Submerged Arc Furnace Flue Gas Waste Heat Utilization Technology

 

1. Technical name: Submerged arc furnace flue gas waste heat utilization technology

 

2. Scope of application: Iron and steel industry, silicon ferroalloy smelting, chemical calcium carbide industry, etc.

 

3. Current energy consumption in production links related to this energy-saving technology:

 

In 2008, my country's output of various ferroalloys was 19 million tons, and power consumption was approximately 110 billion kWh.

 

4. Technical content:

 

4.1.Technical principles

 

Through the waste heat recovery device, the high-temperature flue gas and radiant heat generated during the production process are used for secondary recycling, and medium and low-pressure steam is generated in the waste heat boiler, thereby driving the power generation equipment to generate electricity.

 

4.2. Key technologies

 

The high-temperature flue gas from the submerged arc furnace is introduced into the waste heat boiler, and the steam drives the steam turbine unit to generate electricity.

When the waste heat power generation equipment fails or is undergoing normal maintenance, the flue gas export conversion is performed to restore the existing dust removal state.

 

4.3. Process flow

 

The specific process flow is shown in Figure 1.

Figure 1 Schematic diagram of flue gas waste heat utilization system for silicon-based ferroalloy smelting submersible arc furnace

 

5. Main technical indicators:

 

16 sets of 14,000kVA submerged furnace waste heat utilization systems, with an annual power generation capacity of up to 192 million degrees.

 

6. Technology application:

 

This technology has been used in some ferroalloy companies. The technology is mature and the energy saving effect is significant.

 

7. Typical users and investment benefits:

 

Typical user: Qinghai Baitong High Purity Materials Development Co., Ltd.

 

Construction scale: 8 13-ton waste heat boilers, 24,000kW waste heat generating units and supporting facilities, with a designed annual power generation of 192 million degrees.

 

Main technical transformation content: dismantle all the original flue gas purification air coolers, install 8 13-ton waste heat boilers and related supporting pipe networks, install 24,000kW steam generators and supporting waste heat boilers and power transmission equipment, and transform the ferrosilicon ore furnace smoke hood, construction of cooling pools, cooling towers, chemical water treatment, water supply and drainage and corresponding civil works.

 

The main equipment is 16 14,000kVA submersible furnace hoods, 8 13-ton waste heat boilers, 24,000kW waste heat generating units and supporting facilities.

 

The investment in energy-saving technical transformation is 171 million yuan, and the construction period is 18 months.

 

It can save 67,200tce every year (calculated based on the annual power generation of 192 million kWh), the annual energy saving economic benefit is 61.44 million yuan, and the investment payback period is 2.5 years.