Abstract: A method and means for improved control of the process for directly reducing materials containing iron oxides in a rotary kiln using a solid carbonaceous reducing agent, such as coal, introduced from the charge feed and discharge ends of the kiln, as the source of both fuel and reductant, and oxygen-containing gas introduced along the kiln length is disclosed wherein the portion of the reducing agent fed at the discharge end is blown as a stream in a prescribed manner into the discharge end of the kiln. In particular, the important features of the stream are described including its longitudinal distribution and axial spread over the charge bed, as well as its contact region with the kiln walls and the quandrants of the kiln barrel into which it is directed, whereby the bed and gas phase temperatures may be controlled and heat transfer to the bed enhanced.

Abstract: A system for monitoring the internal conditions in a rotary kiln is disclosed wherein a series of sensors, such as thermocouples, are installed in ports at various longitudinal and angular coordinates along the total length of the kiln for providing temperature signal samples in the form of sequenced millivolt signals, and a single thermocouple is provided which is insertable in a second series of ports along the kiln to permit immediate localized temperature sensing. The sequenced millivolt signals and the single thermocouple millivolt signals are both fed to respective millivolt-to-milliamp converters mounted on a heat shield on the kiln surface, which shield also mounts two sets of continuous slip rings encircling the kiln. The respective milliamp signals are communicated from the converters to the respective slip ring sets from which they are picked off by suitable stationary contact means disposed adjacent the kiln and conducted to appropriate recorders in a control room.

Abstract: A method and means for maintaining optimum operation of the process for directly reducing iron oxides in a rotary kiln, using a solid carbonaceous reducing agent, such as coal fed at both the charge feed end and discharge end as the source of fuel and reductant, and oxygen-containing gases is disclosed wherein the DRI product, charred coal or char, and fine waste found in the kiln discharge materials from the discharge end are separated and measured for fixed carbon content and the process parameters may be adjusted to optimum by establishing an appropriate percentage by weight, in the range from 5% to 15%, of fixed carbon in the total of these discharge materials.

Abstract: A system for feeding coal or other material blown from a pipe in a desired trajectory is disclosed including a positioning device for applying directional force to the midsection of the pipe to produce slight bending for orienting the free end, which device has an horizontal adjustment member and a vertical adjustment member. Each comprising a slotted arm with an integral handle mounted on three congruent support plates and pivoted respectively in the interstices between the middle and outer plates. The plates have concentric circular openings therein through which a sleeve for passing the pipe therethrough axially extends.