Measuring pen for taking measurements on plans and drawings, etc

摘要

According to the invention there is provided an arrangement which can be used in particular in a media-mixing nozzle assembly intended for use with or to be incorporated in a contact reactor. The nozzle assembly enables a first medium to be mixed with a second medium. This medium mixture is used to clean a contaminated medium fed to the contact reactor, by bringing the contaminated medium into contact with the medium mixture, this mixture containing an absorbent which is capable of reacting with the contaminants in the contaminated medium. The first medium and the second medium are supplied under overpressure to a mixing chamber provided in the nozzle assembly and located upstream of the exit orifice of a nozzle. Located adjacent the exit orifice is a device for creating a boundary layer in that part of the medium which is present around the jet of medium and located adjacent the jet of medium and adjacent the exit orifice, in a manner to completely or partially prevent-recycling of the jet of medium to the wall surface of the nozzle assembly.