Rale of flow

Note Friction Factors F] and F2 are based on rale of flow, while Factors and C 2 based on actual pipe diameter. 

M Mass rale of flow of condensate per unit length of perimeter for vertical pipe and per unit length of pipe for horizontal pipe ks/s m ML 1 T 1... 

The origin of coordinates is at the corner of the sphere and the concentration at the spherical surface of radius r is c at lime r. At the same insiaru, the concentration at the spherical surface of radius r + dr is cK + dcA. A control volume is defined between the two surfaces at r and r + dr. The rale of flow of sol me into the control volume is... 

Rale of flow of j into the system (moles/time)... 

D[-., be available in a range of sires such that the polymer (or molecule) of diameter, D, can pass through the large holes freely or the small holes with some difficulty. Both the pressure drop across the membrane and the concentration of effluent are measured continuously while the flow rales of effluent are increased in step-wise or continuous fashion. At this stage of development only the unconfined time-average radius of gyration is considered as k However other viscometric or projection radii may ultimately be more useful. 

The flow rale of water entering a given mini- or discrete body ol workings A collective term for (lie eoids belonging to a particular mine... 

Fig. 4. Temporal variations in isotopic composition and gas/steam ratio (G/S) monitored in two wells (Wl, W2) of the central area in the Larderello geothermal field, located near the re-injection welt. Undisturbed pre-injection values (first point of each series, shown as large open circle) and flow rale of injected water (0 are also shown. I, II and III refer to the three re-injection periods considered.

For fixed beds, redistribution of flow within the bed should be provided at intervals equal to 3-10 times the diameter of the bed (Treybal, 1980). It is a general rale that in fixed beds... 

C( = ntlK or ni(V concentration n, = mots of component i in the reactor rtj = molal flow rale of component /... 

To determine the net rale of adsorption of particles suspended in a fluid that is flowing over the collector, one may then solve the usual convective-diffusion equation subject to a reversible first-order reaction as the boundary condition, provided the diffusion boundary layer is much thicker than the interaction boundary layer. 

The soot collected on the filter leads to an increased pressure drop over the filter, that requires adjustment of the flow rate. When a certain amount of soot is collected on ihe filter, the pressure drop over the filter stabilises. At this point, there is an equilibrium between the rate of soot collected on the filter and the rale of soot oxidised on the fitter. This equilibrium can be achieved at different temperatures, a lower temperature leading to a higher stable pressure drop over the filter. When the temperature is too low, it is not possible to achieve an equilibrium the filter is... 

Coal containing 5.0 wt% S is burned at a rate of 1250 Ibm/min in a boiler furnace. All of the sulfur in the coal is oxidized to SO2. The product gas is sent to a scrubber in which most of the SO2 is removed, and the scrubbed gas then passes out of a stack. An Environmental Protection Agency regulation requires that the gas in the stack must contain no more than 0.018 Ibm SCh/lbm coal burned. To test compliance with this regulation a flowmeter and an SO analyzer are mounted in the stack. The volumetric flow rale of the scrubbed gas is found to be 2867 ft /s, and the SO analyzer reading is 37. Calibration data for the analyzer are given in the table below. 

A stream of pure cydopentane vapor flowing at a rale of 1550 L /s at 150 C and 1 atm enters a cooler in which 55% of the feed is condensed at constant pressure. 

A hair dryer is basically a duct in which a few layers of electric resistors are placed. A small fan pull.s the air in and forces it lo flow over the resistors where it is healed. Air enters a 1200-W hair dryer at 100 kPa and 22 C, and leaves at 47 C. TIte cross-sectional area of the hair dryer at the exit is 60 cm. Neglecting the power consumed by the fan and the heat losses through the walls of the hair dryer, determine (n) the volume flow rale of air at Ihe inlet and (b) the velocity of the air at Ihe exit. Answers (a) 0.0404 mVs, (b) 7.30 m/s... 

Cold conditioned air ai I2°C is flowing inside a 1.5-cm-lhick square aluminum (A = 237 W/m "C) duct of inner cross section 22 cm X 22 cm at a mass flow rale of 0.8 kg/s. 1 he duct is exposed to air at 33°C with a combined convection-radiation heat transfer coefficient of 13 W/m - °C. Tlie convection heat transfer coefficient at the inner surface is 75 W/m C, If the air temperature in the duct should not increase by more than i °C determine the maximuin length of the duct. 

SOLUTION Engine oil flows over a flat plate. The total drag force and the rale of heat transfer per unit width of the plate arc to be determined. 

The local atmospheric pressure in Denver. Colorado (etevalion 1610 m), is 83.4 kPa. Air at this pressure and at 30°C flows with a velocity of 6 m/s over a 2.5-m X 8-m flat plate whose temperature is I20°C. Deleniiine (he rale of heal Iransfer from the plate if the air flows parallel to (he (a) 8-m-long side and (b) tlic 2.5-in side. 

The ineversible pressure loss due to frictional effects and the required pumping power to overcome this loss for a volume flow rale of 1/are... 

An 8-m long, uninsulated square duel of cross section 0.2 m X 0.2 m and relative roughness 10 passes through the attic space of a house. Hot air emers the duct at 1 atm and 80°C at a volume flow rale of 0.15 mVs. The duct surface is nearly isothermal at 60°C. Determine the rate of heat loss from the duct to the attic space and the pressure difference between the inlet and outlet sections of the duct. 

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