Method for controlling a recycle gas stream utilizing an ejector for the cooling of a unit operation
AssigneePraxair Technology, Inc.
InventorsWilliam J. Scharmach, Richard M. Kelly, Mohammad Abdul-Aziz Rashad, Yi Ma Lenhert, Matthew Thomas
Life of this patent
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Abstract
The present invention relates to a method of preparing a gas coolant for the direct cooling of a unit operation under a fixed heat load from its normal operating temperature (e.g., 300° F. and above) to a lower temperature (e.g., below 100° F.) in order to allow for maintenance or other non-routine work to be carried out in said unit operation.
Claims19
A method for the direct cooling of a unit operation under a fixed heat load to a lower temperature wherein the unit operation is cooled with a cooling stream routed from a non-mechanical pump where the cooling stream is a combination of a vaporized motive fluid stream with at least a portion of an effluent gas stream from the unit operation, wherein the direct cooling method comprises:
- a. circulating a portion of the unit operation effluent having a temperature in the range of approximately 50-500° F. with the non-mechanical pump where the vaporized fluid is provided as a motive force;
- b. providing the vaporized motive fluid stream to the non-mechanical pump at a temperature in the range of about −452° F. to about 50° F.;
- c. combining the unit operation effluent and the vaporized motive fluid in said non-mechanical pump, wherein the combined stream has a temperature in the range of about −50° F. to about 300° F.
- d. adjusting the ratio of the mass flow rates of the unit operation effluent stream to the vaporized motive fluid stream combined in the non-mechanical pump wherein the ratio is determined by:
- Recycle
-
-
- Ratio
- mass
- =
- C
- Mot
- *
- (
- T
- C
- -
- T
- Mot
- )
- C
- Eff
- *
- (
- T
- Eff
- -
- T
- C
- )
- where,
- Recycle Ratiomass is the ratio of the mass flow rate of the effluent to the mass flow rate of the vaporized motive fluid;
- CMot is the specific heat of the vaporized motive fluid;
- CEff is the specific heat of the unit operation effluent stream entering the non-mechanical pump;
- TC is the temperature of the combined fluid or the target temperature of the gas stream exiting the non-mechanical pump;
- TMot is the temperature of the vaporized motive fluid, and is selected by the operator;
- TEff is the temperature of the unit operation effluent stream entering the non-mechanical pump.
A method for the direct cooling of a unit operation under a fixed heat load to a lower temperature wherein the unit operation is cooled with a cooling stream routed from a non-mechanical pump where the cooling stream is a combination of a vaporized motive fluid stream with at least a portion of an effluent gas stream from the unit operation, wherein the direct cooling method comprises:
- a. circulating a portion of the unit operation effluent having a temperature in the range of approximately 50-500° F. with the non-mechanical pump where the vaporized fluid is provided as a motive force;
- b. providing the vaporized motive fluid stream to the non-mechanical pump at a temperature in the range of about −452° F. to about 50° F.;
- c. combining the unit operation effluent and the vaporized motive fluid in said non-mechanical pump, wherein the combined stream has a temperature in the range of about −50° F. to about 300° F.
- d. adjusting the temperature of the vaporized motive stream to be combined with the unit operation effluent stream in the non-mechanical pump wherein the temperature is determined by:
- T
- Mot
- =
- T
- C
- -
- RR
-
- (
- Suc
- Mot
- )
- mass
- *
- C
- Eff
- *
- (
- T
- Eff
- -
- T
- C
- )
- C
- Mot
- where,
- Recycle Ratiomass is the ratio of the mass flow rate of the effluent to the mass flow rate of the vaporized motive fluid and is selected by the operator;
- CMot is the specific heat of the vaporized motive fluid;
- CEff is the specific heat of the unit operation effluent stream entering the non-mechanical pump;
- TC is the temperature of the combined fluid or the target temperature of the gas stream exiting the non-mechanical pump;
- TMot is the temperature of the vaporized motive fluid;
- TEff is the temperature of the unit operation effluent stream entering the non-mechanical pump.
A method for the direct cooling of a unit operation under a fixed heat load to a lower temperature wherein the unit operation is cooled with a cooling stream routed from a non-mechanical pump were the cooling stream is a combination of a vaporized fluid stream with at least a portion of an effluent gas stream from the unit operation, wherein the direct cooling method comprises:
- a. circulating a portion of the unit operation effluent having a temperature in the range of approximately 50-500° F. by the non-mechanical pump where the vaporized fluid stream is provided as a motive force;
- b. providing the motive fluid stream to the non-mechanical pump at a temperature in the range of about −452° F. to about 0° F.;
- c. combining the unit operation effluent and the motive fluid in said non-mechanical pump, wherein the combined stream has a temperature in the range of about 50° F. to about 300° F. is introduced into the pipe system
- d. providing an industrial gas liquid at the temperature range of about −452° F. to about 0° F. and combining the liquid with the unit operation effluent upstream of the jet compressor or with the mixture of the unit operation effluent and motive fluid downstream of the jet compressor
- e. adjusting the ratio of the mass flow rates of the unit operation effluent stream to the vaporized motive fluid stream combined in the non-mechanical wherein the ratio is determined by:
- Recycle
-
-
- Ratio
-
- (
- RR
- ″
- ``
- )
-
- (
- Suc
- Mot
- )
- mass
- =
- C
- Mot
- *
- (
- T
- C
- -
- T
- Mot
- )
- C
- Eff
- *
- (
- T
- Eff
- -
- T
- C
- )
- -
- [
- 1
- RR
-
- (
- Suc
- BLiq
- )
- mass
- *
- (
- C
- BLiq
- *
- (
- T
- C
- -
- T
- BLiq
- )
- +
- λ
- BLiq
- )
- ]
- RR
-
- (
- Suc
- Mot
- )
- mass
- is defined by the ratio of the mass flow rate of the unit operation effluent {dot over (M)}Eff to the mass flow rate of the vaporized motive fluid stream {dot over (M)}Mot;
- RR
-
- (
- Suc
- Mot
- )
- mass
- =
- M
- .
