US3589160A
Expired / Lapsed
US
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Apparatus and method for controlling accelerated cooling of hot rolled strip material
Assignee: Bethlehem Steel Corp
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Filing: 1968-06-07
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Granted: 1971-06-29
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Expires: 1988-06-07
Abstract
Abstract Cooling of hot rolled strip material, such as low carbon steel strip, is controlled while the strip moves along a rolling mill runout table. The table is provided with a plurality of selectable spray banks, each bank applying the same unit amount of liquid coolant from a low pressure source. A time-sharing mill computer receiving operating information signals selects a number of spray banks based on a feed forward calculation of a cooling factor and a calculation of a predicted cooling error term, the latter term being based on stored signals from previous strips cooled. Control means, including a full time special purpose computer, establishes the minimal unit amount of coolant application. When spray bank selection is held constant, this computer takes over the control function and varies the minimal unit amount of coolant proportional to strip velocity error and strip discharging temperature error during strip cooling.
Inventors
- 👤 Luther E Gruver
- 👤 Harold A List
- 👤 Rimas A Zinas
- 👤 John W Chang
- 👤 Gary A Scott
- 👤 William Jeuick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:14
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/74; B21B37/76; B21B1/00; B21B1/22; B21B1/24; B21B1/26; B21B45/00; B21B45/02; B21B45/0203; B21B45/0209; B21B45/0215; B21B45/0218
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
325 words
Apparatus for controlling the cooling of hot roller metal strip while moving at a variable velocity along a runout table, said apparatus comprising: a. spray cooling means for establishing a variable length spray cooling zone along the runout table, said means having a plurality of selectable spray banks in said zone adapted to apply controlled amounts of liquid coolant to said moving strip, b. means for affecting spray bank selection, said means including first computer means operative in response to signals from storage and operating information input sources for selecting a variable number of spray banks proportional to a variable cooling factor signal when assuming a minimal unit amount of coolant is applied by each spray bank selected, said cooling factor signal varying according to the equation: MS Ko+ K1VH1n(Tf)/(Tc) + K2Tc+K3Tf+ K4HV+ K5(Tf)/(Tc) + K6H+ K7Vwherein the first two terms are essential and additional terms optional as described, and MS runout table cooling factor V velocity of strip in feet per minute H thickness of strip in thousandths of inches 1n natural logarithm Tf tempErature of strip entering runout table, * F. Tc temperature of strip leaving runout table, * F. Ko to K7 predetermined constants as described, said first computer means programmed to use selected stored values of constants K and a desired value of input variable Tc, and desired or measured values of input variables V and Tf, and c. control means including second computer means operatively associated with the first computer means for establishing the minimal unit amount of liquid coolant applied to said moving strip by each of the spray banks selected to achieve a predetermined value of Tc, said control means maintaining said minimal unit amount of coolant application substantially constant as spray bank selection varies, or when spray bank selection is constant said control means varying the minimal unit amount of coolant application proportional to predetermined values of V error, or Tc error, or V and Tc errors.
Claim 2
Dependent Claim
325 words
Apparatus for controlling the cooling of hot roller metal strip while moving at a variable velocity along a runout table, said apparatus comprising: a. spray cooling means for establishing a variable length spray cooling zone along the runout table, said means having a plurality of selectable spray banks in said zone adapted to apply controlled amounts of liquid coolant to said moving strip, b. means for affecting spray bank selection, said means including first computer means operative in response to signals from storage and operating information input sources for selecting a variable number of spray banks proportional to a variable cooling factor signal when assuming a minimal unit amount of coolant is applied by each spray bank selected, said cooling factor signal varying according to the equation: MS Ko+ K1VH1n(Tf)/(Tc) + K2Tc+K3Tf+ K4HV+ K5(Tf)/(Tc) + K6H+ K7Vwherein the first two terms are essential and additional terms optional as described, and MS runout table cooling factor V velocity of strip in feet per minute H thickness of strip in thousandths of inches 1n natural logarithm Tf tempErature of strip entering runout table, * F. Tc temperature of strip leaving runout table, * F. Ko to K7 predetermined constants as described, said first computer means programmed to use selected stored values of constants K and a desired value of input variable Tc, and desired or measured values of input variables V and Tf, and c. control means including second computer means operatively associated with the first computer means for establishing the minimal unit amount of liquid coolant applied to said moving strip by each of the spray banks selected to achieve a predetermined value of Tc, said control means maintaining said minimal unit amount of coolant application substantially constant as spray bank selection varies, or when spray bank selection is constant said control means varying the minimal unit amount of coolant application proportional to predetermined values of V error, or Tc error, or V and Tc errors.
