Pulverized coal injection (PCI)

Pulverized Coal Injection (PCI) using the dense-flow method

The Küttner developed and perfected dense-flow method offers several advantages over a lower-density system. Higher injection rates are achieved with simultaneously lower coke rates, which can optimize the fuel costs of the blast furnace. In addition, dense-flow technology enables jerk-free and pulsation-free conveyance over long distances, with the best measuring and controllability, and low conveyor speeds in the entire system in the range of 5 m / s and thus in the area in which the wear practically comes to a standstill. Küttner's dense phase technology is based on 36 years of experience, and we have continuously and consistently developed and optimized our technology.

PCI optimization technologies

• OxyCoal

The targeted bringing together of the reactants high-percentage oxygen and injection coal in the right place is the core of this process. This achieves earlier ignition of the injected coal immediately upon exit from the lance and the overall gasification process starts. The sooner and the more completely this happens, the more coal can be blown into the blast furnace and the coke rate can be correspondingly reduced and thus the pig iron production costs are reduced. The photos show impressively the earlier ignition and thus the optimized injection process when using the Oxycoal technology.

• Reactive PCI / Reactive Oxycoal

Typically, fine coal with inert nitrogen is transported through the pneumatic delivery lines. This nitrogen escapes from the lance together with the coal and hinders the gasification reaction inside the coal jet. The targeted addition of reactive gas, which also participates in the gasification reaction, the gasification rate and thus the gasification amount of coal dust can be significantly increased. This patented injection system is called Kuttner Reactive PCI® / Kuttner Reactive Oxycoal®. Particularly suitable gases are hydrogen, converter gas or coke oven gas. Of course, other gases go if this is economically better represented. The positive influence of Reactive PCI and Reactive Oxycoal can be impressively observed on the optical and thermal images showing the blowing process in the blow mold.

• PCI upgrading:

PCI Upgrading is the systematic analysis of vulnerabilities in existing PCI assets and their individual optimization. The goals of individual optimization may be quite different, e.g. Implementation of dense-flow technology in entrained-flow systems, performance enhancements, optimization of control quality, conversion to another blast furnace, optimization of transport gas consumption, etc. It usually pays to show a PCI upgrade. For example, dense phase technology has been implemented in an existing PCI 4 blast line PCI plant at China Steel Corporation in Taiwan, which has significantly increased the rate of coal dust injection while reducing coke rate.

• Blowing in gases | Hydrogen, coke gas, etc.

By injecting gaseous substitute reducing agents, e.g. Hydrogen or coke gas in the blast furnace can kill two birds with one stone. On the one hand, the use of hydrogen or hydrogen-containing gases allows a significant improvement in the carbon footprint of the blast furnace and on the other hand can replace part of the coke by the cheaper hydrogen-containing gases. At the same time, blending hydrogen-containing gases with our Reactive PCI / Reactive Oxycoal technology provides maximum fuel cost optimization for the blast furnace. Overall, there is a win-win situation at the blast furnace: The emission of the greenhouse gas CO₂ is significantly reduced while economic or competitive pig iron production is being achieved.