Tag:centrifugal pump

№10|2017

WASTEWATER TREATMENT

bbk 000000

UDC 628.54

Sazonov D. V.

Influence of the pump type on the parameters of the pneumatic-hydraulic aeration system in flotation apparatus

Summary

Flotation has been one of the efficient water treatment technologies. Flotation treatment is based on small gas bubbles generated by different methods, pneumatic-hydraulic, in particular. A case is considered of air feeding before the pump and subsequent water-air mixture passing through the aerator, and air being broken to small bubbles. Possible operation in the presence of air determines the choice of self-priming pumps (centrifugal and vortex). Experiments were carried out on determining two of the most important aeration parameters: bubbling rate and average size of generated air bubbles that determine the efficiency of water flotation treatment. Based on the data obtained it is shown that in most cases centrifugal pumps have the advantages: considerable part of the air entering the pumps is dispersed at the outlet of the aerator to 30–100 μm bubbles; whereas in case a vortex pump is used air bubbles of more than 200 μm size are generated which is ineffective for water flotation. It is stated that for some wastewater types the use of vortex self-priming pumps can be more reasonable.

Key words

, , , , ,

 

№4|2014

ЭНЕРГОРЕСУРСОСБЕРЕЖЕНИЕ

bbk 000000

УДК 621.65:62-531.3:628.1/.2

Bagaev Yu. G., Karpov N. V., Usachev A. P.

Specific features of frequency regulation of parallel pumps

Summary

One of the options of energy efficient operation of pumping units at the water and sewage pumping stations under pump impeller speed variation with the help of variable-speed electric drives widely used at present time is considered. One variable-speed electric drive is installed either for a group of operating units or on a single pump. Installing a variable-speed electric drive on each operating unit at first sight seems to be a very expensive measure; therefore more often one electric drive is installed for a group of pumps (2–3 units). However, in this case cavitation processes can arise, the dynamic loa­ding on the pump shaft and bearings can increase, the lifting efficiency can decrease, and in the long run the pump energy efficiency can drop. The data of the theoretic and practical substantiation show that installing variable-speed electric drives on each operating pumping unit provides for weakening of the above-mentioned shortcomings, whereas the energy efficiency improves.

Key words

, , , ,

 

№9|2012

POWER RESOURCES CONSERVATION

bbk 000000

UDC 621.671

LEZNOV B. S., Vorobiev S. V.

The operation of centrifugal pumps with variable speed

Summary

The technologic aspects of using variable speed drives in pumping units are considered. The operation of centrifugal pumps with variable speed of the impeller is analyzed with account of the impact produced by water mains characteristics on the working parameters of pumping units. It is shown that reducing the pump impeller rotation speed can in some cases result in cavitation, surging, pump rotation speed resonance and resonance of the free lateral vibration of the shaft. Possible pump operation with rotation speed higher than the rated value is considered.

Key words

, , ,

 

№11|2012

POWER RESOURCES CONSERVATION

bbk 000000

UDC 621.671

LEZNOV B. S., Vorobiev S. V.

The operation of centrifugal pumps with variable speed
(The termination, the beginning see here)

Summary

The technologic aspects of using variable speed drives in pumping units are considered. The operation of centrifugal pumps with variable speed of the impeller is analyzed with account of the impact produced by water mains characteristics on the working parameters of pumping units. It is shown that reducing the pump impeller rotation speed can in some cases result in cavitation, surging, pump rotation speed resonance and resonance of the free lateral vibration of the shaft. Possible pump operation with rotation speed higher than the rated value is considered.

Key words

, , ,

 

№2|2018

ENERGY CONSERVATION

bbk 000000

UDC 628.1.2:658.26.004.18

Usachev A. P.

Control of centrifugal pump parallel operation

Summary

The problems related to the cable capacity of pumping units during their parallel operation (one with variable-frequency control, another one – without variable-frequency control) are considered. In the traditional control schemes (without variable-frequency control) the problem is solved by throttling of each pump with cable capacity levelling of their drive motors. This function is usually carried out by the operator in manual mode. Based on the conducted analysis an algorithm of pump control was developed that provided for their safe operation in the working area and maximum energy efficiency. It is proposed to carry out controlled throttling of the pump without variable-frequency control by controlling the position of the set point of the pump with variable-frequency control at the working area interface. To ensure failure-free operation of the pumping station in case of the pump with variable-frequency control emergency shutdown it is recommended to change the system of the pump without variable-frequency control for automated pressure maintaining with the help of throttling. To implement the given algorithm the use of a special process controller with the sufficient computing power (STK 500 type) and series SP 200 blocks is proposed.

Key words

, , , ,

 

vstmag engfree 200x100 2

mvkniipr ru

Российская ассоциация водоснабжения и водоотведения

Конференция итог

ecw20 200 300

VAK2