Abstract: A condenser-evaporator is constituted in such a way that first fluid chambers and second fluid chambers are alternately formed by multiple vertical partitions and a liquid in the first fluid chambers exchange heat with a fluid in the second fluid chambers, characterized in that a plurality of heat exchanger plates are arranged in multiple stages in the first fluid chambers to form a liquid passage having one end open, a plurality of liquid reservoirs communicating with the liquid passage and having a top open are provided in multiple stages on a side of the other end of the liquid passage, and a liquid is introduced in the liquid passage for heat exchange while being supplied to the liquid reservoir in each stage. Accordingly, the depth of the liquid is shallow so as to prevent a boiling point elevation due to the liquid head pressure, thus improving the efficiency of the condenser-evaporator.

Abstract: A radiator for the cooling system of a vehicle, and having a header tank and a bottom tank interconnected by a core through which air can flow, the header tank being provided with a filler tube fitted with a double seal filler cap through which coolant can flow in opposing directions, depending on the conditions pertaining at a given instant in the header tank, is disclosed wherein the header tank is formed integrally with a coolant recovery tank. The coolant recovery tank is connected to the header tank by a passageway extending from the coolant recovery tank to a point in the filler tube of the header tank which is normally on the unpressurized side of the filler cap, but which is connected to the pressurized side of the filler cap when the predetermined coolant pressure set by the pressure relief valve in the filler cap is exceeded.

Abstract: A calculator apparatus 10 includes the standard calculator mode and several other modes functions namely; a pressure-temperature conversion, a temperature-to-pressure conversion based on refrigerant, a relative humidity reading based on input of the dry bulb and wet bulb temperature; and a flow-energy rate conversion mode based upon a selected fuel meter dial and Metric or English units. In addition, a Fahrenheit-to-centigrade conversion and a centigrade-to-Fahrenheit conversion functions are incorporated. The calculator includes a keyboard 18, a microprocessor 16, a timer 26, a power source 12, a switch 14 and a display screen 22.

Abstract: A heat treating device used in chemical and food industries, including a heat exchanger of jacket type, for example, which surrounds a reaction vessel, wherein heat media such as steam and water are fed to the heat exchanger and also sucked by sucking means such as an ejector to put the interior of the heat exchanger in a reduced pressure state, thereby effecting heat treatment at relatively low temperature below 100.degree. C., for example, the improvement of which is to prevent variation of the reduced pressure level in the heat exchanger for keeping stability of treating temperature.

Abstract: An apparatus is disclosed for heating or cooling food articles including a chamber containing a plurality of tubular, vertically, spaced-apart support means having a fluid inlet and outlet. A plurality of removably mounted hollow plates each having a plurality of spaced-apart tubular members having a fluid sealed therein connected to first and second plenums are positioned on the support means. Supply and return header means are connected to the inlet and outlet, respectively, of the support means and by conduit to a fluid reservoir and pump to circulate a fluid transfer means through each support means. Means for heating and cooling the fluid is also provided and control means for controlling operation of the heating and cooling means individually or in a predetermined sequence and at a preselected temperature is also included. During the heating mode the fluid inside the removable plates vaporizes and condenses.

Abstract: A parameter estimation system (16) automatically determines the relevant thermal and thermodynamic parameters which govern the energy consumption of the climate control system (18) within an enclosure (30).

Abstract: A device to freeze free-flowing and pourable substances in a bath consists of a bath for a low-boiling liquified gas located inside an insulated housing having openings for the introduction of the substances to be frozen and the gas as well as for the removal of the frozen substances. The bath is located in a rotatable hollow cylinder having a rotational axis tilted with respect to the horizontal plane. The inner wall of the cylinder has a ribbon screw above whose lowest point there is a feed mechanism for the substances to be frozen.

Abstract: Imitation thermostat which in its most elaborate form includes a thermostat face with temperature indication and setting indicator, a following device to have the temperature indicator gradually respond to a change in setting but not electrical or mechanical means to interconnect to a heating/cooling system.

Abstract: A fluid sensor for heat exchanger system includes a supporting device such as a tubular hose fitting for mounting the sensor in the system so that heat exchanging fluid circulated in the system comes into contact with the sensor. A window or sight glass is mounted in the supporting device along with corrodible separating means interposed between the sight glass and the heat exchanging fluid. A visual indicator such as a movable flap or a colored ball can be viewed through the sight glass when the separating means is ruptured or broken by corrosion. The viewing of the indicator provides an indication that the heat exchanging fluid has reached a certain corrosive state and requires replacement or treatment. In a preferred embodiment, the separating means is a metal diaphragm spaced from the sight glass.

