n. One who or that which rectifies.n. One who reflnes a substance by repeated distillations or by filtering or any other method; specifically, one who rectifies liquors.n. In the distillation of alcoholic liquors:n. A vessel or receptacle in which a second distillation is carried on, to condense the liquor and increase its alcoholic strength, or to flavor it by exposing the flavoring substance to the vaporized spirit.n. A cylindrical vessel continuous with a primary still, in which repeated distillations occur till the alcohol reaches the desired strength. Also called rectifying column, and simply columnn. An instrument formerly used for indicating the errors of the compass.n. In elect, an apparatus for changing an alternating electric current into a direct current directly, that is, without intermediary transformation of energy. The most common forms of rectifier are: The mechanical rectifier, which consists of a synchronous motor (that is, a motor which keeps step with the alternations of the alternating current) driving a rectifying commutator which reverses the direction of successive impulses of current so as to send them in the same direction into the direct-current circuit. The main objection to this form is the destructive sparking of the commutator-brushes when rectifying large amounts of power.n. The electrolytic rectifier which is based on the property of aluminium, in some salt or acid solutions, of passing current only when negative: a property due, probably, to the formation of a non-conducting film of oxid or basic salt on the aluminium by the oxygen produced on the aluminium when it is the positive terminal. Such a rectifier usually consists of an aluminium and a carbon or metal plate in a solution of some suitable salt. A combination of this sort passes only one half-wave of alternating current, from the carbon to the aluminium, but partly suppresses the reverse half-wave; and by using two such rectifiers, one half-wave of current is passed over the one, the other over the other rectifier, and then recombined and sent into the direct-current circuit. The disadvantage of the electrolytic rectifier is its low efficiency.n. Arc-rectifiers, which are based on the property of arcs to be conducting in one direction, but not in the opposite. In the mercury-arc rectifier, one mercury and two graphite terminals are inclosed in the same glass tube, the two graphite terminals being connected to the terminal of the alternating-current supply, while the direct-current circuit connects between the mercury terminal of the rectifier and a neutral or midway point of the alternating-current circuit, derived from a three-wire transformer or compensator, or by reactances. One impulse of the alternating current then passes from one graphite electrode, the other from the other graphite electrode; but both issue, in the same direction, from the mercury electrode into the direct-current circuit. The mercury-arc rectifier has a very high efficiency, but is so far limited in the amount of current which it can rectify. It is used for charging storage batteries and for arc-lighting.
