FK 40 - Tri-Canada

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Centrifugal pumps Feat ures of t he centrifugal pump Q/H curve Centrifugal pumps are fluid- kinetic machines designed for power increase within a rotating impeller. Therefore it is also called the hydrodynamic pumping principle. According to this principle, the fluid is accelerated through the impeller. In the outlet connection of the centrifugal pump, the resulting increase in speed is converted into delivery head. In centrifugal pumps the delivery head H depends on the flow rate Q. This relationship, also called pump performance, is illustrated by curves. During a bench test, the pump is operated at constant speed and the values Q and H are determined for the various operating points. In order to allow a comparison between the various pump t ypes t hese measurement s are carried out using only wat er as liquid. Wit h these operating points a Q/H curve be drawn connecting the points on the graph. Once the flow rate Q is defined and the delivery head H is calculated, the operating point of the plant can be determined. Usually the operating point is not on the Q/H curve of the pump. Depending on the required delivery head, the centrifugal pump will find its operating point when the plant curve and pump curve meet. The flow rate rises from Q to Q . 1 2
The required operating point is obtained by adapting the pump to the specified operating conditions. This can be done by the following actions: • throttling the flow • correct ing t he diamet er of t he impeller • Adjust ing t he speed of t he drive Partially closing a throttle valve or mounting an orifice plate into the discharge pipe of the pump will increase the pressure drop. The plant curve is shifted. The operating point B1 (intersection point between pump curve and plant curve) moves on t he pump curve t o B2. Note: throttling reduces the overall efficiency. A throttle control or a mounted orifice plate is the less expensive control regarding the investment expenses. In case of significant power requirement, an economic appraisal is highly recommended. The friction loss in an orifice plate can be calculated easily: ρ [kg/m≈] v [m/s] 1 Δp [bar] v Centrifugal pumps Throttling the flow Orifice plate calculation
Page 2 and 3: Content Pump technology terms . . .
Page 4 and 5: Pump technology terms Flow rat e [m
Page 6 and 7: Pump technology terms Flow behaviou
Page 8 and 9: Pump technology terms Types of flow
Page 10 and 11: Pump technology terms NPSH value [m
Page 12 and 13: Loss of head calculation Loss of he
Page 14 and 15: Loss of head calculation Example: F
Page 18 and 19: Centrifugal pumps Correction of the
Page 20 and 21: Centrifugal pumps Pumps connected i
Page 22 and 23: Centrifugal pumps Centrifugal pump
Page 24 and 25: Centrifugal pumps Centrifugal pump
Page 26 and 27: Centrifugal pumps Power consumption
Page 28 and 29: Centrifugal pumps Self- priming cen
Page 30 and 31: Centrifugal pumps Multistage centri
Page 32 and 33: Positive displacement pumps Perform
Page 34 and 35: Positive displacement pumps Selecti
Page 36 and 37: Positive displacement pumps Case 1:
Page 46 and 47: Positive displacement pumps Rotary
Page 58 and 59: Mechanical seal selection Double me
Page 60 and 61: Mechanical seal selection “Face t
Page 62 and 63: Mechanical seal selection Elastomer
Page 64 and 65: Pump cleaning SIP After CIP cleanin
Page 66 and 67:
Index Cavitation . . . . . . . . .
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FK 40 - Tri-Canada

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