Abstract: An arrangement for the controlled production of an essentially linear array of hydrocarbon feed injection jets maintains stable and reliable jets by passing individual piping for each jet through a support shroud that is located in a contacting vessel. Controlled atomization is provided by independently injecting a uniform quantity of gas medium into each of the plurality of uniformly created feed injection streams upstream of a discharge nozzle that separately discharges each mixed stream of hydrocarbons and gas medium into a stream of catalyst particles at or about the inner end of the support shroud. The feed injection jets are suitable for positioning in an inner location of a large contacting vessel. Uniformity of distribution is obtained by dividing the hydrocarbons streams from an oil chamber into an individual oil conduit for each spray injection nozzle. The individual oil conduits receive separate streams of a gas phase fluid that mixes with feed to pass the mixture to a spray nozzle.