US3824388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrocarbon cracking system
Assignee: Individual
•
Filing: 1972-06-26
•
Granted: 1974-07-16
•
Expires: 1992-06-26
Abstract
Abstract Operation of a hydrocarbon cracking furnace is controlled automatically by utilizing various types of equipment to control the flow to the furnace of hydrocarbon feed gas, a mixing gas such as steam, and furnace fuel in such manner as to increase the yield of desirable cracked products while simultaneously operating the furnace closer to its limiting conditions and increasing the amount of furnace on-line time. This is accomplished by monitoring numerous furnace operating parameters to provide data which is used to automatically control equipment which results in controlling the furnace outlet gas velocity in a predetermined desired manner. The system provides for automatic control of furnace outlet gas velocity by controlling the flow of any one or more of the hydrocarbon feed gas, the mixing gas such as steam, or the furnace fuel in an automatically controlled sequence of operations. Equipment and operator-set limiting conditions are imposed on the system and the latter can be changed as desired.
Inventors
- 👤 J Cugini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:18
CPC Classifications
C; C07; C07C; C07C4/00; C07C4/02; C07C4/04; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
212 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of maximum possible outlet velocity, e. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet volocity, f. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, g. selecting a system operating parameter or flow of input material for control and selecting the target value for the selected system operating parameter or flow of input material, and setting the controller therefor to target value.
Claim 2
Independent Claim
212 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of maximum possible outlet velocity, e. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet volocity, f. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, g. selecting a system operating parameter or flow of input material for control and selecting the target value for the selected system operating parameter or flow of input material, and setting the controller therefor to target value.
Claim 3
Dependent Claim
27 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein said steps a through g are iterated at predetermined time intervals.
Claim 4
Dependent Claim
46 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein at least a part of the input material to the furnace is steam, and the gas velocity at the cracking furnace outlet is controlled by controlling the flow of steam.
Claim 5
Dependent Claim
50 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein at least a part of the input material to the furnace is hydrocarbon feed gas and the gas velocity at the cracking furnace outlet is controlled by controlling the flow of hydrocarbon feed gas.
Claim 6
Dependent Claim
47 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein at least one of the monitored system parameters is furnace outlet gas temperature and the gas velocity at the cracking furnace outlet is controlled by controlling the furnace outlet gas temperature.
Claim 7
Dependent Claim
68 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein the flow target for said input material was controlled in step g, and further consisting of the steps of determining whether said flow target can be achieved, selecting a system operating parameter target if said flow target cannot be achieved, and setting a controller to the target for said system operating parameter.
Claim 8
Dependent Claim
83 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein said input material comprises hydrocarbon feed gas and another input material, and further comprising the steps of determining whether the target of the controlled input or system operating parameter can be achieved, choosing one of the targets not previously controlled in step g to be next selected if the target previously selected in step g cannot be achieved, and setting the corresponding controller to the new target.
Claim 9
Dependent Claim
113 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein said input material comprises hydrocarbon feed gas and another input material, and further comprising the steps of determining whether the target of the controlled input or system operating parameter can be achieved, choosing one of the targets not previously controlled in step g to be next selected if the target previously selected in step g cannot be achieved, setting the corresponding controller to the new target, the steps of choosing a target not yet controlled to be next selected if the target last selected cannot be achieved, and setting the corresponding controller to the target just selected.
Claim 10
Dependent Claim
61 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein said input material comprises hydrocarbon feed gas and another input material, and further comprising the steps of choosing a target not yet controlled to be next selected if the target last selected cannot be achieved and setting the corresponding controller to the target just selected.
Claim 11
Dependent Claim
108 words
The method of operating a hydrocarbon cracking furnace system as set Forth in claim 1 wherein said input material comprises hydrocarbon feed gas and another input material, the input material is controlled in step g and is hydrocarbon feed gas, and further comprising the steps of, determining whether the feed gas flow target can be achieved, choosing whether, said another input material or one of said system operating parameters is to be controlled if the feed gas flow target cannot be achieved, and selecting the target for said another input material or said system operating parameter, whichever has been chosen, and setting the corresponding controller to the target.
Claim 12
Dependent Claim
98 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 1 wherein said input material comprises steam and hydrocarbon feed gas, the input material is controlled in step g and is steam, and further comprising the steps of, determining whether the steam flow target can be achieved, choosing whether feed gas or one of said system operating parameters is to be controlled if the steam flow target cannot be achieved, and selecting the target for feed gas or said system operating parameter, whichever has been chosen, and setting the corresponding controller to the target.
