Abstract: A multi stage heater heats items on a conveyor so that they follow a predetermined temperature profile. The heater is used for printed circuit boards or the like when heated for soldering and avoids thermal gradients that can occur with heating different materials. The heater has a first heater for applying a first quantity of heat to items on the conveyor, a temperature sensing device for determining temperature of items leaving the first heater, a second heater downstream of the first heater and a control system which compares signals from the temperature sensing device with a predetermined temperataure profile to produce a first control output to control the first heater and a second control output to control the second heater so that items passing through the heater follow the predetermined temperature profile.

Abstract: A video camera or other scanning device is employed to monitor the loading with articles to be frozen of an endless belt which passes through a freezing apparatus so as to freeze such articles typically by contact with liquid nitrogen or its cold vapor. The video camera is associated with electronic circuits that generate a signal representative of the belt loading and compare it with a signal representative of an optimum belt loading. If the difference between the signals is greater than a chosen threshold the belt speed is adjusted so as to reduce or eliminate the difference. By this means an improvement is made possible in the efficiency with which the liquid nitrogen is utilized.

Abstract: An apparatus controls the temperature of a multi-zone furnace based on a given temperature distribution pattern, which pattern is automatically modified zone by zone as the work being heat-treated is changed by using a memory storing a series of such patterns for different kinds of works.

Abstract: The present invention provides a method and apparatus for determining the temperature of an object as it moves through a heat treating furnace. The furnace includes a hearth adapted to move through it thusly enabling a number of objects placed on the hearth to be heat treated as they move through the furnace. To obtain the temperature of an object being heat treated as it moves through the furnace, a hole is provided in the hearth. A thermocouple wire is inserted through the hole and into the furnace. An end of the wire is connected to an object being heat treated, and the object is placed in the furnace. The other end of the wire is connected to a temperature display device outside of the furnace which moves along with the hearth and the object as they move through the furnace.

Abstract: Disclosed is a method of controlling an enamelling oven, in which a plurality of controlled variables such as temperatures:Y=(Y1 . . . Yl)including a plurality of measured variables:(Y1 . . . Ym)are variable by any one of a plurality of manipulation variables such as the degrees of opening of dampers:U=(U1 . . . Um)where l and m are positive integers equal to or greater than 2 with m>l. The method comprises the step of controlling the controlled variables to reach reference values therefor:YR=(YR1 . . . YRl)by effecting integrating action on each of variable factors:U'c=(Uc1 . . . UcM)which are derived from the differences between the controlled variables and the reference values:Y-YR=(Y1-YR1 . . . Y-YRl)=(.epsilon.1 . . . .epsilon.l)to produce outputsUc=(Uc . . . UcM)which serve as the controlled variables, respectively.

Abstract: An automatic microprocessor-based control system for a diffusion furnace in which the controller is dedicated to a single associated diffusion tube to provide all monitoring and control functions necessary for a variety of diffusion processes. The controller provides direct digital control of time, temperature and gas flow, and can be readily operated with a variety of control algorithms.

Abstract: A heat wrap control for a preheater in a paperboard corrugator adjusts the amount of wrap of a moving web about a heated drum as a linear function of web speed to effect uniform heat transfer to the web.

Abstract: A pressure heat fixing device consisting of a pair of heated fixing rollers rotating in pressure contact with one another and a temperature means supported to contact with the surface of the heated fixing roller, characterized by the provision of a suitable driving means adapted to reciprocatingly displace the said temperature detecting means along with and parallel to the axis of the heated fixing roller.

Abstract: Monitoring the peak temperature of a moving mass, such as a flowing stream of molten material, has in the past been plaqued with problems. The present system and method overcomes these problems by oscillating a temperature sensor, spaced from the moving mass, such that the sensor scans back and forth across the moving mass during each cycle of oscillation. The output signal from the sensor is fed to device that preferably puts out a signal proportional to the peak temperature sensed by the sensor on each half cycle of oscillation, which output signal is caused to decay at a desired rate between peak temperature measurements. This slightly sawtooth shaped output signal can be recorded and/or used for control purposes.

Abstract: Apparatus for providing an expendable refrigerant which is emitted from a snow horn at a low velocity thereby enabling snow agglomeration at a close proximity to the horn exit and accurately delivering a charge of snow with minimum vapor loss. The desired snow is produced by introduction of the relatively warm liquid refrigerant into an insulated compartment and in heat exchange relation with a tube therein having a plurality of length/diameter ratios. The liquid refrigerant is effective to warm the tube walls and results in a slight cooling of such liquid which is then passed to a subcooler and returned to the tube inlet for expansion in several stages therein to form the snow. The product snow is emitted from this horn at a relatively low velocity and may be accurately directed into cavities of such products as eviscerated fowl.