- Eff
- M
- .
- Mot
- RR
-
- (
- Suc
- BLiq
- )
- mass
- is defined by the ratio of the mass flow rate of the unit operation effluent {dot over (M)}Eff to the mass flow rate of the bypass liquid {dot over (M)}BLiq, and is selected by the operator;
- RR
-
- (
- Suc
- BLiq
- )
- mass
- =
- M
- .
- Eff
- M
- .
- BLiq
- CMot is the specific heat of the motive fluid;
- CEff is the specific heat of the unit operation effluent stream entering the non-mechanical pump;
- CBLiq is the specific heat of the liquid bypassing the vaporizer and jet compressor;
- TC is the temperature of the combined fluid or the target temperature of the gas stream exiting the non-mechanical pump;
- TMot is the temperature of the motive fluid, and is selected by the operator;
- TEff is the temperature of the unit operation effluent stream entering the non-mechanical pump;
- TBLiq is the temperature of the liquid bypassing the vaporizer and jet compressor;
- λBLiq is the specific latent heat of vaporization of the liquid bypassing the vaporizer and jet compressor.
A method for the direct cooling of a unit operation under a fixed heat load to a lower temperature wherein the unit operation is cooled with a cooling stream routed from a non-mechanical pump where the cooling stream is a combination of a vaporized motive fluid stream with at least a portion of an effluent gas stream from the unit operation, wherein the direct cooling method comprises:
- a. circulating a portion of the unit operation effluent having a temperature in the range of approximately 50-500° F. with the non-mechanical pump where the vaporized fluid is provided as a motive force;
- b. providing the vaporized motive fluid stream to the non-mechanical pump at a temperature in the range of about −452° F. to about 50° F.;
- c. combining the unit operation effluent and the vaporized motive fluid in said non-mechanical pump, wherein the combined stream has a temperature in the range of about −50° F. to about 300° F.;
- d. providing an industrial gas liquid at the temperature range of about −452° F. to about 0° F. and combining the liquid with the unit operation effluent upstream of the jet compressor or with the mixture of the unit operation effluent and motive fluid downstream of the jet compressor;
- e. adjusting the temperature of the vaporized motive stream to be combined with the unit operation effluent stream in the non-mechanical pump wherein the temperature is determined by:
- T
- Mot
- =
- T
- C
- -
- RR
-
- (
- Suc
- Mot
- )
- mass
- *
- C
- Eff
- *
- (
- T
- Eff
- -
- T
- C
- )
- -
- RR
-
- (
- BLiq
- Mot
- )
- mass
- *
- (
- C
- BLiq
- *
- (
- T
- C
- -
- T
- BLiq
- )
- +
- λ
- BLiq
- )
- C
- Mot
- RR
-
- (
- Suc
- Mot
- )
- mass
- is defined by the ratio of the mass flow rate of the unit operation effluent {dot over (M)}Eff to the mass flow rate of the vaporized motive fluid stream {dot over (M)}Mot, and is selected by the operator;
- RR
-
- (
- Suc
- Mot
- )
- mass
- =
- M
- .
- Eff
- M
- .
- Mot
- RR
-
- (
- Bliq
- Mot
- )
- mass
- is defined by the ratio of the mass flow rate of the bypass liquid {dot over (M)}BLiq to the mass flow rate of the vaporized motive fluid stream {dot over (M)}Mot, and is selected by the operator;
- RR
-
- (
- BLiq
- Mot
- )
- mass
- =
- M
- .
- Bliq
- M
- .
- Mot
- CMot is the specific heat of the motive fluid;
- CEff is the specific heat of the unit operation effluent stream entering the non-mechanical pump;
- CBLiq is the specific heat of the liquid bypassing the vaporizer and jet compressor;
- TC is the temperature of the combined fluid or the target temperature of the gas stream exiting the non-mechanical pump;
- TMot is the temperature of the motive fluid;
- TEff is the temperature of the unit operation effluent stream entering the non-mechanical pump;
- TBLiq is the temperature of the liquid bypassing the vaporizer and jet compressor;
- λBLiq is the specific latent heat of vaporization of the liquid bypassing the vaporizer and jet compressor.
Dependencies are inferred from the claim text.