High efficient contamination free clean heat production

The present li nvestigations relate to the process of electromagnetic induction heat flow through metallic package (s tainless steel) in glass pipeline or vessel. The inverter fed fluid heating appliance is more acceptable than gas combustio n, steam heating and electrical resistive heating methods for better heat transfer and delivery processing under precise temperature management. This technology has been found to improve heat energy storage and heat exchange processing of lank flu id he alin g in the container or vessel or pipeline directly . The other advantages are: contamination··free heat production, good compactness, high reliability, quick response, absence of combustion waste and shock hazards in the boiling vessel. Besides, enrouting water through specially designed metallic assemblies will permit eddy-cUlTent based healing through electromagnetic induction. In the case of steel vessel plant, heat can be generated directly on the vesse l without heat conduction loss . The series-resonant constant-frequency PWM IGBT inverter system has been introduced as a new conceptual inducti on-heated pipeline fluid or vessel fluid heating for medicinal plant, sterilization plant and drier for surgical in struments . In general, an induction heating is known as a contactless method of generating heat energy in a magnetically-conductive work piece assembly by producing both eddy current losses and hysteresis losses in the work piece from an external high frequency alternating magnetic field produced by a hi gh frequency PWM inverter using IGBT'-4. High­ frequency magnetic field is usually established by a magnetic coil wrapped around the work piece or held parallel to the work piece surface. Resonant inverters are widely used fo r induction-heating over wide fr equency ranges (4-500 kHz.i. The inverter operating frequency selected for a particular application is based on heat effectiveness and power conversion efficiencl. The constant high-frequency re sonant inverter circuits using IGBT appear more efficient, compact in size and of faster response as compared to the conventional electrical heating method 3 . 5 . Keeping in view the tremendous advances in power semiconductor switching devices, an electromagnetic induction based fluid heating appliance using a voltage-fed high-frequency PWM resonant inverter using IGBT is reported here. The electromagnetic induction based fluid heating appliance using th e high-frequency resonant inverter and its related system control technologies proposed by the authors can attract interest in the fields of medical, chemical, mechanical and consumer heat energy processing utilization in the pipeline system. Direct fluid heating based on electromagnetic induction principle can be done in two ways, viz. pipeline surface and wall skin effect heating and package-in-pipeline internal eddy current heating. The latter method seems a new and attractive concept. The eddy currents are induced in flow-through metallic package with a large number of heating surface incorporated into the non-metallic pipeline by means of an external working-coil connected to the high­ frequency resonant inverter operated by phase·-shifted PWM scheme. This paper presents a comparison between constant frequency phase-shifted PWM series load resonant inverter using IGBT modules and conventional electric heating to find out the most efficient fluid heating appliance.