Patents
Paul’s U.S. patents represent innovative advancements in the fields of energy efficiency and high efficiency ethylene cracking furnace technology. The listed inventions focus on methods and apparatuses designed to reduce energy consumption, improve thermal performance, and extent on-line time in high-temperature furnaces. These patents contribute to the development of more sustainable, cost-effective, and environmentally responsible petrochemical operations.
Thermodynamic Method for Steam Separation
US Patent No. 4,393,816
7 Claims, 3 Drawing Figures
BACKGROUND OF THE INVENTION
The present invention is related to a novel method for improving the quality of the steam produced by boilers through the removal of water therefrom while economically preheating the feedwater supplied to such boilers.
Steam quality is the percentage of feed water vaporized to steam. In once through type boilers 70 to 90% of the feedwater is converted to steam. The unvaporized water contains and carries dissolved solids and scale forming minerals. When the feedwater contains very high quantities of dissolved solids, silica and other solid impurities, the boilers must operate at lower levels of steam quality. The method of the present invention increases steam quality by first separating the unvaporized water containing the solid impurities and thereafter recovering part of such water and its heat content. The method is particularly applicable to commercial boilers producing saturated to moderately superheated steam at pressures of as great as 2900 psig. Typical of the commercial boilers to which the present thermodynamic method may be applied are oil field steamers, steam generators, hot water floods (fired by crude oil, refined oil or gas), or fluidized or circulating bed combustors burning coal, peat, wood wastes, municipal and household wastes, and waste sludges.
SUMMARY OF THE INVENTION
Once through type boilers producing 20,000 to 200,000 lbs/hr of saturated to moderately superheated steam (600° -970° F.) at pressures of 500-2,900 psig typically yield a steam quality of about 70-90%, i.e., a steam containing an entrained moisture content of as much as 30% by weight.
It is an object of the present invention to provide an improved thermodynamic method for increasing the quality of steam produced by boilers normally yielding saturated to moderately superheated steam (600° -970° F.).
A further object of the invention is to provide an improved thermodynamic method for increasing the quality of steam produced by boilers normally yielding saturated to moderately superheated steam containing up to about 30% by weight of entrained moisture, removing dissolved solids from such steam and preheating the feedwater supplied to the boiler producing such steam.
Another object of the present invention is to provide an improved thermodynamic method for increasing the quality of steam produced by boilers normally yielding saturated to moderately superheated steam containing entrained moisture which is capable of practice in a modulized structure, or packaged combination, of apparatus readily combinable with such boilers.
High Efficiency Furnace
US Patent No. 5,394,837
Frank Tsai, co-inventor
19 Claims, 7 Drawing Sheets
BACKGROUND OF THE INVENTION
Furnaces, as used in the petroleum and petrochemical industries, usually consist of a radiant section and a convection section. For simplicity in construction and low cost, the convection section is built above the radiant section. The radiant coil, which is used for heating and/or reaction of feed, is typically located in the center of the radiant section. The radiant coil consists of a number of horizontal tubes connected by 180° return bends. In order to keep the horizontal tubes from sagging, tube supports are used at three to four feet intervals.
As furnace capacity increases, higher feed rates and firing are used. Higher firing increases the radiant section temperature, which is detrimental to the tube supports. The lives of tube supports are thereby reduced, and they must be replaced often (every three to seven years). As tube supports deteriorate and collapse, damage to the radiant coil results. Hence, the radiant coil has to be replaced prematurely. Therefore, the maximum allowable temperature of tube supports becomes a constraint of the capacity.
SUMMARY OF THE INVENTION
It is a major object of the invention to provide a method of support for the radiant coil (i.e., tube or tubes) that will materially extend the life or lives of the tube supports, and that will not result in sagging of horizontal tubes in the radiant section.
Basically, the invention involves suspending the radiant section tube or tubes to hang generally vertically, the suspension comprising tubular means, as for example elongated, fluid flow-passing tubes, which extend generally horizontally, and supporting those feed-passing tubes by means of grid structure proximate the uppermost extent of the radiant section. As will be seen, the grid structure itself may comprise flow-passing tubing, i.e., tubing that passes the feed, to preheat same or other fluids. Also, the grid structure tubing may extend with serpentine configuration, to provide multiple support points for the elongated tubing that suspends the vertically extending radiant tubing or tubes.
Use of flow-passing tubing as supports allows for reduction in temperature of those supports by heat transfer to the flow, yielding extended support tubing life.