Condensates specific heat

The coolant for the HTGR is helium. The helium is not corrosive has good heat properties, having a specific heat that is much greater than that of CO2 does not condense and can operate at any temperature has a negligible neutron absorption cross section and can be used in a direct cycle, driving a gas turbine with high efficiency. 

It is advantageous to use a low-retentivity carbon to enable the adsorbate to be stripped out easily. When empirical data are not available, the following heat requirements have to be taken into consideration (1) heat to the adsorbent and vessel, (2) heat of adsorption and specific heat of adsorbate leaving the adsorbent, (3) latent and specific heat of water vapor accompanying the adsorbate, (4) heat in condensed, indirect steam, (5) radiation and convection heat losses. 

The overhead condenser on a distillation column is to subcool the condensed vapors from the condensation temperature of 46.4°F down to 35°F. The specific heat of the liquid is 0.3 Btu/lb (°F), and the latent heat of vaporization at 46.4°F is 265 Btu/lb. The vapor rate to the condenser is 740.3 Ib/hr. What is the total heat load on the condenser ... 

Pressure drops from Dowtherm A heat transfer media flowing in pipes may be calculated from Figure 10-137. The effective lengths of fittings, etc., are shown in Chapter 2 of Volume 1. The vapor flow can be determined from the latent heat data and the condensate flow. With a liquid system, the liquid flow can be determined using the specific heat data. 

CD = tube length for vaporization, ft. Figure 10-110. c or Cp = heat capacity or specific heat at constant pressure, Btu/lb(°F) or, heat capacity of condensate, pcu/lb(°C)... 

Follow the step-wise process outlined in Problem 31 to calculate the amount of heat involved in condensing 100.00 g of benzene gas (C6H6) at 80.00°C to liquid benzene at 25.00°C. Use Tables 8.1 and 8.2 for the specific heat, boiling point, and heat of vaporization of benzene. 

Corollani 1.—The specific heat of a condensed solution vanishes at absolute zero. 

In the case of a storage tank with liquor of mass m and specific heat C heated by steam condensing in a helical coil, it may be assumed that the overall transfer coefficient U is constant. If 7 is the temperature of the condensing steam, Tt and To the initial and final temperatures of the liquor, and A the area of heat transfer surface, and T k the temperature of the liquor at any time t, then the rate of transfer of heat is given by ... 

A stirred reactor contains a batch of 700 kg reactants of specific heat 3.8 kJ/kg K initially at 290 K, which is heated by dry saturated steam at 170 kN/m2 fed to a helical coil. During the heating period the steam supply rate is constant at 0.1 kg/s and condensate leaves at the temperature of the steam. If heat losses arc neglected, calculate the true temperature of the reactants when a thermometer immersed in the material reads 360 K. The bulb of the thermometer is approximately cylindrical and is 100 mm long by 10 mm diameter with a water equivalent of 15 g, and the overall heat transfer coefficient to the thermometer is 300 W/m2 K. What would a thermometer with a similar bulb of half the length and half the heat capacity indicate under these conditions ... 

Design a shell-and-tube reactor that has a volume of 24 m and evaluate its performance as the reactor element in the process of Example 6.2. Use tubes with an i.d. of 0.0254m and a length of 5m. Assume components A, B, and C all have a specific heat of 1.9 kJ/(kg-K) and a thermal conductivity of 0.15W/(m-K). Assume 7 ,>, = 70°C. Run the reaction on the tube side and assume that the shell-side temperature is constant (e.g., use condensing steam). Do the consecutive, endothermic case. 

A special care is to be devoted to the control that all the parts of the apparatus have reached the desired temperature when parts remain at higher temperature, due to the high value of the specific heat, the cooling only by radiative exchange is usually impossible. To open a gas heat switch, several hours of pumping are usually necessary to reduce the pressure to a value suitable for the thermal isolation. An insufficient pumping leads to a time-dependent heat leak due to desorption and condensation of the residual gas at the coldest surfaces. 

A single-effect evaporator is used to concentrate 7 kg/s of a solution from 10 to 50 per cent of solids. Steam is available at 205 kN/m2 and evaporation takes place at 13.5 kN/m2. If the overall heat transfer coefficient is 3 kW/m2 K, calculate the heating surface required and the amount of steam used if the feed to the evaporator is at 294 K and the condensate leaves the heating space at 352.7 K. The specific heat capacity of a 10 per cent solution is 3.76 kJ/kgK, the specific heat capacity of a 50 per cent solution is 3.14 kJ/kgK. 

