Washing


In early designs, the reaction heat typically was removed by cooling water. Crude dichloroethane was withdrawn from the reactor as a liquid, acid-washed to remove ferric chloride, then neutralized with dilute caustic, and purified by distillation. The material used for separation of the ferric chloride can be recycled up to a point, but a purge must be done. This creates waste streams contaminated with chlorinated hydrocarbons which must be treated prior to disposal.  [c.285]

As shown in Fig. 10.6, the vapor from the reactor flows into the bottom of a distillation column, and high-purity dichloroethane is withdrawn as a sidestream several trays from the column top. The design shown in Fig. 10.6 is elegant in that the heat of reaction is conserved to run the separation and no washing of the reactor  [c.286]

This procedure indicates the presence or lack of detergents in the fuel. In fact, when the fuel has additives, a large difference is observed between the weight of deposits before and after washing.  [c.242]

Existent gum content after washing  [c.301]

Hydrogen sulfide concentrates in refinery off gases. Before being used as fuel gas, the gas undergoes an amine (MEA, DEA, etc.) washing step in order to extract the H2S.  [c.405]

The corrosion rate of steel in carbonic acid is faster than in hydrochloric acid Correlations are available to predict the rate of steel corrosion for different partial pressures of CO2 and different temperatures. At high temperatures the iron carbonate forms a film of protective scale on the steel s surface, but this is easily washed away at lower temperatures (again a corrosion nomogram is available to predict the impact of the scale on the corrosion rate at various CO2 partial pressures and temperatures).  [c.94]

Coiled tubing can also be used to remove sand bridges and scale. Sometimes simple jetting and washing will suffice, and in more difficult cases an acid soak may be required. For very consolidated sand and massive scale deposits a small fluid-driven drilling sub can be attached to the coiled tubing. In extreme cases the production tubing has to be removed and the casing drilled out. Coiled Tubing Drilling (CTD) is explained in Chapter 3.  [c.355]

This study, carried out with coloured and fluorescent penetrants, is based on french standards NFA 09.520 and NFA 09.521. Some practical tests (removing of penetrant and over-washing) and sensitivity tests have been done for eaeh range of produet.  [c.621]

The over-washing test is performed on holes perforate reference block defined in standard NFA 09.521 and permits the evaluation of the resistance to over-washing of penetrants (see figure 2, annex 1).  [c.621]

The tables 3 and 4 give tire results of over-washing resistance tests.  [c.622]

Table 3 detected holes average number by fluorescent penetrants after over-washing  [c.622]

Table 4 detected holes average number by coloured penetrants after over-washing  [c.622]

The sensitivity test on nickel-chromium test blocks show that products which give bad results to over washing tests generally do not give good results to sensitivity tests.  [c.625]

MP-suspension by automated ASTM-bulb Magnetization current by Hall-Sensor Magnetization time UV-Light intensity All Liquids (fluorescence, contamination) Process times and temperatures Function of spraying nozzles, Level of tanks Flow rates (e.g. washing, water recycling) UV-Light intensity  [c.629]

New test, after these modification s, showed better measurements up to 350 m/min but now it also became evident that oil from the drawing process build up on the transducer surface and damped the signals and made measurements impossible. The oil build up as a combination of inspection length (m of tubes) and inspection speed. At lower drawing velocities (70 m/min) the oil obvious was washed away giving no inspection problems. The water system was modified as follows  [c.899]

Much of ordinary soil involves particulate, more or less greasy matter, and an important attribute of detergents is their ability to keep such material suspended in solution once it is detached from the fabric and thus to prevent its redeposition. Were this type of action not present, washing would involve a redistribution rather than a removal of dirt. Detergents thus do possess suspending power. For example, carbon suspensions that otherwise would settle rapidly are stable indefinitely if detergent is present, and similarly such other solids as manganese dioxide [235, 236]. Evidently, detergent is adsorbed at the particle-solution interface, and suspending action apparently results partly through a  [c.486]

A surfactant is known to lower the surface tension of water and also is known to adsorb at the water-oil interface but not to adsorb appreciably at the water-fabric interface. Explain briefly whether this detergent should be useful in (a) waterproofing of fabrics or (b) in detergency and the washing of fabrics.  [c.490]

