The invention discloses a horizontal dual-drum energy-efficient boiler without a
fireproofing-material furnace-
building process. The horizontal dual-drum energy-efficient boiler comprises an upper drum, a lower drum and a
hearth, wherein the upper drum is connected the lower drum through a plurality of rows of
convection pipe bundles, all an outer partition wall, a middle partition wall and an inner partition wall are in
water pipe type structures, and fins and / or
cast iron hangers are assembled; the
hearth is arranged on outside the inner partition wall, and is composed of an upper header, a lower header and a fire grate as well as an outer
water pipe wall; a
combustion chamber is arranged at the front part of the
hearth, a high-temperature
smoke chamber is arranged on the rear part of the hearth, a plurality of high-temperature water-passing pipes are vertically arranged in the high-temperature
smoke chamber, and the high-temperature
smoke chamber has a three-return
stroke combustion structure; and a smoke outlet is sequentially connected with a hot
air chamber and a
chimney of a smoke residual heat recycling device, and a smoke purifying pond can be additionally arranged. Hot air of the hot
air chamber is supplied to the hearth, high-temperature water of the smoke residual heat recycling device is replenished for the boiler, thus
heat energy utilization rate can be greatly increased, steam yield is high and heat efficiency is high. The energy-efficient boiler has the advantages of light integral weight, convenience and time conservation in hoisting, transporting and installing, and cost conservation.