Distilled water is produced from sea water by evaporation in a single-effect evaporator working on the vapour compression system. The vapour produced is compressed by a mechanical compressor of 50 per cent efficiency, and then returned to the calandria of the evaporator. Extra steam, dry and saturated at 650 kN/m2, is bled into the steam space through a throttling valve. The distilled water is withdrawn as condensate from the steam space. 50 per cent of the sea water is evaporated in the plant. The energy supplied in addition to that necessary to compress the vapour may be assumed to appear as superheat in the vapour. Calculate the quantity of extra steam required in kg/s. The production rate of distillate is 0.125 kg/s, the pressure in the vapour space is 101.3 kN/m2, the temperature difference from steam to liquor is 8 deg K, the boiling-point rise of sea water is 1.1 deg K and the specific heat capacity of sea water is 4.18 kJ/kgK. 

A double-effect forward-feed evaporator is required to give a product which contains 50 per cent by mass of solids. Each effect has 10 m2 of heating surface and the heat transfer coefficients are 2.8 and 1.7 kW/m2 K in the first and second effects respectively. Dry and saturated steam is available at 375 kN/m2 and the condenser operates at 13.5 kN/m2. The concentrated solution exhibits a boiling-point rise of 3 deg K. What is the maximum permissible feed rate if the feed contains 10 per cent solids and is at 310 K The latent heat is 2330 kJ/kg and the specific heat capacity is 4.18 kJ/kg under all the above conditions. 

A salt solution at 293 K is fed at the rate of 6.3 kg/s to a forward-feed triple-effect evaporator and is concentrated from 2 per cent to 10 per cent of solids. Saturated steam at 170 kN/m2 is introduced into the calandria of the first effect and a pressure of 34 kN/m2 is maintained in the last effect. If the heat transfer coefficients in the three effects are 1.7, 1.4 and 1.1 kW/m2K respectively and the specific heat capacity of the liquid is approximately 4 kJ/kgK, what area is required if each effect is identical Condensate may be assumed to leave at the vapour temperature at each stage, and the effects of boiling point rise may be neglected. The latent heat of vaporisation may be taken as constant throughout. 

Formaldehyde is stoichiometrically burned at constant pressure with oxygen (gas) to completion. C02 and H20, condensed as a liquid, are the sole products. The initial temperature before the reaction is 50 °C and the final temperature after its completion is 600 °C. Find, per mole of fuel, the heat transferred in the process, and state whether it is added or lost. Assume a constant specific heat of 35 J/mole K for all the species. Use Table 2.2 for all of your data. 

Figure 1. Left Ai/Ai(T=0) as function of T/Ai(T=0). Dashed Ai = A, solid Ai = A. Right Specific heat as function of T/T c. Solid full calculation, dashed result for M = 0, dotted without spin-1 condensate. The dash-dotted line indicates the result of Eq. (14).

Also in the CFL phase (T < 7).) there is a contribution to the specific heat of Goldstone-like excitations, cf. phonons in the ordinary condensed matter. For T nip.a, where mp.a is the mass of the pseudo-GoIdstone excitation, we get... 

A triple-effect evaporator is fed with 5 kg/s of a liquor containing 15 per cent solids. The concentration in the last effect, which operates at 13.5 kN/m2, is 60 per cent solids. If the overall heat transfer coefficients are 2.5, 2.0 and 1.1 kW/m2 K, respectively, and the steam is fed at 388 K to the first effect, determine the temperature distribution and the area of heating surface required in each effect, assuming the calandrias are identical. What is the economy and what is the heat load on the condenser The feed temperature is 294 K and the specific heat capacity of all liquors is 4.18 kJ/kg K... 

An evaporator, working at atmospheric pressure, is to concentrate a solution from 5 per cent to 20 per cent solids at the rate of 1.25 kg/s. The solution, which has a specific heat capacity of 4.18 kJ/kg K, is fed to the evaporator at 295 K and boils at 380 K. Dry saturated steam at 240 kN/m2 is fed to the calandria, and the condensate leaves at the temperature of the condensing stream. If the heat transfer coefficient is 2.3 kW/m2 K, what is the required area of heat transfer surface and how much steam is required The latent heat of vaporisation of the solution may be taken as being equal to that of water. 

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