Method and apparatus for recovering the energy of expansion of wet dusty gases under pressure

Claim 1

In a method for treating pressurized dust-laden blast furnace gas normally having a water content below the saturation point to recover expansion energy in a turbine coupled to means for using the energy thus recovered, the improvement in which: in a first stage said furnace gas is subjected to wet-scrubbing and in the course thereof the water content of the gas is increased through evaporation of such water; and in a second stage the wet-scrubbed gas is introduced into said turbine with the water content thereof maintained at at least the increased level obtained in said first stage.

Claim 4

An apparatus for treating pressurized dust-laden blast furnace gas normally having a water content below the saturation point to recover expansion energy in a turbine coupled to means for using the energy thus recovered, comprising an expansion turbine of the centrifugal type coupled with means for using the mechanical energy of the turbine; a gas wet-scrubbing system; means for circulating the gas from said furnace to said wet-scrubbing system; a heat-insulated water loop circuit including means in said scrubbing system for contacting said gas with water and evaporating a portion of such water into the gas, means for recovering non-evaporated dust-laden condensation water, means for purifying said water and for eliminating the recovered dust, means for recirculating purified water from said purifying means, and means for adding fresh water to compensate for water losses; and means for discharging said expanded gas from said turbine.

Claim 5

An apparatus for treating pressurized dust-laden blast furnace gas normally having a water content below the saturation point to recover expansion energy in a turbine coupled to means for using the energy thus recovered, comprising an expansion turbine of the centrifugal type coupled with means for using the mechanical energy of the turbine; a gas wet-scrubbing system; means for circulating the gas from said furnace to said wet-scrubbing system; a heat-insulated water loop circuit including means in said scrubbing system for contacting said gas with water and evaporating a portion of such water into the gas, means for recovering non-evaporated dust-laden condensation water, means for purifying said water and for eliminating the recovered dust, means for recirculating purified water from said purifying means, and means for adding fresh water to compensate for water losses; and means for discharging said expanded gas from said turbine.