Splashing

Splashing losses often result from suddent liberation of large volumes of vapor in the two-phase mixture or below the liquid level. Splashing can frequently occur during startup or when liquid levels are permitted to rise for some reason. 

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Experiments involving the use of dimethyl sulphate should be carried out by students only under immediate supervision. Not only is the vapour of dimethyl sulphate highly poisonousy but the cold liquid itself is absorbed easily through the skin, with toxic results individual susceptibility to ditnethyl sulphate poisoning varies and may be very high. If the sulphate is splashed on to the hands, wash immediately with plenty of concentrated ammonia solution in order to hydrolyse the methyl sulphate before it can be absorbed through the skin (see p. 528). 

The main stem of the nitrometer widens into a bulb and then narrows to form a graduated tube. The usual graduation is of 8 ml. in o o2 ml. divisions. The graduations continue to the tap Tj at the top of the stem. Above Tj there is a small reservoir H to prevent splashing of the concentrated alkali when gas is expelled from the nitrometer and also to ensure that a small excess of potash is left as a liquid seal above the tap T ,. 

Fig. 11, 56, 9 depicts a splash head with a pear-shaped bulb and vertical delivery tube this is useful for steam distillation. The bottom cone is 24, 29 or 34 and the side cone is 19 or 24. 

CAUTION, Doth the vapour and the liquid dimethyl sulphate are highly poisonous. Inhalation of the vapour may lead to giddiness and even to more serious results. The cold liquid is easily absorbed through the skin, with toxic results. If the dimethyl sulphate is accidentally splashed upon the hands, wash immediately... 

Some unreaeted sodium may be left 011 the walls of the flask in this method and this may partly reduee soino produet, siieh as an alkylaeetylene, derived from the sodium acetylide. The preparation of sodamide is not attended by mueh splashing and little (if any) unreaeted sodium remains on the walls of the flask. Although more manipulation and a somewhat longer time is required for the sodamide method, the latter is generally preferred as it is more adaptable and somewhat less troublesome. 

To a vigorously stirred suspension of 4 mol of lithium amide (see II, Exp. II) in 2.5 1 of liquid ammonia were added in 25 min 2 mol of propargyl alcohol (commercially available, purified before use by distillation at 100-120 mm). The suspension became very thin. Subsequently, the dropping funnel was combined with a gas inlet tube reaching about 1 cm beneath the surface of the ammonia. The vent on the splashing tube was removed. Methyl iodide (2 mol) was added to the vigorous-... 

Vote 1. The long neck serves only to prevent the reaction mixture from splashing... 

In dynamic FAB, this solution is the eluant flowing from an LC column i.e., the target area is covered by a flowing liquid (dynamic) rather than a static one, as is usually the case where FAB is used to examine single substances. The fast atoms or ions from the gun carry considerable momentum, and when they crash into the surface of the liquid some of this momentum is transferred to molecules in the liquid, which splash back out, rather like the result of throwing a stone into a pond (Figure 13.2). This is a very simplistic view of a complex process that also turns the ejected particles into ions (see Chapter 4 for more information on FAB/LSIMS ionization). 

Eig. 3. Simulation parameters (a) splash onto cylindrical nosetip (b) attached wedge (—fixed -------, varied) and (c) detached wedge. See Table 3. 

Acetic acid is also transported ia barges, sometimes ia amounts of 1500 to 1750 tons. Acetic acid is not as hygroscopic as some other anhydrous organic substances, but barge shipments occasionahy have specification problems because of wave splashing iato the tanks or other careless handling. 

Acrolein vapor is highly irritating to the eyes, causing pain or discomfort in the eye, profuse lacrimation, involuntary blinking, and marked reddening of the conjunctiva. Splashes of Hquid acrolein will produce a severe injury to the eyeHds and conjunctiva and chemical bums of the cornea. 

