Viking Universal Seal Internal Gear Pumps are designed to meet the demands of heavy-duty, industrial pumping applications and incorporate essential features for reliable, low-maintenance pumping, even in the most challenging environments.
For applications in sugar refineries, the Viking Pump sugar pumps in GA can be customized with various seal options, increased clearances to minimize shear, and a ribbed idler gear for applications involving the handling of solid particles.
Viking’s ribbed idler reduces gear-to-gear contact, which is one of the causes of damage to solids, such as sugar crystals, and shear sensitive liquids. This has been achieved by removing 0.9 mm (0.035” or 900 microns) of material from 80% of the flank of each idler gear tooth, on both sides.
The rib alternates position on each tooth to minimize wear on the rotor teeth in any given spot, and since the idler turns at a different speed than the rotor, the contact point changes with each revolution of the rotor gear.
Ribbed idlers on Viking Pump sugar pumps can have an impact on pump performance depending on the viscosity of the liquid. The increased clearances result in additional slip paths that allow liquid to slip back from the discharge side of the pump to the inlet side. On water-thin liquids, there is a significant decrease in capacity, especially at higher pressures.
Minimizing Shear
Shear can reduce conversion efficiency in two-phase slurries like massecuite and so it needs to be kept as low as possible. Positive displacement pumps, and in particular, internal gear pumps, are preferred in applications involving shear-sensitive liquids, such as:
Emulsions (e.g. chocolate and mayonnaise)
Suspensions (e.g. microspheres in carrier liquids)
Polymers (e.g. latex, synthetic rubber and long chain polyelectrolytes)
Shear is the relative motion between adjacent layers of moving liquid, and shear rate is the rate of relative motion between adjacent layers of a moving liquid. It can be minimized by selecting a pump with extra clearances, and by running it very slowly. For most shear-sensitive liquids, Viking recommends a rotor rim speed of <300 feet/minute.
Seal Options for Viking Pump Sugar Pumps
An important feature of Viking Universal Seal Internal Gear Pumps is that they are designed to accommodate virtually all types of seal.
Packed Gland: Packed Glands are the most common shaft sealing for sugar liquids because they are simple, forgiving, and handle very high viscosities. Viking’s Universal pumps feature a drip well with a tapped port on the bracket to collect leakage at the seal gland and divert it to a collection container.
Behind-the-Rotor Mechanical Seal: Where leakage is not allowable, mechanical seal options are available. On H through QS size Viking pumps, the 4124B (non-jacketed) or 4224B (jacketed) series pumps offer an optional Abrasive Liquid Seal with Silicon Carbide faces located immediately behind the rotor.
Cartridge Double Seal: Double cartridge seals with hard faces inboard and water barrier can successfully handle sugar liquids to about 50,000 SSU, or 11,000 cSt, which makes them suitable for some syrups and molasses. These are available on all sizes of Viking pumps.
Cartridge Triple Lip Seal: Cartridge-style triple lip seals are capable of virtually unlimited viscosities but are not well-suited to abrasives. These are available on all sizes of Viking pumps. These seals should be used on syrups and molasses with a water flush or steam quench. They shouldn't be used when pumping massecuite or magma.
For more information regarding Viking Pump sugar pumps, watch this series of videos, then give us a call to discuss how they can benefit your operation:
