I am not sure what it is you are trying to do.
if you are trying to roast them to remove the skin from the flesh.
the best way I have found that is not as labor intensive and the peppers come out still firm and not mussy. Is to use a weed burner.I wash the drive way off or any other concrete area that is safe to burn on, then wash the pepper and lay them in a line, when the water is evaporated I turn on the weed burner and just walk slowly down the line of peppers then turn them over and do the other side.it works fast. then take them in and under cold water peel the skins off. and bag them for the freezer.
thats when do 60 plus lbs. I save the real nice ones and do them over mesquite on the grill. for rellenos ect.
now if you want something for making a sorta ABT out of bells..they have them for sale on line.. a google search will bring the grill up..