Abstract: A flush sprinkler has a sprinkler unit raisable and lowerable in hydraulic manner in a shaft and, several nozzle units, which, as required, can be switched into a sprinkling state with an upper nozzle selecting handle and whose nozzle jets can be modified independently by a jet spreading member adjustable with an associated jet adjusting handle. There are also rings for varying a spray spreading angle as a function of size and position. The handles are raisable and lowerable with the sprinkler unit and therefore easily accessible. For cleaning the bearing of the sprinkler unit, an automatically valve-controlled flushing device is provided. For the reliable draining of the sprinkler, a drain valve is provided directly in the water flow and its body is clipped into a valve bore of the shaft.

Abstract: Wet scrubbing process for cleaning waste gases containing formaldehyde such as those produced in the manufacture of fiber glass insulation has substantial advantages over alternative thermal incineration process in that it requires less capital equipment expense and utilizes far less energy for handling equal volumes of waste gases. The gases are scrubbed in two scrubbing zones, the first of which contains hexamethylenetetramine and ammonium hydroxide to which ammonia is added and the second of which has water added to it. A part of the second scrubbing solution is introduced into the first scrubbing solution and a part of the first scrubbing solution is drawn off from the system.