Abstract: A ladder includes a leveler engages a bottom of each side rail for 1) causing extendable legs to move to a level ground-engaging position, 2) causing the legs to lock when both legs engage the ground, and 3) causing the extendable legs to move to a centered/retracted position when lifted from the ground. The leveler includes pawls, links, pinions, and a shaft forming a four-bar linkage for selectively moving the pawls inward to the disengaged position when the pinion and shaft are each freely rotatable, but selectively moving the pawl outward into locking engagement when the shaft resists movement due to ground engagement by both legs. The leveler can be constructed to attach to an inside of the side rails, thus facilitating pre-assembly.

Abstract: A ladder includes a leveler engages a bottom of each side rail for 1) causing extendable legs to move to a level ground-engaging position, 2) causing the legs to lock when both legs engage the ground, and 3) causing the extendable legs to move to a centered/retracted position when lifted from the ground. The leveler includes pawls, links, pinions, and a shaft forming a four-bar linkage for selectively moving the pawls inward to the disengaged position when the pinion and shaft are each freely rotatable, but selectively moving the pawl outward into locking engagement when the shaft resists movement due to ground engagement by both legs. The leveler can be constructed to attach to an inside of the side rails, thus facilitating pre-assembly.

Abstract: A method and/or apparatus for efficiently operating a combustion device including at least one control zone, with each control zone including at least one burner assembly, is disclosed and includes a) individually supplying fuel to each of the burner assemblies in each of the control zones, b) individually measuring a separate combustion characteristic of the collective combusted gas from each of the burner assemblies in each of the control zones, and c) individually adjusting the flow of air to each of the burner assemblies in response to the value of the combustion characteristic corresponding to each of the control zones to keep the value of each separate combustion characteristic within a predetermined range. In a preferred embodiment, primary air and secondary air are separately supplied and controlled to each of the burner assemblies in each of the control zones in response to the value of the combustion characteristic corresponding to each of the control zones.

Abstract: A process for recovering DCPD from a hydrocarbon feedstock comprising introducing the hydrocarbon feedstock to a first column, recovering an overhead stream from the first column comprising C9− hydrocarbons, recovering a bottom stream from the first column comprising C10+ hydrocarbons, feeding the bottom stream from the first column to a second column, recovering an overhead stream from the second column comprising DCPD, and recovering a bottom stream from the second column comprising fuel oil, wherein the two columns are sized and operated at defined conditions such as pressures, temperatures, reflux rates, and reboil rates.

Abstract: A hydrocarbon feedstock containing C5 olefins, C5 diolefins, CPD, DCPD, and aromatics is processed by the steps of heating a hydrocarbon feedstock containing CPD, DCPD, C5 diolefins, benzene, toluene, and xylene in a heating zone, to dimerize CPD to DCPD, thereby forming a first effluent; separating the first effluent into a C6+ stream and a C5 diolefin stream; separating the C6+ stream into a C6-C9 stream and a C10+ stream; separating the C10+ stream into a fuel oil stream and a DCPD stream; and hydrotreating the C6-C9 stream to thereby form a BTX stream.

Abstract: A system for removing sulfur from a hydrocarbon-containing fluid stream wherein desulfurization is enhanced by oxidizing certain organosulfur compounds of the hydrocarbon-containing fluid stream prior to desulfurization.

Abstract: An apparatus and a method for injecting an antifoulant has been developed for suppressing coke formation during pyrolysis in a cracking furnace. The apparatus and method result in the antifoulant being atomized and vaporized, which is critical for proper distribution of the antifoulant. The proper distribution of the antifoulant through this novel apparatus and method results in longer runtime and higher efficiencies for cracking furnaces.

Abstract: A process for desulfurizing middle distillates by charging a sulfur-containing middle distillate and a hydrogen-containing diluent to a reaction zone in respective amounts and under reaction conditions sufficient to vaporize substantially all of the sulfur-containing middle distillate present in the reaction zone. In the reaction zone, the vaporized middle distillate is contacted with a sorbent comprising a promoter metal and zinc oxide to thereby provide a desulfurized middle distillate comprising less sulfur than the sulfur-containing middle distillate initially charged to the reaction zone.

Abstract: A method and/or apparatus for efficiently operating a combustion device including at least one control zone, with each control zone including at least one burner assembly, is disclosed and includes a) individually supplying fuel to each of the burner assemblies in each of the control zones, b) individually measuring a separate combustion characteristic of the collective combusted gas from each of the burner assemblies in each of the control zones, and c) individually adjusting the flow of air to each of the burner assemblies in response to the value of the combustion characteristic corresponding to each of the control zones to keep the value of each separate combustion characteristic within a predetermined range. In a preferred embodiment, primary air and secondary air are separately supplied and controlled to each of the burner assemblies in each of the control zones in response to the value of the combustion characteristic corresponding to each of the control zones.

Abstract: A hydrocarbon feedstock containing C5 olefins, C5 diolefins, CPD, DCPD, and aromatics is processed by the steps of heating a hydrocarbon feedstock containing CPD, DCPD, C5 diolefins, benzene, toluene, and xylene in a heating zone, to dimerize CPD to DCPD, thereby forming a first effluent; separating the first effluent into a C6+ stream and a C5 diolefin stream; separating the C6+ stream into a C6-C9 stream and a C10+ stream; separating the C10+ stream into a fuel oil stream and a DCPD stream; and hydrotreating the C6-C9 stream to thereby form a BTX stream.