Operation and Performance of the Solar Steam System at the Johnson & Johnson Plant in Sherman, Texas

A solar system that produces 174° C (345° F) steam is in operation at the Johnson & Johnson manufacturing plant in Sherman, Texas. The system uses parabolic trough collectors to heat pressurized water which then flashes to steam in a flash boiler; this steam is fed into the plant steam main for use in several manufacturing processes. The facility’s performance has been monitored continuously since it began operation in January 1980. The collector field typically has delivered energy to the flash boiler at an average daily efficiency of 30 to 40 percent, with an hourly average efficiency ranging from 38 to 42 percent at peak insolation periods. The daily and hourly values for energy collected and steam generated on a clear day in September are presented, as well as a monthly summary for the first 13 months of operation.

Sampling of High-Quality Wet Steam from Steam Mains Operating at 11·4 Bar Pressure

A venturi device was employed to strip and entrain liquid from the wall of a 3 in (7·5 cm) diameter steam main prior to isokinetic sampling. By injecting heated water into dry steam the wetness fraction was controlled between 1 and 5 per cent. Venturi convergence half-cone angles of 20, 30, 40 and 50° were employed and steam flow rates varied from 360–730 kg/h (800–1600 1b/h). Observations were made of the distribution through the test section of static pressure, recovered temperature and film thickness (for pressure 3·8 bar (55 1b/in2 absolute) only). Sampling across a diameter showed that under the most advantageous conditions the ratio, aggregate mass of entrained water: mass of injected water did not exceed 23 per cent. The optimum venturi half-cone angle lay between 40 and 50°. While capable of further development, the stripping-sampling principle seems unlikely to lead to significant improvements in wet steam sampling for quality.

Sampling of High-Quality Wet Steam from Steam Mains Operating at 11·4 Bar Pressure

A venturi device was employed to strip and entrain liquid from the wall of a 3 in (7·5 cm) diameter steam main prior to isokinetic sampling. By injecting heated water into dry steam the wetness fraction was controlled between 1 and 5 per cent. Venturi convergence half-cone angles of 20, 30, 40 and 50° were employed and steam flow rates varied from 360–730 kg/h (800–1600 1b/h). Observations were made of the distribution through the test section of static pressure, recovered temperature and film thickness (for pressure 3·8 bar (55 1b/in2 absolute) only). Sampling across a diameter showed that under the most advantageous conditions the ratio, aggregate mass of entrained water: mass of injected water did not exceed 23 per cent. The optimum venturi half-cone angle lay between 40 and 50°. While capable of further development, the stripping-sampling principle seems unlikely to lead to significant improvements in wet steam sampling for quality.

End Reactions and Stresses in Three-Dimensional Pipe Lines

The authors present a method for the numerical computation of the end forces and couples in a three-dimensional pipe line. The method takes care of a pipe line with any number of straight parts connected by bends. A procedure of computation is also shown when parts of the pipe line are skewed. The ends of the line may be partially or completely constrained against rotation and translation. A construction for the analysis of stresses in the pipe bends is given. The method is illustrated by a sample computation of the end forces and couples in a steam main which is restrained against thermal expansion.