Hybrid desiccant dehumidifier

Abstract

An apparatus and method to dehumidify and reheat an air stream utilizing a combination of conventional direct expansion cooling and a high capacity desiccant dehumidification rotor. Apparatus and method is configured to achieve optimum moisture removal without overcooling at minimum energy consumption. More particularly, the invention relates to an improved method of combining conventional refrigeration with desiccant dehumidification utilizing a single air stream for efficient dehumidification without the need for secondary air streams or overcooling. Moisture is removed as condensed liquid as typical of refrigeration processes however further dehumidification occurs as a result of adsorption by the desiccant dehumidification portion. Heating of the air stream with available condenser heat prevents overcooling the air. This invention combines the two technologies in a higher capacity, more efficient approach than previous methods.

1 . A hybrid desiccant dehumidification apparatus and method of combining refrigeration and rotary adsorption technology comprising: 
 a completely self contained dehumidification unit needing only electrical power input to operate    a single air stream    a single air moving device    an evaporator coil sized for maximum moisture removal under higher than normal latent loads    a single high capacity desiccant dehumidification rotor with drive mechanism to precisely control rotational speed    a condenser coil designed for optimum heat rejection in reduced humidity air    an internal refrigeration compressor, piping, and controls an internal humidity sensor which can be used to prevent over drying as necessary    electrical operating safeties and controls    
   
   
       2 . Apparatus of  claim 1  comprising: 
 a housing for said apparatus    an air filtration device    an air moving device    a high capacity rotary adsorption device    a device to drive and precisely control rotation of adsorption device    a high capacity refrigeration evaporator coil    a refrigeration compressor    a refrigeration condenser coil    a humidity control device    an electrical control system which operates controls, and    electrically protects said apparatus    
   
   
       3 . Apparatus of  claim 2  wherein a single air stream is utilized  
   
   
       4 . Apparatus of  claim 3  wherein a single air moving device is utilized  
   
   
       5 . Apparatus of  claim 2  wherein a single high capacity desiccant dehumidification rotor with precisely controlled speed to optimize performance is used  
   
   
       6 . Apparatus of  claim 2  wherein no heat is used for reactivation of the desiccant rotor.  
   
   
       7 . Apparatus of  claim 2  wherein a direct expansion evaporator coil sized for optimum moisture removal at higher than normal latent loads.  
   
   
       8 . Apparatus of  claim 2  wherein moisture is removed from an air stream as condensed water  
   
   
       9 . Apparatus of  claim 2  wherein rotary adsorption device reduces absolute moisture level below that which can be achieved with conventional refrigeration.  
   
   
       10 . Apparatus of  claim 2  wherein a condenser coil designed for optimum heat rejection in reduced humidity air.  
   
   
       11 . Apparatus of  claim 2  wherein overcooling is prevented by heating the discharge air with rejected heat.  
   
   
       12 . Apparatus of  claim 2  wherein an internal compressor provides direct expansion cooling.  
   
   
       13 . Apparatus of  claim 12  wherein compressor has safety controls and pump down operation upon shut down of apparatus.  
   
   
       14 . Apparatus of  claim 2  where output can be at maximum capacity at all times or switched to humidity control for automatic control to prevent over drying  
   
   
       15 . Apparatus of  claim 12  wherein humidity control feature allows for cycling the refrigeration compressor on and off automatically.