Dacron


Figure 1 gives an enthalpy-concentration diagram for ethanol(1)-water(2) at 1 atm. (The reference enthalpy is defined as that of the pure liquid at 0°C and 1 atm.) In this case both components are condensables. The liquid-phase enthalpy of mixing  [c.89]

Figure 5-1. Enthalpy concentration diagram for ethanol-water at 1.013 bar. Figure 5-1. Enthalpy concentration diagram for ethanol-water at 1.013 bar.
Figure 5-2. Enthalpy concentration diagram for ethanol-n-hexane at 1.013 bar. Figure 5-2. Enthalpy concentration diagram for ethanol-n-hexane at 1.013 bar.
Figure 5-3. Enthalpy concentration diagram for acetic acid-water at 1.013 bar. Figure 5-3. Enthalpy concentration diagram for acetic acid-water at 1.013 bar.
Table 1 gives the measured data, estimates of the true values corresponding to the measurements, and deviations of the measured values from model predictions. Figure 1 shows the phase diagram corresponding to these parameters, together with the measured data.  [c.100]

Figure 6-1. Calculated phase diagram for the acetone(I)-methanol(2) system. Figure 6-1. Calculated phase diagram for the acetone(I)-methanol(2) system.
Figure 3.1c is a schematic diagram of gravity settling chamber. A mixture of vapor or liquid and solid particles enters at one end of a large chamber. Particles settle toward the fioor. The vertical height of the chamber divided by the settling velocity of the particles must give a time less than the residence time of the air.  [c.69]

Figure 3.9a shows the temperature-composition diagram for a maximum-boiling azeotrope that is sensitive to changes in pressure. Again, this can be separated using two columns operating at different pressures, as shown in Fig. 3.96. Feed with, say, rpA = 0.8 is fed to the high-pressure column. This produces relatively pure A in the overheads and an azeotrope with xba = 0.2, Xbb = 0.8 in the bottoms. This azeotrope is then fed to a low-pressure column, which produces relatively pure B in the overhead and an azeotrope with 3 ba = 0.5, BB = 0.5 in the bottoms. This azeotrope is added to the feed to the high-pressure column. Figure 3.9a shows the temperature-composition diagram for a maximum-boiling azeotrope that is sensitive to changes in pressure. Again, this can be separated using two columns operating at different pressures, as shown in Fig. 3.96. Feed with, say, rpA = 0.8 is fed to the high-pressure column. This produces relatively pure A in the overheads and an azeotrope with xba = 0.2, Xbb = 0.8 in the bottoms. This azeotrope is then fed to a low-pressure column, which produces relatively pure B in the overhead and an azeotrope with 3 ba = 0.5, BB = 0.5 in the bottoms. This azeotrope is added to the feed to the high-pressure column.
Figure 8.7 Optimization using a contour diagram. Figure 8.7 Optimization using a contour diagram.
All too often safety and health (and environmental) considerations are left to the final stages of the design. Returning to the hierarchy of design illustrated by the onion diagram in Fig. 1.6, such considerations would add another layer in the diagram outside the utilities layer. This approach leaves much to be desired.  [c.255]

The two inner layers of the onion diagram in Fig. 1.6 (the reaction and separation and recycle systems) produce process waste. The process waste is waste byproducts, purges, etc.  [c.274]

The outer layer of the onion diagram in Fig. 1.6 (the utility system) produces utility waste. The utility waste is composed of the products of fuel combustion, waste from the production of boiler feedwater for steam generation, etc. However, the design of the utility system is closely tied together with the design of the heat exchanger network. Hence, in practice, we should consider the two outer layers as being the source of utility waste.  [c.274]

Figure 11.4 Schematic diagram of flue gas recirculation. Figure 11.4 Schematic diagram of flue gas recirculation.
Figure 16.1 The grid diagram for the data from Table 6.2. Figure 16.1 The grid diagram for the data from Table 6.2.
Figure 16.4a shows the grid diagram with a CP table for design above the pinch. Cold utility must not be used above the pinch, which means that hot streams must be cooled to pinch temperature by recovery. Hot utility can be used, if necessary, on the cold streams above the pinch. Thus it is essential to match hot streams above the pinch with a cold partner. In addition, if the hot stream is at pinch conditions, the cold stream it is to be matched with must also be at  [c.366]

