I need to remove two coats of paint from a concrete patio @ 300 sq ft. Chemical paint removers aren't working. Pressure Washer did nothing. Any ideas? Anybody. Thanks

Check in the yellow pages for Soda Blasting. This is a form of sand blasting that uses bakeing soda as the abrasive to remove the paint.
Be aware however that the paint used on the patio may have stained the cement and you will never get the color out.
What are you trying to accomplish in this paint removal process? Future coats of new paint, or a new surface of some other fashion?

depending on what you are going to put back on / over the concrete, you could always grind off the paint. Check with your local tool / machine rental company for a concrete grinder. It is a diamond wheel disk grinder like they use on terazzo floors.

Tommy