Abstract: An apparatus for separating a resin phase from a solvent solution containing a solvent, demetallized oil and a resin. The apparatus has a vertically-positioned heat-exchange surface having an upper portion which is heated by circulating a heat-exchange fluid and a lower portion which is heated by conduction of heat from the upper portion.

Abstract: A method for thermal storage using an apparatus including an outdoor temperature sensor and at least one indoor zone temperature sensor, includes the steps of: estimating an average on-peak outdoor temperature for tomorrow by adding the average on-peak outdoor temperature for today to the current outdoor temperature minus the outdoor temperature at the same time yesterday; estimating the temperature difference in each zone between the outside on-peak temperature and the indoor on-peak temperature for that zone for tomorrow by subtracting the estimated average on-peak outdoor temperature for tomorrow from the average set point temperature in the respective zone for today; calculating the thermal charge by multiplying yesterday's actual off-peak charge by the estimated temperature difference in each zone divided by the average actual temperature in each zone for today's on-peak period; and charging the thermal storage system.

Abstract: The vapor pump constituted by a mass and heat exchanger comprises an outer enclosure, a set of exchanger tubes disposed inside the enclosure and extending lengthwise therein, opening out at one of the ends in a first radial plane and at their other ends in a second radial plane, which radial planes include means for positioning and supporting the tubes and for closing the empty spaces in the section of the enclosure situated outside the tubes, thereby defining between said radial planes both a first gaseous fluid flow circuit inside the tubes, and a distinct counterflow second fluid flow circuit inside the enclosure but outside the tubes. One of the first and second gaseous fluids constituted by moist hot combustion products from a thermal process while the other gaseous fluid is constituted by new combustion air. Humidifier means are provided for humidifying the air inserted into the enclosure.

Abstract: In combination with a steam generator having a plurality of generator tube support plates, each generator tube support plate having a plurality of openings and a plurality of generator tubes, each tube passing through aligned openings in the support plates, a corrosion monitoring system is provided including a mockup probe, comprising a probe tube support plate having an upper side and a lower side and having substantially the same thickness and being constructed of substantially the same material as the generator tube support plates, having at least one opening of substantially the same size and shape as the openings of the generator tube support plates; at least one probe tube having an upper end and a lower end and having substantially the same diameter as the generator tubes and being constructed of substantially the same material as the generator tubes, the probe tube passing through the opening of the probe tube support plate; and wherein the mockup probe is adapted such that it may be inserted and seal

Abstract: The invention concerns a method for measuring the cleaning effectiveness of cleaning bodies (20) on heat exchangers having a bunch of tubes (16). Further, a plant is proposed in which the heat transfer from steam into cooling water through the walls of the condenser tubes is measured. The measurement is carried out with the aid of an inertialess temperature sensor (15) so that, by highly sensitive measuring of the temperature sequence of a certain control volume, the cleaning effect of the cleaning bodies can be derived.

Abstract: A monitor for measuring heat transfer resistance comprising a housing and one or more test block assemblies, each test block assembly includes a movable test block enclosed on two sides by parallel side supports and attached by a spring to a spring support. Each test block assembly is attached to the housing. The spring urges the movable test block away from the spring support. Additionally, the movable test block will contain a heater, a thermometer, or both the heater and a thermometer.

Abstract: A cooling abnormality detection system for external electronic equipment includes a protection unit, a flowmeter, a water level gauge, a pump operation detector, an abnormal temperature sensor. The flowmeter detects a decrease in flow rate of the liquid coolant supplied from the electronic equipment. The water level gauge is arranged in the coolant tank to detect a decrease in water level of the liquid coolant. The pump operation detector is arranged in a pump to detect an operation of the pump. The abnormal temperature sensor detects an abnormal temperature of the electronic equipment. The protection unit discriminates a cooling abnormality when an abnormal temperature is detected by the temperature sensor during the operation of the pump and discriminates a cooling abnormality when an abnormality is detected by any one of the flow meter, the warer level gauge, and the abnormal temperature sensor during operation of the pump.

