Abstract: A process for generating in a pressure vessel a ready supply of a vapor of a normally liquid active substance in an inert carrier gas under pressure and dispensing vapor intermittently from the supply. Once a body of the active liquid substance and overlying atmosphere of vapor is established in the vessel, the vapor is dispensed intermittently in a series of predetermined doses. Simultaneously with the dispensing of each dose, carrier gas is bubbled under pressure into a bottom zone of the vessel in minute bubbles so as to provide saturated vapor, replacing the dose dispensed. A number of conditions are coordinated to insure that saturated vapor is always dispensed. These conditions include the relationship between the depth of the vapor space, the head of liquid above the bubbling zone, the relative amount of each dose, and the initial size of the bubbles. The process is specially useful for gassing cold box cores.

Abstract: A method of making a number of foundry cores serially in which a foundry aggregate mixed with a curable binder is introduced into a core box cavity to form each green core which is gassed by passing into it a predetermined dose of a saturated vapor under pressure of a normally liquid curing agent for the binder and an inert carrier gas and then a purging gas is passed through the core to drive out unreacted curing agent. A ready supply of a saturated vapor of the curing agent is provided in a generating vessel. Once a body of the active liquid substance and overlying atmosphere of vapor is established in the generating vessel, the vapor is dispensed intermittently to the core box cavity in a series of bursts, one for each core gassed. Simultaneously with the dispensing of each burst, carrier gas is bubbled under pressure into a bottom zone of the vessel in minute bubbles so as to provide saturated vapor, replacing that dispensed.