Elmhurst-Chicago Runs Hot & Cold

About two-and-a-half years ago, management at Illinois-based Elmhurst-Chicago Stone Co., deciding to move beyond its four fixed-location ready mixed operations

About two-and-a-half years ago, management at Illinois-based Elmhurst-Chicago Stone Co., deciding to move beyond its four fixed-location ready mixed operations around the Chicago area, purchased a mobile plant to make the company a more viable player in getting work on the multi-year reconstruction of Illinois tollroads. With I-294 being the main thoroughfare from which the road work stemmed, the tollway has seen a distinct uptick in activity in the last three years.

Due to the sheer volume of work to be done and unexpected delays, Illinois Tollway leadership has been forced to extend the construction season for contractors well into the colder months of late fall and early winter. To combat both the colder end-of-year temperatures and the effects of summer heat on the mobile plant’s water supply, Elmhurst-Chicago Stone purchased a portable combination hot water heater and chiller from Pearson Heating Systems Inc. of Grasonville, Md.

Elmhurst tapped the heating/cooling system at the same time it bought a RexCon portable plant. In its current location, where it has been since mid-summer, the ready mixed supplier has used the Pearson chiller around 10 times to cool water that has been pumped in from Chicago sources. But on other jobs, adds Elmhurst-Chicago Stone Ready Mixed Operations Manager Mark Kroeger, we’ve gone one-and-a-half- to two-month stretches in the summer where we run it every day.

The chiller is capable of producing water for 1,200 yd. per eight-hour production day using 70_F feed water. Sharing a 30,000-gal. tank, the heater and chiller combination unit suits jobs like the Tollway work where available real estate to set up the mobile plant and Pearson unit is extremely limited Û in this case a little more than two acres located inside a cloverleaf at an exit in close proximity to the I-294 Tollway/I-290 junction.

The heater can produce for 1,200 yd. in eight hours (or 50 gallons per yard), and is able to maintain a minimum of 150_F hotter than the incoming feed water. The unit uses a gas/oil combination burner, giving the customer fuel options, which is important since many contractors cannot be sure going into a new job which type of fuel will be available. The unit also features an automated blending valve so Elmhurst-Chicago is able to change the temperature of its batch water.

After doing some calculations, says Marc Marciano, vice president, Pearson Heating Systems, I determined the customer needed our model Portable P-30-2-20W hot water heater and PH-110 chiller. The heater and chiller are all pre-piped together as one unit. The portable aspect of this unit was important since the customer was going to be moving the plant often and wanted the heater/chiller to be easy to move.

Kroeger added that the Pearson staff was willing to adjust the unit’s design to meet Elmhurst-Chicago’s needs and Illinois’ climate changes. The productivity differences that occur when we’re running the heater/chiller and when we’re not are noticeable and substantial, he says.

According to Kroeger, on a busy day the RexCon plant may loadout about 2,800 yd. in nine hours to the company’s 52-truck fleet. (In a unique arrangement, Rick’s Trucking owns and maintains the trucks, while Elmhurst-Chicago Stone owns the mixer bodies.) Ideally, you want to do between 2,000 and 2,500 yd. per day, and you want to dump into tractor trailers rather than smaller mixers, which is a slower and more time-consuming process, explains Kroeger, who estimates that the plant will manufacture about 180,000 yd. for this particular job, scheduled to wrap up by the end of 2008.

The current phase of the contract covers the westbound lanes of the Tollway, with the eastbound lanes on tap for next year. We hope to get that work, but we’d have to change locations, a task Elmhurst-Chicago Stone sees as a fairly easy one, according to Kroeger. With everything on wheels, moving is easy, and set up time varies depending on available power, water, and ease of bracing the plant. Û Pearson Heating Systems Inc., 410/827-8027; www.pearsonsystems.com