Claim 3
Dependent Claim
22 words
The apparatus of claim 1 wherein the spray cooling means includes at least one of said spray banks having fractional bank selectability.
Claim 4
Dependent Claim
58 words
The apparatus of claim 1 wherein the first computer means includes: d. means receiving said storage and operating signals for computing and storing an apparatus cooling error signal prior to current strip cooling, said means also combining said stored signal with the cooling factor signal to modify current strip spray bank selection proportional thereto prior to strip cooling.
Claim 5
Dependent Claim
61 words
The apparatus of claim 3 wherein the apparatus cooling error signal is based on measured values of Tc of previously cooled strip and varies according to the following term: - (1-FB)Hnwherein FB summation of cooling variables producing Tc error as described H thickness of strip n power, value related to thermal properties of strip as described K12 predetermined constant as described.
Claim 6
Dependent Claim
24 words
The apparatus of claim 1 wherein the first computer means includes: e. means for synthesizing the cooling factor signal to effect spray bank selection.
Claim 7
Dependent Claim
35 words
The apparatus of claim 3 wherein the first computer means includes: f. means for synthesizing the cooling factor signal and combining it with the cooling error signal to effect a cooling error-corrected spray bank selection.
Claim 8
Dependent Claim
90 words
The apparatus of claim 1 wherein the first computer means includes: g. means receiving said storage and operating signals for programming the computation of said cooling factor signal using the desired values of parameters prior to the strip entering the runout table, thereby to effect an initial spray bank selection, and then to recompute said signal using the measured values instead of the desired values of V and Tf to finalize spray bank selection at a predetermined value of V when said strip is about to enter the runout table.
Claim 9
Dependent Claim
45 words
The apparatus of claim 1 wherein the first computer means includes: h. logic means operative in response to increases in the cooling factor signal and programmed for spray bank selection to increase the spray cooling zone length in a direction substantially opposite to strip movement.
Claim 10
Dependent Claim
53 words
The apparatus of claim 1 wherein the first computer means includes: i. dual channel holding means driven by the cooling factor signals and alternately operative in response to said operating signals for holding the current spray bank selection constant while setting up the spray bank selection for the next strip to be cooled.
Claim 11
Dependent Claim
64 words
The apparatus of claim 1 including: j. means incorporated in the first computer means for producing an apparatus cooling error signal prior to the strip being cooled, k. means incorporated In the control means receiving the cooling error signal for adjusting the level of the minimal unit amount of coolant applied by the spray banks proportional to the value of said cooling error signal.
Claim 12
Dependent Claim
71 words
The apparatus of claim 1 including: l. means incorporated in the first computer means for producing an apparatus cooling error signal prior to the strip being cooled, and m. means incorporated in the control means receiving the cooling error signal for adjusting the rate at which the V error signal varies the minimal unit amount of coolant applied by the spray banks proportional to the value of said cooling error signal.
