Pakarab fertilizers limited multan
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- Total static head
- Volume flow
- Reynolds Number
- 54 Field Instrumentation GEN Rev) Total flow
| Static suction lift The vertical distance from the center line of the pump to the surface of the liquid to be pumped (source is below pump) is the static suction lift. Static suction head The vertical distance from the center line of the pump to the surface of the liquid to be pumped (source is above pump) is the static suction lift. Total static head Total static head is the vertical distance (in feet) between the surface on the input side and the surface on the discharge side. If the point of discharge is above the surface of the liquid, the horizontal upper arm of the pipe is considered the level of the free surface of the water. Volume flow rate is calculated by equation Q (vol) = Ax V Where, Q (vol) = volume flow rate A = cross-sectional area of the pipe carrying the fluid v = flow velocity. Mass flow rate is calculated by Q (m) = D x Q (vol) Where, Q (m) = mass flow rate D = fluid density (mass per unit volume) Conditions Affecting Flow Rate The rate at which a fluid flows through a channel or pipe depends on three conditions head, viscosity, and frictional resistance. Reynolds Number A Reynolds number is the ratio of a liquid’s (or gas’s) inertial forces to its drag forces. It is calculated by multiplying the velocity of the fluid by the diameter of the pipe and by the density of the fluid, and then dividing that value by the viscosity of the fluid. Reynolds numbers are low at low velocities and high viscosities. Rn = (Vel x Dp x D) / Visc At a low Reynolds number (up to about 2000), the viscosity and velocity of the fluid produce a smooth, laminar flow. Flow changes between laminar and turbulent in the range of Reynolds numbers between 2000 and 4000. At a Reynolds number above 4000, flow is turbulent 54 Field Instrumentation GEN Rev) Total flow is the amount of fluid that flows over an extended time interval. A totalizer accumulates and stores flow- rate values received from a primary flow meter. Flow rate is the instantaneous flow reading at a particular time. It can change greatly from one second to the next. To measure flow rate, an inline flow meter could be used. Download 3.37 Mb. Share with your friends:
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