Quench Vacuum Furnaces offer power management option

Tag: Power Factor Controller

Power Management System for High Pressure Quench Vacuum Furnaces Patent US 7,193,188 B2 - System Saves Over 20% in Energy Costs SECO/WARWICK has recently patented a power management option (US7,193,188 B2) for high pressure quench vacuum furnaces that reduceselectrical consumption by creating a single system of alternatecontrol of the heating and cooling processes using a singlefrequency converter. Since issuing the patent in May of 2007, morethan 10 Vacuum HPQ systems are in successful operation utilizingthis power management system. The sophisticated system results in aminimum of 20% reduction in electrical consumption and improvesefficiency by increasing the heating and cooling systems powerfactor. The system has many operational benefits:

Step-less control of heating and cooling power Programmable cooling rate controlled according to the loadtemperature. Martempering quench capability Works with various cooling gases. No blower motor start-up overcurrent, fewer electrical components

o Field operating results demonstrate a minimum of 20% savings inelectrical consumption in addition to reducing equipment andmaintenance costs

Janusz Kowalewski, VP Vacuum Systems, and the inventor, MaciejKorecki, Director of Research & Development for SECO/WARWICK areavailable to give a presentation on this new concept along withcase studies.

In vacuum furnaces, a system of infinitely variable adjustment ofthe power of resistance heating elements is based on a three-phasesilicon controlled rectifier (SCR) or a variable reactancetransformer (VRT). An SCR connected to the electrical supply,controls the power following a control input from a programmabletemperature controller, through alteration of the effective outputvoltage as a result of switching on and off full cycles ofsinusoidal supply voltage (proportional-time control or groupcontrol, where mean output voltage U is proportional to supplyvoltage U.sub.n and switch-on time T.sub.z and inverselyproportional to period T; U=U.sub.n.times.T.sub.z/T), or throughpartial clipping of the sinusoidal supply voltage (phase control).