APPARATUS FOR HEATING AND STEAM GENERATING PURPOSES, NAMELY, HEAT EXCHANGERS NOT BEING PARTS OF MACHINES, APPARATUS FOR THE EXCHANGE OF SUBSTANCES AND HEAT FOR USE IN THE PRODUCTION OF STEAM, FOR USE IN COOKING AND FOR USE IN REFRIGERATION; ELECTRIC COFFEE FILTERS BEING PARTS OF ELECTRIC COFFEE MAKERS; COFFEE MACHINES; ELECTRIC COFFEE PERCOLATORS; COFFEE ROASTERS