Heat exchanging unit and heat exchanging apparatus

A combined heat exchanging apparatus comprising a heat exchanging unit and a mist processing unit disposed at a location lower than said heat exchanging unit,

• said heat exchanging unit comprising:
• a first closed vessel separated by a vertical partition plate into a first compartment for cooling a fluid to be cooled with a liquid medium and a second compartment for receiving a mist separated from the liquid medium, said vertical partition plate having a height lower than the height of said first closed vessel to thereby define above said vertical partition plate a passage connecting said first and second compartments;
• a first cooling medium inlet pipe connected to said first compartment;
• liquid medium inlet control means and liquid medium outlet control means for respectively controlling flows of the liquid medium into and out of the first compartment of the closed vessel and for collectively maintaining the liquid medium in the first compartment at a predetermined liquid level height lower than said height of said vertical partition plate;
• a first through pipe through which the fluid to be cooled is passed, said first through pipe being arranged to pass through said first compartment and including a first heat exchange member disposed in said first compartment at a height lower than the top of said vertical partition plate;
• a demister disposed in said second compartment;
• a first cooling medium gas outlet pipe connected to said demister;
• and a first cooling medium liquid outlet pipe connected to the lower portion of the second compartment;
• said mist processing unit comprising:
• a second closed vessel having a cooling medium liquid retaining zone;
• a second cooling medium liquid inlet pipe connected to said second closed vessel;
• a second cooling medium gas outlet pipe connected to said second closed vessel;
• a second through pipe through which a fluid to be cooled is passed, said second through pipe being arranged to pass through said cooling medium liquid retaining zone of said second closed vessel and having an inlet and an outlet;
• wherein said first cooling medium liquid outlet pipe of said heat exchanging unit is connected to said second cooling medium liquid inlet pipe of said mist processing unit such that cooling medium liquid separated from said demister is supplied under the effect of gravity from said second compartment to said mist processing unit;
• and
• wherein said second cooling medium gas outlet pipe of said mist processing unit is connected to said first compartment of said heat exchanging unit such that cooling medium gas generated in said mist processing unit is returned to said heat exchanging unit.

A multistage heat exchanging apparatus comprising a series of heat exchanging units, each of said heat exchanging units comprising:

• a closed vessel separated by a vertical partition plate into a first compartment for cooling a fluid to be cooled with a liquid medium and a second compartment for receiving a mist separated from the liquid medium, said vertical partition plate having a height lower than the height of said closed vessel to thereby define above said vertical partition plate a passage connecting said first and second compartments;
• a cooling medium inlet pipe connected to said first compartment;
• liquid medium inlet control means and liquid medium outlet control means for respectively controlling flows of the liquid medium into and out of the first compartment of the closed vessel and for collectively maintaining the liquid medium in the first compartment at a predetermined liquid level height lower than said height of said vertical partition plate;
• a through pipe through which the fluid to be cooled is passed, said through pipe being arranged to pass through said first compartment and including a heat exchanging member disposed in said first compartment at a height lower than the top of said vertical partition plate;
• a demister disposed in said second compartment;
• a cooling medium gas outlet pipe connected to said demister;
• a cooling medium liquid outlet pipe connected to the lower portion of the second compartment;
• and a cooling medium liquid discharge pipe connected to the lower portion of said first compartment of at least each of said heat exchanging units, with the exception of a last said heat exchanging unit of said series;
• wherein said cooling medium liquid discharge pipe of any heat exchanging unit is connected to said cooling medium inlet pipe of the succeeding heat exchanging unit via an expansion valve;
• said cooling medium liquid outlet pipe of any heat exchanging unit is connected to said first compartment of a succeeding heat exchanging unit via an expansion valve;
• and
• said outlet of said through pipe of any heat exchanging unit is connected to the inlet of said through pipe of a succeeding heat exchanging unit.

A combined multistage heat exchanging apparatus comprising a series of heat exchanging units and a mist processing unit disposed at a location lower than the last heat exchanging unit of said series of heat exchanging units,

• each heat exchanging unit comprising:
• a first closed vessel separated by a vertical partition plate into a first compartment for cooling a fluid to be cooled with a liquid medium and a second compartment for receiving a mist separated from the liquid medium, said vertical partition plate having a height lower than the height of said first closed vessel to thereby define above said vertical partition plate a passage connecting said first and second compartments;
• a first cooling medium inlet pipe connected to said first compartment;
• liquid medium inlet control means and liquid medium outlet control means for respectively controlling flows of the liquid medium into and out of the first compartment of the closed vessel and for collectively maintaining the liquid medium in the first compartment at a predetermined liquid level height lower than said height of said vertical partition plate;
• a first through pipe through which the fluid to be cooled is passed, said first through pipe being arranged to pass through said first compartment and including a first heat exchange member disposed in said first compartment at a height lower than the top of said vertical partition plate;
• a demister disposed in said second compartment;
• a first cooling medium gas outlet pipe connected to said demister;
• a first cooling medium liquid outlet pipe connected to the lower portion of the second compartment;
• and a cooling medium liquid discharge pipe connected to the lower portion of said first compartment of at least each of said heat exchanging units, with the exception of a last said heat exchanging unit of said series;
• said cooling medium liquid discharge pipe of any heat exchanging unit being connected to said first cooling medium inlet pipe of the succeeding heat exchanging unit via an expansion valve;
• said first cooling medium liquid outlet pipe of any heat exchanging unit, with the exception of said last said heat exchanging unit of said series, being connected to said first compartment of a succeeding heat exchanging unit via an expansion valve;
• said outlet of said first through pipe of any heat exchanging unit being connected to the inlet of said first through pipe of a succeeding heat exchanging unit;
• said mist processing unit comprising:
• a second closed vessel having a cooling medium liquid retaining zone;
• a second cooling medium liquid inlet pipe connecting said second closed vessel to said first cooling medium liquid outlet pipe of the last said heat exchanging of said series such that cooling medium liquid separated from said demister of the last said heat exchanging unit of said series is supplied under the effect of gravity to said mist processing unit;
• a second cooling medium gas outlet pipe connecting said second closed vessel to said first compartment of the last said heat exchanging unit of said series such that the cooling medium gas generated in said mist processing unit is returned to the last heat exchanging unit of said series of heat exchanging units;
• a second through pipe through which a fluid to be cooled is passed, said second through pipe being installed to pass through said cooling medium liquid retaining zone of said second closed vessel and having an inlet and an outlet.