Goulds Pumps

PHV - Packaged Hydrovar Series

PERFORMANCE WITH VARYING SPEED FOR CENTRIFUGAL PUMPS

Fitting the electric pump with a variable speed drive makes it possible to vary the pump rotation speed, normally accor- ding to the system pressure parameter. Variations in electric pump speed result in modified performances according to the equivalence relations, called affinity laws.

Flow Rate

Q1

 

n1

 

 

 

 

 

Q2=

n2

 

Head

H1=

 

n1

 

2

 

 

 

H2

n2

 

 

P1

 

n1

 

3

 

 

 

Power

=

 

 

 

 

P2

n2

 

 

 

 

 

 

 

 

 

n1 = initial speed;

n2= speed required.

Q1 = initial flow rate;

Q2= flow rate required.

H1 = initial head;

H2= head required.

P1 = initial power;

P2= power required

Head

 

 

 

H

n1

 

 

H1

 

A

 

 

 

 

 

n2

 

 

H2

B

 

 

 

 

 

 

Q2

Q1

Q

 

 

 

Flow

Frequency ratios can be used instead of speed in practical applications, keeping 30 Hz as the bottom limit.

Example : 2-pole 50 Hz electric pump n1 =2900 (point A) Flow rate (A) = 100 l/min; Head (A) = 50m

By reducing the frequency to 30 Hz the speed is reduced to approx. n2 = 1740 rpm (point B) Flow rate (B) = 60 l/min; Head (B) = 18 m

The power of the new work point B is cut to about 22% of the initial power.

SIZING THE DIAPHRAGM TANK IN SYSTEMS WITH SPEED VARIATION

Variable speed booster sets need smaller tanks compared to traditional systems. Generally speaking, a tank with a capacity of just 20% of the nominal capacity of a single pump, expressed in gallons per minute, is needed. The gradual starting of the pumps controlled by the drive reduces the need to limit the number of hourly starts; the main purpose of the tank is to compensate for small system losses, stabilize the pressure and make up for pressure variations caused by sudden demand (fast acting valves).

Make the following calculation:

Set made up of three electric pumps, each with a maximum flow rate of 100 GPM, for a total capacity of 300 GPM. The volume required for the tank is 20 gallons. This is total capacity, not drawdown. Mount downstream of the check valves in discharge manifold.

18

Page 18
Image 18
ITT BPHV Performance with Varying Speed for Centrifugal Pumps, Sizing the Diaphragm Tank in Systems with Speed Variation

BPHV specifications

ITT BPHV, short for ITT's Bacterial Purified Water and High Purity Valves, represents a breakthrough in the field of fluid control technology, particularly designed for applications requiring the highest standards of cleanliness and reliability. These valves are typically utilized in industries where the quality of fluid handling is crucial, such as pharmaceuticals, biotechnology, and food and beverage manufacturing.

One of the standout features of the ITT BPHV is its ability to handle both high purity and aggressive fluids without compromising system integrity or cleanliness. The design focus on valve components ensures that they are free from contaminants, which is essential for processes where even minute impurities can lead to significant quality issues.

The materials used in the construction of ITT BPHV valves are particularly noteworthy. They feature advanced polymers, stainless steel, and other corrosion-resistant materials that withstand the rigors of high-purity applications. These materials not only ensure durability and longevity but also meet stringent industry standards for safety and compliance.

Innovative technologies integrated into ITT BPHV valves enhance their performance. These include advanced actuation systems that allow for precise control and responsiveness, ensuring that the flow of fluids can be managed effectively, even in highly dynamic environments. Additionally, the valves are designed to facilitate easy maintenance, with features that allow for quick disassembly and cleaning without the need for specialized tools.

Another vital characteristic of ITT BPHV valves is their compact design, which maximizes space efficiency within installations. This is particularly beneficial in industries where real estate is at a premium and where large equipment can impede operational efficiency. The modularity of the valve design also means that it can be adapted easily to different system configurations.

Furthermore, ITT BPHV valves are engineered with safety in mind. They incorporate features such as fail-safe functionality and pressure regulation, providing operators with peace of mind during critical operations. The seamless integration of these valves into automated systems enhances productivity by enabling consistent and reliable fluid movement.

Overall, ITT BPHV stands as a pioneer in high purity fluid handling, offering cutting-edge technology and robust engineering to meet the demands of modern industries. With their focus on cleanliness, reliability, and operational efficiency, these valves are an essential component for any facility striving for excellence in fluid management.