Characterization of a Jacket Steam Injector to Avoid Water Hammer

Steam injection is an effective method of direct-contact heating, but it is subject to condensation-induced water hammer (CIWH). CIWH can create loud noise, severe vibration, and pressure spikes sometimes sufficient to rupture pipes, fittings, or connected equipment. The objective of this study was to determine the boundary of operating conditions void of CIWH. That boundary was represented by the process liquid outlet temperature at water hammer initiation (TWH). The steam injector used in this study was a steam-jacketed tube with orifices drilled in the wall of the inner tube. Experiments were conducted by recycling water or sucrose solution through the steam injector so that the temperature increased slowly to the point of water hammer, which was detected by rapid fluctuations in water pressure. For the range of experiment conditions studied, the number of injector orifices and the differential pressure between steam and liquid were found to have small or no effects on TWH. Liquid flow rate and liquid pressure were found to be good predictors, and one equation based on those two variables gave R2 = 0.916 when the process liquid was water. When sucrose solution was used as the process liquid, TWH increased more than what could be attributed to increased boiling point temperature. Experiments with segmented flow operation indicated that the segmenting barriers did not substantially affect TWH.