Dewatering Solutions for Construction Sites

One of the primary tasks involved in any construction site is dewatering. The site needs to be dewatered and dried before laying foundation. Groundwater level needs to be lowered before beginning any kind of excavation on the site. So, dewatering solutions are crucial on construction sites and submersible pumps play a vital role in controlling the water level. Not just groundwater, even rain water can cause problems on a construction site. Whether the construction site needs dewatering or not is never a question; the question is what kind of dewatering solution the site needs.

Construction dewatering is the removal or draining groundwater or surface water from a riverbed, construction site, mine shaft and other areas.

Dewatering solutions are required during – 

• Foundation work for construction of building
• Road construction
• Control of Ground water level
• Sedimentations tanks at construction sites
• Tunnel construction

Type of dewatering solution ideal for construction site depends on water quality & various solids/impurities present in water. The concentration and type of solids influence the choice of pump & MOC of pump which can be used to dewater the site. Basically, different types of pumps used for dewatering construction sites include –

• One of the most commonly used pumps, a drainage pump is used for pumping water with less abrasive solids, like clay. Sand, not in a concentrated form, and solids in suspension can also be pumped using drainage pumps.
• Sludge pumps are suitable for pumping water with solids as well as for pumping sludge.
• Slurry pumps are designed to handle abrasive solids in suspension, like sand, gravel and others in high concentration. 

For custom dewatering solutions and an array of dewatering submersible pumps in India, get in touch with Darling Pumps. We are providing efficient and reliable pumping solutions to our customers over the past 35 years. Talk to pump experts at Darling Pumps, call +91 99819 92838.

 

Basics of Pump Assessment

The work performed by a pump is a function of the total head and of the weight of the liquid pumped in a given time period. Pump shaft power (Ps) is the actual horsepower delivered to the pump shaft. It can be calculated as follows:

Pump Shaft Power (Ps) = Hydraulic power (hp) / Pump efficiency (ηpump)

Pump Efficiency (ηpump) = Hydraulic power / Pump shaft power (Ps)

Pump output, water horsepower or hydraulic horsepower (hp) is the liquid horsepower delivered by the pump, and can be calculated as follows:

Hydraulic Power hp = Q (m3/s) x (hd - hs in m) x ρ (kg/m3) x g (m/s2) / 1000

            Where:

            Q = flow rate

            hd = discharge head

            hs = suction head

            ρ = density of the fluid

            g = acceleration due to gravity

Difficulties in Pump Assessment

• Absence of pump specification data to assess pump performance - Pump specification data are required to assess the pump performance. Most companies do not keep original equipment manufacturer (OEM) documents that provide these data. In these cases, the percentage pump loading for a pump flow or head cannot be estimated satisfactorily.
• Difficulties in flow measurement and flows are often estimated - It is difficult to measure the actual flow. The methods are used to estimate the flow. In most cases the flow rate is calculated based on type of fluid, head and pipe size etc, but the calculated figure may not be accurate. Another method is to divide the tank volume by the time it takes for the pump to fill the tank. This method can, however, only be applied if one pump is in operation and if the discharge valve of the tank is closed. The most sophisticated, accurate and least time consuming way to measure the pump flow is by measurement with an ultrasonic flow meter.
• Improper calibration of pressure gauges & measuring instruments - Proper calibration of all pressure gauges at suction and discharge lines and other power measuring instruments is important to obtain accurate measurements. But calibration has not always been carried out.  Sometimes correction factors are used when gauges and instruments are not properly calibrated. Both will lead to incorrect performance assessment of pumps.

If you have any queries regarding pump assessment, feel free to get in touch with Darling Pumps. Our ability to integrate different systems to provide customized technical solutions has made us the leader for custom pumping solutions in India. 
For further details, visit www.darlingpumps.in or call +91 99819 92838.

Why does Pump Motor Burn?

Pumping systems account for nearly 20% of the world’s electrical energy demand. Furthermore, they account for 25-50% of the energy usage in certain industrial plant operations. The use of pumping systems is widespread. They provide domestic, commercial and agricultural services. In addition, pumping systems provide municipal water and wastewater services, and industrial services for food processing, chemical, petrochemical, pharmaceutical, mechanical and other industries.

Problems Faced with Pump Motor

When a pumping motor has been installed properly, it can run for several years with minimal maintenance. One of the most commonly faced problems is failure of pump motor. There is a common misconception that motor fails due to voltage. But, it needs to be understood that motor does not fail because of voltage, in fact it burns because of current.

•          Over Load – Voltage fluctuations, mechanical and electrical malfunctioning, phase failure (single phasing). 
•          Under Load - Dry run, reverse rotation, mechanical failure, phase failure (single phasing)

To safeguard pump motor, we can monitor and control the current variation for its higher and lower allowable value.

Why it is critical to use control panel along with the pump?

A reliable & proper control panel is very critical for proper running of any pump set. A pumping motor does not understand -

• When it is under load.
• When it is running in reverse direction.
• When it is getting over heated.
• When it is running dry
• When it is getting overloaded

By adding a control panel to the system -

·         You can ensure consistent & stable electric supply that is not within our control under normal setup.

·         Pump by itself is not an intelligent device & panel, in turn, acts as an intelligent device of the pump.

Darling Control Panel is designed with advanced technology based system. It is safe and complete failure proof solution for long life, trouble free and continuous pump operation. Darling Control Panel positively monitors and controls current variations and safe guard’s pump set during those critical moments.

Different Types of Control Panel –

• Direct Online (D.O.L)
• Star delta (Y-Type)
•  Auto transformer (A.T.S)

For further details on submersible pumps and pump control panels, visit www.darlingpumps.in or call +91 99819 92838.