Ask the Experts
TOTAL THERMAL SOLUTION consist of measurement and control of the thermal regime of a system to meet the following goals:
Improve the efficiency of resources such as energy, raw materials, equipment and labor.
Improve product quality; reduce waste, rework, repair and rejections.
Improve process flow, and increase productivity.
Develop new, improved or innovative processes and products.
TOTAL THERMAL SOLUTION involves the following tasks:
Energy efficiency improvement by better combustion and heating control;
Heat transfer and process modeling to determine the heating rates and time at temperature for materials including steels, stainless steels and superalloys;
Energy audit and analysis of heating/cooling conditions to reduce fuel consumption;
Scheduling of furnace loading to optimize furnace loads for increasing productivity;
Control of heating and heat treatment to improve product quality and reduce rejects;
Technical assistance in reducing manufacturing and energy cost;
How Thermal control leads to more efficient resource utilization?
Thermal Processes use energy as a major input. In addition, some processes use materials, which provide the thermal energy. When the cost of energy was lower, there was very little incentive to optimize the operation of energy systems to reduce the cost of energy. For example, the amount of combustion air required for burning fossil fuel was far in excess of that required for stoichiometric combustion, thus resulting in higher fuel cost. Control of temperature, thermal flows and the system environment (deformation rate, atmosphere, pressure, feed rate, speed, etc.) are necessary to ensure that the processes remain within the desired thermal regime. Lack of control can lead to excessive time, wastage of energy or materials or an increase in production cost. In thermal treatment of metals to produce the specified properties, process control is necessary for the development of metallurgical microstructures within an economically acceptable time, with the consumption of energy, capital and labor. Since temperature can be measured at critical locations, it can enable the control of the process, equipment and machinery by means of simulation modeling of the thermal process. Temperature measurements can also be related to other parameters, which in turn control the process and equipment efficiency. Analyses of thermal and other parametric data can enable establishment of such correlation and process control. The net result is an improved resource-efficient process and better utilization of the equipment and machinery.
How Thermal control leads to improvement in product quality, reduction in waste, rework, repair and rejections?
When the properties or the functionality of a product depends on its thermal history, then thermal control is of paramount importance. This is true for all products ranging from engineered products to food products, where the thermal processing determines the product quality. If the thermal regime, which includes the temperature and system environment, deviates from the specified range, then the frequency of rejects will increase. In some cases the system environment (for example the deformation rate) can become more damaging when the temperature regime is at or near the extreme end of the specified temperature range. In other cases the optimum thermal regime may depend on the nature of the material being processed. Therefore, maintaining the uniformity of the thermal regime by proper design and operation of the thermal processing equipment, machinery and their components is very crucial.
In addition, since there are variations in the inputs to any commercial system, it is necessary to change and maintain proper thermal regimes when the input conditions change. Monitoring the inputs to the system and then controlling the temperature-environment (deformation rate, atmosphere, pressure, feed rate, speed, etc.) regime to maintain or improve product quality can reduce rejects and rework. Computer based algorithms and heuristics based decisions remove the arbitrariness of the judgement by operators and ensure process control for higher quality products.
How Thermal control increases productivity and process flow?
In many engineered products requiring thermal treatment, the specified temperature is a function of its dimension. When a large number of products with varying dimensions are thermally processed, the products, which reach the temperature range earliest, and the ones which lag behind, determine the rate of production. This is especially critical when heat has to travel large distances by conduction in the products. Increasing the temperature to speed the thermal processing may cause the former to be “over processed”. Mathematical simulation of the aggregate system of irregular geometry and packing can enable development of thermal processing to increase productivity while maintaining product quality.
When sequentially processed products require different thermal regimes, changes in temperatures can result in significant idle time. By proper sequencing of products requiring different thermal regimes, it is possible to reduce the non-productive time and increase throughput. This can be attained by mathematical simulation of scheduling and thermal treatment. Aggregating products, which have closer temperature regime by “forward scheduling”, is another technique to increase flow.
How thermal control leads to new, improved or innovative processes and products?
Simulation of thermal processing and scheduling identifies some inherent limitations. For example, heat treatment of a large number of cylindrical objects placed randomly in a basket can lead to poor heat transfer, lower energy efficiency and increase the rejection rate for the parts which are not properly heat treated. Fluidized bed heat treatment in a properly designed basket can alleviate some of these difficulties.
Understanding the differences in the heating characteristics of electrical resistance heating, induction heating and gas fired furnace heating can lead to adoption of the more appropriate process or innovation in product design.