Transportation liquids

Safe handling techniques enable the transport liquid fluorine by the ton. 

Figure 16.1 shows part of a steel tank which came from a road tank vehicle. The tank consisted of a cylindrical shell about 6 m long. A hemispherical cap was welded to each end of the shell with a circumferential weld. The tank was used to transport liquid ammonia. In order to contain the liquid ammonia the pressure had to be equal to the saturation pressure (the pressure at which a mixture of liquid and vapour is in equilibrium). The saturation pressure increases rapidly with temperature at 20°C the absolute pressure is 8.57 bar at 50°C it is 20.33 bar. The gauge pressure at 50°C is 19.33 bar, or 1.9MN m . Because of this the tank had to function as a pressure vessel. The maximum operating pressure was 2.07 MN m" gauge. This allowed the tank to be used safely to 50°C, above the maximum temperature expected in even a hot climate. 

Figure 9-14. Unusual arrangement of relief valve and pipevimk on tank truck used to transport liquid carbon dioxide. The relief valve was cooled by the liquid and became blocked by ice from condensed atmospheric moisture. (Illustration courtesy of the Institution of Chemical Engineers.)...

Liquid-liquid extraction Bulk liquid membrane transport Liquid surfactant membrane transport... 

Two cases are considered. The first, the laminar flow of a thin film down an inclined surface, is important in the heat transfer from a condensing vapour where the main resistance to transfer lies in the condensate film, as discussed in Chapter 9 (Section 9.6.1). The second is the flow in open channels which are frequently used for transporting liquids down a slope on an industrial site. 

Concerning function integration, for example, micro-flow membrane reactors can exhibit similar process intensification, as shown already for their large-scale counterparts [75]. Separation columns for proteomics, immobilizing enzymes, utilize the large surface-to-volume ratios. Surface tension differences can guide and transport liquids selectively. 

Obviously the NPSH must be positive, or the liquid would be vaporized and the pump would be filled with gas. Since a pump is designed to transport liquids, if this happened it would just spin in its housing and no transfer would be accomplished. There is an increase in velocity as the liquid enters most pumps. This conversion of pressure energy to kinetic energy may reduce the pressure enough to cause fluids that have a positive NPSH to vaporize. Therefore, each pump has some minimum NPSH below which it will not operate properly. For most pumps an NPSH of 14 ft (4.2 m) of fluid is adequate. Some positive displacement pumps can operate at an NPSH of 6 ft (2 m). Use equation 5 to calculate the NPSH for each pump to be specified. 

A large variety of hose constructions are produced by the rubber industry for a wide range of applications. To contain transported liquids, usually under pressure, it is necessary to reinforce the hose construction with fabric, yam or short fibres to constrain expansion of the rubber. Although hand-built construction using fabric still represents a proportion of the production, it is also very common to use yams either braided or knitted directly onto the hose liner. For heavy duty purposes it is also necessary to use wire, in a braided form, to either reinforce or protect the hose from external damage. Use of short fibres as reinforcement represents a small proportion of hose production and requires specialised dies for extrusion to orientate the fibres circumferentially. 

A pipe transporting liquid is shown in Figure 4-6. A pressure gradient across the pipe is the driving force for the movement of liquid. Frictional forces between the liquid and the wall of the pipe convert kinetic energy into thermal energy. This results in a decrease in the liquid velocity and a decrease in the liquid pressure. 

For road transport, liquid hydrogen (LH2) is transported in cylindrical super insulated cryogenic vessels in a semitrailer (see Fig. 12.5). The gross weight of a truck capable of carrying the LH2 container is typically about 401. The investment for a LH2 semitrailer amounts to about 500 000. The investment for a tractor capable to haul a semitrailer is about 160000. Table 12.3 displays the technical characteristics of hydrogen trailers. 

Flow near the interface that is influenced by gradients of interface tension is called Marangoni convection. It may have further modes [27]. Thus, a low Marangoni convection in an interface, which results from small concentration differences, may be increased to a strong flow in the shape of rolling cells by mass transfer. These rolling cells transport liquid out of the... 

Processing of metals-contaminated feedstocks has been practiced since 1961 by Phillips at Borger, Texas. By 1981, 24 other units were using heavy oils in their FCC operations (29-30). At the present, it is believed that by 1989, 15-20 resid units will be operational and that by 1995, 25-30% of the world s FCC units will be partially operating as resid crackers (2). Refiners without the capability of converting resids and less costly oils into transportation liquids will probably suffer in a most competitive energy market. 

Before inventing his Dynamite in 1863, Alfred B. Nobel (1833 1896) proposed a rather safe method of transporting liquid NG. 

Pipeline transport involves the application of force to the material being moved, either through the use of pumps to transport liquids, compressors to move gases, or flowing water to move solids. In some applications, vacuum may create the pressure differential. 

