Abstract: The efficiency of a furnace is determined by determining the percentage of the heat supplied to the furnace in the form of fuel which is lost due to a plurality of phenomena in the furnace operation. The thus determined efficiency may be displayed for use by an operator or may be utilized for automatic control of the furnace so as to substantially maximize the efficiency of the furnace.

Abstract: For continuous combustion air control in a hazardous waste incinerator, two signals are generated which totalize the air required on a fuel supplied basis. One signal is responsive to measured totalized fuel flow and this total can include fuel flow signals which are limited to the fraction of available air which corresponds to the fuel flow. The other signal is responsive to the totalized fuel flow that is commanded for maintaining an incinerator condition. In use the signal which requires the greater air flow is selected as the actual control signal for combustion air, and this control signal is biased to increase the air flow to obtain complete combustion of the hazardous waste by a controller acting on the measured amount of oxygen in the flue gas. In this manner the combustion air is manipulated in parallel with the waste fuel and if the fuel flow is limited by the available air, the air flow is limited to match the limited fuel flow.

Abstract: Boiler optimization is included in on-line control of parallel boilers by multiplying the total heat per unit time which must be supplied to all parallel boilers by the percentage of the total heat which should be supplied to each boiler in order to substantially maximize energy efficiency. The result of such multiplication is the heat per unit time which should be supplied to each boiler. The fuel and air supplied to each boiler is controlled so as to supply the thus determined heat per unit time which not only results in maintenance of a desired header pressure but also results in substantially maximizing energy efficiency of the parallel boilers.

Abstract: Boiler optimization is included in on-line control of parallel boilers by multiplying the total heat per unit time which must be supplied to all parallel boilers by the percentage of the total heat which should be supplied to each boiler by primary and secondary fuels in order to substantially maximize energy efficiency. The result of such multiplication is the heat per unit time which should be supplied to each boiler by the primary and secondary fuels. The fuel and air supplied to each boiler is controlled so as to supply the thus determined heat per unit time which not only results in maintenance of a desired header pressure but also results in substantially maximizing energy efficiency of the parallel boilers even where multiple fuels are combusted to supply heat.

Abstract: A desired ratio of offgas to fuel gas is maintained for a fuel mixture supplied to the burners associated with a boiler by venting steam as required to insure than all offgas may be combusted while maintained the desired offgas to fuel gas ratio. The venting of steam causes the fuel gas control, which is based on steam pressure, to vary the flow rate of the fuel gas so as to maintain the desired offgas-fuel gas ratio. Control of the combustion process for the boiler in this manner results in total combustion of the offgas without violating process constraints.

Abstract: The control of the actual liquid level in a boiler is accomplished by using the flow rate of the fuel to the combustion system associated with the boiler to generate a signal which is utilized to bias a control signal generated in response to steam flow rate and the output from a conventional level controller in such a manner that swell and shrink caused by changes in fuel flow rate is compensated for and the desired liquid level is maintained in the boiler.

Abstract: The flow rate of quench fluid in a furnace process is manipulated in response to the water content of process air.

Abstract: Carbon black process control system wherein in the preferred embodiment responsive to a determination of the humidity or water content in the free oxygen-containing gas flowing into the carbon black reactor two separate modes of control are calculated and a selection between the modes is made depending upon the influence each of the modes has on further properties of the overall operation. For example, the iodine number of the carbon black is controlled by either manipulating the air flow or the oil flow into the carbon black reactor to maintain the iodine number constant despite changes in the humidity and the selection between the two control modes (air flow control or oil flow control) is made in accordance with a determination of the respective conversion achieved.

Abstract: A batch distillation operation is automatically controlled from a start-up mode to a shut-down mode.

Abstract: A carbon black process control is described wherein in the preferred embodiment responsive to a determination of the humidity or water content in the free oxygen-containing gas flowing into the carbon black reactor two separate modes of control are calculated and a selection between the modes is made depending upon the influence each of the modes has on further properties of the overall operation. For example, the iodine number of the carbon black is controlled by either manipulating the air flow or the oil flow into the carbon black reactor to maintain the iodine number constant despite changes in the humidity and the selection between the two control modes (air flow control or oil flow control) is made in accordance with a determination of the respective conversion achieved.

Abstract: The flow rate of quench fluid in a furnace process is manipulated in response to the water content of process air.

Abstract: A batch distillation operation is automatically controlled from a start-up mode to a shut-down mode.