- Email: [email protected]
Blade adjustment cuts energy costs
28
Feature WORLD PUMPS
August 2009
Energy saving
Blade adjustment cuts energy costs Cooling water pumps for power plants can save energy by adjusting the flow rate. Gerd Witte and Dr Manfred Stollenwerk explain that pumps with an adjustable pitch angle of propeller blades can lead to cost savings. Depending on the load profile and internal energy costs, the ROI can be reached within two to three years.
T
he production of electrical energy is secured by the mix of different power plants. On the one hand side, power plants for the base load are running continuously with a capacity of 100% load. Other power plants are covering times with fluctuating energy demand and therefore running with different load cycles. In time of lower load, these power plants need less cooling water respectively. The usage of cooling water pumps with adjustable flow rate can save energy compared to pumps without the possibility to adjust the flow rate. For the estimation of the energy and cost saving potential we have made a comparison between pumps with a constant flow rate and pumps with an adjustable flow at different load profiles.
tVariable pitch angle adjustment of the
adjusting shaft
propellers: Most suitable for an active adjustment of the flow rate due to the special head/flow characteristic for different angles of the propeller blades.
threaded bush adjusting element
adjusting lever
Figure 1. Technical detail of the gear and the propeller head with the adjustable blades.
tMotor speed control by means of a
frequency converter: Relative expensive and less suitable due to the relatively high static part of the system resistance curve.
tPre-vortex controllers: More suitable to
Flow rate control There are three different technical realisations known for an active flow rate control of cooling water pumps:
adjust the pump to changing head. The ground floor of the inlet chamber in front of the pumps must be excavated deeper due to the length of the pre-vortex controller and its pressure losses, which are resulting in higher NPSHR.
Therefore, this article focuses on the technical solution using propeller pumps with variable pitch angle of the propeller blades. The statements included in this article therefore are valid only for pumps of this type and comparable applications. For other circumstances other control systems may be preferable.
Variable pitch angle adjustment The variable pitch angle adjusting device is mainly consisting of three gears and a hollow drive shaft witch contains the adjusting shaft (Figure 1). The adjusting of the pitch angle can be performed during operation or also during shut-down of the pump. A geared electrical motor is energized, when adjustment is performed. Via the differ-
Table 1. Summary of the energy and cost saving potentials Load Profile
Average load
Energy saving
Cost saving
Return of investment within
#1
91%
123.581 kWh/a
193 k€/a
2,1 years
#2
88%
162.691 kWh/a
254 k€/a
1,6 years
#3
85%
150.931 kWh/a
235 k€/a
1,7 years
www.worldpumps.com
0262 1762/08 © 2008 Elsevier Ltd. All rights reserved
WORLD PUMPS
Feature August 2009
adjustment is performed. Via the differential gear a relative rotation is transmitted to the adjusting shaft, so that the speed of it is higher or lower – for both directions of adjustment – than the speed of the hollow drive shaft.
Characteristic curves fixed blade impellers
55,0 50,0
This relative rotation effects an axial movement of the adjusting element within the propeller hub by means of a threaded bush. The adjusting element is provided with inclined grooves, in which the adjusting levers of the propeller blades are mounted. When the adjusting element is moving axially, the propeller blades are rotating simultaneously by approximately 20° from min. to max. angle. All positions within these limits are adjustable, depending on the duration the geared adjusting motor is energized. The extreme positions are protected by limit switches as well as the max. torque.
total head [m]
45,0
2 pump operation
40,0 35,0
Qtot
30,0
1 pump operation
25,0
Qtot*0,6
20,0 15,0 10,0 0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
5.500 5.000 shaft power [kW]
4.500 4.000 3.500 3.000 2.500 2.000
Comparisons 100
The comparison of the energy consumption is made for following pump types:
efficiency [%]
80
tPump with mixed flow impeller with fixed blades, n = 426 rpm
60 40 20
tPump with mixed flow propeller with
0
adjustable pitch gear angle; n = 370 rpm
Both pump types have a motor power of P= 3.000 kW incl. 15% margin. The diameter of the discharge elbow is 1.800 mm (72”).
NPSH [m]
18
The calculations are based on the cooling water demand of a conventional, coal-fired 800 MW power plant with a cooling tower and two 50% cooling water pumps. The 100% operating point of the cooling water circuit is defined by a total flowrate of Q= 66.574 m³/h (293.145 gpm US), respectively of 33.287 m³/h per pump
16 14 12 10
Flow rate [m /h]
Figure 2. Characteristic curves of pumps with fixed blade impellers.
