GB808412A - Improvements in combined heat and moisture exchangers - Google Patents

Abstract

808,412. Conditioning air. MUNTERS, C. G. Feb. 3, 1955 [Feb. 3, 1954], No 3184/55. Class 137 [Also in Group XIII] Apparatus for heating and moistening air supplied to an enclosed space, e.g. a room, comprises a housing 10 which is divided by partitions 12 into spent air outlet, and fresh air inet, ducts 14, 16 respectively, openings 18, 24 and 20, 28 at the ends of the ducts communicating respectively with the outside atmosphere and the room. Heat and moisture transfer bodies 36, 38, consisting of drums 44 each accommodating a spirally wound web 40 or 42 of the kind described in Specification 770,201 extend transversely across the ducts 14, 16 and pass through sealing packings 52 in the partitions 12, each drum being sealed against a circular opening in a partition 50 secured to the housing 10. Each drum 44 is rotatably supported by a medial peripheral flange 58 which engages three supporting rollers 60 mounted on the inner face of the casing 10 and is in driving contact with a pulley 62 mounted on a shaft 64 which is driven through gearing 66 by a driving motor 54 or 56. Removable filters 32, 34 are mounted adjacent the openings 24, 20 in the ducts 16, 14 respectively, and a heater 68 is incorporated between the rotor bodies 36, 38 either as shown, in the duct 14, or in the duct 16. The. amount of spent and fresh air passed through the ducts, 14, 16 by fans 22, 26 respectively can be controlled by dampers 29, 30 arranged in the corresponding openings 20, 24. In one mode of use, e.g. in winter, spent air passing out of the room through the duct 14 first deposits moisture on the rotor body 36 and is then heated, to a temperature, e.g. of 77‹F., by the heater 68, heat and further moisture then being transferred to the rotor body 38. The air entering the opening 24 in the duct 16, taking up heat and some moisture from the rotor body 38, is further moistured by the rotor 36 before passing in to the space to be ventilated. If the supply of heat to the heater 68 is decreased the rotor 36 has a correspondingly increased share in the heat transfer action. the latter action becoming at a maximum when the heat to the heater 68 is entirely cut off. The heat supplied to the heater 68 can be automatically controlled by means of a hygrostat 69 in the opening 18, and the dampers 29, 30 may be controlled manually, or automatically, in response to the temperature of the atmosphere. During summer. the element 68 is shut off and heat and moisture transfer is effected from the incoming atmospheric air to the spent air escaping from the room. In a modification the heater 68 is replaced by a non- hygroscopic, motor driven, heat exchange rotor which has no moisture transfer proparties and which extends through the boundary wall of, and across, the duct 14, and also across a third duct, not shown. adjacent the duct 14, the third duct being supplied with a small amount of spent air by means of the fan 22. A filter is arranged adjacent the spent air inlet of the third passage within which there is also arranged a damper, the air stream leaving the duct being recirculated through a pipe back into the room. In the arrangement shown in Fig. 4 the air in a room 96 is conditioned by a unit 98 incorporating a moistening and a refrigerating, or heating, device and communieating with the room through a fan 100 and conduit 102, spent air in a conduit 106 being connected to a conduit 104 for returning the desired proportion to mix with the fresh air supplied by a pipe 110 to the unit 98, the remainder being discharged by a fan 108. An exchanger 112 of the kind shown in Fig. 1 is connected to the 'fan 108 and the conduit 110. When the modified arrangement is used to ventilate cold storage rooms, the extra rotor may be made hygroscopic in order to transfer moisture from the air stream in the duct 14 to the air stream in the third duct, thus avoiding precipitation of moisture in the rotor 38. Specifications 748,311 and 808,411 also are referred to.