# Lab Report

Department of Chemical & Biomolecular Engineering

THE NATIONAL UNIVERSITY

Of SINGAPORE

Chemical Engineering Process Laboratory I

SEMESTER 4

Experiment F2

Flow Measurement in Closed Conduit and

Centrifugal Pump Characteristics

Name : Ang Sok Gek Chai Chang Er Cherry Chen Mingli

Matriculation No. : U046941L U046938W U046882J

Group : Th1

Date of Experiment : 16th March 2006

Table of Contents Page

Summary 2

Part I: Flow Measurement in Closed Conduit

A. Introduction 3

B. Objectives 3

C. Theoretical Background 4

D. Experimental Procedures 9

E. Results and Calculations 12

F. Discussion 50

G. Error Analysis 58

H. Conclusion 61

Part II: Centrifugal Pump

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In this experiment, we are only concerned about the head loss due to fittings.

[pic]

Figure I.1: Setup of the Closed Conduit for Flow Measurement.

Based on energy balance for a control volume, we obtained the equation below:

δQ/dt – δWs/dt = ∫∫c.s (e +P/ρ) ρ (v ∙ n) dA + δ/δt ∫∫∫c.v eρ dV + δWμ/dt

where δQ/dt is the rate of heat transfer δWs/dt is the shaft work rate δWμ/dt is the work rate to overcome viscous effects at the control surface [pic] is the differential change in the area of the control volume [pic] is the differential change in the volume of the control volume [pic] is the specific energy ρ is the density P is the pressure n is the direction vector normal to the surface of the control volume v is the velocity vector of the flowing fluid cs is the control surface cv is the control volume

Assuming that there is no work done by shear stress or against viscous force and that the flow is under a steady state condition. δWs/dt = 0; δWμ/dt = 0; δ/δt ∫∫∫ c.v eρ dV = 0;

Considering a unit mass, the energy balance reduces to:

-Q = ∫∫c.s (e +P/ρ) ρ (v ∙ n) dA

-Q = ( -v12+ v22 )/2 + (-gy1 + gy2) + (-P1 + P2)/ρ + (-u1 + u2) + ∫A2 (v22 /2) ρv2dA2 -∫A1 (v12 /2) ρv1dA1 ----- (1)

where g is the gravitational constant u is the internal energy per unit mass Q is the rate of heat per unit mass y is the