Two horizontal multistage dewatering pumps reduce power consumption and spare part stock keeping at a UK cement plant

Today, we’re going to be drilling into a recent project we worked on with a UK-based cement manufacturer.

Our client contacted us to say they were looking to standardise two pumps in operation at one of their quarries. The pumps were used to dewater the quarry to give access to stone reserves that they need for the cement manufacturing process.

The pumps had been installed for over seven years and were different models from different manufacturers. In effect, they had two different pumps for the same application with different motors and pump sizes.

This gave our client three major problems:

• Different shaft sizing and power requirements meant that the pumps weren’t interchangeable, and were using more energy than necessary - savings could probably be made in energy consumption

• They had to store twice the number of spare parts which also weren’t interchangeable
  

• To replace both existing pumps, the manufacturers were quoting long lead times to supply new pumps

Why dewatering is vital at a quarry

The need for dewatering is obvious. As soon as any excavation is carried out below groundwater level, water will be drawn into the pit whenever the drilling goes through permeable strata, fissures or fractures.

This water will need to be pumped out. Therefore dewatering pumps are vital for many reasons, including productivity, employee safety, equipment protection and environmental compliance.

In fact, high pressure multistage pumps are regularly used to remove water in many environments, such as quarries, power plants, mines, building sites and industrial mills.

Better productivity

Excessive water will clearly lead to hazardous conditions that can stop work immediately. This is one of the biggest production setbacks on a quarry site.

Dewatering pumps ensure that work can carry on in even the wettest conditions. In short, waterlogging won’t affect production schedules and deadlines, which can have a big impact on productivity and profitability.

Improved safety

Rainwater, groundwater and surface water at a quarry can cause very slippery surfaces, electrical hazards and a real risk of injury or drowning at the worst.

Dewatering pumps are the most effective way to deal with this problem – indeed, without them the quarry site would quickly become flooded with water, making it virtually impossible to carry on mining operations. Pumps remove the water and the associated risks.

More protection for equipment

As well as potential injury to employees, water at a quarry site can cause damage to expensive machinery and costly delays to the entire operation. Quarry high pressure multistage dewatering pumps provide valuable protection to key machinery and help ensure continuous site operation.

Tighter environmental compliance

These days, environmental considerations are more important than ever. Sites can certainly operate without dewatering pumps. But aside from the negative effect on safety and productivity, there’s also the environment to think about.

This is why most parts of the UK have strict environmental regulations in place that require site operators to manage water effectively and prevent pollution in the local area. Dewatering pumps can do all this automatically.

What did we specify for this project?

At North Ridge Pumps, we’re not limited to choosing just one type of pump.

As the UK’s largest pump supplier with over 25 years in the business, we’re highly experienced at providing engineered pumps for a wide range of applications. We use this expertise to give each client a tailor-made solution, not a standard product taken straight off the shelf.

Above all, we choose the best pump for every job – offering the lowest lifetime cost. For this particular project, we specified two of our XMZ end suction horizontal centrifugal multistage dewatering pumps.

These are capable of high pressures up to 45 bar and flow rates of up to 400m³/hr. In addition, they are very robust thanks to the extra bearings added to the pump head, which take the strain away from the motor during pump operation.

What does multistage mean?

Centrifugal pumps usually have just one impeller. A multistage pump however has multiple impellers or stages of impellers fitted back-to-back.

This configuration enables the pump to generate much higher pressures than with a single impeller. This makes multistage pumps ideal for applications that need higher pressures, or a mixture of high pressure combined with low to medium flow rates.

Where are multistage centrifugal pumps used?

This type of pump is specifically designed to transfer low viscosity clean or slightly contaminated fluids which don’t contain solid or fibrous particles.

This makes it particularly suitable for an extensive range of applications in the marine and industrial sectors. Typical fluids which are pumped include fresh water, sea water and a variety of fuels like diesel, petrol and kerosene.

Some of the most popular applications are water supply, dewatering, cooling and heating conditioning (HVAC), reverse osmosis, water treatment, pressurisation and irrigation, plus chemical and energy plants, mining, firefighting and building systems.

Collaboration with the client

At the start of the project, we worked closely with the customer to specify the best pumps for the job. These had to be fully interchangeable and be able to deliver the required flow and pressure at a lower installed power.

To replace both existing pumps, the manufacturers were quoting long lead times. In fact, these were twice as long as the timescales we presented to the client.

After getting the go-ahead, we supplied two high pressure multistage pumps coupled to motors, plus a spare bareshaft pump which could quickly be installed when the existing pumps needed servicing.

A bareshaft pump is simply a standalone pump without a motor or base attached. They’re designed and manufactured to transfer a range of liquids in a variety of industries - food processing, pharmaceuticals, beverages, dairy and other allied sectors.

Pumps with many benefits

Our horizontal multistage dewatering pumps are an end suction design, and for greater flexibility, the discharge flange can be positioned on the top or either side of the casing depending on client requirements.

As well as this, multiple closed impellers and diffusers are fitted to enable the unit to deliver very high pressures. It has a maximum casing pressure of 63bar and sacrificial wear rings which are replaced periodically. These protect the casing and impellers from wearing out too soon.

In addition, our XMZ end suction horizontal centrifugal multistage pump can be supplied with an external electric or air-powered priming pump for applications requiring a suction lift.

It is also available in an ATEX version for handling flammable fluids, or for use in a non-safe or hazardous area.

If your company needs pumps capable of high-pressure operation in extreme conditions, speak to North Ridge Pumps to see how we can help.