Cryostat "UV" Relief Valve Selection and Process Flow

This report describes the selection of the relief valves for the D-Zero cryostats. The selection was based on the flow requirements calculated in D-Zero engineering note 3740.214,224-EN-6 under fire conditions (1200 F, no vacuum) for the central cryostat; 264 SCFM. This value was calculated from section 5.3.5 of 'Pressure Relief Device Standards; S 1.3-Compressed Gas Storage Containers', published by the Compressed Gas Association, Inc. The flow calculated above is far greater than the required fire condition flow capacity of 264 SCFM. The improbable 70 F flow temperature value of 738 SCFM is still much greater than the required fire capacity. The flow capacity of the paralleled supplemental rupture disc is 2640 SCFM, independently greater than the fire condition flow requirement

A novel method of supplying nutrients permits predictable shoot growth and root: shoot ratios of pre-transplant bedding plants

BACKGROUND AND AIMS: Growth of bedding plants, in small peat plugs, relies on nutrients in the irrigation solution. The object of the study was to find a way of modifying the nutrient supply so that good-quality seedlings can be grown rapidly and yet have the high root : shoot ratios essential for efficient transplanting. METHODS: A new procedure was devised in which the concentrations of nutrients in the irrigation solution were modified during growth according to changing plant demand, instead of maintaining the same concentrations throughout growth. The new procedure depends on published algorithms for the dependence of growth rate and optimal plant nutrient concentrations on shoot dry weight Ws (g m–2), and on measuring evapotranspiration rates and shoot dry weights at weekly intervals. Pansy, Viola tricola ‘Universal plus yellow’ and petunia, Petunia hybrida ‘Multiflora light salmon vein’ were grown in four independent experiments with the expected optimum nutrient concentration and fractions of the optimum. Root and shoot weights were measured during growth. KEY RESULTS: For each level of nutrient supply Ws increased with time (t) in days, according to the equation {Delta}Ws/{Delta}t=K2Ws/(100+Ws) in which the growth rate coefficient (K2) remained approximately constant throughout growth. The value of K2 for the optimum treatment was defined by incoming radiation and temperature. The value of K2 for each sub-optimum treatment relative to that for the optimum treatment was logarithmically related to the sub-optimal nutrient supply. Provided the aerial environment was optimal, Rsb/Ro{approx}Wo/Wsb where R is the root : shoot ratio, W is the shoot dry weight, and sb and o indicate sub-optimum and optimum nutrient supplies, respectively. Sub-optimal nutrient concentrations also depressed shoot growth without appreciably affecting root growth when the aerial environment was non-limiting. CONCLUSION: The new procedure can predict the effects of nutrient supply, incoming radiation and temperature on the time course of shoot growth and the root : shoot ratio for a range of growing conditions

D-Zero Cryostat Supplemental Rupture Disc

The common relief and rupture disc vent line requires a double disc assembly with vented interspace for accurate disc burst pressures. The first disc must take pump and purge vacuum loading, but be set to operate at 110% of the MAWP, 18.3 psig (ASME code). The available solution is 18.3 psig with a burst tolerance of +/- psig. The interspace should be locally vented by a flow limiting vent valve to decouple the vent line backpressure from the vessel rupture disc. The second disc must take the worst case vent line backpressure, the steady state value found in D-Zero engineering note 3740.000-EN-63 with all three cryostats simultaneously venting at the fire condition into the 4-inch x 6-inch and 6-inch x 8-inch sections. This value is less than 2 psid. The maximum rupture value for the second disc must be less than the minimum rupture value for the first disc less 2 psid i.e. < 16.3

Specification for 20,000 Gallen Liquide Nitrogen Storage Tank

This specification defines the requirements for a liquid nitrogen storage tank to be installed at Fermilab, Batavia, Illinois

