All-ceramic heat exchangers, systems in which they are used and processes for the use of such systems

Abstract

Landfill gas combustion and landfill leachate evaporation systems and the use of forest products or some such fuel to fire a gasifier that will eventually provide energy. Novel all-ceramic heat exchangers, systems in which they are used, and processes that can be handled by such systems.

1 . An all-ceramic heat exchanger comprising
 (i) an elongate body, the body having a first end and a second end,   (ii) a plurality of ceramic tubes extending from the first end to the second end,   (iii) a first sprung jack arch tube sheet for supporting ceramic tubes positioned adjacent the first end, the first sprung jack arch tube sheet being fixed with respect to the body,   (iv) a second sprung jack arch tube sheet for supporting ceramic tubes positioned adjacent the second end, the second sprung jack arch tube sheet being movable with respect to the body,   (v) at least one baffle positioned between the first end and the second end for directing air flow within the all-ceramic heat exchanger,   wherein the first end terminates in a first dome, and wherein the second end terminates in a second dome.   
   
   
       2 . The all-ceramic heat exchanger of  claim 1  wherein the all-ceramic heat exchanger is oriented such that
 (a) the second end is in vertical alignment with the first end, and   (b) the second end generally overlies the first end,   wherein the expansion of the ceramic tubes during use causes upward movement of the second sprung jack arch tube sheet such that the distance between the second sprung jack arch tube sheet and the first sprung jack arch tube sheet is increased, and   wherein the second sprung jack arch tube sheet is maintained in a sealing relationship with the ceramic tubes by force of gravity acting on the combination of second dome and second sprung jack arch tube sheet at pressures of less than about 15 psig.   
   
   
       3 . The all-ceramic heat exchanger of  claim 1  wherein the all-ceramic heat exchanger is oriented such that
 (a) the second end is in vertical alignment with the first end, and   (b) the second end generally overlies the first end,   wherein the expansion of the ceramic tubes during use causes upward movement of the second sprung jack arch tube sheet such that the distance between the second sprung jack arch tube sheet and the first sprung jack arch tube sheet is increased, and   wherein the second dome comprises adjustable securement means, the adjustable securement means maintaining the second sprung jack arch tube sheet in a sealing relationship with the ceramic tubes.   
   
   
       4 . The all-ceramic heat exchanger of  claim 3  wherein the adjustable securement means comprises spring loaded rods fastening the second dome to the body so as to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       5 . The all-ceramic heat exchanger of  claim 3  wherein the adjustable securement means comprises hydraulic controllers, the hydraulic controllers using hydraulic pressure to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       6 . The all-ceramic heat exchanger of  claim 3  wherein the adjustable securement means comprises pneumatic controllers, the pneumatic controllers using pneumatic pressure to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       7 . A system for processing landfill products, the system comprising
 (i) a gas burner,   (ii) a staged oxidizer,   (iii) at least one all-ceramic heat exchanger, and   (iv) a leachate evaporator,   wherein any all-ceramic heat exchanger comprises   (a) an elongate body, the body having a first end and a second end,   (b) a plurality of ceramic tubes extending from the first end to the second end,   (c) a first sprung jack arch tube sheet for supporting ceramic tubes positioned adjacent the first end, the first sprung jack arch tube sheet being fixed with respect to the body,   (d) a second sprung jack arch tube sheet for supporting ceramic tubes positioned adjacent the second end, the second sprung jack arch tube sheet being movable with respect to the body,   (e) at least one baffle positioned between the first end and the second end for directing air flow within the all-ceramic heat exchanger, and   wherein the first end terminates in a first dome, and wherein the second end terminates in a second dome,   wherein the system combusts landfill gas within the gas burner using preheated air from the all-ceramic heat exchanger, the gas burner generating combustion gas,   the combustion gas from the gas burner being oxidized within the staged oxidizer using preheated air from the all-ceramic heat exchanger, the oxidizer discharging a hot flue gas,   the hot flue gas from the oxidizer being directed through the tube side of the all-ceramic heat exchanger where heat is transferred through the ceramic tubes so as to heat clean air on the air-side of the all ceramic heat exchanger, the tube side flue gas then being discharged to the atmosphere, the heated clean air being directed from the heat exchanger to the gas burner, the oxidizer, and the evaporator, the evaporator percolating the heated clean air from the all-ceramic heat exchanger through landfill products to heat and evaporate liquids within the landfill products, and, discharging landfill gas which is directed to the gas burner, and discharging dried landfill products.   
   
