Liquid heaters and vaporizers – Industrial – Waste heat
Reexamination Certificate
2000-08-07
2001-08-28
Wilson, Gregory (Department: 3749)
Liquid heaters and vaporizers
Industrial
Waste heat
C423S522000
Reexamination Certificate
active
06279514
ABSTRACT:
BACKGROUND OF THE INVENTION
Sulfuric acid production plants include those of the sulfur combustion type or waste sulfuric acid combustion type which are designed to generate high-pressure superheated steam useful as a power generation heat source or turbine drive source or for other application by using the heat of sulfur dioxide gas of high temperature produced in the plant. The present invention relates to a method for use in sulfuric acid production plants of such type which is adapted to generate a greater amount of steam by utilizing the heat generated in a drying tower and/or an absorption tower for heating the water to be supplied to a boiler.
The conventional sulfuric acid production plant of the sulfur combustion type has a drying tower for drying air for burning the material, i.e., molten sulfur, with circulating concentrated sulfuric acid, and an absorption tower for causing the circulating concentrated sulfuric acid to absorb sulfur trioxide produced by the conversion of sulfur dioxide. The drying and absorption involve generation of heat, which is not suited for recovery, therefore cooled with cooling water for removal and eventually released into the atmosphere since the circulating concentrated sulfuric acid can not be given a higher temperature because of the limitations imposed on the material used for the circulating acid system.
The development of new materials in recent years has made it possible to raise the temperature of the circulating concentrated sulfuric acid to about 200 to about 220° C. This has led to the proposal of techniques for recovering the heat generated in the drying tower and absorption tower in the form of saturated steam of 500 to 600 kPa(G), whereas the steam is low in pressure and therefore of low value for use as steam.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a heat recovery method for use in sulfuric acid production plants by which the heat generated in the step of drying SO
2
gas or the step of drying air, and the step of absorbing sulfur trioxide in the plant can be effectively utilized for heating the water to be supplied to a boiler although the heat is conventionally discarded because of the difficulties encountered in using the heat effectively.
For use in a sulfuric acid production plant including a drying tower for drying air with circulating concentrated sulfuric acid for burning molten sulfur serving as a material, a sulfur combustion furnace for burning the molten sulfur to produce sulfur dioxide, a converter for converting the sulfur dioxide to sulfur trioxide, and an absorption tower for causing the circulating concentrated sulfuric acid to absorb the sulfur trioxide produced by the conversion of the sulfur dioxide, the present invention provides a heat recovery method of heating the water to be supplied to a boiler by utilizing the heat generated by drying and/or absorption in the drying tower for drying the sulfur burning air or the sulfur dioxide and/or in the absorption tower for causing the circulating concentrated sulfuric acid to absorb the sulfur trioxide produced by the conversion of the sulfur dioxide.
Preferably, the water to be supplied to the boiler is heated by being passed through an acid cooler for cooling the drying tower and/or the absorption tower by circulating concentrated sulfuric acid therethrough.
The heat generated in the step of drying SO
2
gas or the step of drying air, and the step of absorbing sulfur trioxide in the sulfuric acid production plant can be effectively utilized by the method of the invention for heating the water to be supplied to a boiler whereas the heat is conventionally discarded because of the difficulties encountered in using the heat effectively.
REFERENCES:
patent: 4582122 (1986-04-01), Fan
patent: 5118490 (1992-06-01), McAlister
patent: 5130112 (1992-07-01), McAlister et al.
patent: 5554350 (1996-09-01), Gurvich et al.
patent: 5711928 (1998-01-01), Morisaki
Browder Dora J.
Browder Timothy J.
Browder Todd W.
Katagiri Takeshi
Nakamura Yozo
Armstrong Westerman Hattori McLeland & Naughton LLP
Browder Timothy J.
Wilson Gregory
LandOfFree
Method of recovering heat in sulfuric acid production plant does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of recovering heat in sulfuric acid production plant, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of recovering heat in sulfuric acid production plant will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2482371