The problem with the fiowsheet shown in Fig. 10.5 is that the ferric chloride catalyst is carried from the reactor with the product. This is separated by washing. If a reactor design can be found that prevents the ferric chloride leaving the reactor, the effluent problems created by the washing and neutralization are avoided. Because the ferric chloride is nonvolatile, one way to do this would be to allow the heat of reaction to raise the reaction mixture to the boiling point and remove the product as a vapor, leaving the ferric chloride in the reactor. Unfortunately, if the reaction mixture is allowed to boil, there are two problems  [c.285]

Rgure 10.6 The direct chlorination step of the vinyl chloride process using a boiling reactor eliminates the washing and neutralization steps and the resulting effluents. (From McNaughton, Chem. Engg., December 12, 1983, pp. 54-58 reproduced by permission.)  [c.286]

The existing gum content (NF M 07-004) is obtained by evaporating a 50 cm fuei sampie piaced in a constant temperature bath at 160°C while subjected to a stream of air for 30 minutes. After evaporation, the residue is weighed giving the unwashed gum content. An extraction with heptane foliows which leaves only the existing gums. The French specification concerns existing gums after washing and sets the upper limit at 10 mg/100 ml.  [c.242]

A first operation on the crude, desalting (washing by water and caustic), extracts salts (NaCl, KCl and the MgCb that is cdn eft4rdJt6 NaCl by the caustic), reduces acid corrosion as well as it minimizes fouling and deposits. /  [c.367]

The specimens have been cleaned according to the NFA 09.521 standard, dried at ambient temperature 5 minutes, immerged 10 minutes in the penetrant and hung up 10 minutes. The excess penetrant has been removed at the washing unit. The developer has been applied immediately after the drying, and the indications examination has been performed 5, 10 and 20 minutes after the developer application.  [c.623]

The removal tests show important variations between products which do not influence the results because all penetrant can be washed easily. Resistance test to over washing give an evaluation of the hanging up of the product on the pieee and because the washing is an operation realized by an operator for our applications, they permit to have a good idea on the influency of this operation on the end of the test one operator who washes too much a penetrant increases the probability to make the indications desappear.  [c.625]

After comminution, soluble impurities either inlrerent to tire raw materials or introduced during processing can be extracted by washing (e.g. witli water), followed by filtration [6, 21]. Chemical leaching and magnetic separation are also used to purify raw materials. In a more specialized process, a frothing agent can be used to promote differential adsorjDtion of impurity particles onto gas bubbles to separate out tire desired product [23].  [c.2765]

The most important example for ion exchange applications is the use of zeolites as detergent additives for tire removal of mainly Ca and partly Mg from washing waters. As an enviromnentally acceptable alternative, zeolites have taken over tire traditional role of sodium polyphosphate which was a major contributor to the eutrophication of waters. Zeolite A is mainly used for tliis purjDose and commercial syntlieses have been optimized for tire efficient preparation of large quantities from cheap, natural resources giving products witli a homogeneous crystal size below 5 pm. The annual global production for tliis application has reached several hundred thousand tons [33]. Important natural zeolite-based ion exchange applications comprise tire selective removal of ammonium from industrial and municipal wastewater and the removal of " Cs and Sr from radioactive wastewater [29].  [c.2788]

How well do these quantura-semiclassical methods work in describing the dynamics of non-adiabatic systems There are two sources of eiiors, one due to the approximations in the methods themselves, and the other due to errors in their application, for example, lack of convergence. For example, an obvious source of error in surface hopping and Ehrenfest dynamics is that coherence effects due to the phases of the nuclear wavepac kets on the different surfaces ar e not included. This information is important for the description of short-time (few femtoseconds) quantum mechanical effects. For longer timescales, however, this loss of information should be less of a problem as dephasing washes out this information. Note that surface hopping should be run in an adiabatic representation, whereas the other methods show no preference for diabatic or adiabatic.  [c.298]


See pages that mention the term Washing : [c.62]    [c.63]    [c.76]    [c.77]    [c.91]    [c.110]    [c.192]    [c.219]    [c.275]    [c.313]    [c.354]    [c.363]    [c.366]    [c.384]    [c.385]    [c.425]    [c.405]    [c.834]    [c.850]    [c.486]    [c.489]    [c.734]    [c.2310]   
Textbook on organic chemistry (1974) -- [ c.131 ]