Abstract: A slightly acid solution nebulizer comprises a gas generator, a reservoir device, a nebulization device and a cleaning device, wherein the gas generator generates chlorine gas by electrolyzing diluted hydrochloric acid, the reservoir device reserves water to be mixed with the chlorine gas to produce a hypochlorous acid solution, the nebulization device nebulizes the hypochlorous acid solution, and the cleaning device cleans the gas generator by leading the water reserved in the reservoir device to the gas generator after production of the hypochlorous acid solution.

Abstract: A surface hard coating composition for a synthetic resin lens including:(A) at least one organic silicon compound represented by the general formula ##STR1## wherein R.sup.1 is a hydrocarbon group having from one to six carbon atoms or an organic group including vinyl, methacryloyloxy or an epoxy radical, R.sup.2 is a hydrocarbon group having from one to four carbon atoms, R.sup.3 is a hydrocarbon or alkoxy alkyl group having from one to five carbon atoms or a hydrogen atom and l is 0 or one;(B) colloidal silica;(C) at least one poly functional epoxy compound; and(D) magnesium perchlorate.

Abstract: In the process of thermally cracking a heavy hydrocarbon oil by feeding said oil into a fluidized bed reactor as a high-velocity atomized gas stream by blowing said oil therein from a gas-mixing type nozzle along with an atomizing gas and carrying out the thermal cracking of the oil at above 500.degree. C., the improvement which comprises blowing in an inert gas to the eddying part formed in the environs of said atomized gas stream in said fluidized bed reactor thereby blocking the formation of eddies to thus prevent the accumulation of coke deposits on the outside wall of said nozzle and the walls of the fluidized bed reactor in the vicinity of said nozzle.

Abstract: A process for controlling the coke balance as well as the size of coke particles within a fluidized bed in the range adapted for continuous operation of a heavy residual oil cracking apparatus, wherein thermal cracking of heavy residual oil is performed under fluidization of coke particles and steam, which comprises classifying one portion of the coke particles withdrawn from the fluidized bed into coarse particles and fine particles by means of a pneumatic classifier, and after the size of said coarse particles have been reduced by combustion, returning them to the fluidized bed along with said fine particles.