DAB, South Side, ODH Analysis

This report covers the ODH concerns of the south side of the D0 Assembly Building. from the bottom (el. 700-feet) to the top (774-feet 6-inches). volume by volume. Each volume is covered in its own section. with each section broken down into three parts. The first is a description of the volume. including its function. dimensions. and all relative ODH concerns; cryogenic piping and ventilation. Second. the actual ODH analysis of the volume is shown. Third. the provisions for the ODH condition of the volume are detailed. including securing the area and the posting of signs. The liquid argon dewar room is at an elevation of 701-feet 6-inch (38-feet underground), with the dewar surrounded by 7700 cubic feet of air. The area is accessible only through a single door. which has a small window and a lock (lock out only). There is small metal scaffolding in front of the dewar to facilitate maintenance and U-tube pulling and installation. The room is directly on top of the Pipe Chase Well and the Cryo Sump, and the bottom of the Stairway is just outside the door. The dewar is designed to be completely operated by remote computer control and the area will be unmanned during normal operation. Room occupancy will occur only during dewar or central control junction box maintenance, or U-tube changes. The dewar has these additions to it: 20 valves, 10 bayonet connections (or 5 U-tubes), 8 bolted flanges, 100 pipe sections (approx.). 100 brazed joints and welds (approx.). and 10 pipe elbows. In addition, 3 of the U-tubes will be changed twice a year on average

Technical Appendix to Cryogenic Pressure Vessels

The 20,000 gls. Liquid Argon dewar stores up to 15,000 gls. of high purity (<1.0 ppm O{sub 2}, 0.999995) LAr for use in the Liquid Argon calorimeters of E740, the D0 collider detector, at elevation 707-feet. The dewar provides for the total detector volume of 11,000 gls and a 4,000 gls. storage inventory. The large gas volume ({ge}5,000 gls.) serves operational needs and guards against overfill concerns. The LAr dewar functions in two modes: (1) low pressure (16 psi relief) storage, and liquid and gas transfer operations to and from the low pressure (13 psi relief) detector cryostats, and (2) high pressure (65 psi relief) liquid transfer operations to and from a delivery trailer at elevation 743-feet. The storage function is intended to be long term and nonventing. The dewar is equipped with a 40 kW LN{sub 2} condenser that operates to maintain the pressure constant in the storage mode. This service exactly parallels the NeH{sub 2} and D{sub 2} storage dewar services provided at the 15-feet bubble chamber for its operation

Cryostat "UV" Relief Valve Selection and Process Flow

This report describes the selection of the relief valves for the D-Zero cryostats. The selection was based on the flow requirements calculated in D-Zero engineering note 3740.214,224-EN-6 under fire conditions (1200 F, no vacuum) for the central cryostat; 264 SCFM. This value was calculated from section 5.3.5 of 'Pressure Relief Device Standards; S 1.3-Compressed Gas Storage Containers', published by the Compressed Gas Association, Inc. The flow calculated above is far greater than the required fire condition flow capacity of 264 SCFM. The improbable 70 F flow temperature value of 738 SCFM is still much greater than the required fire capacity. The flow capacity of the paralleled supplemental rupture disc is 2640 SCFM, independently greater than the fire condition flow requirement

Technical Appendix to Cryogenic Pressure Vessels

The 20,000 gls. Liquid Argon dewar stores up to 15,000 gls. of high purity (<1.0 ppm O{sub 2}, 0.999995) LAr for use in the Liquid Argon calorimeters of E740, the D0 collider detector, at elevation 707-feet. The dewar provides for the total detector volume of 11,000 gls and a 4,000 gls. storage inventory. The large gas volume ({ge}5,000 gls.) serves operational needs and guards against overfill concerns. The LAr dewar functions in two modes: (1) low pressure (16 psi relief) storage, and liquid and gas transfer operations to and from the low pressure (13 psi relief) detector cryostats, and (2) high pressure (65 psi relief) liquid transfer operations to and from a delivery trailer at elevation 743-feet. The storage function is intended to be long term and nonventing. The dewar is equipped with a 40 kW LN{sub 2} condenser that operates to maintain the pressure constant in the storage mode. This service exactly parallels the NeH{sub 2} and D{sub 2} storage dewar services provided at the 15-feet bubble chamber for its operation