In Chap. 6 it was discussed how the use of multiple utilities can give rise to multiple pinches. For example, the process from Fig. 6.2 could have used either a single hot utility or two steam levels, as shown in Fig. 6.26a. The targeting indicated that instead of using 7.5 MW of high-pressure steam at 240°C, 3 MW of this could be substituted with low-pressure steam at 180°C. Where the low-pressure steam touches the grand composite curve in Fig. 6.26a results in a utility pinch. Figure 16.17a shows the grid diagram when two steam levels are used with the utility pinch dividing the process into three parts.  [c.381]

Batch processes can be synthesized by first synthesizing a continuous process and then converting it to batch operation. A Gantt (time-event) diagram can be used to identify the scope for improved equipment utilization and the need for intermediate storage.  [c.401]

The streams (including utilities) are drawn in a grid diagram which shows the intervals, their Nk values, and the pinch location.  [c.441]

The diagram shows the method applied to butan-2-ol, for which the laevorotatory ( —) isomer is known to have the (R)-configuration.  [c.288]

Proteins consist of large numbers of amino-acids joined by the p>eptide link —CO —NH — into chains, as shown in the diagram, where R and R" are amino-acid residues. These chains are called peptides and may be broken into smaller chains by partial hydrolysis (see peptides). Proteins may contain more than one peptide chain thus insulin consists of  [c.332]

Asphaltenes are obtained in the laboratory by precipitation in normal heptane. Refer to the separation flow diagram in Figure 1.2. They comprise an accumulation of condensed polynuclear aromatic layers linked by saturated chains. A folding of the construction shows the aromatic layers to be in piles, whose cohesion is attributed to -it electrons from double bonds of the benzene ring. These are shiny black solids whose molecular weight can vary from 1000 to 100,000.  [c.13]

The sample should be liquid or in solution. It is pumped and nebulized in an argon atmosphere, then sent through a plasma torch that is, in an environment where the material is strongly ionized resulting from the electromagnetic radiation produced by an induction coil. Refer to the schematic diagram in Figure 2.8.  [c.37]

Schematic diagram of an argon plasma emission spectrometer. Schematic diagram of an argon plasma emission spectrometer.
A schematic diagram of the apparatus is shown in Figure 3.2. The molecules are introduced under a partial vacuum of 10 torr into a buffer chamber that communicates via molecular slipstream with the source itself at 10 to 10 torr in order to ensure a constant concentration in the source at all times during the analysis.  [c.47]

Figure 5.3 gives an example of a combustion diagram recorded during knocking conditions. This is manifested by intense pressure oscillations which continue during a part of the expansion phase.  [c.194]

Design starts at the reactor because it is likely to be the only place in the process where raw materials are converted into desired products. The reactor design dictates the separation and recycle problem. The reactor design and separation and recycle problem together dictate the heating and cooling duties for the heat exchanger network. Those duties which cannot be satisfied by heat recovery dictate the need for external utilities. This hierarchy is represented by the layers in the onion diagram (see Fig. 1.6).  [c.13]

Figure 6.9a shows a design corresponding to the flowsheet in Fig. 6.2 which achieves the target of Q/fmin = 5 MW and Qcmin = 10 MW for ATnjjn = 10°C. Figure 6.96 shows an alternative representation of the flowsheet, known as the grid diagram. The grid diagram shows only heat transfer operations. Hot streams are at the top running left to right. Cold streams are at the bottom running right to left. A heat exchange match is represented by a vertical line joining two circles on the two streams being matched. An exchanger using a hot utility is represented by a circle with a H. An exchanger using cold utility is represented by a circle with a C. The importance of the grid diagram is clear in Fig. 6.96, since the pinch, and how it divides the process into two parts, is easily accommodated. Dividing the process into two parts on a conventional diagram such as that shown in Fig. 6.9a is both difficult and extremely cumbersome.  [c.169]

An alternative way to view the tradeoflEs shown in Fig. 8.6 is as a contour diagram. The contours in Fig. 8.7a show lines of constaint total cost. The objective of the optimization is to find the lowest point. The shape of the contours dictates the optimization strategy. A naive strategy would fix the first variable, then optimize the second variable, and then fix the second variable and optimize the first. This is shown in Fig. 8.76, where reactor conversion (X) is first fixed and inert concentration (yiNF.Rr) optimized. Inert concentration is then fixed and conversion optimized. In this case, after two searches the solution is close to the optimum. Whether or not this is adequate depends on how fiat the solution space is in the region of the optimum. Whether or not such a strategy will find the actual optimum depends on the shape of the solution space and the initialization for the optimization. In fact, such a strategy will only be sure to find the optimum if the contours are circular. In Fig. 8.7, the contours are not circular therefore, searching across each variable once will not be sure to identify the optimum. What would be required would be to repeat the strategy of fixing the first variable and optimizing the second and fixing the second and optimizing the first several times until the cost did not change significantly (see Fig. 8.7c). Much more efficient strategies for optimization based on the slope of the solution space can be developed.  [c.248]

