Innovative Graco Electric Pump Provides Risk-free Operation

Phil Black - PII Editor 13/10/2015

219 5 minutes read

Key points

Listen to this article

Graco’s Husky™ 1050e electric double diaphragm pump offers dry running and stalling, as well as significant energy and cost savings over equivalent electric pumps and conventional air-operated diaphragm pumps.

Pump failures are a frustrating waste of time, energy and money. So it comes as no surprise to find that Graco, a world leader in fluid handling systems and components, has devoted considerable resources to attempt to eliminate them. In addition, Graco constantly seeks to improve the energy efficiency of pumps and create a quieter working environment for operators and nearby employees.

Does this seem like an impossible combination? Not with Graco’s new Husky™ 1050e electric double diaphragm pump, which has been designed to meet such a mix of demanding requirements.

“The Graco Husky 1050e is the only electric diaphragm pump on the market that will stall under pressure, to prevent pump failures from clogged lines or closed valves,” says Walter Leeten, Product Marketing Specialist Process at Graco.

“Its energy efficient electric drive reduces energy consumption by up to five times compared to traditional air operated diaphragm pumps. In addition, the 1050e can be set to reduce pulsations, so you no longer need a pulsation dampener – which contributes to its low noise levels.”

The thinking behind developing an electric double diaphragm pump certainly makes sense. It will immediately remove the significant costs of purchasing, running and maintaining an air compressor. And of course you might need to run a pump in locations where no air is available – or will take a lot of time and logistics to get an air supply up and running. In these situations an electric pump is an excellent alternative.

How it works

The Husky 1050e is an electric operated 1” double diaphragm pump (EODD). It works like a conventional air-operated double diaphragm pump (AODD).

However, don’t view the 1050e merely as an AODD connected to the nearest electricity supply instead of an air compressor. There’s some innovative stand-out technology inside.

The 1050e consists of the same fluid parts as a conventional AODD. Where it differs is that it uses an air pressurised center. “Compare it to a bicycle wheel,” explains Leeten.

“You need to load the pump with air to start it working, but after that you don’t need a constant supply of air to keep it running. In fact you only need 0.6 litres of air a day!”

When the pressure pushing on the outside of the diaphragm (fluid pressure) is equal to or greater than the center section (air) pressure, the pump will stall, removing the risk of pressure being built up. This avoids damaging the pump or the production line.

If then the air pressure in the center section increases so that it is greater than the fluid pressure, or the fluid pressure decreases so that it is less than the air pressure, the pump will start pumping again. The motor will keep running all the time.

Interesting advantages over AODDs

One of the key advantages of the Husky 1050e is that it stalls under pressure. Historically, pneumatic diaphragm pumps stall under pressure, which makes them unique.

Electric motors typically do not stall under pressure, but the 1050e does; the only electric diaphragm pump to do so. Stalling under pressure avoids the risk of damaging the pump or pipeline when it’s blocked or a valve is closed. It also negates the necessity for installing an extra pressure sensor.

The 1050e also comes into its own in applications that require low pulsation and a smooth flow. The patented air charged drive allows for the elimination or reduction of pulsation without expensive pulsation dampeners or surge tanks.

It also gives a good level of control – especially important for metering and batching. And there is no risk of contamination of products due to the absence of hydraulic backing.

Its seal-less diaphragm pump design eliminates leaking rotational seals and failures due to run-dry pump conditions. Other advantages include the lack of exhaust air, the ability to handle abrasives, and its quietness, making it ideal for applications in close proximity to people.

Significant cost savings

Now let’s look at the bottom line: operating costs. It’s interesting to compare the 1050e EODD 1” with a conventional 1” AODD; both operating for 24 hours at a flow rate of 95 litres per minute and a fluid pressure of 3.5 bar.
The required air for the 1050e is a paltry 0.6 litres PER DAY. Compare this to the air required for a conventional 1”AODD, which needs 700 litres PER MINUTE.

This corresponds to an annual operating cost for the 1050e of 460 EUR, compared to 2300 EUR for the conventional 1050 AODD: a 5x cost saving!

Suitable for a wide range of applications

“We see the 1050e as highly suitable for the waste water treatment industry – for applications such as the pumping of sludge and slurry – where it can replace large peristaltic pumps,” says Leeten.

“In applications where saving energy is the key driving force, the 1050e is an interesting replacement for AODD pumps running in continuous duty applications. Moreover, the 1050e can handle particles up to 3.2 mm.”

If lack of air is your specific challenge, then the 1050e, with its small air requirement, is the ideal solution. For example, you may have no additional compressor capacity, or an installation where air is simply not available.

You may have a temporary lack of air due to compressor maintenance or shutdown. Or you may simply want to save the cost of a large compressor. In all these situations, the 1050e is perfect.

Another area of use is where more control is required from process pumps. You can get more control through replacing your existing electrically driven pumps with the 1050e, and at the same time you will get improved metering accuracy.

Flexible and efficient

The 1050e is available in brushless DC, AC and AC ATEX options. The brushless 2HP DC motor, for example, offers increased control, maintenance and alarm notification, batch operation, and meets API 675 and ANSI 7.1-7.5. The electric 2HP AC motor offers increased efficiency, ATEX options, and runs on 110V, 220V or 480V.

The center section can be aluminium or stainless steel, while the fluid section can be aluminium, polypropylene or stainless steel. Maximum fluid working pressure is 4.8 bar (0.48 MPa / 70 psi). Air pressure operating range is 1.4 to 5.5 bar (0.14 to 0.55 MPa / 20 to 80 psi). Cart mounted systems are available.

A final point to remember is that this highly energy efficient electric pump runs up to five times more efficiently than other air operated diaphragm pumps.

The 1050e in the field

The 1050e was tested in a water treatment facility where it was used to pump lime slurry. In this application, one 1050e replaced two size 4 eccentric pumps. It racked up more than 24 million pumping cycles at a fluid flow rate of 68 litres per minute and a fluid pressure of 2.8 bar.

With the previous eccentric pumps, hoses were having to be replaced every two to six weeks. In eight months of operation, there was no need to replace a single diaphragm of the Husky 1050e.

All in all, the Graco Husky 1050e electric double diaphragm pump looks set to have a major and long-lasting impact in industry.
www.graco.com