Record keeping. We all hate the task but it's important in a well run business. Without it we wouldn't be able to track expenses or payroll or our most important asset: profits.
Daily asphalt plant reports provide information not always readily available to management, like fuel consumption, oil percentages and plant 'idle' time. They also provide an inventory record of oil and fuel in case the plant operator isn't available to ask.
A plant report is also a powerful tool to the alert operator. It can indicate problems with the burner or with the asphalt oil delivery system. For example: In July, a drum plant produced 2,970 tons of hot mix. In doing so it burned 4,455 gallons of diesel for a rate of 1.5 gallons per ton.
Cold feed samples indicate a moisture content of 5.4%. The fuel rate seems high to the operator, so he goes back through his plant reports to May when he first fired the plant after its winter maintenance regimen. One day in early May, he produced 2,125 tons of hot mix, burning 2,550 gallons of fuel for a yield of 1.2 gallons per ton.
A glance at the report indicates cold feed moisture was 5.9%. It's now obvious to the operator that something has changed and he needs to look into it. A check of fuel filters on the burner reveals a partially plugged filter which caused a drop in fuel pressure resulting in a higher burner setting to yield the same amount of heat, thus higher fuel consumption. The plugging happened so gradually that the operator never noticed the progressively higher settings he was using on the burner controls.
Without the plant reports to reference, he might have soldiered onward, blissfully unaware that he was wasting .3 tenths of a gallon of burner fuel per ton. At $2.70 per gallon that equals $.57 per ton wasted. That's a total of $1,453.50 for the day.
Finding the source of the problem
Daily plant reports can also point out problems in oil content. Let's use a Stansteel RM-80 batch plant as an example. On August 12, the second day of a major state contract, All State Paving received the results from state sample #4, sub-lot 1. As its predecessor did, the sample shows an oil content of 6.7%, a tenth of a percent out of spec and in penalty territory. The previous day's samples indicated a range of 6.3% to 6.5%.
Since the target value was 6.1% the plant operator reduced the batch menu oil content by .3%, expecting a 6% on his next test. When this didn't happen, he fell back of the traditional asphalt plant operator's defense: the state got a couple of inaccurate tests or the nuke gauge is faulty.
In the example above, an investigation later revealed that the oil content listed by the state was correct. This particular plant uses an external oil weigh pot. The problem was traced to a build-up of asphalt/aggregate in the hole under the oil distribution bar where it enters the pug mill. The material restricted the downward movement of the scales as they loaded up, causing the scale outputs to indicate a weight lighter than reality. This forced an excessive amount of oil to be loaded in order to satisfy the batching computer's demand for a set weight.
Since this condition did not occur overnight, it's a fair assumption that if the operator had kept daily records of oil consumption he would have noticed that his tank stickings were indicating a progressively higher yield than his plant's computer was requesting.
Saving dollars
In both examples a daily plant report proves to be a valuable asset in operations. While the actual amount of dollars saved by a plant report program can be hard to estimate and likely varies from plant to plant, few people would argue that the potential is great.
The plant report can also contain other useful information, like venturi pressure drop, water pressure and gallons per minute (gpm) for the wet systems. Baghouse data can be substituted where needed. Plant reject and mix wasted can also be tracked. By including a section for operator comments, plant down time can also be recorded. If the plant's temperature 'chart recorder' disk is included a very accurate picture of daily operations emerges.
These forms are not hard to generate. I suggest creating a hard copy with two carbons. One copy is for the main office, one for the plant superintendent and the hard copy stays at the asphalt plant. In some states asphalt plants are required to provide asphalt tank measurements and mix produced tonnages to the plant inspectors at the end of each day. For this purpose a third carbon can be added, with inappropriate data like fuel consumption and operator comments blanked out.
A word of caution: Only provide the information required. It's amazing how unnecessary and poorly understood data in uneducated hands can sometimes come back to haunt you.
I have examples of these forms that can be easily modified to fit your company. To request one, please email me: [email protected]
