Pressure drop, losses

Inlet piping is held to a minimum, with the safety device preferably mounted directly on the equipment and with the total system pressure drop loss to pres.sure relief valve inlet not exceeding 3% of the set pressure in psig, of maximum relief flowing conditions [10]. To conform to code (see ASME code. Sect. Vlll, Div. l-UG-127 [1]) avoid high inlet pressure drop and possible valve chatter ... 

To size the fan it is necessary to know the total air volume and the pressures in the system. These are calculated from the losses in the system on the longest or index leg, and begin with the hood. The hood entry loss can be expressed as 0.6 of the velocity head and is accurate enough for first estimates. The losses are then calculated on the velocities in the ducts. Each change of direction means a small loss in each length of duct. Added to the pressure drop loss across the collector and the outlet losses, these give the total static pressure required in the system. 

The tube friction loss can be calculated using the familiar equations for pressure-drop loss in pipes (see Volume 1, Chapter 3). The basic equation for isothermal flow in pipes (constant temperature) is ... 

Smeltzer, E. E., Weaver, M. L., and Klinzing, G. E., Pressure drop losses due to electrostatic generation in pneumatic transport, Indust. Engrg. Chem, Proc. Des. Dev., 21 390-394 (1982)... 

In the MCFC there must be carbon dioxide recirculation from anode to cathode, as per Figure 5.3. The recirculation of anode gas as a means of getting at the carbon dioxide represents an irreversibility, since additional circulator power must be committed, and additional pressure drop losses encountered. 

The required liquid and vapor rates are the amount of vapor entering the tray and the amount of liquid leaving the tray. This combination gives the correct pressure balance for the liquid inventory in the downcomer and the vapor pressure drop loss through the tray (Fig. 3). Today, engineers most often use simulation packages to calculate the vapor and liquid traffic. Care should be taken to extract the appropriate... 

Table 2.2. Typical pressure drop losses in gas turbine...

As the observed power deficit had been explained to a very large extent, several measures were identified to enable its reduction. One measure would be to optimize the flow conditions for the inflow and outflow areas of the compressor and turbine sections in order to minimize the pressure drop losses and to achieve an optimum inflow into the blading. Moreover, a reduction of the blade gap losses would be required. That could be achieved by a reduction in rotor vibration and better selection of materials. The materials for both the rotor and the stationary blade carrier should be selected to optimize thermal expansions to achieve minimum gaps at operating conditions. One approach would be the replacement of the non-cooled austenitic stationary blade carrier in favor of a ferritic one, with cooling provided at necessary locations. Preferably no cooling at 750 C should be provided at all, taking into account possible improvements in avaible blade and rotor materials. A third approach that seems to be possible would be a further optimization of the stationary blade profiles and rotor blade profiles. 

Pressure drop Loss of pressure with distance downstream from any point in tubes, channels, and other flow devices. 

Valve types with low K values or L/D ratios are required due to the need to minimize pressure drop losses to optimize and maintain system efficiency. Hence, standard globe-type valves, angle or in-line... 

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