Abstract: A heat-exchange apparatus for separating a resin phase from a solvent solution containing a solvent, demetallized oil and resin which comprises: (a) at least one generally vertically positioned heat-exchange surface; (b) a means for directing the flow of the solvent solution in a downward direction over a portion of the heat-exchange surface thereby heating the solvent solution to precipitate a resin phase; (c) an outlet means to recover a solvent solution having a reduced concentration of resin which outlet means is located to essentially reverse the flow of the solvent solution having a reduced concentration of resin to a generally upward direction before exiting the heat-exchange apparatus; and (d) an outlet means to recover the resin phase from a lower portion of the heat-exchange apparatus.

Abstract: A method for detecting changes in the rate of heat transfer through a tube wall due to the deposition or removal of deposits formed thereon. The method involves obtaining a segment of tubing, placing a highly conductive material in contact with one of the inner surface and outer surface of the tubing wall, contacting the other of the inner and outer surface of the tubing wall with a heating or cooling medium, and measuring the time required for the temperature of the thermally conductive material to change between two predetermined temperature measurement points. Subsequently, the wall of the tubing segment is cleaned or the tubing segment is replaced with a different tubing segment, and the rate of temperature change of the tube walls is tested again in a similar manner. By comparing the times measured in the first and second trials, the difference in the rate of heat transfer before and after cleaning of the tubing segment can be determined.

Abstract: The inner-surfaces of heat exchanger tubing is cleansed with a sulfamic acid aqueous mixture and then subjected to a purplish-colored aqueous solution of potassium permangenate adapted to seep through to and become visually discernible at the heat exchanger tubing outer-surface to thusly visually indicate breach-faulted heat exchanger tubing. Any thusly inspected non-breach heat exchanger is purged with an oxalic acid aqueous solution and retained as acceptable for future re-use. The breach detecting method is generally applicable to all heat exchangers of the heat-conductive metallic tubing type, and, inter alia, specificaly applicable to dairy plate heat exchangers having metallic tubings.

Abstract: In this air-conditioner, combustion test of a refrigerant heater is conducted through a control valve on the basis of a minimum combustion command signal and a maximum combustion command signal set in advance at a plurality of stages to store values of the minimum combustion command signal and the maximum combustion command signal presenting an optimum combustion state from the above-mentioned command signals, whereby in an actual operation, control of the control valve is carried out by using stored values with respect to the minimum combustion command signal and the maximum combustion command signal.

Abstract: A barometric direct-contact steam condenser (10) in which a stream of vapor and formed condensate contacts a free surface of the condensate, which surface is preferentially removed, preferably continuously, so as to provide a cooler surface against which and/or as a result of which more vapor can condense.

Abstract: Rooms in a building each have a heating, ventilating and air conditioning system (HVAC), a room control unit having a temperature controller, and various sensors. The control unit monitors the presence of persons in the room, determines the season, sets back the temperature in an empty room by a variable amount which the HVAC can restore in a given time, and restores the temperature to the previous user request when the user returns but to a standard temperature if the user has newly checked in. An outside hallway panel briefly displays, when interrogated by a maid, a person's presence. By monitoring maid requests, door status and maid activity, the unit indicates on a room map whether the room is being cleaned, clean, or ready to rent. By establishing the heat loss/gain (lg) factor of a room with the HVAC off and comparing it with the time to heat or cool the room, HVAC failures are determined. By comparing a room's lg factor with those of its neighbors, room environment failures are determined.

Abstract: An interactive electronic thermostat operates to communicate with an installer through an audible or visual display and keypad to instruct the installer to perform tasks and enter observations to effect proper connections at the thermostat of heater/air conditioner wires in spite of the absence of labels identifying the functions of those wires. The thermostat requires entry of coded indicia representing operator-observed conditions in the system in response to displayed instructions carried out by the operator. Control circuits are automatically assigned functional tasks in response to the operator-observed conditions entered into the system. Different program routines are invoked depending upon the number of system wires and the type of heater/air conditioner being controlled. Under appropriate circumstances, messages are displayed informing the operator/homeowner that the thermostat is incompatible, or has no advantageous use, with the heater/air conditioner.

Abstract: A passive type of filter apparatus for an automotive type cooling system utilizes a conventional gasoline fuel filter for filtering a portion of the liquid coolant moving through the system. Pickup and return conduits are positioned within the coolant flow circuit, and part of the coolant flow is diverted through the pickup conduit so as to pass through the fuel filter. After the coolant has passed through the fuel filter, it is returned to the coolant system through the return conduit. Two different types of sight glasses can be employed in the system to allow a viewing of the coolant flow and to also provide an indication of when the coolant is no longer acceptably clean.

Abstract: An air liquefier and separator of air constituents for a liquid air engine. Its unique structure captures the ambient air and guides it through guide vanes into a bank of spiral tubes or channels where the air is completely contained while being liquified and separated into its constituents. The spiral tubes or channels provide a compact heat exchanger design with long tube length or channel length for efficient heat transfer and liquefying of the air which is accomplished by a flow of liquid hydrogen flowing either inside a concentric tube inside the air condensing tube or flowing in a tube or channel with a common wall in contact with the air condensing tube or channel. The liquefier can easily be designed to be an integral part of a liquid air jet engine installation.

Abstract: A jet condenser of the type comprising a water chamber in a mixing chamber (24) and an after-cooler (52), wherein the water chamber is subdivided in a narrower upper water chamber portion (38a) and a broader lower water chamber portion (39b). The after-cooler (52) is fixed at the junction (66) of both water chamber portions (38a, 38b). Cooling water is injected into the mixing chamber (24) by nozzles (40) of the upper water chamber portion (38a) where it flows in vertical direction. By the reduced width of the upper water chamber portion (38a) flow resistance of steam flow in the mixing chamber (24) and, thereby, undesired subcooling is substantially diminished. (FIG. 3).

Abstract: A single bimetal automatic changeover thermostat has heating, cooling and changeover switches mounted to the bimetal. A single control point adjustment lever for rotating the bimetal has separate shaped heat and cool set point indicators which are movable along a temperature scale.

Abstract: A stack type evaporator according to the invention comprises a plurality of plate-shaped tubular elements stacked in a direction of their width with a fin member interposed between two of such tubular elements which have inlet header portions at their ends and outlet header portions at their further ends so that coolant can flow straight within said tubular elements, a pair of dish-shaped core plates which constitute each tubular element having inner surfaces provided with ribs arranged at regular intervals in a direction of coolant flow, wherein an end surface of each rib protruding from one core plate is alternately bonded to a flat body of the other core plate whereby the coolant paths within each tubular element are formed parallel with each other and straight from the inlet header portion toward the outlet header portion.

Abstract: A machining fluid temperature deviation alarm device is attached to an electrical discharge machining device which, having a temperature sensor (S1) for machining fluid temperature detection and a cooler (2) for machining fluid cooling, controls the cooler in response to a temperature sensor output signal, thereby controlling the machining fluid temperature within an allowable range. The alarm device employs a second temperature sensor (S2) for determining whether the machining fluid temperature is within a predetermined temperature range set by means of a second setter (5) and encompassing the allowable machining fluid temperature range.

Abstract: A method and apparatus for heat and mass transfer is described that is applicable to: regeneration of liquid desiccant solutions, heat pumping of humid gases, cooling and dehumidifying of gases for air conditioning, and water absorption from air. Generally, using a moving gas, at a constant pressure, a continual change in a vapor-liquid equilibrium is created between proximate but continually changing gas and liquid desiccant temperatures within an energy transferring chamber. Chamber wetting, implemented segmentedly, allows mass transfer into and from the moving gas. A forced temperature differential between heat sinks and sources causes heat transferred by means of thermally conductive barriers. Concurrent with temperature variances, the segmented wetting further allows liquid desiccant concentrations caused by evaporation or condensation, to vary between wetted sectors.

Abstract: A nuclear energy plant housing a boiling-water reactor utilizes an isolation condenser in which a single chamber is partitioned into a distributor plenum and a collector plenum. Steam accumulates in the distributor plenum and is conveyed to the collector plenum through an annular manifold that includes tubes extending through a condenser pool. The tubes provide for a transfer of heat from the steam, forming a condensate. The chamber has a disk-shaped base, a cylindrical sidewall, and a semispherical top. This geometry results in a compact design that exhibits significant performance and cost advantages over prior designs.

Abstract: A heat exchanger in the form of a vessel for heat exchange of a pulverulent solid material and a gas, e.g.

Abstract: A fluid sensor for heat exchanger system includes a supporting device such as a tubular hose fitting for mounting the sensor in the system so that heat exchanging fluid circulated in the system comes into contact with the sensor. A window or sight glass is mounted in the supporting device along with corrodible separating means interposed between the sight glass and the heat exchanging fluid. A visual indicator such as a movable flap or a colored ball can be viewed through the sight glass when the separating means is ruptured or broken by corrosion. The viewing of the indicator provides an indication that the heat exchanging fluid has reached a certain corrosive state and requires replacement or treatment. In a preferred embodiment, the separating means is a metal diaphragm spaced from the sight glass.

