Compact gas fired humidifier

Abstract

A compact fuel fired steam generating type humidifier. The apparatus uses a gaseous fuel as the source of heat to generate steam used to humidify air in heating, ventilation and air conditioning of buildings. The humidifier may be a stand alone unit that disperses the steam into the space, or the steam generated by the apparatus may be dispersed in forced air flow of the building heating system. The steam generating unit includes an insulated casing housing a dry firebox combustion chamber with the boiler immersed in the firebox chamber. The boiler has a high rate internal recirculation of the boiling water and is spaced from the interior walls of the firebox chamber providing an effective passage and contact of the hot combustion products with the vertical heat transfer surfaces of the boiler. The production of the steam from feed water is controlled by a humidistat and is maintained by automatic periodic intake of the feed water. Concentration of total solids in the boiling water is maintained by automatic periodic blowdown of the recirculating boiling water that is cooled by the incoming feed water.