Liquid heat exchange system

A Recirculating Inert Liquid Heat Removal System. While standard inert atmosphere gloveboxes may be used to perform ambient temperature reactions, the lack of a facility for localized heat removal (as provided externally be running tap water) precludes all syntheses requiring reflux, distillation, or sublimation. This limitation may be eliminated by the installation of a recirculating liquid heat exchange system. 

Heat transfer operations. Heat transfer fluids other than steam and cooling water utilities are sometimes introduced into the design of the heat exchange system. These heat transfer media are sometimes liquid hydrocarbons used at high pressure. When possible, higher boiling liquids should be used. Better still, the flammable material should be substituted with a nonflammable medium such as water or molten salt. 

In the inter-alkali alloys, eutectic equilibria have been observed in a number of systems very low melting points have been determined for instance in the Rb-Na system (L (Rb) + (Na), at 82.5 at.% Rb and —4.5°C) and even lower melting temperatures have been observed in ternary systems. Binary sodium-potassium alloys, liquid at room temperature (at 25°C in a composition range of about 15-70 at.% Na, about 7-57 mass% Na), have a good thermal conductivity and a wide temperature range where they are liquid they may be used in heat-exchange systems. Their extremely high chemical reactivity must of course be taken into account. 

Fig. 9. Plate heat exchangers (a) plate—frame heat exchanger when hot fluid from the heat source enters the heat exchanger through connections in the stationary frame plate and is channeled over one side of each plate. Cold fluid enters through different frame plate connections and flows on the other side of each plate in a direction opposite to the hot fluid direction. Courtesy of Bell Gosset. (b) Limco model 6502 plate—fin heat exchanger having compact plate—fin aluminum brazed liquid-to-aii construction. The brazed plate—fin construction provides the most efficient heat-exchanger system in terms of size,...

The first term depends entirely on the physical properties of the reactor contents and degree of agitation. It represents resistance to heat transfer of the internal film and of eventual deposits at the wall, which may determine the overall heat transfer [3], Therefore, the reactor should be regularly cleaned with a high pressure cleaner. Both last terms depend on the reactor itself and on the heat exchange system, that is, reactor wall, fouling in the jacket, and external liquid film. They are often grouped under one term the equipment heat transfer coefficient (cp) [4, 5],... 

Liquid anhydrous ammonia is used extensively as a coolant in heat exchange systems because of its chemical stability, low corrosiveness, and high latent heat of vaporization. However, anhydrous ammonia is readily contaminated during handling and storage. The gas chromatographic analysis of trace contaminants (O2, N2, CO, CH4, CO2, and water) in liquid ammonia was described by Mindmp and Taylor. An F M Model 5750 equipped with a Carle Microcavity Thermistor detector was used with dual columns for analysis. Table 9.3 lists the experimental parameters for both columns, which were conditioned for a minimum of 12 h at a temperature of 180°C and a... 

The butene conversion level is highly dependent on its initial concentration. For instance, today commercial Dimersol-X technology achieves 80% conversion of butenes with up to 85% octene selectivity. A process flow diagram is depicted in Figure 1. The reaction takes place at low temperature (40-60 °C) in three or four consecutive well-mixed reactors. The pressure of 1.5 MPa is sufficient to maintain all reactants and products in the liquid state. Mixing and heat removal are ensured by an external recirculation loop over a heat exchanger system. The two components of the catalytic system are injected separately into this reaction loop under precise flow control. The residence time is between 5 and 10 h. 

In this chapter in Section 3.1 we consider mechanical drives. In Sections 3.2 and 3.3 furnaces and exchangers, condensers and reboUers are considered followed by fluidized bed with coil in the bed, Section 3.4 and static mixers. Section 3.5. Direct contact systems are considered next liquid-liquid. Section 3.6 gas-liquid cooling towers. Section 3.7 gas-liquid quenchers. Section 3.8 gas-liquid condensers. Section 3.9, and gas-gas thermal wheels. Section 3.10. Heat loss to the atmosphere is described in Section 3.11. Refrigeration, steam generation and high temperature heat transfer fluids are presented in Sections 3.12 to 3.14, respectively. Tempered heat exchange systems are considered in Section 3.15. 

Figure 7.3 Cross-section of PL-DSC showing heat-exchange system for handling liquid N2 and...

Column feed is sometimes preheated in other heat-exchanger systems, some of which are quite complex. Overhead vapor from the column, sidestreams (liquid and, particularly, vapor), and other process streams are sometimes used to minimize energy consumption. 

The same water may be used for humidification and to remove the heat from the stack. Heat is discharged from the system through a radiator or a liquid/liquid heat exchanger (depending on the application). Figure 9-7 shows an example of a hydrogen-oxygen closed loop system [8]. 

Check valve failure Blocked discharge Control valve failure Thermal expansion of liquid Heat exchanger tube rupture Reflux failure and overhead system Loss of reboiler heat Venting of storage tank Failure of individual motor Accidental closure of valve... 

After compression and removal of impurities, the air is cooled ia heat exchangers and expanded to low pressure through a turbiae, to recover energy, or through a valve. Liquid air, which forms at about 80 K, is separated via a distillation column. The column as well as the heat exchangers and the associated piping are placed within a cold box, which is packed with iasulation to minimise heat transfer (qv) between streams and to protect the system from the ambient air external to the cold box. 

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