Abstract: A method and apparatus of regulating cycles of a burner in a forced air heating system. A control unit uses a sensor at an output of a heat exchanger to make measurements of a temperature of air output from the heat exchanger. The control unit observes temperature measurements, after the burner has turned on. It initializes a confirmation interval when two consecutive temperature measurements are the same. If the temperature is the same at an end of the confirmation interval. The invention interrupts firing of the burner for an interrupt interval. The interrupt interval is insufficient to allow the heat exchanger to cool below a temperature useful for heating below which the circulation fan would shut off.

Abstract: An apparatus for the controlled heating of a process fluid has a heater, a process fluid vessel containing the process fluid, and a bundle of thermosyphons extending between a burner chamber of the heater and the process fluid inside the vessel for transferring heat from the heater to the process fluid. Burners in the burner chamber are controlled to maintain the bulk temperature of the process fluid T.sub.BULK substantially within an operating range defined by preset upper T.sub.HIGH and lower T.sub.LOW temperature setpoints. The burners can be turned on to maintain an outside metal temperature T.sub.EVAP of the evaporator ends of the thermosyphons above a preset dew point temperature T.sub.DEW to prevent corrosion. The burners can also be shut down if an outside surface temperature T.sub.OD of at least one of the condenser ends of the thermosyphons extending into the vessel exceeds a predetermined setpoint temperature T.sub.ALARM.

Abstract: For determining the average radiation of a surface region of a burning bed, an infrared camera is used in a firing installation, which camera is aligned with this region and is equipped by means of appropriate flame filters in such a way that it operates at the minimum of the interfering radiation emanating from the flame, whereby this interfering radiation is already largely eliminated. In order then also to eliminate the solids radiation from moving particles and thus to obtain a temperature measurement of the burning bed, recordings are made successively at short intervals of time by means of the infrared camera and these are evaluated in the evaluation and control device.

Abstract: According to the method a relatively dry heated airflow is made to sweep around the product and the heat flow rate imparted to the airflow is controlled in dependence on the surface temperature of the product in the place where the product is expected to reach the highest temperature. The plant includes a heating assembly, a blower and means to provide a flow duct in which the products are piled with spaced relationship along part of said duct. A temperature sensor is disposed on an upstream surface of a product farthest upstream in the pile and a microprocessor receives signals from the temperature sensor and emits a control signal to the heating assembly.

Abstract: Information relating to combustion conditions within a fossil-fueled boiler that includes a plurality of burners adapted to produce flames combining to form a fireball is provided by acquiring data relating to the physical and temperature characteristics of the fireball with at least one imaging camera having optical and temperature measuring capabilities; receiving, storing and processing data received from the camera to provide data representative of the NO.sub.x content of the hot gases produced by the fireball; and transmitting the processed data from the processor to a monitor for display. Transmitted, processed data may include current, historical and target information relating to the physical appearance and temperature profile of the fireball.

Abstract: A temperature sensing system contains a plurality of thermocouple pairs which are connected to an interface. The interface contains a microprocessor and a memory and provides for fault tolerance within the system by comparing measurements from each thermocouple within a thermocouple pair to a predetermined threshold value. If the difference between the thermocouple readings is greater than the threshold value, a malfunction is identified and corrective action is taken. The system determines which thermocouple has malfunctioned by comparing the readings of each of the thermocouples to a projected value based on historical data contained in the memory. The thermocouple whose reading varies to the greatest degree from its associated projected value is identified as the malfunctioning thermocouple. The reading from the properly functioning thermocouple is then used to produce an output signal.

Abstract: Method of thawing deep-frozen packed products in which a relatively dry heated airflow sweeps around the product for a period of time, the duration of which is determined by the temperature measured in the middle of the product. The heat flow rate imparted to the airflow is controlled in dependence on the surface temperature of the product at the place where the product is expected to reach the highest temperature.

Abstract: An embodiment of the present invention is a temperature forcing system and method for precision temperature control of a device-under-test. The system comprises a thermal test head suspended by a support arm that receives a temperature controlled air flow through an output hose from an air supply system. A pair of temperature sensors, one attached to the device-under-test and the other in the output hose, are used differentially by a closed-loop temperature controller when the temperature of the device-under-test comes within a temperature window surrounding a target temperature setpoint point. Outside the temperature window control is linear and within the temperature window control is compensated by a correction factor obtained during a single calibration test that amalgamates the effects of the mass of the device-under-test, the ambient conditions and other factors.

Abstract: A thermal reactor, and a method of operating the thermal reactor, in which the thermal reactor includes: a chamber which is thermally isolated by refrigerated air circulating in the walls of the chamber, and which holds a tray of sample vials; means for supplying air to the chamber and for exhausting air from the chamber; heaters for heating the air supplied to the chamber; sensors for sensing the temperature of the air supplied to the chamber and of the sample vials, and a computer which pulses the heaters according to the measured temperatures of the vials and the air in the chamber to maintain the temperature of the vials at a desired level.

