blast furnace gas resources, with thermal energy utilization rate exceeding 80%, further reducing energy consumption costs.
3. Efficient and stable operation: The system’s heating and conveying capacity is ≥150t/h, accurately matching the converter production rhythm without material shortage and shutdown; the service life of key equipment components (preheating section hood, vibration device, water-cooled trough) is ≥1 year, with low failure rate and controllable maintenance costs.
4. Compliance with environmental protection standards: The dynamic sealing and waste heat recovery design effectively inhibits flue gas overflow, and the flue gas emission is connected to the existing dust removal system, meeting environmental protection requirements; the equipment operates with low noise and energy consumption, complying with clean production standards.
5. Convenient and intelligent operation: The PLC automatic control system and HMI man-machine interface realize precise control of temperature, pressure and conveying speed; the video monitoring and CO detection alarm system ensure safe operation under unattended conditions.

V. Customer Evaluation

The QSFZL2200*48000 scrap preheating EAF system provided by Henan Quanshun Vibration Equipment Co., Ltd. has completely solved the long-standing industry problems of low scrap steel utilization rate and limited production capacity faced by us. The system achieves a stable preheating temperature of 700-800℃, and the scrap steel addition ratio is increased to 40%, which fully matches the converter production rhythm, making it a domestically pioneering efficient solution.

During the operation of the system, the thermal energy utilization rate is high, making full use of our factory’s blast furnace gas resources, with remarkable energy conservation and environmental protection effects; the intelligent control system is easy to operate, and the safety protection measures are in place. It has been stable and reliable since operation with extremely low failure rate. The technical team of Henan Quanshun provided full-process professional support from scheme design, on-site installation to commissioning and training, and the after-sales service response is rapid, truly making us worry-free and assured.

This scrap preheating EAF system not only improves our production efficiency and product competitiveness but also reduces comprehensive production costs, making it a high-quality equipment and partner worthy of long-term trust.

• Company: Henan Quanshun Vibration Equipment Co., Ltd.