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Temperature in heat exchangers

For purposes of refrigeration conservation, all separated streams are returned to ambient temperature in heat exchange with the feed stream. [Pg.246]

Hydrate formation is possible only at temperatures less than 35°C when the pressure is less than 100 bar. Hydrates are a nuisance they are capable of plugging (partially or totally) equipment in transport systems such as pipelines, filters, and valves they can accumulate in heat exchangers and reduce heat transfer as well as increase pressure drop. Finally, if deposited in rotating machinery, they can lead to rotor imbalance generating vibration and causing failure of the machine. [Pg.173]

Gas leaving the economizer flows to a packed tower where SO is absorbed. Most plants do not produce oleum and need only one tower. Concentrated sulfuric acid circulates in the tower and cools the gas to about the acid inlet temperature. The typical acid inlet temperature for 98.5% sulfuric acid absorption towers is 70—80°C. The 98.5% sulfuric acid exits the absorption tower at 100—125°C, depending on acid circulation rate. Acid temperature rise within the tower comes from the heat of hydration of sulfur trioxide and sensible heat of the process gas. The hot product acid leaving the tower is cooled in heat exchangers before being recirculated or pumped into storage tanks. [Pg.185]

Mixing of two saturated streams at different temperatures. This is commonly seen in the plume from a stack. Since vapor pressure is an exponential function of temperature, the resultant mixture of two saturated streams will be supersaturated at the mixed temperature. Uneven flow patterns and cooling in heat exchangers make this route to supersaturation difficult to prevent. [Pg.1413]

Thermal shock In biphase systems, steam bubbles may become trapped in pools of condensate in a flooded main, branch, or tracer line, as well as in heat exchanger tubing and pumped condensate lines. Since condensate temperature is almost always below saturation, the steam will immediately collapse. [Pg.313]

Another serious problem in heat exchangers is corrosion. Severe corrosion can and does occur in tubing and very often with common fluids such as water. Proper material selection based on a full analysis of the operating fluids, velocities and temperatures is mandatory. Very often, heavier gauge tubing is specified to offset the effects of corrosion, but this is only a partial solution. This should be followed by proper start-up, operating and shut-down procedures. [Pg.30]

As a comparison, Table 4.1 lists the coefficients of thermal conductivity (at room temperature) for some metals employed in heat exchangers, together with some minerals commonly found in boiler deposits. [Pg.148]

The sulfoxidation of normal Cl4-CI7 paraffins with sulfur dioxide, oxygen, and water is performed under UV radiation in parallel reactors (1 in Fig. 3). The reaction enthalpy is dissipated by cooling of the paraffin in heat exchangers. The 30- to 60-kW UV lamps are cooled by a temperature-controlled water cycle. The reaction mixture leaving the reactors separates spontaneously into two phases in 2. The lighter paraffin phase is recirculated to the reactors. The composition of the heavy raw acid phase is shown in Table 5. [Pg.150]

Whenever possible, streamline conditions of flow are avoided in heat exchangers because of the very low heat transfer coefficients which are obtained. With very viscous liquids, however, turbulent conditions can be produced only if a very high pressure drop across the plant is permissible. In the processing industries, streamline flow in heat exchangers is most commonly experienced with heavy oils and brines at low temperatures. Since the viscosity of these materials is critically dependent on temperature, the equations would not be expected to apply with a high degree of accuracy. [Pg.426]

A Trim Minimum temperature difference in heat exchanger 9... [Pg.130]

One thing to be careful of in heat exchangers is a design having a so-called temperature cross. An example is shown in Figure 7-1. [Pg.82]


See other pages where Temperature in heat exchangers is mentioned: [Pg.358]    [Pg.909]    [Pg.921]    [Pg.474]    [Pg.139]    [Pg.483]    [Pg.227]    [Pg.237]    [Pg.1346]    [Pg.114]    [Pg.898]    [Pg.667]    [Pg.358]    [Pg.909]    [Pg.921]    [Pg.474]    [Pg.139]    [Pg.483]    [Pg.227]    [Pg.237]    [Pg.1346]    [Pg.114]    [Pg.898]    [Pg.667]    [Pg.166]    [Pg.1914]    [Pg.459]    [Pg.320]    [Pg.481]    [Pg.495]    [Pg.495]    [Pg.204]    [Pg.61]    [Pg.427]    [Pg.285]    [Pg.515]    [Pg.312]    [Pg.2463]    [Pg.174]    [Pg.287]    [Pg.494]    [Pg.56]    [Pg.288]    [Pg.696]    [Pg.1224]    [Pg.268]    [Pg.44]    [Pg.332]   
See also in sourсe #XX -- [ Pg.46 , Pg.47 ]




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