Q: What applications are best suited for drum unloading systems?

A: Drum unloaders are best suited for unloading highly viscous materials. A drum unloader can easily transfer tomato pastes and peanut butters, personal care products like lotions and creams, and cosmetics like mascara.

Today, a majority of food and personal care processors have someone manually scooping product out of a drum; others are chaining or clamping the drum, raising it and then dumping the product into a kettle or hopper. They then spray water to evacuate the residual material from the bottom and sides of the drum. These processes can be hazardous due to potential employee injury and food safety. Installing a drum unloading system can help to prevent both of these issues within a processing facility.

Q: What main benefits would a food/personal care processing facility experience from the installation of a drum unloading system?

A: Drum unloaders save processors time and money. The typical evacuation time for a drum unloader is about five minutes vs. comparable processes that take over 30 minutes to manually scoop or to clamp/chain up a drum and dump it and then spray out the residual. Also, when water is introduced to the material, it typically needs to be removed at a later part in the process, which takes more time and money and can introduce contaminants into the product.

The drum unloader not only saves time in the actual evacuation process, but it also saves money in the amount of residual product left in the bottom and sides of the drum. Processors will see a significant amount of residual product left in the bottom of their drums with drum scooping or dumping processes. A high-performing drum unloader with an inflatable wiper seal will leave less than 1 percent residual product in the bottom of the drum.

Q: What types of pumping technologies are common on drum unloaders? Are some better than others?

A: One of the most common pumps on a drum unloader in the market today is a sanitary air-operated double diaphragm pump. A diaphragm pump unloading system can move materials up to 100,000 cps. Typical materials that a diaphragm pump unloader can handle are fruit juice concentrates, salad dressings, condiments, and sauces.

If the processor is trying to unload materials over 100,000 cps out of a drum, one of the only ways to do it is with a sanitary piston pump on a drum unloader. Piston pumps are capable of higher pressures to move high viscosity materials longer distances.

Piston pumps come in ratios. For example, a 12-to-1 piston pump gives an outlet fluid pressure 12 times the pressure of the inlet air, up to 1,200 psi. This outlet fluid pressure coupled with the down pressure of the drum unloader’s ram plate allows the processor to easily unload highly viscous materials like peanut butter and caramel, an application that would be impossible with a double diaphragm pump.

Q: Health and safety are always of concern in sanitary processing operations. How can a drum unloader improve health and safety?

A: We all read about contamination problems in processing facilities every day. Think about the potential of contamination when people are leaning over drums and manually scooping the product. This in addition to allowing an open drum of product exposed to airborne bacteria while it is getting unloaded–something a drum unloading system would help to prevent altogether via the use of a ram plate and inflatable wiper seal.

Plant personnel safety is also a concern. Picture the potential of a clamped or chained 500 pound drum being dropped to the plant floor as it moves up to be dumped into a hopper. Drum unloading systems eliminate this type of in-plant accident potential.

Q: Drum unloading systems have been in the market for years. What recent advancements, if any, have been made to these systems?

A: There have been huge advancements in drum unloader technology. The first is the creation of the inflatable wiper seal technology on the ram plate. After the ram plate and seal enter the drum, the user flips a switch, which inflates the seal to the appropriate pressure. The seal holds this pressure and gently scrapes the side of the drum as the ram plate moves from top to bottom. This is a main reason users can achieve greater than 99 percent evacuation rates; the inflatable seal prevents product “blowing by” the ram plate–something that a flat wiper seal cannot accomplish.

There also have been major strides in improving “cleanability” of the drum unloader. Processors need products that are easy to take apart, clean, and put back together. Quick-disconnect clamps are replacing bolted designs. Easy to repair air valves are replacing air valves with 30 or more parts, and PTFE-overmolded diaphragms are replacing diaphragms with an exposed fluid-side diaphragm plate. These PTFE-overmolded diaphragms eliminate potential for bacteria to harbor between the fluid-side diaphragm plate and the diaphragm. All of these advancements help to minimize line downtime due to cleaning.

Q: What is the biggest market trend today that poses one of the largest challenges to processors?

A: A huge challenge is product arriving to food processing facilities in drums that are different sizes and shapes. Suppliers are constantly changing the size and shape of their drums, from conical to straight-sided. For many years, processors had to be cautious when considering a drum unloader purchase. Graco SaniForce unloaders have an inflatable wiper seal and can accommodate drums with ID’s ranging from 19 inches (48.26 cm) to 24 inches (60.96 cm) for added flexibility when it comes to drum size and shape changes.

Q: List price on a drum unloading system can be over $30,000. What kind of return on investment can a processor expect to realize after the purchase of a drum unloading system?

A: There can be huge returns after the installation of drum unloading systems. For example, a facility that is manually scooping 10 drums of tomato paste a day for 300 days a year could have a new drum unloader completely paid off via the material and labor savings that the unloader yields in less than one year.

Kellie Momchilovich is product marketing manager for Graco Industrial Products Division, Minneapolis, MN. You can reach Kellie at kmomchilovich@graco.com.