Abstract: A passive type of space heater having a vertical air heating duct located at the rear of the combustion chamber and a flue duct extending through the air heating duct with its inlet located so as to draw the flue gases from the combustion chamber around the surfaces of the air heating duct. Air for combustion is supplied to the top of the combustion chamber by an air supply duct which extends inside of the flue duct and has orifices to provide air in the flue duct for secondary combustion of the flue gases passing through the flue duct. The air supply duct also has an ejector to draw a portion of the flue gases into the air supply duct for recirculation to the combustion chamber for tertiary combustion. A separate air supply duct is provided for supplying air for combustion during start-up.

Abstract: A focusing solar collector which utilizes an elongated parabolic shaped mirror made from a sheet of drapable material so that when draped in a catenary like curved configuration, the sun's rays may be focused on a linear target which is axially aligned with the axis of the mirror. Means are provided for adjusting the angle of the drape of the catenary like curve in order to maintain the focus of the sun's rays on the linear target as the relative diurnal position of the sun to the collector changes. The optimum catenary like curve for the range of the drape angles involved is achieved by using a non-linear distribution of weight along the cross-section of the draped mirror material.

Abstract: A universal module serves as the basis for creating a plurality of different embodiments of electrical display stations. The universal module is adapted to be connected to remotely located process control instrumentation from which it may receive and to which it may transmit analog and digital signals. The different embodiments are created by connecting to the universal module a selected combination of components such as status indicators, switches and signal adjusting devices. The universal module includes a micro-processor system having a central processing unit, a clock circuit and a non-volatile type of program storage unit with an address provided for each different embodiment. An embodiment selector provides the interconnection between the components connected to an embodiment and the circuits of the universal module and activates the address for the embodiment.

Abstract: A method and apparatus for controlling the operation of a distillation column which utilizes cost factors to achieve the best economical production of a product within acceptable purity limits while maintaining the column at maximum operating capacity. The control is based on a series of priorities in which each of the following control signals is selectively used in turn to modify the control the heat-input to the column; cost factors applying to the column, cost factors applying to the several columns in the system, the purity of the product, the operating pressure limit of the column and, for lighter products, the rate of fluid velocity through the column. For heavier products, the rate of fluid velocity through the column is used independently of the heat-input control to restrict the flow of overhead product to the condenser to increase the back pressure on the column.

Abstract: A beehive heater for installation between the lower brood chamber and the bottom board of a standard beehive for protecting a colony during the winter with a minimum of winter brood production and for accelerating spring brood production. The beehive heater provides an insulating curtain of heated air adjacent to the walls of the brood chambers. Air enters a plenum chamber where it is heated by a low temperature heating element and flows out of the plenum chamber through a series of holes located adjacent to the periphery of the lower brood chamber to form the insulating curtain of heated air adjacent to the walls. A landing board and entrance is provided near the upper edge of the beehive heater as means for the bees to enter and leave the lower brood chamber. The temperature of the air in the plenum chamber is thermostatically controlled with the control point adjustable so that it may be set for winter or spring operation.

Abstract: A flame ionization detector adapted for use in hazardous areas and for mounting in any attitude, capable of using as small a flame as can be dependably maintained because of an arrangement of the flame at the open end of a thin-walled small diameter tubular electrode inside a relatively long open ended cylindrical collector and the regulation of the rates of flows which make it possible to maximize the sensitivity of the detector to the presence of an organic vapor. Excess air is maintained at a predetermined minimum. The inside diameter of the collector is made approximately twice the visible diameter of the widest point of the flame. A curtain of air flowing at a predetermined rate through the annular passage between the electrode and collector is directed into encompassing contact with the flame and the proximity of the collector to the flame maintains a relatively dense ion bearing layer of gases at the surface of the collector.

Abstract: A deviation meter, responding to a deviation signal, is mounted on a turntable which rotates in response to a set point adjustment. Rotation of the turntable maintains the null position of the deviation meter pointer at a scale position corresponding to a set point value, so that a direct readout of the actual measurement value is provided.