Rf regeneration of hydro-absorptive material

Abstract

Disclosed herein is a dehumidifier comprising a regenerable sorption matrix disposed within a drum or wheel in which microwave radiation directed by a waveguide antenna is used to regenerate the sorption matrix within a desorption segment using a programmable controller to coordinate the advancement of the rotation of the sorbent through desorption segment. A method of dehumidifying a process fluid is also disclosed.

What is claimed is: 
     
         1 . A dehumidifier comprising:
 a rotatable sorption drum having variable portion in communication with one or more microwave sources dimensioned and arranged to direct microwave radiation into the portion of the sorption drum for selective excitation of a sorbate from the portion of the sorption drum.   
     
     
         2 . The dehumidifier of  claim 1 , wherein the microwave source comprises a slotted antenna. 
     
     
         3 . The dehumidifier of  claim 1 , further comprises a programmable controller comprising instructions to coordinate the rotation of the sorbent drum with the microwave radiation in response to microwave radiation detected by a receiver. 
     
     
         4 . A dehumidifier, comprising:
 (a) a sorption chamber having a cylindrical section housing a coaxial sorption drum with first and second end faces at opposite ends thereof;   (b) a regenerable sorption matrix comprising sorbent disposed in the sorption drum and comprising axial fluid permeability between the first and second end faces to selectively sorb water from a process fluid;   (c) a driver to rotationally advance the sorption drum about a longitudinal axis with respect to a desorption segment;   (d) an axial process fluid flow path through the sorption chamber passing through the sorption drum from the first end face to the second end face in fluid isolation from the desorption segment to remove the water from the process fluid;   (e) an axial desorption fluid flow path through the desorption segment;   (f) a desorption segment supply head fluidly connected against one of the first and second faces of the sorption drum and housing at least one waveguide antenna operatively connected with an Rf generator comprising at least one magnetron to direct microwave radiation into the sorption matrix at a frequency for selective excitation of the sorbate water;   (g) a desorption segment receiver head fluidly connected against the other one of the first and second end faces of the sorption drum and housing a receiver comprising an Rf detector to detect microwave radiation passing through the sorption matrix from the antenna; and   (h) a programmable controller comprising instructions to coordinate the advancement of the rotation of the sorbent drum with the microwave irradiation of the sorption matrix in response to the microwave radiation detected at the receiver.   
     
     
         5 . The dehumidifier of  claim 4 , wherein the sorption matrix comprises a plurality of tortuous axial flow passages through the sorption matrix, and no transverse fluid permeability or a transverse fluid permeability less than 10% of the axial fluid permeability. 
     
     
         6 . The dehumidifier of  claim 4 , wherein the programmable controller instructions comprise holding the sorption drum in a rotational position with respect to the desorption segment while the sorption matrix is irradiated. 
     
     
         7 . The dehumidifier of  claim 4 , wherein the programmable controller instructions further comprise a cycle including the irradiation of the sorption matrix while holding the sorption drum in the position and, when the receiver detects a set level of radiation passing through the sorption matrix, advancing the rotation of the sorption drum to introduce a sorbate water-rich portion of the sorption drum into the desorption segment. 
     
     
         8 . The dehumidifier of  claim 4 , wherein the programmable controller instructions comprise continuously advancing the rotation of the sorption drum to introduce a sorbate water-rich portion of the sorption drum into the desorption segment. 
     
     
         9 . The dehumidifier of  claim 4 , wherein an angular velocity of the advancement of the rotation of the sorption drum is controlled to maintain the detection of microwave radiation at the receiver at a set point. 
     
     
         10 . The dehumidifier of  claim 4 , wherein the programmable controller instructions provide for passage of the desorption fluid through a portion of the sorption matrix to cool the sorption drum following the microwave irradiation before return of the portion of the sorption matrix to the sorption chamber. 
     
     
         11 . The dehumidifier of  claim 4 , the desorption segment supply head further comprising an energy input sensor to measure a level of microwave radiation emitted from the wave guide antenna. 
     
     
         12 . The dehumidifier of  claim 4 , wherein a cross-sectional flow area through the sorption drum in the desorption segment is less than 25% of the cross-sectional flow area available for the process fluid through the sorption drum. 
     