Abstract: Temperature controlling means for a thermostat for use in viscosity measurement including: a first thermometer detecting the temperature of a fluid sample which is immersed in a thermostat and whose viscosity is measured; a first controller obtaining the difference between a desired set point and the detected value of the sample temperature, momently calculating a set point of temperature of the thermostat according to an operation formula expresed as a function of the above temperature difference and making a controlled signal corresponding to the calculated set point; a second thermometer detecting the temperature of the thermostat; a heating and cooling device for heating and cooling a medium bath of the thermostat; and a second controller making a controlled signal for operating the heating and cooling device under a PID control formed on the basis of the difference between the calculated set point and the detected value of the thermostat temperature and inputting the PID controlled signal into the heatin

Abstract: A control apparatus for controlling the temperature of an environmental chamber within which a device is tested for thermal characteristics employs a pair of control elements connected in cascade. The first element produces a required air temperature in response to a desired temperature and to the temperature of the device; the second produces a temperature set point in response to the required and actual air temperatures. Possible stress on the device is avoided by limiting the range of required air temperature. Response is accelerated by a pass-through circuit, parallel to the first element, which responds to a change in the desired temperature by adding to the required air temperature of value proportional to the change.

Abstract: A computerized method of digitally controlling the temperature profile of a heated article in which the temperature profile is defined by a plurality of temperature zones spaced about the article. The temperature profile of the article is monitored and a heating cycle requirement of the temperature zones of the profile is computed. A train of minute increments of power is supplied to heat each respective zone in accordance with the computed heating cycle requirements to achieve a precision approximately between .+-.0.1.degree. and .+-.0.5.degree. C. in a temperature range of approximately 400.degree. C. to 1,350.degree. C.

Abstract: A temperature controlled probe assembly (58) for measuring log temperatures in a furnace (10) for heating metal logs (20) includes a carriage (88) selectively movable by a pneumatically controlled air cylinder (64). The carriage (88) includes a barrel (92) having an air chamber (102), a pair of thermocouple probe rods (40, 42) extending through the barrel (92), and cooling air channels (126) opening into the air chamber (102) for supplying air to cool the probes (40, 42). Another thermocouple (94) measures the temperature of the environment surrounding the thermocouple probe rods (40, 42) and a cooling air regulator (160) is selectively actuated when the temperature of the probe environment is greater than a predetermined temperature. The regulator (160) varies the amount of cooling air supplied to the probe rods (40, 42) in accordance with the amount of combustion air being used by the furnace (10).

Abstract: An electric range having a self-cleaning oven utilizes a digital electronic microprocessor based oven temperature control system having multiple, redundant oven temperature sensing elements. The output signal from a first one of the multiple oven temperature sensing elements disposed in the cavity of the oven is used as a primary sensed bake temperature signal for controlling the temperature of the oven during its BAKE mode of operation and as a redundant or back-up sensed clean temperature signal for safely shutting down the oven during its CLEAN mode of operation in the event that the sensed oven temperature significantly exceeds the top of the clean temperature range.

Abstract: A temperature control system (50) for use in a furnace (10) for heating metal logs (13) as the logs (13) move through a furnace heating chamber (12) includes thermocouples (52a-52e) adapted to sense log temperatures by direct contact during intermittent time intervals when the logs (13) are stationary. Radiation sensors (64a-64 e) continuously sense radiant energy emitted from the logs (13) and a temperature compensation circuit (62) compares signals representative of log temperatures as measured by thermocouples (52a-52e) and the radition sensors (64a-64e). The difference between the signals is utilized during time intervals when the logs (13) are moving as a compensation factor for the continuous signals representative of log temperatures based on sensed radiation. The compensated signals and signals representative of desired set point temperatures are applied to log temperature controllers (80a-80e) to regulate the thermal energy applied to the logs (13).

Abstract: In heating control method of a heat furnace, three non-linear models, model to calculate furnace temperature based on the fuel flow rate by unsteady heat balance system, model to estimate furnace wall temperature distribution based on the furnace temperature and model to estimate material temperature based on the furnace temperature, are used, linearization is performed by perturbation simulation to vary the flow rate stepwise and the optimization to minimize the fuel flow rate is performed and the optimum furnace temperature per each material is determined, and the mixed combustion ratio of plural fuels obtained by dividing total calorific value of each fuel by total calorific value of all fuels and the furnace temperature setting value are calculated using the optimum furnace temperature per material and then set.

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: In controlling furnace temperature, a desired temperature profile of a slab in a direction along its movement through a furnace is calculated by using an expression for total fuel flow as a function of slab temperature and minimizing the total fuel flow. The present slab temperature is calculated by using the distribution of present gas temperatures in the furnace. The heating of the furnace is adjusted based on the temperature difference between the present slab temperature and a desired temperature.

Abstract: In a low NO.sub.x emission incinerator a refuse supply stoker (1), a dry-ignition stoker (2), a gas generation stoker (3), and a complete combustion stoker (4) are positioned in descending stair-step fashion beneath a combustion chamber (A). In the dry ignition stoker (2) and the gas generation stoker (3) refuse is thermally decomposed under an amount of air which is less than the amount of air theoretically required for complete combustion, so that reducing gases such as CO, NH.sub.3, and the like are generated. At the complete combustion stoker (4) the residuum of the refuse is completely combusted under an amount of air greater than the required theoretical amount. Air is supplied through nozzles (7,8,9) at successive points above the flow route of combustion gas inside the combustion chamber (A) so that the temperature in the combustion chamber (A) is maintained in a range to reduce the amount of NO.sub.x generated by the combustion of gases.

Abstract: This disclosure relates to apparatus of the kind suitable for taking spot measurements of the heat loss or stack loss and/or efficiency (.eta.) in flue gases (stack loss) and comprises respective sensors (5, 3) for producing output signals which vary with the temperature and the concentration of a constituent gas e.g. O.sub.2 of the flue gases and microprocessor-based computation means (10) arranged to derive measurement values of (and numerically equal to) the measured temperature and constituent gas concentration, from the two sensors and to apply these measurement values in the computation of a predetermined formula relating the stack loss or efficiency to the measured quantities. In accordance with the invention, the apparatus is arranged to automatically calibrate each sensor signal from a test measurement prior to deriving the measurement values.

Abstract: The temperature of an open textile web is monitored by a sensing unit including an infrared pyrometer. The pyrometer is disposed at a viewing angle between about 5.degree.-25.degree. with respect to the horizontal. A housing mounts the pyrometer, a fan, a filter bag connection, and an exhaust tube. The exhaust tube extends through the wall of a textile-treating oven, with an air flow through the tube preventing pyrometer contamination.

Abstract: A ceramic encased thermocouple placed within a kiln electrically controls an array of signal classifiers which, in turn, control the operation of the kiln heating elements. The temperature value at which the classifier array terminates the whole kiln heating operation is preselected as one of a plurality of discrete predetermined values corresponding to pyrometric cone temperature values.

Abstract: The process for freezing cell suspensions by locating the suspension in a freezing chamber and simultaneously monitoring the temperature of the suspended cells and of the chamber. The cooling of the chamber is regulated at predetermined rates in response to given temperature levels of the sample. The cooling chamber includes a fan, a heater, and a source of refrigerant. The process includes the steps of selectively decreasing and increasing the temperature of the freezing chamber responsive to predetermined temperature points on the freezing curve of the cell sample.

Abstract: An electronically controlled space heater includes a ceramic block heating element fed by a metering pump with fixed volume charges of liquid fuel at a rate dependent on temperature requirements. The heating element is located within a combustion chamber. Exhaust gases vented from the combustion chamber are applied directly to a thermocouple whose voltage output is utilized to vary or maintain the frequency of a pulse circuit driving the metering pump. An operator-adjustable potentiometer functions as a thermostat to establish a desired temperature reference value to which the thermocouple output is continuously compared. Start-up and shutdown circuitry precludes the development of unsafe operating conditions.

Abstract: A temperature control circuit particularly for use with a graphite tube atomizer of an atomic absorption spectrometer provides rapid temperature rise and a leveling at a constant predetermined temperature. A.C. power applied through a transformer to electrodes on the ends of the graphite tube rapidly heats the tube and the visible radiation thus produced is measured by a photocell, the output of which is amplified to control a relay in the graphite tube power circuit. When the desired tube temperature is approached, the photocell output actuates the relay so that the tube power circuit will switch from the high voltage rapid heating mode to a controlled lower voltage that will automatically maintain the constant predetermined tube temperature.

Abstract: A high frequency energy apparatus is provided in which high frequency energy is supplied into a heating chamber containing an object to be heated for heating the same. A temperature sensor unit senses either the temperature of air within the heating chamber or the temperature of air flowing out of the heating chamber and a memory unit memorizes a sensed air temperature. When a difference between the air temperature sensed and the memorized temperature reaches a preset value, the amount of supply of the high frequency energy is varied. The preset value is varied with the heating time for heating the object more properly.

Abstract: An electronic circuit has been devised for precisely controlling the temperature of one zone in response to a change in temperature in another zone. Two sensors, one in each zone, are wired in opposing polarity so as to emit a signal when a temperature imbalance occurs. The circuit is designed to actuate a temperature controller in response to the signal. One application for the device is the establishment of adiabatic conditions for a reaction by controlling the temperature of the zone surrounding the reaction vessel to coincide with that within the vessel.