Disc Pumps

Disc pumps offer various advantages in hard-to-pump applications making them the future of pump technology. Some key features of these pumps are:

• Disc pumps are capable of transferring abrasive, air-entrained fluids, as well as viscous fluids and high solid slurries. 
• Fluids with particulate matter, solids, and trapped air can also be transferred through these pumps. 
• Unlike the other conventional pumps, these pumps have no close tolerances, offer a pulsation-free flow and operate based on a non-contact pumping action. All the mentioned features contribute to high reliability and uptime by preventing solids from clogging
• As much as these pumps can handle highly viscous fluids and solids, they can also process fragile products without any damage. 
• They are sturdy and corrosion resistant; therefore, the wear and tear that occurs due to abrasive fluids is minimal. Therefore, both repairs and spare parts requirements are low.
• They have dry-run capability. They can operate without processing fluid; however, in this case, the mechanical seal needs to be flushed.
• Their discs have low radial and axial loads, which help to extend shaft, bearing, and seal life.
• The net positive suction head (NPSH) required is far lower than most other pumps.

All these features reduce the overall cost and time in the long run.

Disc pumps are extremely versatile units. They have the appearance of centrifugal units, but can work like gear pumps, impellers, progressive cavity pumps, and chopper pumps. Here are some basic steps of their operation:

• Disc pumps are designed on the basis of fluid engineering principle of boundary layer and viscous drag. This phenomenon facilitates the transfer of energy from the motor to the fluid. 
• The pump has a boundary layer inside, which minimizes loss of friction and enables pulsation-free flow of the fluid. 
• The molecules of the fluid entering the pump form the boundary layer by adhering to the surface of serial discs. 
• This boundary layer and viscous drag together create centrifugal force that sucks in the fluid in a smooth, pulsation-free manner.
• The rotation of the fluid along with the impeller discharges it to the other end of the pump. 
• The pace at which this mechanical movement happens decides the discharge pressure. Other factors such as the diameter of the impeller, inlet fluid supply pressure, motor power, and so on affect the pressure and flow within the pump.
• Along with the disc, the fluid also rotates and is pumped out in a spiral manner. 
• The boundary layer reduces the contact between the fluid and the pump, thus eliminating corrosion, abrasion, or any other chemical reaction.

Disc pumps have applications across industries with varying requirements, especially processing hard-to-pump materials. They are commonly used in wastewater treatment by city-based municipal corporations. Here are a few important application areas:

• Metals and mining: Drilling processes and precious metals recovery
• Wastewater management: Filter aids, scum mixing, sludge handling processes and recirculation
• Municipal corporations: Water treatment plants, recycling and purification
• Food & beverage: Food processing industries to process canned sauces, soups, baby foods, fruit juices, breweries, beverages, hydrogenation, milk & milk products, crystallizing
• Pharmaceutical: Salt crystal slurries, filter aid, and tablet coating 
• Chemicals: Pumping of inks, chemicals, dyes, adhesives, paints, emulsions, foundries, varnishes, and gelatins
• Oil & gas: Drilling processes for mud and crude oil, subsea cutting recovery, oil refining processes

Other general applications: Heat transfer, latex, cutting fluids, fertilizers, solid suspension, slurry mixtures, pulp & paper

Disc pumps are made of sturdy metals and their alloys. Some commonly used metals are:

• Carbon steel
• Cobalt base alloy
• Hastealloy B
• Hastealloy C
• Stainless steel
• Monel
• Cast iron
• Bronze
• Titanium