Dry nitrogen seals

Dry Nitrogen Seal. The dry gas seal for the offshore platforms and LNG terminals use portable inert gas generators to reduce the emission of the greenhouse gases like methane. Compact membrane systems have been designed by various vendors for use in these hazardous environments. 

Contamination from Bearing Lubrication Oii. A barrier seal is required on the outboard side of the dry gas seal, between the gas seal and the compressor bearing. The primary function of the barrier seal, typically buffered with air or nitrogen, is to prohibit the flow of bearing lubrication oil into the gas seal. Contamination of the dry gas seal from lube oil can occur when the barrier seal fails to function as intended. 

The dry gas seal has one of two types of barrier seal (seal between the bearing and dry gas seal) either a labyrinth or single or double carbon rings. Normally the seal system includes provision to supply buffer gas to the barrier seal, also known as a separation seal. The gas to this seal is referred to as separation gas. One reason for choosing the carbon ring style bander seal is to keep the separation gas usage to a minimum. The gas is normally nitrogen. The basic control is by a direct-operated pres sure control valve. 

Beyond the complexities of the dispersive element, the equipment requirements of infrared instrumentation are quite simple. The optical path is normally under a purge of dry nitrogen at atmospheric pressure thus, no complicated vacuum pumps, chambers, or seals are needed. The infrared light source can be cooled by water. No high-voltage connections are required. A variety of detectors are avail-... 

While still slightly warm from the drying oven, the photolysis vessel with a water-jacketed quartz immersion well (Note 1) (section A of Figure 2) is charged with 500 ml. of anhydrous tetrahydrofuran (Note 2) and 10 ml. (8.05 g., 0.122 mole) of cyclopentadiene (Note 3). The solution is cooled in an ice bath and purged with dry nitrogen for 2 minutes. Then the vessel is sealed, the lamp inserted, and the solution irradiated at 0° for 30 minutes. During this period, sections B and C... 

Preparation of Emulsions. The entire aqueous phase was stirred until all solids were dissolved. Sufficient water was withheld from the formulation so small volumes of experimental and control components could be added to emulsion subsamples. Sulfuric acid (1 N) was added to the aqueous phase to decrease the pH to 5.7. The two phases in separate containers were blanketed with nitrogen, sealed, and heated to 75 in an 80 water bath (about 30 minutes). The hot oil phase was stirred slowly and blanketed with nitrogen, then the hot aqueous phase was quickly added while stirring. The emulsion was blanketed with nitrogen and slowly stirred (about 2 hours) in the stoppered container until ambient temperature ( 25 ) was reached. Subsamples of the master batch were removed for the addition of experimental components and stored in 1-oz containers. The containers had been washed with hot tap water, deionized water, and methanol, then dried at 120 . 

A solution of 10.5 g. (0.046 mol) of freshly distilled bis(tri-fluoromethyl)-l,2-dithiete (Note 2) in 200 ml. of n-pentane is cooled to —10° in a 1-1. round-bottomed flask equipped with an efficient reflux condenser and protected from moist air by a dry nitrogen blanket. A solution of 3.0 ml. (0.023 mol) of nickel carbonyl dissolved in 100 ml. of w-pentane is added down the condenser in one portion to this solution. The mixture is swirled to mix. An intense blue-violet color develops in about 15 to 20 seconds and after 1 to 2 minutes, vigorous evolution of carbon monoxide occurs. This evolution subsides in 10 minutes and the deep violet solution is allowed to warm to 0° during 2 hours to ensure complete reaction. Most of the pentane is removed by distillation at atmospheric pressure, the remaining 50 to 60 ml. is removed in vacuo (0.1 mm.), and the resultant crystalline mass is evacuated (0.1 mm.) at 50° for 4 hours. The crude product consists of shiny black-purple needles and weighs 11.8 g. (98%). Recrystallization from dry benzene (Note 3) gives shiny black crystals, m.p. 134 to 135° (sealed tube). The complex is air-stable but should be kept out of contact with moist air. 

A. (Tn fluoromethyl)trimethylsilane. A 2-L, three-necked flask is fitted with an efficient, over-head, sealed mechanical stirrer, a cold-finger condenser (30-cm in length and 8-cm in diameter) and a rubber septum (Note 1). The top outlet of the condenser is attached to an oil bubbler. The flask is flushed with dry nitrogen and charged with 118.8 g (1.09 mol) of chlorotrlmethylsilane (Note 2) in 100 mL of... 

All glass apparatus is dried in an oven at 100°C and assembled while still hot under dry nitrogen flow. All ground glass joints are tightly sealed with a Teflon tape and then wrapped with parafilm. 

The reaction is conducted in a 500-inl. three-necked flask equipped with a sealed mechanical stirrer, a dropping funnel, and a reflux condenser carrying a drying tube. The flask is flushed with dry nitrogen, and 104 g. (0.50 mole) of phosphorus pentachloride in 150 ml. of dry benzene is added. The mixture is cooled in an ice bath (Note 1) and stirred while a solution of 26 g. (0.25 mole) of styrene in 50 ml. of dry benzene is added... 

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