Claims
- 1. A method for determining the amount of finely divided particulate solids added to a stream of a fluid to form a mixture of said particulate solids and said fluid, said fluid being at a different temperature than said particulate solids, said method comprising:
- (a) determining the temperature and quantity of said fluid prior to addition of said particulate solids;
- (b) determining the temperature of said particulate solids prior to addition of said particulate solids to said fluid;
- (c) adding said particulate solids to said stream of fluid to form a mixture of said particulate solids and said fluid;
- (d) determining the temperature of said mixture; and
- (e) calculating the amount of said particulate solids in said mixture according to the equation: ##EQU2## where: W.sub.c equals the amount of particulate solids in said mixture,
- W.sub.a equals the amount of fluid in said stream of fluid,
- T.sub.a equals the temperature of the fluid in said stream of fluid prior to addition of said particulate solids to said stream of fluid,
- T.sub.c equals the temperature of the particulate solids added to said stream of fluid prior to addition of said particulate solids to said stream of fluid,
- T.sub.ac equals the temperature of said mixture,
- C.sub.pa equals the heat capacity of said fluid, and
- C.sub.pc equals the heat capacity of said particulate solids.
- 2. The method of claim 1 wherein the difference between the temperature of said fluid and the temperature of said particulate solids is at least double the difference between the temperature of said mixture and the temperature of said particulate solids.
- 3. The method fo claim 1 wherein the difference between the temperature of said fluid and the temperature of said particulate solids is at least 50.degree. F.
- 4. The method of claim 3 wherein said difference is at least about 100.degree. F.
- 5. The method of claim 1 wherein said fluid is a gas.
- 6. The method of claim 5 wherein said gas is air.
- 7. The method of claim 1 wherein said particulate solids are catalyst solids.
- 8. The method of claim 1 wherein said fluid is a liquid.
- 9. A method for dispersing controlled amounts of finely divided particulate solids from a finely divided particulate solids storage vessel through a transfer line, said transfer line being in communication with a discharge line from said vessel to receive said particulate solids from said discharge line to produce a mixture of said particulate solids and a fluid in said transfer line said discharge line including means for regulating the flow of said particulate solids through said discharge line, said method comprising:
- (a) flowing said fluid through said transfer line at a rate sufficient to move said particulate solids through said transfer line and at a temperature different than the temperature of said particulate solids;
- (b) determining the temperature of said particulate solids prior to addition of said solids to said fluid;
- (c) determining the temperature of said fluid prior to addition of said solids to said fluid;
- (d) determining the amount of said fluid flowing in said transfer line;
- (e) discharging a quantity of said particulate solids into said transfer line at a selected discharge rate to produce said mixture;
- (f) determining the temperature of said mixture;
- (g) calculating the amount of said particulate solids in said mixture by the equation: ##EQU3## where: W.sub.c equals the amount of particulate solids in said mixture,
- W.sub.a equals the amount of fluid flowing through said transfer line,
- T.sub.a equals the temperature of the fluid flowing through said transfer line prior to addition of said particulate solids to said transfer line,
- T.sub.c equals the temperature of the particulate solids added to said transfer line prior to addition of said particulate solids to said transfer line,
- T.sub.ac equals the temperature of the mixture flowing in said transfer line,
- C.sub.pa equals the heat capacity of the fluid flowing through said transfer line,
- C.sub.pc equals the heat capacity of the particulate solids added to said transfer line, and
- (h) controlling said discharge rate of said solids to a desired rate based upon said calculation.
- 10. The method of claim 9 wherein the difference between the temperature of said fluid and the temperature of said particulate solids is at least double the difference between the temperature of said mixture and the temperature of said particulate solids.
- 11. The method of claim 9 wherein the difference between the temperature of said fluid and the temperature of said particulate solids is at least 50.degree. F.
- 12. The method of claim 11 wherein said difference is at least about 100.degree. F.
- 13. The method of claim 9 wherein said fluid is a gas.
- 14. The method of claim 13 wherein said gas is air.
- 15. The method of claim 9 wherein said particulate solids are catalyst solids.
- 16. The method of claim 9 wherein said fluid is a liquid.
- 17. The method of claim 9 wherein said particulate solids comprise fluid catalyst cracking process catalyst.
Parent Case Info
This is a division of application Ser. No. 07/181,803, filed Apr. 15, 1988 now U.S. Pat. No. 4,840,726, which was a continuation-in-part of application Ser. No. 06/932,852, filed Nov. 20, 1986, now abandoned.
This invention relates to a method for determining the amount of finely divided particulate solids added to a stream of a fluid.
This invention also relates to a method for controlling the amount of finely divided particulate solids added to a stream of fluid.
This invention also relates to a method for determining and controlling the amount of particulate catalyst added to a fluid catalytic cracking process.
In many processes, it is necessary to transfer finely divided particulate solids from a storage vessel to a processing unit. Such processes include a variety of chemical processes wherein particulate catalyst is used. Such problems can also arise in other industries where particulate solids are produced or handled when it is necessary to transfer particulate solids from a first point to another point by the use of a transfer line in which a flowing fluid is used to transport the particulate solids through the line.
In such processes, it is frequently desirable that the amount of particulate solids transferred be accurately measured or closely controlled or both. In previous attempts to achieve such transportation and control, various devices such as conveyors and fluidized lines have been used. Such processes have frequently failed to achieve the desired reliability and ease of handling and the desired control.
One instance in which it is highly desirable that finely divided particulate solids, i.e., particulate catalyst, be added to a process in an accurate and controlled manner, is the process generally referred to as "fluid catalytic cracking." Such a fluid catalyst cracking process is described in the Chemical Engineers Handbook, John H. Perry, Editor, McGraw-Hill Book Company, 1950, Page 1619. Such processes are considered to be known to those skilled in the art and are widely used in the processing of petroleum. It is desirable that the addition of particulate catalyst to such units be accomplished reliably and desirably in a steady and controlled manner. In other words, slugs of fresh catalyst can adversely effect the process efficiency and the failure to add adequate amounts of particulate catalyst when desired can also adversely effect the efficiency of the process. It is highly desirable that fresh particulate catalyst be added at a steady rate sufficient to supply the desired make-up catalyst on a constant basis.
It has now been found that the amount of finely divided solids added to a stream of fluid to form a mixture of the particulate solids and the fluid can be determined by a method comprising (a) determining the temperature and quantity of fluid in the stream of fluid; (b) determining the temperature of the particulate solids; (c) determining the temperature of the mixture; and (d) calculating the amount of the particulate solids in the mixture. Such a method can also be used to control the amount of finely divided particulate solids added to the stream of fluid. The fluid is at a different temperature than the finely divided solids.
US Referenced Citations (11)
Divisions (1)
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Date |
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181803 |
Apr 1988 |
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Continuation in Parts (1)
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932852 |
Nov 1986 |
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Patent Grant
4911824