Claim 13
Independent Claim
268 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of the highest percent loading on the system from the monitored selected system parameters, e. generating a representation of the incremental velocity available in the system for the flow of said input material or for said system operating parameters to be controlled, f. generating a representation of maximum possible outlet velocity, g. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, h. setting target velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, i. selecting a system operating parameter or flow of input material for control and selecting the target value for the selected system operating parameter or flow of input material, and setting the controller therefor to target value, and j. iterating steps a through i at predetermined time intervals.
Claim 14
Independent Claim
268 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of the highest percent loading on the system from the monitored selected system parameters, e. generating a representation of the incremental velocity available in the system for the flow of said input material or for said system operating parameters to be controlled, f. generating a representation of maximum possible outlet velocity, g. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, h. setting target velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, i. selecting a system operating parameter or flow of input material for control and selecting the target value for the selected system operating parameter or flow of input material, and setting the controller therefor to target value, and j. iterating steps a through i at predetermined time intervals.
Claim 15
Dependent Claim
99 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 12 wherein the cracking furnace system includes a quench tower and a steam valve and at least some of the selected system parameters monitored are the quench tower top temperature, the quench tower differential pressure and the steam valve position, and the highest percent loading on the system is selected from among the largest of the percent loadings of the aforesaid monitored parameters wherein each percent loading is defined as the ratio of the monitored parameter value divided by the maximum allowable monitored parameter value.
Claim 16
Dependent Claim
132 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 12 wherein the cracking furnace system includes a furnace having a cracking tube supported by tube hangers and a combustion stack, a transfer line heat exchanger and a furnace fuel feed control, and at least some of the selected systEm parameters monitored are the temperatures of the cracking tube skin and cracking tube hangers and combustion stack and transfer line heat exchanger outlet, the furnace stack draft, and the furnace fuel feed control, and the highest percent loading on the system is selected from among the largest of the percent loadings of the aforesaid monitored parameters wherein each percent loading is defined as the ratio of the monitored parameter value divided by the maximum allowable monitored parameter value.
Claim 17
Dependent Claim
60 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 12 wherein at least a part of the input material to the furnace is steam and wherein the said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling steam flow.
Claim 18
Dependent Claim
64 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 12 wherein at least a part of the input material to the furnace is hydrocarbon feed gas and said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling the flow of hydrocarbon feed gas.
Claim 19
Dependent Claim
61 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 12 wherein at least one of the monitored system parameters is furnace outlet gas temperature and said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling the furnace outlet gas temperature.
Claim 20
Dependent Claim
60 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 13 wherein at least a part of the input material to the furnace is steam and wherein the said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling steam flow.
Claim 21
Dependent Claim
64 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 14 wherein at least a part of the input material to the furnace is hydrocarbon feed gas and said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling the flow of hydrocarbon feed gas.
Claim 22
Dependent Claim
61 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 14 wherein at least one of the monitored system parameters is furnace outlet gas temperature and said step of generating a representation of the incremental velocity available in the system consists of generating said representation of said incremental velocity available by controlling the furnace outlet gas temperature.
Claim 23
Independent Claim
116 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial conditions of feed gas flow, steam flow, furnace temperature, and determining desired target outlet velocity, b. monitoring furnace outlet gas temperature (To) and pressure (Po), hydrocarbon feed rate (F), steam feed rate (S), and the molecular weights of the outlet and feed gases, and other selected system parameters, c. generating a representation of the outlet gas velocity from the monitored data in accordance with the equation. VEL (0.00769 (To/Po) (FE + S))/(Ao + Aoe - Aoc) Where:
Claim 24
Independent Claim
116 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial conditions of feed gas flow, steam flow, furnace temperature, and determining desired target outlet velocity, b. monitoring furnace outlet gas temperature (To) and pressure (Po), hydrocarbon feed rate (F), steam feed rate (S), and the molecular weights of the outlet and feed gases, and other selected system parameters, c. generating a representation of the outlet gas velocity from the monitored data in accordance with the equation. VEL (0.00769 (To/Po) (FE + S))/(Ao + Aoe - Aoc) Where:
Claim 25
Dependent Claim
32 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein the gas velocity at the cracking furnace outlet is controlled by controlling the flow of steam.
Claim 26
Dependent Claim
33 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein the gas velocity at the cracking furnace outlet is controlled by controlling the flow of feed gas.
Claim 27
Dependent Claim
31 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein the gas velocity at the cracking furnace outlet is controlled by controlling furnace outlet temperature.
Claim 28
Dependent Claim
27 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein said steps a through i are iterated at predetermined time intervals.
Claim 29
Dependent Claim
85 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein the flow target for steam has been controlled in step i and further comprising the steps of, determining whether the steam flow target can be achieved, choosing whether feed gas or outlet gas temperature is to be controlled if the steam flow target cannot be achieved, and selecting the target for feed gas or outlet gas temperature, whichever has been chosen, and setting the corresponding controller to the target.