Table 2. Comparison of the different pump types Variable pitch angle propeller pump
Fixed mixed flow impeller pump Advantages
Lower energy costs during part load operation
Lower pump price
Extended operating range, cooling water flow rate can be adjusted to the actual demand The system is prevented from damage due to smooth start-up without pressure surge The driver is started at min. pitch angle, therefore the start-up current is limited Disadvantages Higher pump price (which will be compensated by less energy costs within approximately 2 years)
Higher energy costs at part load condition, depending on the load profile Higher consumption of make-up water for the cooling water circuit Pressure surge occurs at start-up High start-up current of the driver
www.worldpumps.com
29
Feature WORLD PUMPS
1 pump operation 38,00
2 pump operation
The efficiencies versus flow rate complete the diagrams. The pump efficiency considering the internal head losses is plotted. Motor efficiency is not considered, this would increase the power savings by approx. 5%. The difference between the system resistance curves is due to the minimum or maximum water level in the cooling tower basin.
possible operation range
34,00
Total Head [m]
23°
Qtot*0,6
30,00
Qtot
19°
26,00
15° 13°
22,00 18,00 14,00 10,00 10.000
12 5°
20.000
30.000
40.000
15°
13°
50.000
17°
19°
60.000
20°
21°
70.000
21,5°
80.000
Below the Q-H-curves the pump shaft power is plotted, for single and two-pump operation. An additional requirement of the project is that at shut-down of one pump the remaining operating pump shall discharge a minimum flow rate of 60% of full load ( = 39.944 m³/h).
5500
Shaft power [kW]
4500 3500 2500 1500 500 10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
100 23°, 1P
80
Efficiency
August 2009
available and required NPSH of the pumps. These graphs for 0%-head drop are plotted at the bottom of the diagrams.
Characteristic curves adjustable impellers
12,5°, 2P 21°, 2P 21,5°, 2P
60
Both pump types selected can be operated at this run-out point, however, with some advantages for the propeller pump with regards to NPSHR and efficiency.
40
Energy saving
20 0 10.000
17
20.000
30.000
40.000
50.000
60.000
70.000
80.000
NPSH A
15
NPSH [m]
30
21°, 2P
23°, 1P
13 11
21,5°, 1P
9
12,5°, 2P
7 10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
Förderstrom [m³/h]
Flow rate [m³/h] Figure 3. Characteristic curves of pumps with adjustable blade impellers.
(146.573 gpm US). The total head at full load is H= 25,4 m (83,3 ft).
Results For both types of pumps we have calculated the characteristic curves of the total head H(Q), shaft power P(Q), efficiency η(Q) and NPSHR (Q). The results are shown in Figure 2 (fixed impellers) and Figure 3 (adjustable impellers). The pump and system characteristic curves are shown for single and parallel operation. The latter is the nominal operating point of the plant at 100% load. On top of the diagrams the characteristic curves head [m] versus flow rate [m³/h] are shown. For the fixed impeller pump there is only one intersection of the Q-H-curve with the www.worldpumps.com
system resistance curve – which represents the operating point – for single pump or two-pump operation, respectively. The curves for two-pump operation are resulting from the addition of the flow rate of two pumps at the same head. This is valid also for the variable pitch angel propeller pumps. For the adjustable pitch angle propeller pump there are several Q-H-curves plotted, each of them for a certain pitch angel, which is noted at the graph. Because it is possible to adjust any number of pitch angels within the possible range from min to max, there is a large operating range of cooling water flow rate available from approximately 30% to 60% (single pump operation) and 60% to 105% (twopump-operation). Please note, that the indicated operating range is not only limited by the min. and max. possible pitch angle, but also by the
For the calculation of energy consumption and saving, we have analysed three different load profiles with an average load from 90% (profile 1), 87% (profile 2) and 85% (profile 3). The details of the power load profiles are shown in Figure 4. The detailed energy consumption is calculated for pumps with fixed impeller blades without flow control and for the pumps with variable impeller blades, where the impellers are adjusted to the optimum operation point of the needed cooling water amount. It can clearly been seen that there are reasonable energy saving potentials, especially for lower power loads. For the estimation of the cost saving we have assumed production cost for the energy of 0,03 € per kWh.
Summary In summary, using pumps with adjustable pitch angle of the propeller blades can lead, depending on the load profile, to cost savings of up to €254 000 per year. Taking the additional costs for the pitch angle control of approx. €200 000 per pump (400 k€ for two pumps) into consideration, a return of investment can be achieved within approx. two years. Please note, that the adjusting gears are active only during the changing of the blade pitch angle, the predominant operating time the gears are free of load. Therefore the maintenance intervals and
WORLD PUMPS
Feature August 2009
the economic life cycles are the same as for fixed blade impeller pumps.
Assumed load profile No. 1 Load in %
Load in %/week Load in h/week
time * load
100%
60,00%
100,8
60.00%
90%
10,00%
16,8
9,00%
80%
10,00%
16,8
8,00%
70%
20,00%
33,6
14,00%
60%
0,00%
0
0,00%
Average load
91,00%
shaft power fixed impeller
As a conclusion of our study it can clearly be determined that the usage of pumps with active pitch angle control can be strongly recommended for power plants with a variable power load profile. ■
Contact
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
515.491
2557
2557
515.491
2557
2557
85.915
2200
2200
73.920
2557
2557
85.915
1750
1750
58.800
2557
2557
171.830
1300
1300
87.360
0
0
0
0
0
0
total
859.152
total
735.571
€/a
192.786
delta kWh per week
123.581
Assumed load profile No. 2 Load in %
Load in %/week Load in h/week
time * load
100%
40,00%
67,2
40,00%
90%
20,00%
33,6
18,00%
80%
20,00%
33,6
16,00%
70%
20,00%
33,6
14,00%
60%
0,00%
0
0,00%
Average load
88,00%
shaft power fixed impeller
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
343.661
2557
2557
343.661
2557
2557
171.830
2200
2200
147.840
2557
2557
171.830
1750
1750
117.600
2557
2557
171.830
1300
1300
87.360
0
0
0
0
0
0
total
859.152
total
696.461
€/a
253.798
delta kWh per week
123.581
Load in %/week Load in h/week
time * load
100%
40,00%
67,2
40,00%
90%
10,00%
16,8
9,00%
80%
20,00%
33,6
16,00%
70%
20,00%
33,6
14,00%
60%
10,00%
16,8
6,00%
Average load shaft power fixed impeller
85,00%
Sterling Fluid Systems specialises in liquid pumps, vacuum pumps and systems. The organisation provides a broad range of engineered solutions to support the fluid handling requirements of the process industries. Founded in 1920 as Siemen & Hinsch (SIHI) in north Germany by the inventor of side channel pumps Otto Siemen and Johannes Hinsch, SIHI became a member of Sterling Fluid Systems Group in 1997 and changed the company name to Sterling SIHI in Germany and to Sterling Fluid Systems in Europe and Asia. Sterling SIHI has been manufacturing liquid pumps, vacuum pumps, compressors and engineered systems for many applications in the chemical, pharmaceutical, power, water/waste water, food/beverage, plastic, steel, paper and machinery manufacturing industries. Sterling Fluid Systems has over 10 manufacturing centres, 60 sales offices and more than 100 service centres around the world to provide a support network at a local level.
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
343.661
2557
2557
343.661
2557
2557
85.915
2200
2200
73.920
2557
2557
171.830
1750
1750
117.600
2557
2557
171.830
1300
1300
87.360
2408
0
40.454
2394
total
813.691
delta kWh per week
Sterling Fluid Systems
The company has more than 1,600 employees worldwide and a turnover of more than €250 million. It is a member of the Thyssen Bornemisza Gruppe (TBG), which achieves more than €2 bn annually. In 2007, TBG sold Peerless pump Co to Grundfos. In 2004, the company’s industry segments were divided into three divisions, which are chemical, industrial and energy & environmental. Brands include SIHI, Halberg and LaBour. SPP Pumps Ltd was sold to India’s Kirloskar Brothers Ltd in 2003.
Assumed load profile No. 3 Load in %
Gerd Witte Product manager tubular casing pumps Sterling SIHI GmbH [email protected] http://www.sterlingsihi.com
150.931
40.219 total
662.760
€/a
235.453
International Rotating Equipment conference This paper was first presented at the Pump Users International Forum 2008 held in Düsseldorf, Germany in October 2008, and is reproduced with permission from VDMA eV.
