Positive pressure transfer

There was no significant damage to equipment in the fire tests, and it was demonstrated that a Jet Airmix mixer may safely handle the mixing of RP formulations on a routine basis. Since a high risk of fire is always associated with any method of transfer of RP, a pneumatic conveying system [dynamic air, two phase positive pressure transfer system was evaluated to load RP into the Jet Airmix mixer. Electrostatic charge measurements were minimal and indicated the system was satisfactory to load the blender. 

Pocket blotting, centrifugal transfer and vacuum or positive pressure transfer... 

Provide positive displacement feed pump instead of centrifugal pump or pressurized transfer... 

A dry 1-L, three-necked, round-bottomed flask equipped with a large Teflon-covered magnetic stirring bar, a thermometer, and a dry ice condenser (Note 1) is flushed with argon (Note 2), then capped with a serun stopper and subsequently maintained under a positive pressure of argon (Note 3). A 30 dispersion of lithium metal (in mineral oil) containing 1% sodium (13.9 g, 2.00 g-atom of lithium) (Note 4) is rapidly weighed and transferred to the flask. 

Contactor design is important in order to maximize the ozone-transfer efficiency and to minimize the net cost for treatment. The three major obstacles to efficient ozone utilization are ozone s relatively low solubility in water, the low concentrations and amounts of ozone produced from ozone generators, and the instability of ozone. Several contacting devices are currently in use including positive-pressure injectors, diffusers, and venturi units. Specific contact systems must be designed for each different application of ozone to wastewater. Further development in this area of gas-liquid contacting needs to be done despite its importance in waste treatment applications. In order to define the appropriate contactor, the following should be specified ... 

Rotary valves have been specified for the receivers of the vacuum pneumatic conveying systems (RV-601 and RV-602) and for the feeders (RV-40 1) and receivers (RV-501) of the positive-pressure system transferring powder from the dryers to the extruders. Perry72 gives some recommended sizes for rotary valves. The power required by all these valves will probably not exceed 2 kw and will be ignored. 

Start-up of the exhaust ventilation system and critical equipment must be sequenced to prevent a hazardous condition. In addition, the starting of the supply air handling unit and the exhaust fan services each room shall initiate simultaneously to avoid placing the room under positive pressure. Automatic transfer switching will be used. 

Supersaturated sodium aluminate solutions were prepared using an autoclave which was operated at 150 C and about 600 kPA. The hot caustic solution was filtered through three Whatman filter papers of 4 pm pore size under positive pressure. Three litres of the filtered solution was transferred to the crystallizer, maintained at a constant temperature, which was set for a particular run. 

Most of the product is transferred under a carbon monoxide atmosphere into a Schlenk tube (250 mL) the last traces of solid are recovered from the frit with the help of five 10-mL portions of DMF previously saturated with NaOH. A magnetic stirring bar and NaOH pellets (2 g) are introduced into the Schlenk tube, and the suspension is stirred at room temperature for 10h while maintaining a slight positive pressure of carbon monoxide, which must contain < 2 ppm of oxygen. 

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