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Reliable, efficient and accurate auxiliary fuel tuyere injection systems are vital for cost effective blast furnace operation. Paul Wurth is involved in the development and application of all forms of gaseous, liquid and solid fuel tuyere injection systems.
Some important aspects of Paul Wurth’s Pulverised Coal Injection (PCI) Technology are:
Paul Wurth has been involved in the development of PCI technologies since the early 1980s.
While different configurations of PCI plants can be provided - an important parameter is to achieve high control accuracy in the delivery of coal to the tuyeres.
Ongoing Paul Wurth development focuses on supporting blast furnace operation with injection levels above the 200 kg/thm target.
Simultaneous development is focused on improving the combustion/consumption of coal at the tuyeres.
Paul Wurth’s injection technology is based on our advanced ‘Dense Phase’ know-how resulting in minimum nitrogen consumption (reduced operating costs) and low coal conveying speed - resulting in low pipeline and component abrasion, very stable coal flow rates and reduced capital costs.
Paul Wurth has developed high coal rate flow control accuracy for the transport of coal to the furnace.
Similarly Paul Wurth has developed its PCI systems to enable excellent, high accuracy coal distribution to the tuyere injection lances.
Paul Wurth offers optical systems for detection of blocked tuyeres and for tuyere monitoring.
Paul Wurth has developed technologies to upgrade existing PCI systems to meet higher throughput or delivery accuracy requirements.
Paul Wurth PCI System Configurations – Basic Types:
1. Individual Flow Control System: Pulverised coal is fed by gravity from a storage bin into a single injection hopper. Individual feed lines from the injection hopper feed coal to each furnace tuyere. Closed loop flowrate control is provided for each individual feed line. This configuration provides the highest coal delivery accuracy to each tuyere injection lance.
2. Global Flow Control System with Static Distributor: Pulverised coal is fed by gravity from a storage bin into parallel injection hoppers (2 or 3 units). A common line conveys the coal from the hoppers to the distributor (static splitter). The coal flow rate in the common conveying line is closed loop controlled with in-line flow measurement and a Paul Wurth GRITZKO® flow control valve. A static splitter is located close to the furnace proper. Flow balancing tuyeres in the individual feed lines from the static splitter give excellent control of the distribution of coal to each tuyere injection lance.
3. Global Flow Control System with Dynamic Distributor: Rather than using the flow balancing tuyeres in the individual feed lines, this configuration uses in-line flow measurement and Paul Wurth GRITZKO® flow control valves to achieve even higher coal distribution accuracy.
Improvement of Coal Combustion/Consumption at the Tuyeres:
Paul Wurth offers oxycoal lance and coal pre-heating technologies to increase injected coal efficiency and throughput for the furnace process.
Plastic Waste Injection:
Paul Wurth has adapted its PCI technology to permit and optimise the injection of plastic waste into the blast furnace: This technology provides a real solution for recycling lower grades of plastic waste with attractive commercial benefits.
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