Their features and benefits make them ideal for the many liquid-transfer points in the soft drink production chain.
by Tom Zuckett & Grant Gramlich

Although per-capita consumption of carbonated soft drinks in the U.S. has been on a steady decline since peaking in the 1990s, the average American still consumes more than 41 gallons of the fizzy drinks annually—the equivalent of 437 12-ounce servings, or 1.2 cans a day. To address this decline, major soft drink conglomerates have been expanding their product portfolios to include beverages such as juice drinks and, to a greater extent, energy drinks that have become popular with millennials.

AODD PumpsImage 1. Specific AODD pumps can offer a number of operational benefits that make them better-suited for soft-drink production than centrifugal pumps, including sealless design, dry-run capability, shear sensitivity and higher energy efficiency. (Images courtesy of PSG)

The result is that billions of gallons of soft drinks are produced and consumed annually. It also means that soft drink producers must employ the best systems and technologies in order to meet production quotas that can be strained if the manufacturing process experiences any inefficiencies or breakdowns.

Air-operated double-diaphragm (AODD) pumps can help streamline the soft drink manufacturing process by optimizing liquid-transfer operations at several critical points along the production and supply chain.

The Challenge

The U.S. landscape is dotted with soft drink production facilities, known as canning and bottling plants, that use ingredients such as high fructose corn syrup, various concentrates, flavorings and phosphoric acid (which adds acidity to the final beverage) to create products that are ready for consumption.

In many instances, the large multinational corporations that dominate the global soft drink market contract with bottling companies to produce their beverages in accordance with their highly guarded, tried-and-true formulas. Mom and pop operations also produce, for example, small-batch root beers and ginger ales on a much smaller scale, but these operations still require canning and bottling companies.

Soft Drink ManufacturingImage 2. From the time raw materials—including concentrates, corn syrup, flavorings, phosphoric acid and more—arrive at the soft drink manufacturing and bottling plant to the point where finished products are put in bottles and cans, a large number of liquid-transfer operations must be completed successfully.

All of these soft drink production operations require the manufacturing process to not deviate from strict protocols—or the finished product will not live up to a company’s long-established standards for look, mouth feel and—most important—taste.

Achieving the desired end product requires carbonated soft drinks to be manufactured using a strict regimen:

  • Common tap water is treated at the production facility to remove any impurities that may affect the drink’s taste or color. The water’s alkalinity level also is adjusted to meet a regulated pH level.
  • The treated water is sterilized to destroy any bacteria or organic compounds. A small amount of chlorine is used to complete the sterilization process.
  • After the sterilized water “rests” in a storage tank for a few hours, it passes through an activated-carbon filter for dechlorination. From there, the completely sterilized water is transferred to a dosing station.
  • Arriving at the facility in drums and totes, the pre-mixed concentrate that gives a soft drink its color, flavor and sugar content is pumped into the dosing station, where it combines with the water. The amounts of concentrate used at this stage are usually determined by weight, not volume, so the batch tank is placed on a load cell or scale, and the pump turns off when a pre-programmed weight is pumped into the tank.
  • This concentrate/water mixture moves to the batch tank where it is blended to form the soft drink’s base. It is then flash pasteurized—a process that uses ultraviolet radiation to quickly heat and cool the mixture to remove impurities.
  • At a precise temperature, the mixture is passed through a carbonator that adds carbonation to the product at predetermined levels according to the beverage’s recipe. Generally, juice drinks require far less carbonation than traditional soft drinks or carbonated energy drinks.
  • The finished carbonated product is transferred to filling lines, where it is injected into bottles and cans of at high flow rates. When filled, the containers are sealed with pressure-resistant closures like aluminum caps or twist-off plastic tops.
  • The cans and bottles (which must be labeled) are packed into cartons or trays before being placed on larger pallets for shipment to distributors.

Transfer pumps are required at several junctures along the production and supply chain. For many years, centrifugal-style pumps were the main choice for soft drink bottlers and canners. The lower purchase price of centrifugal pumps, compared with the cost of positive-displacement (PD) pump technologies, was the key determinant in their selection.

Pages