   
       8 . The system for processing landfill products of  claim 7  wherein the system further comprises a turbine, a compressor, a generator, and at least one additional heat exchanger,
 wherein the tube side flue gas from the all-ceramic heat exchanger is directed to the tube side of the at least one additional heat exchanger, the tube side flue gas then being discharged to the atmosphere,   wherein ambient air is compressed within the compressor, the compressor discharging heated, compressed air,   the heated compressed air from the compressor directed to the air side of the at least one additional heat exchanger,   the heated compressed air is then discharged from the air side of the at least one additional heat exchanger and is directed to the air side of the all ceramic heat exchanger where it receives additional heat energy,   the heated compressed air is then discharged from the air side the all-ceramic heat exchanger and is directed to a turbine, the heated compressed air expanding within the turbine so as to drive the generator and produce power, the expanded air being discharged to the evaporator.   
   
   
       9 . The system for processing landfill products of  claim 7  wherein the staged oxidizer is stacked on the gas burner such that it overlies the gas burner in vertical alignment with the gas burner,
 wherein the all-ceramic heat exchanger is stacked on the staged oxidizer such that it overlies the staged oxidizer in vertical alignment with the staged oxidizer, the all-ceramic heat exchanger being oriented such that   (a) the second end is in vertical alignment with the first end, and   (b) the second end generally overlies the first end,   wherein the expansion of the ceramic tubes during use causes upward movement of the second sprung jack arch tube sheet such that the distance between the second sprung jack arch tube sheet and the first sprung jack arch tube sheet is increased, and   wherein the second sprung jack arch tube sheet is maintained in a sealing relationship with the ceramic tubes by force of gravity acting on the combination of second dome and second sprung jack arch tube sheet regardless of temperature of the all-ceramic heat exchanger.   
   
   
       10 . The system for processing landfill products of  claim 7  wherein the staged oxidizer is stacked on the gas burner such that it overlies the gas burner in vertical alignment with the gas burner,
 wherein the all-ceramic heat exchanger is stacked on the staged oxidizer such that it overlies the staged oxidizer in vertical alignment with the staged oxidizer, the all-ceramic heat exchanger being oriented such that   (a) the second end is in vertical alignment with the first end, and   (b) the second end generally overlies the first end,   wherein the expansion of the ceramic tubes during use causes upward movement of the second sprung jack arch tube sheet such that the distance between the second sprung jack arch tube sheet and the first sprung jack arch tube sheet is increased, and   wherein the second dome comprises adjustable securement means, the adjustable securement means maintaining the second sprung jack arch tube sheet in a sealing relationship with the ceramic tubes.   
   
   
       11 . The all-ceramic heat exchanger of  claim 11  wherein the adjustable securement means comprises spring loaded rods fastening the second dome to the body so as to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       12 . The all-ceramic heat exchanger of  claim 11  wherein the adjustable securement means comprises hydraulic controllers, the hydraulic controllers using hydraulic pressure to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       13 . The all-ceramic heat exchanger of  claim 11  wherein the adjustable securement means comprises pneumatic controllers, the pneumatic controllers using pneumatic pressure to maintain the second dome in a position abutting the body, thereby maintaining the second sprung arch jack tube sheet in a sealing relationship with the ceramic tubes. 
   
