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Gaddis, J. L.

Publications and source records attributed to Gaddis, J. L..

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Hyperfiltration wash water recovery subsystem - Design and test results

The Hyperfiltration Wash Water Recovery (HWWR) subsystem, designed to offer low-power high-volume wash water purification for extended mission spacecraft, is discussed in terms of preprototype design and configuration. Heated wash water collected from the shower, hand wash, and laundry flows into a temperature-controlled (374 K) waste storage tank. Two parallel 25 micron absolute filters at the tank outlet remove large particles from the feed stream. A positive displacement feed pump delivers wash water to the hyperfiltration module at a constant flow rate of 0.20 lpm with discharge pressure variations from 4181-7239 Kpa. The hyperfiltration membrane module is a single-pass design including 36 porous stainless steel tubes, and is designed to provide an approximate water recovery rate of 90 percent. Permeate and brine water flows are monitored by flow meters, and removal of urea and ammonia is achieved by adding 15 percent NaOCl solution to the permeate fluid stream. An alternate module design using two diameters of tubing (allowing a smaller pressure drop and a larger membrane area) gave a superior predicted performance over the first module with larger tubing throughout.

Reysa, R. P.↗
NASA NTRS1979

Forming "dynamic" membranes on stainless steel

"Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

Brandon, C. A.↗
NASA NTRS1978

Dynamic hyperfiltration membranes for high-temperature spacecraft wash water recycle

The effect of operating parameters on the performance of the hyperfiltration membrane when operating on washwater was examined. The parameters were pressure, temperature, velocity, and concentration. Data taken included rejections of organic materials, ammonia, urea, and an assortment of ions. The membrane used was a dual layer, polyacrylic acid over zirconium oxide, deposited in situ on a porcelain ceramic substrate.

Gaddis, J. L.↗
NASA NTRS1975

Parametric evaluation of a dual-layer dynamic hyperfiltration membrane for recovery of spacecraft wash water at elevated temperature

Performance data consisting of solute rejections and product flux have been measured, as dependent on the operational parameters. These parameters were pressure, 5,000,000 N/sq m (750 psia) to 7,000,000 N/sq m (1040 psia); temperature, 347 K (165 F) to 368 K (200 F); velocity, 1.6 m/s to 10 m/s; and concentration (up to 14x). Tests were carried out on analog wash water. Data taken include rejections of organic materials (TOC), ammonia, urea, and an assortment of ions. The membrane used was a dual-layer, polyacrylic acid over zirconium oxide, deposited in situ on a porcelain ceramic substrate.

Brandon, C. A.↗
NASA NTRS1975

Parametric test of a zirconium (4) oxide-polyacrylic acid dual layer hyperfiltration membrane with spacecraft washwater

Performance data consisting of solute rejections and product flux were measured, as dependent on the operation parameters. These parameters and ranges were pressure (500,000 n/m2 to 700,000 n/m2), temperature (74 C to 95 C), velocity (1.6 M/sec to 10 M/sec), and concentration (up to 14x). Tests were carried out on analog washwater. Data presented include rejections of organic materials, ammonia, urea, and an assortment of ions. The membrane used was deposited in situ on a porcelain ceramic substrate.

Brandon, C. A.↗
NASA NTRS1972

Laboratory prototype flash evaporator

A laboratory prototype flash evaporator that is being developed as a candidate for the space shuttle environmental control system expendable heat sink is described. The single evaporator configuration uses water as an evaporant to accommodate reentry and on-orbit peak heat loads, and Freon 22 for terrestrial flight phases below 120,000 feet altitude. The design features, fabrication techniques used for the prototype unit, redundancy considerations, and the fluid temperature control arrangement are reported in detail. The results of an extensive test program to determine the evaporator operational characteristics under a wide variety of conditions are presented.

Gaddis, J. L.↗
NASA NTRS1972

Development of a laboratory prototype spraying flash evaporator.

A functional description of the flash evaporator that is being developed as a candidate for the Space Shuttle Environmental Control System thermal control is presented. A single evaporator configuration uses water as an evaporant to accommodate on-orbit peak heat loads and Freon 22 for terrestrial flight phases below 120,000 ft altitude. Development history, test plans, and operational characteristics are described. Detailed information is included to show: design features, fabrication techniques used for a prototype unit, redundancy considerations, and the control arrangement.

Gaddis, J. L.↗