     
         13 . The dehumidifier of  claim 4 , wherein the programmable controller further comprises instructions to control an operating parameter relative to a set point or limit, wherein the operating parameter is selected from one or more of a sorption matrix heating rate, a desorption fluid heating rage, a water removal rate, a sorption matrix temperature, a desorption fluid temperature, a process fluid temperature, a safety condition, a process alarm condition, an equipment alarm condition, a fluid flow rate, a process fluid flow rate, a desorption fluid rate, a process fluid humidity level, a desorption fluid humidity level, or a combination thereof. 
     
     
         14 . The dehumidifier of  claim 4 , wherein at least a portion of the desorption segment is located within the sorption chamber. 
     
     
         15 . The dehumidifier of  claim 4 , wherein the waveguide antenna comprises one or more slotted waveguides. 
     
     
         16 . A method, comprising:
 a) supplying process fluid to a sorption chamber having a cylindrical section housing a coaxial sorption drum with first and second end faces at opposite ends thereof;   b) passing the process fluid axially through a regenerable sorption matrix comprising sorbent disposed in the sorption drum between the first and second end faces to selectively sorb water from the process fluid;   c) rotationally advancing the sorption drum about a longitudinal axis with respect to a desorption segment in fluid isolation with the sorption chamber;   d) directing microwave radiation into the sorption matrix at a frequency for selective excitation of the sorbate water from a waveguide antenna positioned in a desorption segment supply head fluidly connected against one of the first and second faces of the sorption drum;   e) detecting microwave radiation passing through the sorption matrix from the antenna at a receiver positioned in a desorption segment receiver head fluidly connected against the other one of the first and second end faces of the sorption drum;   f) passing a desorption fluid axially through the desorption segment and a corresponding segment of the sorption drum to enrich the desorption fluid with the sorbate; and   g) coordinating the advancement of the rotation of the sorption drum with the irradiation of the sorption matrix in response to the radiation detected at the receiver.   
     
     
         17 . The process of  claim 16 , wherein the process fluid flow is directed counter current to the desorption fluid flow. 
     
     
         18 . The process of  claim 16 , wherein the directing microwave radiation into the sorption matrix, the coordinating the advancement of the rotation of the sorption drum, or a combination thereof comprises a cycle including irradiation of the sorption matrix while holding the sorption drum in a position and, when the receiver detects a set level of radiation passing through the sorption matrix, advancing the rotation of the sorption drum to introduce a sorbate water-rich portion of the sorption drum into the desorption segment. 
     
     
         19 . The process of  claim 16 , wherein the directing microwave radiation into the sorption matrix, the coordinating the advancement of the rotation of the sorption drum, or a combination thereof comprises continuously advancing the rotation of the sorption drum to introduce a sorbate water-rich portion of the sorption drum into the desorption segment. 
     
     
         20 . The process of  claim 16 , wherein an angular velocity of the advancement of the rotation of the sorption drum is controlled to maintain the detection of microwave radiation at the receiver at a set point. 
     
     
         21 . The process of  claim 16 , wherein the directing microwave radiation into the sorption matrix, the coordinating the advancement of the rotation of the sorption drum, or a combination thereof includes passage of the desorption fluid through the sorption matrix in the absence of microwave irradiation to cool the segment of the sorption drum following the microwave irradiation before return the segment of the sorption drum from the desorption segment to the sorption chamber. 
     
     
         22 . The process of  claim 16 , further comprising determining a level of microwave radiation emitted from the wave guide antenna from an energy input sensor and the directing microwave radiation into the sorption matrix, the coordinating the advancement of the rotation of the sorption drum, or a combination thereof is relative to the level of microwave radiation emitted from the antenna in combination with the radiation passing through the sorption matrix. 
     
     
         23 . The process of  claim 16 , wherein the directing microwave radiation into the sorption matrix, the coordinating the advancement of the rotation of the sorption drum, or a combination thereof further comprises controlling an operating parameter relative to a set point or limit, wherein the operating parameter is selected from one or more of a sorption matrix heating rate, a desorption fluid heating rage, a water removal rate, a sorption matrix temperature, a desorption fluid temperature, a process fluid temperature, a safety condition, a process alarm condition, an equipment alarm condition, a fluid flow rate, a process fluid flow rate, a desorption fluid rate, a process fluid humidity level, a desorption fluid humidity level, or a combination thereof 
     
     
         24 . The process of  claim 16 , further comprising preheating the desorption fluid to a temperature below the vaporization level of the sorbate water prior to directing microwave radiation into the sorption matrix, wherein the temperature of the desorption fluid is increased by heat exchange with a source of the microwave radiation, by heat exchange with an external heater, or a combination thereof.