Abstract: A supervisory control unit for lighting, heating and air conditioning equipment containing an occupancy sensor, a temperature limit detector, an entry delay detector and incorporating time cycle operation intended to limit the use of said equipment for the purposes of energy conservation.The unit outputs low voltage control signals that by means of external switching devices makes or interrupts the power and/or control signals normally connected to the lighting, heating and air conditioning equipment, thereby limiting the use of said equipment unless certain criteria are met.

Abstract: A process for the containment and recycle of organic vapors from an open container or tank that utilizes a chilled gas blanket over the surface of the organic liquid, with a continuous recirculaton of the chilled gas through a condenser heat exchanger for cooling the gas flow and condensing and returning the condensed vapor to the tank or container. Included are the means of distribution of the recirculated chilled gas, the means of collecting the recirculated chilled gas, the means of providing an enclosed chilled gas recirculation system, the apparatus for condensing the vapor to liquid, the apparatus for collecting and recycling the condensed vapor, the apparatus for providing a full open access to the top of the tank or container and the apparatus for control of the flow of the recirculated chilled gas.

Abstract: An air conditioning apparatus in which one outdoor unit is connected to several indoor units through respective refrigerant tubes and signal conductors. The outdoor unit has compressors for discharging refrigerant and an outdoor heat exchanger. Each outdoor unit has an indoor heat exchanger and an indoor heat exchanger temperature sensor. When an operating device signals a check node, the compressors are stopped for a predetermined time period. Then the compressors are operated to sequentially discharge refrigerant to each indoor unit. A checking device then monitors the signal conductors of each indoor unit for a signal indicating a certain temperature condition. Based on the signals received, the checking device determines whether the indoor units are properly connected to the outdoor unit.

Abstract: A method and apparatus for heat and mass transfer are described using a moving gas, such as air at a constant and atmospheric pressure, to provide a continual change in a vapor-liquid equilibrium between proximate but continually changing gas and liquid temperatures within energy transferring chambers. Chamber wetting, implemented segmentedly, allows mass transfer into and from a first substance in a first chamber and a second substance in a second chamber. A forced temperature differential in each chamber causes heat transfer between chambers by means of thermally conductive petitions and by means of a heat exchanger. The heat exchanger provides for heat transfer between the first and the second substances of corresponding sectors of the first and second chambers. This heat transfer can allow condensation causing further evaporation in the corresponding chamber sector resulting in recycling of energy.

Abstract: A system for cooling flue gases from a fossil fuel boiler plant, and removing pollutants from the flue gas, is disclosed. In a first section of the apparatus, heat exchange cools the flue gas to just above the condensation point of water, and condensed H.sub.2 SO.sub.4 is collected. In a second section, the gas is cooled further and an acid-containing condensate is collected.

Abstract: A freeze-thaw air dryer utilizes a heat pump to remove moisture from air by cooling the air to below the freezing point of water, causing the water to pass directly from the vapor state to the solid state and thereby to be removed from the flow of air. The vapor frozen on the cold surfaces is periodically thawed by either turning off or reversing the heat pump, and the condensate and thawed ice are automatically drained out of the device without interruption of the airflow. The geometry of the cold surfaces and the generally centripetal airflow path are designed expressly to cause a buildup of ice without impairing efficiency or blocking the airflow.

Abstract: Condenser fluid comprising vaporized working fluid and non-condensable gases is treated by extracting fluid from the condenser and pressuring the fluid to liquefy the vaporized working fluid therein in such a way that the noncondensable gases are separated from the working fluid and can be vented from the extracted fluid.

Abstract: For multi-cell, mechanical draft, vacuum steam condensers, a design of a noncondensible gas removal system that isolates bundles and fan cells from external/internal influences and gas/vapor interchange and allows bundles to operate in a reverse air-flow direction, all of which promotes freeze protection and improved performance.

Abstract: Apparatus for purging non-condensable gases from a condenser containing vaporized, condensable working fluid, includes an enclosed chamber located above the condenser, a movable diaphragm in the chamber for dividing the latter into upper and lower portions, two flow control valves serially connected together and located between the condenser and the lower portion of the chamber, and a venting valve connected to the lower portion. Each of the valves are selectively operable and have an open and a closed state. A mechanism is provided for moving the diaphragm for changing the volume of the lower portion; and a mechanism is provided for synchronizing the states of the valves with changes in the volume of the lower portion.