Figure 4. Different load profiles. www.worldpumps.com
31
Feature WORLD PUMPS
August 2009
Energy saving
Blade adjustment cuts energy costs Cooling water pumps for power plants can save energy by adjusting the flow rate. Gerd Witte and Dr Manfred Stollenwerk explain that pumps with an adjustable pitch angle of propeller blades can lead to cost savings. Depending on the load profile and internal energy costs, the ROI can be reached within two to three years.
T
he production of electrical energy is secured by the mix of different power plants. On the one hand side, power plants for the base load are running continuously with a capacity of 100% load. Other power plants are covering times with fluctuating energy demand and therefore running with different load cycles. In time of lower load, these power plants need less cooling water respectively. The usage of cooling water pumps with adjustable flow rate can save energy compared to pumps without the possibility to adjust the flow rate. For the estimation of the energy and cost saving potential we have made a comparison between pumps with a constant flow rate and pumps with an adjustable flow at different load profiles.
tVariable pitch angle adjustment of the
adjusting shaft
propellers: Most suitable for an active adjustment of the flow rate due to the special head/flow characteristic for different angles of the propeller blades.
threaded bush adjusting element
adjusting lever
Figure 1. Technical detail of the gear and the propeller head with the adjustable blades.
tMotor speed control by means of a
frequency converter: Relative expensive and less suitable due to the relatively high static part of the system resistance curve.
tPre-vortex controllers: More suitable to
Flow rate control There are three different technical realisations known for an active flow rate control of cooling water pumps:
adjust the pump to changing head. The ground floor of the inlet chamber in front of the pumps must be excavated deeper due to the length of the pre-vortex controller and its pressure losses, which are resulting in higher NPSHR.
Therefore, this article focuses on the technical solution using propeller pumps with variable pitch angle of the propeller blades. The statements included in this article therefore are valid only for pumps of this type and comparable applications. For other circumstances other control systems may be preferable.
Variable pitch angle adjustment The variable pitch angle adjusting device is mainly consisting of three gears and a hollow drive shaft witch contains the adjusting shaft (Figure 1). The adjusting of the pitch angle can be performed during operation or also during shut-down of the pump. A geared electrical motor is energized, when adjustment is performed. Via the differ-
Table 1. Summary of the energy and cost saving potentials Load Profile
Average load
Energy saving
Cost saving
Return of investment within
#1
91%
123.581 kWh/a
193 k€/a
2,1 years
#2
88%
162.691 kWh/a
254 k€/a
1,6 years
#3
85%
150.931 kWh/a
235 k€/a
1,7 years
www.worldpumps.com
0262 1762/08 © 2008 Elsevier Ltd. All rights reserved
WORLD PUMPS
Feature August 2009
adjustment is performed. Via the differential gear a relative rotation is transmitted to the adjusting shaft, so that the speed of it is higher or lower – for both directions of adjustment – than the speed of the hollow drive shaft.
Characteristic curves fixed blade impellers
55,0 50,0
This relative rotation effects an axial movement of the adjusting element within the propeller hub by means of a threaded bush. The adjusting element is provided with inclined grooves, in which the adjusting levers of the propeller blades are mounted. When the adjusting element is moving axially, the propeller blades are rotating simultaneously by approximately 20° from min. to max. angle. All positions within these limits are adjustable, depending on the duration the geared adjusting motor is energized. The extreme positions are protected by limit switches as well as the max. torque.
total head [m]
45,0
2 pump operation
40,0 35,0
Qtot
30,0
1 pump operation
25,0
Qtot*0,6
20,0 15,0 10,0 0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
0
10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
5.500 5.000 shaft power [kW]
4.500 4.000 3.500 3.000 2.500 2.000
Comparisons 100
The comparison of the energy consumption is made for following pump types:
efficiency [%]
80
tPump with mixed flow impeller with fixed blades, n = 426 rpm
60 40 20
tPump with mixed flow propeller with
0
adjustable pitch gear angle; n = 370 rpm
Both pump types have a motor power of P= 3.000 kW incl. 15% margin. The diameter of the discharge elbow is 1.800 mm (72”).
NPSH [m]
18
The calculations are based on the cooling water demand of a conventional, coal-fired 800 MW power plant with a cooling tower and two 50% cooling water pumps. The 100% operating point of the cooling water circuit is defined by a total flowrate of Q= 66.574 m³/h (293.145 gpm US), respectively of 33.287 m³/h per pump
16 14 12 10
Flow rate [m /h]
Figure 2. Characteristic curves of pumps with fixed blade impellers.
