The problem.
A contractor operating a batch plant contacted Stansteel/Hotmix Parts & Service because the company was preparing for the changes in their future operations. The 10,000 lb. batch plant was almost 40 years old and had been in an ideal urban environment. Over the years, however, many other businesses had moved in around it.
This migration of people and businesses had begun to cause the plant operation difficulties. They were only able to run about 5% recycle because every time they added wet RAP to the batch tower, the large steam explosion gained complaints from the neighbors. The complaints only grew if the operation even attempted to run over the 5% RAP.
The customer also wanted to utilize new continuous mixing technology but was very limited to what kind of changes could be made to the operation since the location was grandfather-permitted. In addition, the advent of foaming warm mix had come into existence and the contractor believed this technique would be very beneficial while operating throughout a large city.
After some study and review, the Stansteel/Hotmix Parts Team made a number of recommendations to improve the situation.
The solution.
One immediate opportunity that the Stansteel/Hotmix Parts & Service team discovered was a mountain of millings stored in the yard. The millings were very good quality and contained high liquid asphalt; being nicknamed “LaCrema” (translated, “The cream”) because of their quality. In fact, money was being made by using these millings. The contractor was being paid to let these excellent millings be disposed of on his property.
The team’s recommendation was that the customer upgrade components to the plant to meet their needs. It was recommended that a rotary recycle mixer be added to the plant. They had a 10’ diameter drum and a new shell was suggested. It was also recommended to add two recycle bins, replacing the material transfer on the silos to a heavy duty Stansteel slat conveyor, replacing the top of the silo conveyors and batchers on the four-silo cluster system. The Accu-Track Total Plant Control was added to blend all these materials along with an Accu-Shear Multi-Foaming and Blending System.
The changes made resulted in great success! The plant went from running 5% recycle to 35% to 40% every day and the new system helped to eliminate the steam explosions. They were foaming all their mixes by utilizing the Accu-Shear and operating to maximize their recycle usage and make special mixes. Ultimately, the contractor was able to improve the operation of the plant while adhering to the allowed permits.
The payback on the investment was in two ways. First, they saved over $4 million on the cost of a new plant. Second, with utilizing more recycle and increasing production. They made the payback on their investment in a matter of weeks.