In normal practice, good ventilation to reduce exposure to vapors, splash-proof goggles to avoid eye contact, and protective clothing to avoid skin contact are required for the safe handling of acrylic monomers. A more extensive discussion of these factors should be consulted before handling these monomers (67). 

A generic multipurpose fluidized bed is illustrated in Figure 2 (1). The soHds are contained in a vessel and gas is introduced into the system via a distributor, which is typically a drilled plate at the bottom of the vessel. A plenum chamber is provided below the distributor plate. The height of the soHds level above the distributor is called the bed height, and the vertical space above the bed height is called the freeboard. A splash zone may exist as a transition between the bed and freeboard. Cyclones, located either in the freeboard or external to the vessel, are used to remove soHds from the gas stream. Diplegs can return entrained soHds directly to the bed. 

Hydraziae is toxic and readily absorbed by oral, dermal, or inhalation routes of exposure. Contact with hydraziae irritates the skin, eyes, and respiratory tract. Liquid splashed iato the eyes may cause permanent damage to the cornea. At high doses it can cause convulsions, but even low doses may result ia ceatral aervous system depressioa. Death from acute exposure results from coavulsioas, respiratory arrest, and cardiovascular coUapse. Repeated exposure may affect the lungs, Hver, and kidneys. Of the hydraziae derivatives studied, 1,1-dimethylhydrazine (UDMH) appears to be the least hepatotoxic monomethyl-hydrazine (MMH) seems to be more toxic to the kidneys. Evidence is limited as to the effect of hydraziae oa reproductioa and/or development however, animal studies demonstrate that only doses that produce toxicity ia pregaant rats result ia embryotoxicity (164). 

The space immediately above the resin bed may or may not be filled with Hquid in downward flow systems, depending on the design. If not filled, water entering the column from the top and impinging on the upper surface of the resin bed forms hills and valleys unless the flow is dispersed over the cross-sectional area. A distributor similar to the one used to collect resin below the bed, or splash plate, is placed a short distance above the resin bed to improve the distribution of the process stream flow. 

Upon satisfactory deterrnination of nontoxicity of a lubricant, the USDA issues one of two ratings HI for use where there is incidental or possible food contact as by splashing or dripping from machinery above an edible product, or H2 for no food contact as in sealed gear boxes or machinery below a product line (82—84). These classes include a number of petroleum and synthetic oils and greases. 

Appropriate protective clothing and equipment should be worn to minimize exposure to methacrylate liquids and vapors. Chemically resistant clothes and gloves and splash-proof safety goggles ate recommended. The working area should be adequately ventilated to limit vapors. Should chemical exposure occur, contaminated clothing should be removed and the affected area washed with copious amounts of water. Medical attention should be sought if symptoms appear. Eurther information about methyl methacrylate and other methacrylates is available (141). 

Protective equipment and clothing such as face shields and gloves should be worn and safety showers should be available wherever there is a possibihty of being splashed or otherwise contacted by nickel-containing solutions. If dermatitis should occur, the possibiUty that it is nickel-related should be brought to the attention of a physician. 

Safety Showers. Safety showers and eyewash fountains or hoses should be installed where corrosive or toxic materials are handled. A large-volume, low velocity discharge from directly overhead should effect continuous drenching, ie, a minimum flow of 20 L/min (50 gal /min). Water to outside showers may be heated to a maximum temperature of 27°C by an electric heating cable. The valves for all safety showers should be at the same height and relative position to the shower head, and they should operate in the same way and direction. The shower station should be identified by paint of a bright, contrasting color. In areas where chemicals harmful to the eyes may be encountered, an eyewash fountain or spray should be available in case of splash accidents. 

Fatty amine products are normally shipped in 55-gal (208 L), lined and unlined, steel dmms or in tank cars or tank tmcks for bulk shipments. High melting amines can be flaked and shipped in cardboard cartons or paper bags. The amines are corrosive to skin and eyes. Protective splash goggles and gloves should be worn when handling these materials. 

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