Exploring the world of Submersible Pumps

When it comes to the world of water pumps in general, there are many options. Each pump has a different design and serves a different purpose. They differ in sizes, shapes, capacities, prices etc. They also differ in quality depending on which provider the customer chooses to go for.

However, in this large world of water pumps, there is also a unique category of pumps i.e. the submersible pumps. The general perception is that submersible pumps are good or are available only as sewage pumps. Is it so?

No, today there are few good companies who are offering Submersible pumps for all kind of water processes. i.e. from pumping Clear Water to Pumping Slurry. In this article, we’ll be sharing the very basics of a submersible pump.

• How does it get its name?
A submersible pump is called so because of its ability to operate in fully submerged condition, in water. It is also known by the name of an electric submersible pump.

• The motor of a submersible pump
The motor of a submersible pump is close-coupled (mounted on common shaft) to the pump & is like a heart of the pump. Sealing forms a very important aspect of motor, sealing can be either mechanically sealed or it can be hermetically sealed.

• The basic function of a submersible pump
A submersible pump basically aims at pushing the water to the surface. It functions in this way by converting the rotary energy into kinetic energy and further converting that into pressure energy.

• How does the pump execute this process?
This process is executed by pulling of the water into the pump. Firstly, it goes in the intake. This is where the rotation of the impeller starts pushing the water through the Volute. And then, from here, it finally goes to the surface.

• Why are submersible pumps advantageous?
Few of the major advantages of a submersible pump is that it is self-priming, no suction lift limitations, no negative suction & less power consumption.

Add to this there is no noise pollution, no wastage of surface space, pump is not necessary & last but not the least it also acts as a protection against possible theft.

• A tip of caution for using submersible pumps
The pumps must be fully submerged into the water, as it actually helps to cool the motor of the slurry pump. However, if the pump is used out of water, it may lead to overheating & burning.

In the end, if you are planning to go for a pump, its always advisable to check whether you have an option in submersible pumps & chose are the type that suits your purpose, keep these advantages in mind and go ahead about it. You should however, make sure that the quality you are attaining is great and reliable. For our product details get in touch at 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.

Know The Basic of Slurry Pumping

Slurry can be really tough on pumps! Being thick, abrasive & with high specific gravity, slurry is one of the most challenging fluids to move. 

 

What is slurry?

Slurry is a mixture of solids and liquid, generally water. The particles can be both abrasive & non abrasive, although abrasive particles are very much common. The purpose to move slurry can be transporting as much solids particles as possible, hydraulically, along with the given liquid.

Factors to be Considered in Slurry Pumping

• Particle size- d85= 3mm- means 85% of particles have a diameter of 3 mm or less.

• Specific gravity of solids particles (SGs)

• Specific gravity of liquid (normally water which is 1)

• Concentration of solids by volume (Cv)

• Concentration of solids by weight (Cm) (where Cv, Cm is given in % it means it is for slurry)

• Specific gravity of slurry (SGsl)

• Mass fraction (% of particles below 75 μm)

• Shape of particles (Round or Flat)

Characteristics of Slurry

1. Non – Settling Slurry - In this particle size is less than 60-100 μm. A non settling slurry can be defined as a Homogenous Mixture. It is comparatively easy to pump non-settling slurry.

2. Settling Slurry- In this particle size is greater than 100μm. Settling slurry can be defined as Pseudo-Homogenous Mixture OR Heterogeneous Mixture. This is where the demand on slurry pumps increase.

Few Slurry Pump Applications

• Steel Plant- Pumps for mill scale transportation.

• Thermal Power Plants- Pumps for fly Ash slurry handling.

• Hydel Plants & projects- Pump for removing silt and sediment from tailing dams, trenches, channels, Dam gallery, coolant sumps, etc…

• Mineral Processing Units.

• Mines & Quarries

• Various industrial uses like E.T.P, Cement plants, Fertilizer & Pharmaceutical Plants.

• Sand dredging, washing and cleaning.

• Lagoon cleaning & dredging near dockyard and ports.

Why Darling Pumps?

Darling Pumps with its comprehensive series of pumps can provide unique solutions for pumping of both - Settling as well as Non Settling Slurries.

We handle water of all types & quality.

• From clear water pumping to slurry handling we have solution for all.

• As we understand water better, we can help you handle it in a more effective manner.

• We provide customized solutions to all your pumping needs.

Check out our range of slurry pumps at http://www.darlingpumps.in/slurry_pumps.html To know more, call 

+91 99819 92838.