Claim 13
Independent Claim
319 words
A method of controlling the cooling of hot rolled metal strip while moving at a variable speed along a runout table, said method comprising: a. establishing a variable length spray cooling zone along the runout table using a plurality of selectable spray banks in said zone adapted to apply controlled amounts of liquid coolant to said moving strip, b. affecting spray bank selection including selecting a variable number of the spray banks proportional to a computed variable cooling factor signal using first computer means operative in response to signals from storage and operating information input sources, assuming a minimal unit amount of coolant is applied by each spray bank selected, said cooling factor signal varying according to the equation: MS Ko+ K1VH1n(Tf)/Tc) + K2Tc+ K3Tf+ K4HV+ K5(Tf)/(Tc) + K6H+ K7V wherein the first two terms are essential and additional terms optional as described, and MS runout table V velocity of strip in feet per minute H thickness of strip in thousandths of inches 1n natural logarithm Tf temperature of strip entering runout table, * F. Tc temperature of strip leaving runout table, * F. Ko to K7 predetermined constants as described, said first computer means programmed to use selected stored values of constants K and a desired value of input variable Tc, and desired or measured values of input variables V and Tf, and c. establishing the minimal unit amount of liquid coolant applied to said moving strip by each of the spray banks selected using control means including second computer means operatively associated with the first computer means to achieve a predetermined value of Tc, and maintaining said minimal unit amount of coolant application constant by the control means when spray bank selection varies, or when spray bank selection is constant, varying the minimal unit amount of coolant application by said control means proportional to predetermined values of V error, or Tc error, or V and Tc errors.
Claim 14
Independent Claim
319 words
A method of controlling the cooling of hot rolled metal strip while moving at a variable speed along a runout table, said method comprising: a. establishing a variable length spray cooling zone along the runout table using a plurality of selectable spray banks in said zone adapted to apply controlled amounts of liquid coolant to said moving strip, b. affecting spray bank selection including selecting a variable number of the spray banks proportional to a computed variable cooling factor signal using first computer means operative in response to signals from storage and operating information input sources, assuming a minimal unit amount of coolant is applied by each spray bank selected, said cooling factor signal varying according to the equation: MS Ko+ K1VH1n(Tf)/Tc) + K2Tc+ K3Tf+ K4HV+ K5(Tf)/(Tc) + K6H+ K7V wherein the first two terms are essential and additional terms optional as described, and MS runout table V velocity of strip in feet per minute H thickness of strip in thousandths of inches 1n natural logarithm Tf temperature of strip entering runout table, * F. Tc temperature of strip leaving runout table, * F. Ko to K7 predetermined constants as described, said first computer means programmed to use selected stored values of constants K and a desired value of input variable Tc, and desired or measured values of input variables V and Tf, and c. establishing the minimal unit amount of liquid coolant applied to said moving strip by each of the spray banks selected using control means including second computer means operatively associated with the first computer means to achieve a predetermined value of Tc, and maintaining said minimal unit amount of coolant application constant by the control means when spray bank selection varies, or when spray bank selection is constant, varying the minimal unit amount of coolant application by said control means proportional to predetermined values of V error, or Tc error, or V and Tc errors.
Claim 15
Dependent Claim
17 words
The method of claim 12 wherein at least one of said spray banks has fractional bank selectability.
Claim 16
Dependent Claim
43 words
The method of claim 13 wherein step (b) includes: d. computing an apparatus cooling error signal prior to current strip cooling and combining said signal with the cooling factor signal to modify current strip spray bank selection proportional thereto prior to strip cooling.
Claim 17
Dependent Claim
61 words
The method of claim 14 wherein said apparatus cooling error signal is based on measured values of Tc of previously cooled strip and varies according to the following term: e. -(1-FB)Hn/K12wherein FB summation of cooling variables producing Tc error as described H thickness of strip n power, value related to thermal properties of strip as described K12 predetermined constant as described.
Claim 18
Dependent Claim
24 words
The method of claim 13 wherein step (b) is carried out by: f. electrically synthesizing the cooling factor signal to effect spray bank selection.
Claim 19
Dependent Claim
24 words
The method of claim 14 wherein step (b) includes: g. electrically synthesizing the cooling factor signal to effect a cooling error-corrected spray bank selection.
