DIRECT OXYGEN INJECTION FOR METAL PRODUCTION

Injecting productivity directly into your business

Inject your business with one of our state-of-the-art systems that lowers costs and improves productivity in your electric arc furnaces (EAF) and cupolas. Introducing pure oxygen into your metal production operations can result in more efficient use of your resources, improved productivity and lower costs. And because our injection technologies have been installed worldwide, you can trust our expertise and experience to boost your business.

Our CoJet Gas Injection system uses a process and injector nozzle that delivers a 3- to 5-foot laser-like coherent jet of oxygen at supersonic speeds into the molten bath in an electric arc furnace. The fixed, wall-mounted injector nozzle retains the original diameter and velocity of the oxygen jet, delivering precise amounts of oxygen to the steel bath with less cavity formation and splash compared to traditional manipulators. Once the oxygen jet impinges on the steel bath, the concentrated momentum of the oxygen beam dissipates in the steel as fine bubbles, providing deep penetration and effective slag-metal mixing. The nozzle also operates as a conventional sidewall burner to melt scrap and as a supplemental oxygen source for post-combustion, improving furnace productivity and decreasing power consumption.

In addition, our CoJet Gas Injection Technology allows for automatic furnace operation, decreases metal production costs through lower power consumption, extended furnace life and decreased maintenance, and decreases refractory erosion, arc flare damage and maintenance gunning. It also enhances slag foaming, speeds decarburization, eliminates the need for lance manipulators, decreases splashing, and improves slag-metal stirring.

CoJet Technology for EAFs
CoJet Technology – Principles and Results
CoJet Installation at Sumikin Steel
CoJet Flame Guard Panel

Praxair's supersonic direct injection process blasts pure oxygen into the cupola, which pushes the combustion front toward the center of the cupola, resulting in more efficient use of energy resources. The process can be tailored to increase production, raise melting temperature or reduce coke — whatever is best for your business. For example, in one installation, conversion from conventional subsonic direct injection to the new supersonic process improved the metal-to-coke ratio nearly 10%. The net benefit to this customer was savings of almost $1 per ton in melting costs.

Direct Oxygen Injection Paper
Oxygen Use Technologies in Cupolas