These rules are both necessary and sufficient for the design to achieve the energy target, given that no individual exchanger should have a temperature difference smaller than ATmin- To comply with these two rules, the process should therefore be divided at the pinch. As pointed out in Chap. 6, this is most clearly done by representing the stream data in the grid diagram. Figure 16.1 shows the stream data from Table 6.2 in grid form with the pinch marked. Above the pinch, steam can be used (up to and below the pinch, cooling water  [c.364]

Figure 16.45 shows the grid diagram with a CP table for design below the pinch. Hot utility must not be used below the pinch, which means that cold streams must be heated to pinch temperature by recovery. Cold utility can be used, if necessary, on the hot streams below the pinch. Thus it is essential to match cold streams below the pinch with a hot partner. In addition, if the cold stream is at pinch conditions, the hot stream it is to be matched with also must be at pinch conditions otherwise, the AT in constraint will be violated. Figure 16.45 shows a design arrangement below the pinch that does not use temperature differences smaller than ATmin-  [c.367]

When developing a chemical process design, it helps if it is recognized that there is a hierarchy which is intrinsic to chemical processes. Design starts at the reactor. The reactor design dictates the separation and recycle problem. The reactor design and separation problem together dictate the heating and cooling duties for the heat exchanger network. Those duties which cannot be satisfied by heat recovery dictate the need for external utilities. This hierarchy is represented by the layers in the onion diagram (see Fig. 1.6).  [c.399]

Although the sequence of the design follows the onion diagram in Fig. 1.6, the design rarely can be taken to a supcessful conclusion by a single pass. More often there is a flow in both directions. This follows from the fact that decisions are made for the inner layers on the basis of incomplete information. As more detail is added to the design in the outer layers with a more complete picture emerging, the decisions might need to be readdressed, moving back to the inner layers, and so on.  [c.403]

Figure B.l shows a pair of composite curves divided into vertical enthalpy intervals. Also shown in Fig. B.l is a heat exchanger network for one of the enthalpy intervals which will satisfy all the heating and cooling requirements. The network shown in Fig. B.l for the enthalpy interval is in grid diagram form. The network arrangement in Fig. B.l has been placed such that each match experiences the ATlm of the interval. The network also uses the minimum number of matches (S - 1). Such a network can be developed for any interval, providing each match within the interval (1) satisfies completely the enthalpy change of a strearh in the interval and (2) achieves the same ratio of CP values as exists between the composite curves (by stream splitting if necessary). Figure B.l shows a pair of composite curves divided into vertical enthalpy intervals. Also shown in Fig. B.l is a heat exchanger network for one of the enthalpy intervals which will satisfy all the heating and cooling requirements. The network shown in Fig. B.l for the enthalpy interval is in grid diagram form. The network arrangement in Fig. B.l has been placed such that each match experiences the ATlm of the interval. The network also uses the minimum number of matches (S - 1). Such a network can be developed for any interval, providing each match within the interval (1) satisfies completely the enthalpy change of a strearh in the interval and (2) achieves the same ratio of CP values as exists between the composite curves (by stream splitting if necessary).
Tanabe-Sugano diagram Graphs showing the relation between the splitting of electronic energy levels E/B) and crystal field stabilization energy (A/B) where B is a. Racah parameter. Used in assigning electronic transitions in complexes and obtaining values of A and B. tanacetyl alcohol See thujyl alcohol.  [c.384]


See pages that mention the term Dacron : [c.6]    [c.79]    [c.214]    [c.62]    [c.112]    [c.158]    [c.161]    [c.170]    [c.302]    [c.348]    [c.403]   
Carey organic chemistry (0) -- [ c.868 ]

Engineering materials Ч.2 (1999) -- [ c.221 ]

Plastics materials (1999) -- [ c.584 , c.607 , c.695 , c.713 ]

Organic chemistry (0) -- [ c.868 ]