Claim 20
Dependent Claim
75 words
The method of claim 12 wherein step (b) includes: h. computing the cooling factor signal prior to the strip entering the runout table using the desired values of parameters to effect an initial spray bank selection; and i. repeating step (h) when the strip is about to enter the runout table using the measured values instead of the desired values of V and Tf to finalize spray bank selection at a predetermined value of V.
Claim 21
Dependent Claim
38 words
The method of claim 12 wherein step (b) includes: j. programming spray bank selection to increase the spray cooling zone length in a direction substantially opposite to strip movement in response to increases in said cooling factor signal.
Claim 22
Dependent Claim
50 words
The method of claim 12 wherein step (b) includes: k. holding current spray bank selection constant while setting up the spray bank selection for the next strip to be cooled in dual channel holding means driven by said cooling factor signal and alternatively operative in response to said operating signals.
Claim 23
Dependent Claim
9 words
The method of claim 12 including the steps of:
Claim 24
Dependent Claim
66 words
The method of claim 12 including the steps of: n. computing an apparatus cooling error signal prior to current strip cooling and combining said signal with the cooling factor signal, and o. causing the control means to adjust the rate at which the V error varies the minimal unit amount of coolant applied by the spray banks proportional to the value of said cooling error signal.
Claim 25
Dependent Claim
24 words
The apparatus of claim 1 wherein the spray cooling means is adapted to apply said coolant at pressures of up to about 10 p.s.i.
Claim 26
Dependent Claim
56 words
The apparatus of claim 1 wherein the spray cooling means is adapted so that the variable length spray cooling zone is located adjacent at least one variable length radiation cooling zone along the runout table, and said first computer means is adapted to account for a predetermined radiation cooling effect in computing the cooling factor signal.
Claim 27
Dependent Claim
60 words
The apparatus of claim 3 wherein the spray cooling means is adapted so that the variable length spray cooling zone is located adjacent at least one inversely variable length radiation cooling zone along the runout table, and said first computer means is adapted to account for a predetermined radiation cooling effect in computing the cooling factor and cooling error signals.
Claim 28
Dependent Claim
108 words
The apparatus of claim 1 wherein the first computer means includes: n. means receiving said storage and operating signals for computing a signal representing predicted temperature of strip entering the runout table based on a measured temperature made during strip rolling for use as measured Tf when computing the cooling factor signal, said predicted temperature signal varying according to the equation: Tf K8+ K9VH+ K10T5+ K11H where Tf predicted temperature of strip entering runout table, * F. V measured velocity of strip, feet per min. H thickness of strip in thousandths of inches (fixed value) T5 temperature of Strip during rolling K8 to K11 predetermined constants as described.
Claim 29
Dependent Claim
18 words
The method of claim 12 wherein said coolant is applied at pressures of up to about 10 p.s.i.
Claim 30
Dependent Claim
42 words
The method of claim 12 wherein the variable length spray cooling zone is located adjacent at least one variable length radiation cooling zone along the runout table, and said computed cooling factor signal includes an accounting for a predetermined radiation cooling effect.
Claim 31
Dependent Claim
46 words
The method of claim 14 wherein the variable length spray cooling zone is located adjacent at least one variable length radiation cooling zone along the runout table, and said computed cooling factor and apparatus cooling error signals include an accounting for a predetermined radiation cooling effect.
Claim 32
Dependent Claim
97 words
The method of claim 12 wherein step (b) includes p. computing a signal representing predicted temperature of the strip entering the runout table based on a measured temperature made during strip rolling for use as measured Tf when computing the cooling factor signal, said predicted temperature signal varying according to the equation: Tf K8+K9VH+K10T5+K11H where Tf predicted temperature of strip entering the runout table, * F. V measured velocity of strip, feet per min. H thickness of strip in thousandths of inches (fixed value) T5 temperature of strip during rolling K8 to K11 predetermined constants as described.
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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |