Diaphragma Pumps Saving up to 60% of Pressurized Air with in AODD Pumps
A workhorse takes the spotlight: AODD pumps perform reliably even in difficult conditions – But now, they can do even more: By significantly reducing the air consumption through a clever setup, pump manufacturer Wilden claims to have created a pump that needs 60% less pressurized air than common designs…
You can find it in food and beverage applications as well as in pharma plants. Petrochemical companies rely on it as in dewatering several in mines miles underground applications. It works underwater as well as in hazardous atmospheres and is the first choice for many process engineers: The Air Operated Double–Diaphragm Pump (AODD). AODD pumps have many advantages over other common pump designs: They perform reliably with a relatively simple design. Their purely mechanical setup allows for installations in remote locations, underwater or in explosive atmospheres as the pump does not need electrical power– only pressurized air.
And yet, while AODD pumps have many virtues, they also share a common flaw: The pressurized air that is used to drive the diaphragm is only controlled rather crudely, resulting in a behaviour known as ‘overfilling’ of the air chamber. While the liquid pressure already decreases as the pump discharges, the compressor still blows air into the air chamber – air that is, in the end, wasted. Elaborate pump designs featuring microcontroller that monitor and adjust the airflow are able to minimize these losses, at the expense of an expensive technology. The microcontroller also brings electricity into the system, making it less safe for hazardous areas.
A Small Step for a Pump, But a Giant Leap for Energy Efficiency?
Now Wilden, a company named after the inventor of AODD pumps, states they have overcome this problem: “A giant leap forward in the energy efficiency and performance of AODD pumps”, states Chris Distaso, Director of Engineering for Wilden. The company’s engineers claim to have achieved both up to 60% savings in air consumption, while providing more product yield per standard cubic foot per minute with the new Pro–Flo Shift Air Distribution System (ADS) – a real plus factor in times of energy and emissions awareness. “We maximize the efficiency by minimizing air consumption”, Greg Duncan, Wilden’s Director of Business Development states.
The key to this performance is a newly designed air control systems that, with the help of a bone shaped oscillating spool precisely controls the airflow. This technology helps to cut off the air before it ‘overfills’ the pressure chamber in the pump. By doing so, it doses the air precisely and just on time to where it is needed. Despite needing less air, the required pressure does not change, Duncan explains. The airflow is the crucial factor and a costly factor too: Many companies have 10, 20 or even up to 100 pumps in their facilities. Cutting the air consumption could in the end even mean switching of whole compressor chains.
Apart from the encouraging performance, the design could be kept relatively simple: “The design of the ADS doesn’t require any additional bolted-on equipment or bulky electronics, allowing operators to keep the same compact footprint,” Chris Distaso confirmed. The robust setup allows for a submerged operation or application in hazardous areas, including an ATEX compliance. Its fewer operating parts can help to reduce failures and downtimes, the manufacturer states. Not relying on electronics, it should be well suited for the harsh environments typically found in industrial applications. “There’s beauty in this simplicity”, Duncan states. The pump does not need to be calibrated with complicated flow curves, neither does it have a learning curve as a microcontroller setup would have. It’s a simple plug and pump solution.
New Pump Design reduces Air Consumption, Increases Service Life
And it performs too: In attesting scenario, the Pro–Flo Shift pump showed significant advantages other pump designs, even modern microcontrolled ones. And it works just as easy as common AODD pmps: “It works straight out of the box,” confirms Wilden engineer Carl Glauber. “No warm up and no learning period required.“ Plus, it can be retrofitted: The manufacturer works on retrofit kits for the ADS system of both its pumps as well as others of similar design. “The customer will not want to change his piping system”, Glauber states. Nor will he make allowances to a reduced flow rate. But a reduced air consumption as well as less pumps strokes, thus a longer service life of the pump, could be very attractive.
The Wilden Pro-Flo Shift is available in 38 mm (1-1/2”), 51 mm (2”), and 76 mm (3”) sizes and features maximum discharge pressures to 8.6 bar (125 psig), maximum flows to 923 lpm (243 gpm) and maximum solid-handling size to 13 mm (1/2”). The Pro-Flo Shift is available with maximum suction lifts to 7.2 m (23.8’) dry and 9.6 m (30.6’) wet.