I brew on my kitchen stove all the time. It usually takes me about 45 minutes to get ~7 gallons boiling. I use a 32 quart kettle that is large enough for me to cover 2 of the stove burners. So you might try that, see if you can position it so that you can get flame from 2 burners on it.... It doesn't need to be anywhere near centered, one of them can be right on the edge of the kettle and it will still help.