Discharge through a Pipe

The total flow, Q, is inversely proportional to the length of the pipe and to the viscosity. It is proportional to the pressure differential and to the 

Ohm s law, V=J R (voltage equals current times resistance), electricity has the same form as equation 9.1-14 which may be written as equation 9.1-15, where AP is the pressure differential, Q is the flow rate and resistance is given by equation 9.1-16, where t] is the viscosity of the fluid. Table 9.1-2 shows that the viscosity of liquids is highly temperature-dependent. Gases are much less temperature dependent because of the greater separation between molecules. If there are multiple discharge paths the equivalent resistance is the same as electrical resistors in 

At what rate will a process fluid with approximately the viscosity of water discharge through a 2 in. i.d. pipe 100 ft. long under a differential pressure of 100 psi  

---

As felt above, the concept of powder blend homogeneity cannot be dissociated from the scale at which a mixture is observed. For continuous mixers, homogeneity must be defined at the level of the blend flowing out of the vessel, and falling down to a conveyor or any other transportation equipment. In the case of a batch mixer, the mixture structure can be particularly complex to define, but in practice and when the mixer is emptied, the content of the vessel is discharged through a pipe to a container or a tableting machine. Hence, in both cases and if we take into account the entire cross-section of the pipe, the mixture flow can be assimilated as a 1-D particle stream. 

Example 3 Liquid Discharge through a Piping System Input Data ... 

FIGURE 2.12. Spreadsheet output for Example 3 Liquid discharge through a piping system. 

Propane is stored in a vessel at its vapor pressure of 95 bar gauge and a temperature of 298 K. Determine the discharge mass flux if the propane is discharged through a pipe to atmospheric pressure. Assume a discharge coefficient of 0.85 and a critical pipe length of 10 cm. Determine the mass flux for the following... 

In applications, centrifugal pumps can be supplied with liquid via piping, or the pump may be submerged. Vertical pumps are called dry-pit or wet-pit types. The wet-pit pump (submerged) discharges up through a pipe system to some point above the pump. 

Sulphuric acid of density 1300 kg/m3 is flowing through a pipe of 50 mm, internal diameter. A thin-lipped orifice, 10 mm in diameter is fitted in the pipe and the differential pressure shown on a mercury manometer is 0.1 m. Assuming that the leads to the manometer are filled with the acid, calculate (a) the mass flow rate of acid and (b) the approximate drop in pressure caused by the orifice in kN/m2. The coefficient of discharge of the orifice may be taken as 0.61, the density of mercury as 13.550 kg/m3 and the density of the water as OHIO kg/m ... 

A cylindrical tank. 5 m in diameter, discharges through a mild steel pipe 90 m long and 230 ntm diameter connected to the base of the tank. Find the time taken for the water level in the tank to drop from 3 m to 1 m above the bottom. Take the viscosity of water as 1 mN s/m2. 

A boat is tied to a dock by a line from the stern of the boat to the dock. A pump inside the boat takes water in through the bow and discharges it out the stem at the rate of 3 ft3/s through a pipe running through the hull. The pipe inside area is 0.25 ft2 at the bow and 0.15 ft2 at the stern. Calculate the tension on the line, assuming inlet and outlet pressures are equal. 

Equations are also available for orifices7 and for changes in pipe sizes.8 The 2-K method also represents liquid discharge through holes. From the 2-K method an expression for the discharge coefficient for liquid discharge through a hole can be determined. The result is... 

Even though the reaction force due to the exhaust jet to atmosphere is significantly greater than the change in momentum component, the API makes no distinction for SRVs discharging into a closed header system compared with discharging through a tail pipe or direct to atmosphere. 

A viscous fluid flows through a pipe with slightly porous walls so that there is a leakage of kP, where P is the local pressure measured above the discharge pressure and A is a constant. After a length l, the liquid is discharged into a tank. 

---