Closed vessel

Mercury-sealed stirrers are used in the following operations (1) simultaneous stirring and refluxing of a reaction mixture (2) stirring the contents of a closed vessel (3) agitation with prevention of the escape of a gas or vapour and (4) stirring in an inert atmosphere, such as... 

Ethyl bromoacetate vapour is extremely irritating to the eyes. The preparation must therefore be conducted in a fume cupboard provided with a good draught the material should be kept in closed vessels as far as possible. 

When the closed vessel is heated to 390°C bottom and 330°C top, the resulting pressure is 170 MPa (25,000 psi) and a single fluid fills the vessel. It dissolves nutrient at the bottom and flows by convection, controlled by a baffle, to the upper region, where growth occurs at the lower temperature. A typical 4 cm x 152 cm x 1 mm thick seed plate grows to a 5-cm thickness in about 3 weeks in a 3-m long production vessel. 

Closed Vessels. Liquid level can be measured by the static pressure method also at non atmospheric pressures. However, ia such cases the pressure above the Hquid must be subtracted from the total head measurement. Differential pressure measuriag instmments that measure only the difference ia pressure between the pressure tap at the bottom of the tank and the pressure ia the vapor space are used for this purpose. At each tap, the pressure detected equals the Hquid head pressure plus the vapor pressure above the Hquid. Siace the pressure above the Hquid is identical ia both cases, it cancels out. Therefore, the change ia differential pressure measured by the instmment is due only to the change ia head of Hquid ia the vessel. It is iadependent of the pressure within the tank and is an accurate measure of the level. 

Halogenation. Succinic acid and succinic anhydride react with halogens through the active methylene groups. Succinic acid heated in a closed vessel at 100°C with bromine yields 2,3-dibromosuccinic acid almost quantitatively. The yield is reduced in the presence of excess water as a result of the formation of brominated hydrocarbons. The anhydride gives the mono- or dibromo derivative, depending on the equivalents of bromine used. 

The process of sulfurization is usually carried out by a sulfur bake, in which the dry organic starting material is heated with sulfur between 160 and 320°C a polysulfide bake, which includes sodium sulfide a polysulfide melt, in which aqueous sodium polysulfide and the organic starting material are heated under reflux or under pressure in a closed vessel or a solvent melt, in which butanol, CeUosolve, or dioxitol are used alone or together with water. 

Interaction between Gaseous and Condensed Phases. In a closed vessel of volume Ucontaining a nonionized, unexcited molecular gas having total number of molecules A/, the change in the pressure P in the gas can often be predicted if the steady-state absolute temperature Tis changed to another steady, constant level ... 

S has been approximated for flames stabili2ed by a steady uniform flow of unbumed gas from porous metal diaphragms or other flow straighteners. However, in practice, S is usually determined less directly from the speed and area of transient flames in tubes, closed vessels, soap bubbles blown with the mixture, and, most commonly, from the shape of steady Bunsen burner flames. The observed speed of a transient flame usually differs markedly from S. For example, it can be calculated that a flame spreads from a central ignition point in an unconfined explosive mixture such as a soap bubble at a speed of (p /in which the density ratio across the flame is typically 5—10. Usually, the expansion of the burning gas imparts a considerable velocity to the unbumed mixture, and the observed speed will be the sum of this velocity and S. ... 

At temperatures above 50°C, irreversible hydrolysis to formate and ammonia becomes important. If the heat of reaction is not removed, the increased temperature accelerates the decomposition and can create high pressure in a closed vessel. 

P F = plate and frame-type cell St Ves = stacked electrodes placed in a closed vessel. 

United States Filter Corp. Maxi-Flo Filter. The Maxi-Flo Filter is an example of the upflow closed-vessel design. Filtration rates to 0.0081 mV(m--s) [12 gaJ/(ft- min)] and filter cross-section areas up to 10.5 m" (113 ft") are possible. Deep-bed filtration has been reviewed... 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

Autoclave A closed vessel or reactor for chemical reaction to take place under pressure. 

Two types of boundary conditions are considered, the closed vessel and the open vessel. The closed vessel (Figure 8-36) is one in which the inlet and outlet streams are completely mixed and dispersion occurs between the terminals. Piston flow prevails in both inlet and outlet piping. For this type of system, the analytic expression for the E-curve is not available. However, van der Laan [22] determined its mean and variance as... 

Closed vessel One in whieh the rate of diffusion aeross the vessel entranee and exit boundaries is negligible eompared to the rate of eonveetive motion aeross the boundaries. 

Consider a lean phase, j, which is in intimate contact with a rich phase, i, in a closed vessel in order to transfer a certain solute. The solute diffuses from the rich phase to the lean phase. Meanwhile, a fraction of the diffused solute back-transfers to the rich phase. Initially, die rate of rich-to-lean solute transfer surpasses that of lean to rich leading to a net transfer of the solute from the rich phase to the lean phase. However, as the concentration of the solute in the rich phase increases. 

Morphothebaine, CigHigOgN. This tertiary base results from th( action of hydrochloric acid on thebaine at 80-90° in closed vessels, or ii a similar manner from codeinone. It forms colourless crystals, whicl become tinted green or blue when kept, m.p. 197° (dec.), [a]p ° — 130 (EtOH). The base furnishes a characteristic acid hydrochloride, Bg. 3HC1 colourless needles, m.p. 254-5°, which is converted by water or alcohol t< the normal hydrochdoride, B. HCl, minute needles, m.p. 256-60°. Th(... 

When heated with acetic anhydride in closed vessels at 180°, either base yields in addition to methylethylamine the same tetracetyl-di-sinomenol, C40H34O12, m.p. 253°, from which disinomenol, m.p. >310°, is readily obtained by hydrolysis. 

The reaction between 2,2 -biphosphole and dimanganese decacarbonyl was studied under different conditions [86JOM(316)271]. In boiling xylene and under inert atmosphere, the main product is the isomeric bis(ri -diphospholyl) complex 186, and complexes 187 and 188 are also produced. When performing the reaction in a closed vessel and at 420 K, the new tt complex 189 is formed. 

The same compound is obtained when proceeding according to the following alternative procedure. A mixture of 39.4 parts by weight of 2,4-dioxo-3,3-diethyl-5-oxymethylene-piperidine and 27 parts by weight of dibutylamine are heated to 150°C in a closed vessel. The 2,4-dioxo-3,3-diethyl-5-dibutylamino-methylene-piperidine formed melts at 77°C after having been recrystallized in petroleum ether. 

To 3.8 g of 2-methyl-3-(10,11-dihydro-5H-dibenzo[a,d] cycloheptene-5-ylidene)-1-pyr-roline, there were added 8 g of ethyl iodide. This mixture was placed into a closed vessel and heated at 80°C in a water-bath for one hour. After completing the reaction, the reaction mix-... 

To 5 grams of N,N -bis[1-methyi-3-(2,2,6-trimethylcyclohexyl)propyl]-N,N -dimethyl-1,6-hexanediamine dissolved in 100 ml of methanol, at 4°C, were added 100 ml methanol containing 10 grams of methyl chloride. The solution was heated in a closed vessel at 60°C for 15 hours. The colorless solution was concentrated and the resulting white solid crystallized from ethanol-acetonitrile-ether to obtain N,N -bis[1-methyl-3-(2,2,6-trimethylcyclo-hexyOpropyl] -N,N -dimethyl-1,6-hexanediamine bis(methochloride) hemihydrate. 

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