INDUSTRIES

Pulp & Paper:

The award-winning, patented Delta T moisture control system (more info) is based on a unique moisture sensor that allows it to be installed in harsh environments such as inside dryers, kilns, Yankee Hood dryers, flotation dryers, coaters, etc. It consistently has reduced the moisture variation from 30% to 45% in many process industries, thus enabling an increase in production, a reduction in unit energy consumption and an improvement in product quality.

Lime Mud Kiln Control:

Lime mud enters a fixed length kiln and progresses through four zones: drying, heating, calcining, and finally burning. The lime mud must be subjected to a time-temperature period in each zone to prepare for successive zones. Steady-state operation at a given production rate requires a certain hot end temperature to maintain the lime quality. If the water load to the kiln changes as a result of either a production or lime mud density change, and an appropriate change in heat input to the kiln is not made, the time-temperature parameter for the burning zone will be distorted and lime quality will suffer. The present control method uses two control loops: a hot end temperature (HET) loop, and a cold end temperature (CET) loop. If a change in CET is detected, the loop controller adjusts the kiln draft to return the CET to set point. The result of the CET loop action causes a change in the HET, and its loop action adjusts that temperature back to set point by manipulating the gas flow to the kiln. The CET is a function of the cumulative effect of heat transfer shell losses from the kiln, the heat absorbed by the lime mass, and the amount of water in the drying zone. Since the variation of the water to be evaporated is the largest variable, the CET is actually being used as a surrogate for the moisture content of the lime mud. However, as a result of our experience (more info) with controlling the moisture from many rotary dryers, the best representation of the moisture content of the lime may be obtained by using the difference in the HET and the CET. Since (HET – CET) = delta T is a better representation of the lime mud moisture in the drying zone, the delta t value, rather than the CET, is used as the controlled variable in the Delta T lime mud kiln control system to stabilize the drying zone which in turn stabilizes the heating, claiming and burning zones. Under a US Department of Energy grant (more info), a Delta T moisture control system was operated on a lime mud kiln for a few weeks and the results were quite good. A 3 – 4% reduction in fuel consumption was measured and no problems were encountered.

Dryers: lime kilns, Yankee Hood, flotation, coaters, can, flash.

Dryers & Coaters:

The award-winning, patented Delta T moisture control system (more info) is based on a unique moisture sensor that allows it to be installed in harsh environments such as inside Yankee Hood dryers, flotation dryers, coaters, etc. (more info) The Delta T has consistently reduced the product moisture variation exiting various dryer-types 30% to 45%, thus enabling an increase in production, a reduction in unit energy consumption and an improvement in product quality.

Corrugated Board CD Warp Control:

Cross-direction (CD) warp is caused primarily by an imbalance in moisture between the top and bottom liner board at the time it is finished in the double facer. The Delta T warp control system (more info) is able to measure and control the moisture content much more simply and effectively in each liner board as it exits the pre-heater. Knowing both liner moisture contents enables the moisture content of each board to be forced to converge to a value that prevents warp formation.