Best Practices Make Better Operation
Article three will look at ways the operator influences the effectiveness and efficiency of the concrete boom pump. From rookie to seasoned veteran, the operator may miss details or develop habits that defeat the Putzmeister advantages.
OPTIMUM-VOLUME PUMPING
The greater the pump output volume setting, the greater the horsepower required to meet the demand. Of course, greater work requires higher fuel use. However, the ratio between fuel use and horsepower requirement is not a one-to-one linear relationship and fuel use continually increases as the horsepower climbs.
In Article one, the 100 yd3/hr output required 247 hp. An output demand of 70 yd3/hr, a 30% output decrease, would only require about 132 hp, which is a 47% horsepower decrease (a 1 to 1.56 ratio). Similarly, an output demand of 130 yd3/hr, a 30% output increase, would require 394 hp, a 60% horsepower increase (a 1 to 2 ratio). The important take-away here is that pumping at a steady pace that meets the abilities of the finishing crew and supply of concrete is more fuel and work efficient.
Reminder: It is always a good practice to not leave the volume control at elevated levels when shutting down and starting up the concrete pump. This is especially true for fuel-efficient Econo-Gear™ applications as the engine may not be able to keep up with a very rapid increase in volume demand. For perspective, turning up the volume quickly is similar to jack-rabbit starts on the road; it wastes fuel and is harder on the engine.
In addition, if the chassis is not fitted with a horsepower limiter, it is possible to crank up the demands on the engine to the point that the horsepower required for the pour approaches the engine’s horsepower availability limit. While it is sometimes required for the worst of jobs, this practice should be avoided since it greatly increases fuel use. As the engine approaches its limit, it becomes very fuel inefficient.
MATCH THE BOOM TO THE JOB
Every company dispatcher knows the goal is to send the boom length that matches the customer’s jobsite needs. The farther the concrete is pumped the more work is done and the more fuel spent.
This is especially true if that length is vertical, since pumping upward takes four to five times more work to accomplish than the same horizontal distance. For every primarily horizontal-reach jobsite, the use of a longer boom will usually result in a greater height at the boom’s peak. In general terms, a boom fitted with 5" pipe will take almost 1 hp more to pump vertical for every extra foot you go up.
WORK ONLY WHAT IS NEEDED
Some systems on a concrete pump, while very effective when needed, use up energy (fuel) when active. The fuel-efficient operator will only run the features and systems that are required for a particular job, or portion of a job.
Setup & Clean Out
Every job requires a machine set up and a clean up period. Both of these activities are low in power requirements, yet take a significant amount of time to do. The fuel-efficient operator will perform them while using Econo-Gear or the lowest possible engine RPM setting that gets the job done. This alone could save up to 40% - 50% of the fuel used during this relatively large percentage of your day.
Pump Mode
Every time a jobsite situation or conditions do not require active pumping, the fuel-efficient operator will take the controls out of “pump” mode. Even when the volume setting is turned to zero, the hydraulic pumps continue to circulate oil within the system. There may not be any load requirements for moving concrete, yet one to two gallons of fuel per hour is being used to move the oil around. (Note: cold-weather use may require this circulation to keep the oil in an effective operating temperature range.)
Ergonic® Boom Control Only When Needed
Putzmeister’s Ergonic Boom Control (EBC) is an ideal computer-controlled programming tool for ensuring both the maximum height of the boom arms in low-clearance areas, as well as, the consistent elevation of the end hose. However, this is not needed on every jobsite. During these times, the EBC system should be turned off. This tool does require extra fuel when active because it is always making relatively small boom movements to ensure the elimination of boom bounce.
Minimize Idle Time
Each pumping company has its own policies regarding the times when idling is recommended or discouraged. Regardless of the reasons behind those policies, it should be recognized that an idling chassis uses about one and a half gallons of fuel per hour when all systems on the pump are disabled.
