Manual material handling is the principal source of compensable injuries, according to OSHA. Four out of five of these injuries affect the back. When manual material handling involves transporting bulk dry materials, safety hazards can also include a poor respiratory environment and fugitive dust problems.
Pneumatic conveyors can be an effective alternative. These use vacuum to gently and quickly move materials from point to point with nothing in the way to impede the efficiency of its movement. Used to convey, batch and weigh dry materials from fine powders to plastic pellets and caps, pneumatic conveyors consist of five basic components that work as one: a pick-up point, convey tubing, a vacuum receiver, a vacuum producer and a control module.
A common dilemma in the industrial world is the manual transport of materials to raised platforms where ingredients are dumped into hoppers. For example, when increased demand turned up the notch on production for a particular product, a chemical manufacturer’s primary goal was to eradicate the need for workers to dump 20-40 drums of powder chemicals, each weighing up to 225 pounds, from a raised platform. Although the company hadn’t had any injuries with that process, its policy was to wipe out any potential.
This job only required a single operator, but the organization staffed it with two to reduce the potential for injuries. After looking at a variety of alternatives, the company decided to spec out a pneumatic conveying system.
The size of such a system depends on the desired speed of product transfer as well as the distance between two transfer points. Because this company wanted to eliminate an ergonomic problem and timing wasn’t an issue, it chose a smaller conveying system—a “tube hopper.” It was designed to move several hundred pounds of claylike material up a level into a volumetric feeder within 30 minutes. Another tube hopper was added to a separate line that pulled granular material from awkward shaped drums, weighing over 200 pounds each, up into a liquid mixing tank.
Although the time to transfer the products stayed about the same, the job went from requiring two people to a single operator and eliminated a hazard. This enabled a payback in the first year of use.
Elevated falls are less frequent but more severe than same-level falls in the workplace. In 2011, falls, slips and trips claimed the lives of 666 workers and one in four resulted from a fall of less than 10 feet.
Manufacturers experienced 47 of the fall fatalities in 2011. A 2003 mean estimate of direct costs for a single fatality in the workplace was approximately $900,000.
Direct costs are budgeted costs, or insured costs. Indirect costs are those that are not budgeted (not insured) and eat away at profits. An indirect cost is estimated to be anywhere from two to 20 times that of a direct cost. Indirect costs include training replacement employees, accident investigation and implementation of corrective measures, lost productivity, fines and penalties, repairs and any other costs not covered by insurance, including loss of employee morale.
Pain in the Back
Back injuries require a median of 10 days for workers to recuperate. Using OSHA’s $afety Pays worksheet, calculating with a 5% profit margin, a strain has indirect costs in excess of $33,000 and requires an additional $672,122 in sales to recoup those costs. Anytime organizations can eliminate the possibility of back injuries, injury costs should be taken into consideration when determining ROI.
A tea manufacturer wanted to cut down the amount of lifting its operators were doing manually in the production department. The operators were manually weighing individual hundred-pound batches into barrels, using forklifts to transfer them to the top level, and then dumping them into hoppers by hand.
One of the biggest concerns for the tea manufacturer was the breakdown of the materials themselves. Using pneumatic conveying, operators insert a wand into the barrels and product is pneumatically transferred from the wand to the blenders, eliminating the forklift traffic and wear and tear on workers’ backs. The company also had a 20 percent increase in productivity.
Fugitive Dust Dangers
Pneumatic conveying systems are fully enclosed, protecting materials from air, dirt and waste. Because product does not escape from a pneumatic conveying system, particulates that can endanger workers respiratory health or settle on equipment and surfaces posing an explosion hazard are prevented from entering the environment. Costs associated with housekeeping are also diminished.
Indirect costs for a single dust disease, according to the SP worksheet, are around $25,000 with an additional $509,000 needed in sales to recoup the cost. The worksheet lists other respiratory illnesses as well as associated illnesses that can be caused by dusty environments, such as dermatitis. A single injury for dermatitis can result in indirect costs around $10,000 with over $200,000 of additional sales to make up for those costs.
Muscular and respiratory hazards can be diminished with pneumatic conveying systems.
Doan Pendleton is vice president of VAC-U-MAX (www.vac-u-max.com), makers of pneumatic conveying systems.