Claim 30
Dependent Claim
120 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 21 wherein the flow target for steam has been controlled in step i) and further comprising the steps of, determining whether the steam flow target can be achieved, choosing whether feed gas or outlet gas temperature is to be controlled if the steam flow target cannot be achieved, and selecting the target for feed gas or outlet gas temperature, which ever has been chosen, setting the corresponding controller to the target just chosen, choosing the target which has not yet been controlled to be the target next selected if the target last selected cannot be achieved, and setting the corresponding controller to the target just selected.
Claim 31
Dependent Claim
29 words
The method of operating a hydrocarbon cracking furnace system as set forth in claim 27 wherein the sequence of steps set forth therein is iterated at predetermined time intervals.
Claim 32
Independent Claim
191 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for systeM operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, g. generating a representation of maximum possible outlet velocity, e. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, f. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, g. selecting the flow target for said input material, and setting said controller to target value.
Claim 33
Independent Claim
191 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for systeM operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, g. generating a representation of maximum possible outlet velocity, e. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, f. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, g. selecting the flow target for said input material, and setting said controller to target value.
Claim 34
Independent Claim
248 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of the highest percent loading on the system from the monitored selected system parameters, e. generating a representation of the incremental velocity available in the system for the flow of said input material or for said system operating parameters to be controlled, f. generating a representation of maximum possible outlet velocity, g. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, h. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, i. selecting the flow target for said input material, and setting said controller to target value, and j. iterating steps a through i at predetermined time intervals.
Claim 35
Independent Claim
248 words
A method of operating a hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, consisting of the steps of, a. setting controllers for initial feed condition of input material which is to pass through the cracking furnace, for system operating parameters and for desired target outlet velocity, b. monitoring the flow of input material and selected system parameters by means of which the furnace outlet gas velocity is determinable, c. generating a representation of the outlet gas velocity from the aforesaid monitored conditions, d. generating a representation of the highest percent loading on the system from the monitored selected system parameters, e. generating a representation of the incremental velocity available in the system for the flow of said input material or for said system operating parameters to be controlled, f. generating a representation of maximum possible outlet velocity, g. comparing the representation of maximum possible outlet velocity with a representation of operator desired target outlet velocity, h. setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operator desired target outlet velocity, i. selecting the flow target for said input material, and setting said controller to target value, and j. iterating steps a through i at predetermined time intervals.
Claim 36
Dependent Claim
220 words
A hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, comprising in combination, a. a plurality of controllers for controlling the feed of input material which is to pass through the cracking furnace and for setting system operating parameters, b. input material monitoring means for monitoring the flow of input material, and system parameter monitoring means for monitoring selected system parameters, c. outlet gas velocity determining means coupled to said monitoring means effective to determine the outlet gas velocity from the aforesaid monitored conditions, d. means for determining maximum possible furnace outlet velocity, e. comparator means for comparing the maximum possible outlet velocity with operator desired target outlet velocity, f. target control means responsive to said comparator means and coupled to and effective to operate said plurality of controllers for setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operaTor desired target outlet velocity, said target control means including selection means operative to select which of said plurality of controllers shall be operated to move toward said target outlet velocity.
Claim 37
Dependent Claim
220 words
A hydrocarbon cracking furnace system to minimize residence time of hydrocarbon feed gas passing therethrough by controlling the gas velocity at the cracking furnace outlet, comprising in combination, a. a plurality of controllers for controlling the feed of input material which is to pass through the cracking furnace and for setting system operating parameters, b. input material monitoring means for monitoring the flow of input material, and system parameter monitoring means for monitoring selected system parameters, c. outlet gas velocity determining means coupled to said monitoring means effective to determine the outlet gas velocity from the aforesaid monitored conditions, d. means for determining maximum possible furnace outlet velocity, e. comparator means for comparing the maximum possible outlet velocity with operator desired target outlet velocity, f. target control means responsive to said comparator means and coupled to and effective to operate said plurality of controllers for setting target outlet velocity to operator desired target outlet velocity if the maximum possible outlet velocity is larger than operator desired target outlet velocity, and setting target outlet velocity to the maximum possible outlet velocity if the maximum possible outlet velocity is smaller than operaTor desired target outlet velocity, said target control means including selection means operative to select which of said plurality of controllers shall be operated to move toward said target outlet velocity.
Claim 38
Dependent Claim
62 words
A hydrocarbon cracking furnace system as set forth in claim 31 further including load determining means for determining the highest percent loading on the system from the monitored selected system parameters, and means for determining the incremental velocity available in the system for a change in the flow of said input material or for a change in said system controllable operating parameters.
Claim 39
Dependent Claim
40 words
A hydrocarbon cracking furnace system as set forth in claim 31 further including cycling means effective to cause said determining means, said comparator means and said target control means to cyclically carry out their aforesaid functions at predetermined time intervals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |