Process variable

About: Process variable is a research topic. Over the lifetime, 3983 publications have been published within this topic receiving 43130 citations. The topic is also known as: process parameter.

Pilot process variable study of coolside desulfurization

Abstract: The Coolside desulfurization process is a dry sorbent injection technology developed for retrofit SO/sub 2/ control in coal-fired utility power stations. The process is low in capital and space requirements since, in its ideal configuration, the existing ductwork and particulate collector are used as the SO/sub 2/-sorbent reaction spaces. It has been developed through laboratory and 1 MW-scale field tests using hydrated lime as the primary process sorbent by Conoco Coal Research Division, the research branch of Consolidation Coal Company. The field work showed promising results with observed SO/sub 2/ removal ranging up to 80%. In order to optimize the process performance through improved understanding of the process fundamentals, Conoco constructed and is operating a 0.15 MW pilot test unit. This paper describes the results of a process variable test program, a first series of tests made in the pilot unit, and the unit operability observed during the test work.

System and method for automatic temperature control in vehicles using predictive coding

Abstract: A system and method for controlling temperature within a vehicle cabin include monitoring various temperature sensors to determine current operating conditions, determining a desired temperature or temperature range based on occupant input, dynamically estimating a temperature gradient based on changes in the current operating conditions over a predetermined time, predicting when the desired temperature or temperature range will be attained based on the gradient and the current operating conditions, and controlling a heating/cooling system based on the predicted time. Controlling the heating/cooling system may include shutting off the system at a predicted time, or turning on the system at a predicted time. The process of prediction can be linear, non-linear, or empirical, i.e., based on a table.

In-situ metrology system and method

Abstract: At least one dimensional characteristic of a workpiece is measured, in situ, while at least one surface of the workpiece is subjected to a finishing operation. The measurements are obtained using an interferometer that generates interfering wavefronts reflected from the front and rear surfaces of the workpiece. Variations in the optical thickness of the workpiece can be determined from the resulting interferogram. The resulting optical thickness data can be used directly and/or combined with other pre-acquired data about the workpiece to obtain information concerning a desired dimensional characteristic of the workpiece. This dimensional characteristic may be transmitted wavefront error, work surface smoothness, and/or work surface profile. These measurements then can be used to terminate the finishing process at an optimal time and/or to control the operation of the surface-finishing machine. The difference in temperature between a workpiece's work surface and the surface opposed to it can also be extracted from the metrology results when measured in conjunction with a witness sample or monitor plug which demonstrates a differing thermal deformation characteristic due to a different thickness or having a differing coefficient of thermal expansion. Preferably, the witness sample or monitor plug should be made from a material that is relatively insensitive to temperature changes with respect to the workpiece. This temperature differential then can be used to control the temperature of a finishing process parameter such as slurry temperature. A finishing process that incorporates in situ metrology can dramatically reduce the surface finishing process time as compared to conventional finishing processes.