Abstract: A multi-flow tubular heat exchanger is enclosed. The heat exchanger includes a shell that encloses one or more cooling stream tubes, one or more heating stream tubes, and a heat transfer fluid.

Abstract: Paper pulp mill chemical recovery boiler steam piping is monitored for leaks by an acoustic leak detection system responsive to atmospherically carried sound transmissions. Energy level amplitudes of respective analog electrical signals generated sequence multiplicity of microphones are converted in a rapid time sequence to a first electric pulse signal sequence representative of corresponding digital values. Such digital values are temporarily stored in a data memory bank to be subsequently processed by a Fast-Fourier Transform spectral analysis into a second electrical pulse signal sequence representative of corresponding digital values in the amplitude vs. frequency domain. Such amplitude vs. frequency signal values respective to each microphone are further refined for comparison to historical threshold data for a probability determination of a leak status.

Abstract: A direct contact condensing heat-exchanger is provided with a water heat transfer medium in which combustion product gases are dispersed in finely divided bubble form against a relatively low hydrostatic pressure differential for efficient sensible heat and latent heat recovery purposes. In one actual application, a warm-air furnace system having a burner that produces combustion product gases as a heat source is provided with the novel direct contact condensing heat-exchanger as a seondary heat-exchanger that advantageously recovers both sensible heat and latent heat from the combustion product gases.

Abstract: The present invention provides for a self-programming temperature control system for automatically adjusting the temperature control setpoint of a heating and cooling system of a space in accordance with the present or anticipated occupancy status of the space.

Abstract: A liquid cooling apparatus includes a heat exchanger, a tank, leakage sensors, first and second level sensors, a timer counter, and a control section. The heat exchanger cools a coolant to be supplied to a heat generating portion in an electronic device. The tank temporarily stores the coolant cooled by the heat exchanger before the coolant is supplied to the electronic device. The leakage sensors detect leakage of the coolant in a circulation path for repeatedly performing cooling and heat absorbing operations. The first and second level sensors detect a decrease in amount of the coolant in the tank. The timer counter counts a time interval between the instant at which a leakage detection output is output from one of the leakage sensors and the instant at which a coolant decrease detection output is output from one of the first and second level sensors. The control section stops an operation of the electronic device when a value of the timer counter is a predetermined value or less.

Abstract: A condenser in which the condenser tubes can be accessed for endoscopic examination in situ, without taking any part of the condenser off-line (except the specific tube being examined). The condenser's outlet water box has one or more inspection ports in its endwall, and a hollow rigid probe can be inserted through the outlet water box to dock with the end of a tube in the condenser. A flexible endoscopic probe can then be inserted through the rigid probe, to inspect the interior of the tube thus accessed. The rigid probe can also be used to isolate the flow of a single tube, if desired.

Abstract: A method and apparatus for measuring and monitoring critical parameters of a chiller, such as the chiller efficiency. Specifically, temperature and pressure sensors are disposed in the inlet and outlet lines of a condenser and chiller unit. A sensor is also placed on the compressor motor for determining the amount of power being expended by the motor. The actual flow rate of the chilled water entering and leaving the chiller unit is calculated based upon the sensor inputs. The actual kilowatts per unit ton rating for the evaporator is determined. The design kilowatts per unit ton rating for the evaporator is corrected to take into account any variation between the actual motor voltage and design motor voltage, and the total temperature deviation. The chiller efficiency is then calculated based on these two kilowatt per ton ratings.

Abstract: A robot arm apparatus is provided for inspecting and/or maintaining an interior of a steam generator which has an outside wall and a port for accessing the interior of the steam generator. The robot arm apparatus includes a flexible movable conduit for conveying inspection and/or maintenance apparatus from outside the steam generator to the interior of the steam generator. The flexible conduit has a terminal working end which is translated into and around the interior of the steam generator. Three motors located outside the steam generator are employed for moving the terminal working end inside the steam generator in "x", "y", and "z" directions, respectively. Commonly conducted inspection and maintenance operations include visual inspection for damaged areas, water jet lancing for cleaning sludge deposits, core boring for obtaining sludge deposits, and scrubbing of internal parts.