Fig. 9.6. Schematic representation of die BEST system (Brnker Biospin see also [21]). 1, Bottle with transport liquid 2, dilutor 402 single syringe (5mL) with 1100 iL tube 3, dilutor 402 3-way valve 4, sample loop (250-500 pL) 5, 6-way valve (standard version) loading sample 6, 6-way valve (standard version) injecting sample 7, injection port 8, XYZ needle 9, rack for sample vials 10, rack for recovering vials 11, rack for washing fluids and waste bottle (3 glass bottles) 12, external waste bottle 13, flow probe with inner lock container 14, inert gas pressure canister for drying process.

In 1989, over 500,000 t/yr of ethylene were traded internationally. The principal exporting countries were in the Middle East, and the principal importing countries were in Western Europe and Asia/Pacific. The tanker fleet that transported the ethylene numbered approximately 30 vessels with capacities ranging from 2000—6500 t (110). These tankers are of the semi-refrigerated type, and transport liquid ethylene at atmospheric pressure and — 104°C. The tankers include reliquefaction plants on board since it is too expensive to vent ethylene. To accommodate the increase in international trade of ethylene, ethylene terminals have been built in the United States, Far East, Western Europe, and the Middle East with capacities of 35,000 t, 300,000 t, and 70,000 t, respectively (110). 

The assessment of the role of kf during protein adsorption in a fluidized bed may be performed with the help of a dimensionless transport number. Slater used the correlations provided by Rodrigues to simulate film transport limited adsorption of small ions to fluidized resins [54], In this study dimensionless groups were used to describe the influence of the system parameters particle side transport, liquid dispersion, and fluid side transport. Dispersion was accounted for by the column Peclet number analogous to Bo as introduced above and mass transport from the bulk solution to the resin was summarized in a fluid side transport number NL. 

Liquid-solid mass transport (liquid reactant) Amount of catalyst Catalyst particle size Concentration of reactant in liquid phase Temperature Agitation rate Reactor design Viscosity Relative densities Concentration of gas-phase reactant Concentration of active components on catalyst... 

The most widespread efforts made towards the achievement of selective oxidation of alkanes are targeted on methane, a principal constituent of natural gas f 6-8]. Activation of the very stable C-H bond of methane is a particularly demanding problem. One example in which this has been achieved on industrial scales is the Degussa process [9], Methane is coupled to ammonia by heterogeneous catalysis in order to produce HCN, an important fundamental material for industrial chemistry. An unsolved problem is the selective oxidation of methane to methanol a reaction that would convert the methane gas into a transportable liquid. In nature, monooxygenases have evolved. These are able to activate molecular oxygen and to... 

The basic reaction for conversion of syn gas to mixtures of hydrocarbons is called the Fischer-Tropsch reaction, used in Germany during World War II to produce fuel mixtures for diesel and gasoline engines. Since the 1950s South Africa has also used this reaction, and currently there is much interest in using it to convert natural gas (methane) to more easily transported liquids. 

Drawbacks of the RTP ports are that they cannot be hooked into the isolator clean in place (CIP) system so, they must always be considered dirty until an adequate cleaning procedure is developed. There are also size limitations to the RTP ports and their corresponding containers. Once a certain size port is selected for the isolator, this is the only diameter container that can be used, unless the isolator port is modified. The port also requires an additional penetration of the isolator wall and serves as another potential point for air leaks. In addition, the RTP containers are not amenable to the transport of flasks into and out of the isolator they require rotation and maneuvering of the RTP container to dock it into the isolator. Unless the port is mounted into the isolator floor, which will take up valuable space, the ability to transport liquids into and out of the isolator is limited to securely closed vials or bottles. The final limitation is the tendency of the seals on the mating surfaces of the RTP ports to become contaminated with potent material during transport operations. Procedures should be put in place to ensure that the mating surfaces of the RTP ports are thoroughly decontaminated as soon as the transport container is undocked from the isolator wall. 

The mesomixing time t , is the time for "significant mixing of an incoming jet of feed liquid with the surrounding fluid. A formula for estimating f , is the time for turbulent diffusion to transport liquid over a distance equal to the feed pipe diameter d0. 

Ureter Mucosa, muscularis, fibrosa Transports liquid waste... 

Downcomer top area, ft3. (Note In multipass trays, AD is the sum of the top areas of all downcomers transporting liquid from the trey.)... 

Develop simple models and experiments to find out how a wick works. (A wick is a string that transports liquid, such as in a candle. However, a wick can also transport liquid downwards.)... 

Catalysis has little direet impaet on transportation costs for a given produet. However eatalysis can be used to eonvert gaseous and solid materials that are expensive to transport into eheaper to transport liquids. Examples of this inelude the eonversion of methane in remote locations, via synthesis gas, into methanol or liquid hydroearbons [Sections 4.1.2 and 4.7]. 

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