US 4,411,136 A · System for treating and recovering energy from exhaust gases

Abstract

A method and apparatus for treating hot exhaust gas to purify the gas and/or to recover the heat values therein includes removing particulate matter from the gas, cooling the gas by transferring its heat to regenerators and purifying the cooled gas by subliming or "freezing out" harmful, less volatile components. The heat energy of the exhaust gas may be recovered by passing a heat exchange medium, such as compressed air and/or purified cooled gas, through the heated regenerators. A major advantage of this method and apparatus is that exhaust gases at 300.degree.-350.degree. C. may be purified and the heat energy recovered using thermodynamically efficient regenerators. As a result the air preheater stage of conventional boilers or combustion units, which comprise 60% to 70% of the heat exchange surface area, may be eliminated.

Claims25

Dependent claims

A process of treating hot exhaust gas containing environmentally harmful components to separate said components and recover at least a portion of the thermal energy of said gas, comprising the steps of:

(a) removing particulate matter from the gas;
(b) passing said gas through a heat exchange zone in direct heat exchange relationship with a relatively high heat capacitance solid material to transfer a portion of the thermal energy of the gas to the solid material for concurrently cooling said gas and heating said solid material;
(c) separating the harmful, less volatile components of said gas from the more volatile components;
(d) compressing the gas at some time prior to the completion of step (c);
(e) discharging the more volatile components of the cooled gas to atmosphere;
(f) processing the less volatile components of the cooled gas;
and
(g) recovering at least a portion of the thermal energy of said gas by passing a first heat transfer fluid other than said gas in direct heat exchange relationship with said heated solid material to concurrently cool said solid material and heat said first fluid.

5 more elements

An apparatus for treating hot exhaust gas containing environmentally harmful components to separate said components and recover at least a portion of the heat energy of said gas, comprising:

(a) separator means for removing particulate matter from the hot gas;
(b) first heat exchange means for passing a gas into direct heat exchange relationship with a relatively high heat capacitance solid material to exchange heat between said gas and said solid material, whereby said hot gas is passed through said first heat exchange means to concurrently cool said gas and heat said solid material;
(c) means for separating said cooled gas into less volatile and more volatile components;
(d) discharge means for discharging the more volatile components of said gas to atmosphere;
(e) recovery means for recovering and processing the less volatile components of said gas;
(f) compressor means for compressing the gas at a point upstream of said recovery means;
and
(g) second heat exchange means for passing a fluid into direct heat exchange relationship with said relatively high heat capacitance solid material to exchange heat between said fluid and said solid material, whereby a heat transfer fluid is passed through said second heat exchange means to concurrently cool said solid material and heat said fluid.

5 more elements

Dependencies are inferred from the claim text.

System for treating and recovering energy from exhaust gases

Life of this patent

System for treating and recovering energy from exhaust gases

Life of this patent

Abstract

Claims25