   
       14 . A all ceramic heat exchanger comprising in combination:
 (i) a metal jacketing and support frame having a top end and a bottom end;   (ii) a lower fixed sprung arch tube sheet mounted in the bottom end of the metal support frame for supporting:   (iii) multiple ceramic heat exchanger tubes fitted into openings in the lower fixed sprung arch tube sheet;   (iv) a moveable upper sprung jack arch tube sheet mounted in the top end of the metal support frame such that the ceramic heat exchanger tubes of (iii) are fitted into respective openings in the moveable upper sprung jack arch tube sheet, said moveable upper sprung jack arch tube sheet having an outside edge surface;   (v) a ceramic gasket mounted on the outside edge surface of the moveable upper sprung jack arch tube sheet;   (vi) a means for entry of air or gas into the ceramic heat exchanger;   (vii) a means for exit of air or gas out of the heat exchanger;   (viii) at least one air baffle mounted in the interior of the heat exchanger.   
   
   
       15 . A system for handling landfill produced products said system comprising in combination:
 (A) a housing and support frame having a top, a bottom and a middle section;   (B) supported in the bottom of the support frame, a gas burner assembly having a top end, bottom end, and a middle zone;   (C) supported in the middle section of the support frame, and mounted on the top of the gas burner assembly, a staged oxidizer unit having a bottom section, an upper section, and a middle section, said upper section of the staged oxidizer unit having a top end, said top end of said upper section of the staged oxidizer unit having mounted therein an air manifold assembly, said bottom and middle section of the staged oxidizer being fitted with a multiplicity of air conveyance ceramic tuyeres;   (D) means for conveying and controlling air to the staged oxidizer through the tuyeres and the air manifold assembly;   (E) mounted on the upper end of the staged oxidizer unit, an all-ceramic heat exchanger;   (F) mounted on the all-ceramic heat exchanger, a stack for conveying products of combustion from the burner, staged oxidizer and all-ceramic heat exchanger to the atmosphere;   (G) an evaporator for heating and evaporating liquid materials, said evaporator being heated by percolating high temperature air through liquid materials contained therein;   (H) a means for conveying air to the all-ceramic heat exchanger;   (I) a means for conveying heated air from the all-ceramic heat exchanger to the evaporator;   (J) means for conveying volatile products from the evaporator to the burner and the staged oxidizer;   (K) means for supplying liquid materials to the evaporator;   (L) means for controlling the system.   
   
   
       16 . A process for handling landfill produced products, said process comprising:
 (I) providing a burner that will burn landfill produced gases, said burner having a top and a bottom;   (II) feeding landfill produced gases to the burner along with controlled amounts of preheated combustion air to provide a zone temperature in the burner of not more than about 2200° F.;   (III) moving the products of combustion from (II) to a staged oxidizer having a bottom, and mixing said products of combustion with heated vapors from an evaporator capable of heating and evaporating liquid landfill produced products, such that the zone temperature in the bottom of the staged oxidizer is in the range of about 1600° F. to about 2200° F.:   (IV) providing a means of introducing air to the staged oxidizer essentially throughout the length of the staged oxidizer;   (V) mixing the products of (III) with the air in (IV) as the products move through the staged oxidizer;   (VI) allowing the mixture from the staged oxidizer to exit into a multiplicity of ceramic tubes in an all-ceramic heat exchanger, and then through the heat exchanger tubes to exit through the stack to the atmosphere;   (VII) supplying landfill produced liquid material to an evaporator,   (VIII) while carrying out steps (I) to (VI), providing a controlled amount of air into the interior of the all-ceramic heat exchanger to move in and around the ceramic tubes of the all-ceramic heat exchanger using at least one air baffle in the heat exchanger, to heat said air to a temperature of about 1200° F. to about 1800° F.;   (IX) allowing the heated air to exit from the all-ceramic heat exchanger and conveying said heated air to the evaporator and percolating said heated air into any liquid material present in the evaporator:   (X) collecting and conveying the evaporate from the evaporator to the burner to provide a portion of the fuel for the burner;   (XI) while moving the evaporate to the burner, separating a small portion of the evaporate and conveying it to the bottom of the staged oxidizer to mix as in step (III).   
   