Table 2. Comparison of the different pump types Variable pitch angle propeller pump
Fixed mixed flow impeller pump Advantages
Lower energy costs during part load operation
Lower pump price
Extended operating range, cooling water flow rate can be adjusted to the actual demand The system is prevented from damage due to smooth start-up without pressure surge The driver is started at min. pitch angle, therefore the start-up current is limited Disadvantages Higher pump price (which will be compensated by less energy costs within approximately 2 years)
Higher energy costs at part load condition, depending on the load profile Higher consumption of make-up water for the cooling water circuit Pressure surge occurs at start-up High start-up current of the driver
www.worldpumps.com
29
Feature WORLD PUMPS
1 pump operation 38,00
2 pump operation
The efficiencies versus flow rate complete the diagrams. The pump efficiency considering the internal head losses is plotted. Motor efficiency is not considered, this would increase the power savings by approx. 5%. The difference between the system resistance curves is due to the minimum or maximum water level in the cooling tower basin.
possible operation range
34,00
Total Head [m]
23°
Qtot*0,6
30,00
Qtot
19°
26,00
15° 13°
22,00 18,00 14,00 10,00 10.000
12 5°
20.000
30.000
40.000
15°
13°
50.000
17°
19°
60.000
20°
21°
70.000
21,5°
80.000
Below the Q-H-curves the pump shaft power is plotted, for single and two-pump operation. An additional requirement of the project is that at shut-down of one pump the remaining operating pump shall discharge a minimum flow rate of 60% of full load ( = 39.944 m³/h).
5500
Shaft power [kW]
4500 3500 2500 1500 500 10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
100 23°, 1P
80
Efficiency
August 2009
available and required NPSH of the pumps. These graphs for 0%-head drop are plotted at the bottom of the diagrams.
Characteristic curves adjustable impellers
12,5°, 2P 21°, 2P 21,5°, 2P
60
Both pump types selected can be operated at this run-out point, however, with some advantages for the propeller pump with regards to NPSHR and efficiency.
40
Energy saving
20 0 10.000
17
20.000
30.000
40.000
50.000
60.000
70.000
80.000
NPSH A
15
NPSH [m]
30
21°, 2P
23°, 1P
13 11
21,5°, 1P
9
12,5°, 2P
7 10.000
20.000
30.000
40.000
50.000
60.000
70.000
80.000
Förderstrom [m³/h]
Flow rate [m³/h] Figure 3. Characteristic curves of pumps with adjustable blade impellers.
(146.573 gpm US). The total head at full load is H= 25,4 m (83,3 ft).
Results For both types of pumps we have calculated the characteristic curves of the total head H(Q), shaft power P(Q), efficiency η(Q) and NPSHR (Q). The results are shown in Figure 2 (fixed impellers) and Figure 3 (adjustable impellers). The pump and system characteristic curves are shown for single and parallel operation. The latter is the nominal operating point of the plant at 100% load. On top of the diagrams the characteristic curves head [m] versus flow rate [m³/h] are shown. For the fixed impeller pump there is only one intersection of the Q-H-curve with the www.worldpumps.com
system resistance curve – which represents the operating point – for single pump or two-pump operation, respectively. The curves for two-pump operation are resulting from the addition of the flow rate of two pumps at the same head. This is valid also for the variable pitch angel propeller pumps. For the adjustable pitch angle propeller pump there are several Q-H-curves plotted, each of them for a certain pitch angel, which is noted at the graph. Because it is possible to adjust any number of pitch angels within the possible range from min to max, there is a large operating range of cooling water flow rate available from approximately 30% to 60% (single pump operation) and 60% to 105% (twopump-operation). Please note, that the indicated operating range is not only limited by the min. and max. possible pitch angle, but also by the
For the calculation of energy consumption and saving, we have analysed three different load profiles with an average load from 90% (profile 1), 87% (profile 2) and 85% (profile 3). The details of the power load profiles are shown in Figure 4. The detailed energy consumption is calculated for pumps with fixed impeller blades without flow control and for the pumps with variable impeller blades, where the impellers are adjusted to the optimum operation point of the needed cooling water amount. It can clearly been seen that there are reasonable energy saving potentials, especially for lower power loads. For the estimation of the cost saving we have assumed production cost for the energy of 0,03 € per kWh.