   
       17 . A system for handling landfill produced products, said system comprising in combination;
 (A) a housing and support frame having a top, a bottom and a middle section;   (B) supported in the bottom of the support frame, a gas burner assembly having a top end, bottom end, and a middle zone;   (C) supported in the middle section of the support frame, and mounted on the top of the gas burner assembly, a staged oxidizer unit having a bottom section, an upper section, and a middle section, said upper section of the staged oxidizer unit having a top end, said top end of said upper section of the staged oxidizer unit having mounted therein an air manifold assembly, said bottom and middle sections of the staged oxidizer being fitted with a multiplicity of air conveyance ceramic tuyeres;   (D) means for conveying and controlling air to the staged oxidizer through the tuyeres and the air manifold assembly;   (E) mounted on the upper end of the staged oxidizer unit, a all-ceramic heat exchanger;   (F) mounted on the all-ceramic heat exchanger, a stack for conveying products of combustion from the burner, staged oxidizer and all-ceramic heat exchanger to the atmosphere;   (G) an evaporator for evaporating liquid materials, said evaporator being heated by percolating medium high temperature air through liquid materials contained therein;   (H) a metal heat exchanger, said metal heat exchanger receiving high temperature heated air from the all-ceramic heat exchanger and supplying medium high temperature heated air to the all-ceramic heat exchanger;   (I) a turbine, said turbine being driven by high temperature heated sir from the all-ceramic heat exchanger;   (J) a means for conveying high temperature heated air from the all-ceramic heat exchanger to the turbine;   (K) a compressor, said compressor being driven by the turbine and said compressor supplying low temperature heated air to the metal heat exchanger;   (L) a means of supplying ambient air to the compressor;   (M) a means of conveying medium high temperature heated air from the turbine to the evaporator;   (N) means for conveying volatile products from the evaporator to the burner and the staged oxidizer;   (O) means for conveying low temperature heated air from the compressor to the metal heat exchanger;   (P) means for conveying medium temperature heated air from the metal heat exchanger to the all-ceramic heat exchanger;   (Q) a means of mixing medium temperature heated air from the metal heat exchanger, and ambient air, and conveying said air mixture to the staged oxidizer and,   (R) a means for controlling the system.   
   
   
       18 . A process for handling landfill produced products, said process comprising:
 (I) providing a conventional burner that will burn landfill produced gases, said burner having a top and a bottom;   (II) feeding landfill produced gases to the burner along with controlled amounts of preheated combustion air to provide a zone temperature in the burner of not more than about 2200° F.;   (III) moving the products of combustion from (II) to a staged oxidizer having a bottom, and mixing said products of combustion with heated vapors from an evaporator capable of heating and evaporating liquid landfill produced products, such that the zone temperature in the bottom of the staged oxidizer is in the range of about 1600° F. to about 2200° F.;   (IV) providing a means of introducing air to the staged oxidizer essentially throughout the length of the staged oxidizer;   (V) mixing the products of (III) with the air in (IV) as the products move through the staged oxidizer;   (VI) allowing the mixture form the staged oxidizer to exit into a multiplicity of ceramic tubes in an all-ceramic heat exchanger, and then through the all-ceramic heat exchanger tubes to a metal heat exchanger and then exit through a stack to the atmosphere;   (VII) while carrying out steps (I) to (VI), providing a controlled amount of air into the interior of the all-ceramic heat exchanger to move in and around the ceramic tubes of the all-ceramic heat exchanger using at least one air baffle in the all-ceramic heat exchanger, to heat said air to a temperature of about 1200° F. to about 1800° F.;   (VIII) allowing the heated air to exit from the all-ceramic heat exchanger and conveying said heated air to a turbine, thereby driving the turbine;   (IX) conveying the heated air from the turbine to an evaporator and percolating said heated air into any liquid material present in the evaporator;   (X) collecting and conveying the evaporate from the evaporator to the burner to provide a portion of the fuel for the burner;   (XI) while moving the evaporate to the burner, separating a small portion of the evaporate and conveying it to the bottom of the staged oxidizer to mix as in step (III).