Summary In summary, using pumps with adjustable pitch angle of the propeller blades can lead, depending on the load profile, to cost savings of up to €254 000 per year. Taking the additional costs for the pitch angle control of approx. €200 000 per pump (400 k€ for two pumps) into consideration, a return of investment can be achieved within approx. two years. Please note, that the adjusting gears are active only during the changing of the blade pitch angle, the predominant operating time the gears are free of load. Therefore the maintenance intervals and
WORLD PUMPS
Feature August 2009
the economic life cycles are the same as for fixed blade impeller pumps.
Assumed load profile No. 1 Load in %
Load in %/week Load in h/week
time * load
100%
60,00%
100,8
60.00%
90%
10,00%
16,8
9,00%
80%
10,00%
16,8
8,00%
70%
20,00%
33,6
14,00%
60%
0,00%
0
0,00%
Average load
91,00%
shaft power fixed impeller
As a conclusion of our study it can clearly be determined that the usage of pumps with active pitch angle control can be strongly recommended for power plants with a variable power load profile. ■
Contact
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
515.491
2557
2557
515.491
2557
2557
85.915
2200
2200
73.920
2557
2557
85.915
1750
1750
58.800
2557
2557
171.830
1300
1300
87.360
0
0
0
0
0
0
total
859.152
total
735.571
€/a
192.786
delta kWh per week
123.581
Assumed load profile No. 2 Load in %
Load in %/week Load in h/week
time * load
100%
40,00%
67,2
40,00%
90%
20,00%
33,6
18,00%
80%
20,00%
33,6
16,00%
70%
20,00%
33,6
14,00%
60%
0,00%
0
0,00%
Average load
88,00%
shaft power fixed impeller
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
343.661
2557
2557
343.661
2557
2557
171.830
2200
2200
147.840
2557
2557
171.830
1750
1750
117.600
2557
2557
171.830
1300
1300
87.360
0
0
0
0
0
0
total
859.152
total
696.461
€/a
253.798
delta kWh per week
123.581
Load in %/week Load in h/week
time * load
100%
40,00%
67,2
40,00%
90%
10,00%
16,8
9,00%
80%
20,00%
33,6
16,00%
70%
20,00%
33,6
14,00%
60%
10,00%
16,8
6,00%
Average load shaft power fixed impeller
85,00%
Sterling Fluid Systems specialises in liquid pumps, vacuum pumps and systems. The organisation provides a broad range of engineered solutions to support the fluid handling requirements of the process industries. Founded in 1920 as Siemen & Hinsch (SIHI) in north Germany by the inventor of side channel pumps Otto Siemen and Johannes Hinsch, SIHI became a member of Sterling Fluid Systems Group in 1997 and changed the company name to Sterling SIHI in Germany and to Sterling Fluid Systems in Europe and Asia. Sterling SIHI has been manufacturing liquid pumps, vacuum pumps, compressors and engineered systems for many applications in the chemical, pharmaceutical, power, water/waste water, food/beverage, plastic, steel, paper and machinery manufacturing industries. Sterling Fluid Systems has over 10 manufacturing centres, 60 sales offices and more than 100 service centres around the world to provide a support network at a local level.
shaft power variable pitch
pump 1
pump 2
kWh total
pump 1
pump 2
kWh total
2557
2557
343.661
2557
2557
343.661
2557
2557
85.915
2200
2200
73.920
2557
2557
171.830
1750
1750
117.600
2557
2557
171.830
1300
1300
87.360
2408
0
40.454
2394
total
813.691
delta kWh per week
Sterling Fluid Systems
The company has more than 1,600 employees worldwide and a turnover of more than €250 million. It is a member of the Thyssen Bornemisza Gruppe (TBG), which achieves more than €2 bn annually. In 2007, TBG sold Peerless pump Co to Grundfos. In 2004, the company’s industry segments were divided into three divisions, which are chemical, industrial and energy & environmental. Brands include SIHI, Halberg and LaBour. SPP Pumps Ltd was sold to India’s Kirloskar Brothers Ltd in 2003.
Assumed load profile No. 3 Load in %
Gerd Witte Product manager tubular casing pumps Sterling SIHI GmbH [email protected] http://www.sterlingsihi.com
150.931
40.219 total
662.760
€/a
235.453
International Rotating Equipment conference This paper was first presented at the Pump Users International Forum 2008 held in Düsseldorf, Germany in October 2008, and is reproduced with permission from VDMA eV.
Figure 4. Different load profiles. www.worldpumps.com
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