Abstract: A building aperture frame system including a window mounting surface and an integrally-formed storm shutter mounting structure. The frame system includes of first and second elongated profiled jambs, an elongated profiled header mounted to and traversing a distance between an upper portion of each of the first and second jambs, and an elongated profiled sill mounted to and traversing a distance between a bottom portion of each of the profiled jambs. Each of the profiled jambs, header and sill have a width sufficient to traverse at least a portion of a distance between an interior and an exterior surface of a building wall defining a building aperture. Alternatively, the building aperture frame system may be comprised of first and second profiled jambs capable of extending vertically along first and second vertical side walls of a building aperture. Each of the profiled jambs is capable of extending along a horizontal distance of at least a portion of the vertical side walls.

Abstract: A prefabricated lintel having two spaced apart parallel upstanding legs extending along the length of the lintel and having laterally aligned holes defined therethrough and spaced therealong. The lintel further has a flat lower surface and an upper surface defining flat, horizontal shoulders positioned along outer edges of the lintel on opposite sides of the upstanding legs and extending the length of the lintel. The lintel is placed to span a doorway and a course of blocks is laid on the flat shoulders, with a second course laid on the first course and a rebar positioned on the upper surface. A plurality of wire stirrups, each defining a rebar receiving loop, are engaged over the rebar and extend through openings in the two courses with end portions of the stirrups engaged in each of the holes defined in the upstanding legs of the lintel. The block openings are filled with grout.

Abstract: A window fabrication with plant-on is disclosed for simulating different building architectures. The apparatus includes at least one sash, a pair of glazings, a frame and at least one plant-on. The plant-on can be either a factory plant-on which is applied to the window fabrication before final installation or a field plant-on which is applied to the window fabrication substantially concurrent with final installation.

Abstract: A facade for a dormer window having side trim members and a pediment of molded plastic duplicating the appearance and texture of expensive wood millwork. The plastic is molded around boards having exposed rear faces. The boards give the structural strength of wood millwork to the trim and pediments and provide means for securely fixing by fasteners, such as screws the molded plastic members to a metallic skeleton frame defining an opening for pre-existing window frames.

Abstract: A building construction of longitudinal and cross hollow components includes building unit bodies each of which consists of joggles, scarfs, extension paths and wiring holes, such that, after a plurality of such unit bodies are formed into a wall, it forms transverse penetrating wiring paths with a gradient and longitudinal paths to assure convenient wiring construction. It also has the advantages of fire-proofing, heat discharging, and prolongation of rescue time when the building is on fire.

Abstract: Interlocking concrete form modules (21) suitable for creating a concrete wall form is disclosed. The modules (21) have the general shape of a right rectangular parallelepiped with parallel side walls (23a, 23b) joined by integral webs (25a, 25b, 27a, 27b, 27c) that define a plurality of parallel elongate cavities (31). The edges of the side walls (23a, 23b) include tongues (33a, 33b) and grooves (35a, 35b) that allow the modules (21) to be interlocked to form a wall. The ends of the webs are undercut such that cavities between the modules are created when the modules are suitably interlocked. The between-the-module cavities lie orthogonal to the through-the-module cavities. The modules (21) are formed of an insulating material and left in place. Preferably, the tongues along one edge include notches aligned with the webs. In one embodiment, the modules (21) substantially entirely are formed of relatively dense (3-5 lb./ft..sup.3) expanded polystyrene (EPS).

Abstract: An imitation weatherboard assembly has two or more weatherboard elements (1) of plastics material which simulate overlapped weatherboard and a preformed backing sheet (11). The backing sheet (11) has a front surface (12) which, in use, abuts the back surface of the weatherboarding elements (1), the front surface of the backing sheet being formed to conform to the rear profile of the imitation weatherboarding elements so that the backing sheet (11) establishes contact with a significant portion of the rear area of the weatherboard elements. A planar edge (8) along the upper edge of an element (1) engages a slot (13) formed in the front of backing sheet (11).

Abstract: A decorative facing can be placed on a block so as to render an ordinary block decorative. This provides the advantage of reducing transportation costs, since locally produced construction blocks can be used in place of the glazed blocks produced at a relatively limited number of facilities. The facing in addition to being decorative enhances the water impermeability of the block and facilitates clean-up.

Abstract: A multi-component modular system for use in fabricating wall structures of the type which may be fortified with concrete or other similar materials. The system includes in one embodiment a plurality of identical prefabricated forms, each form comprising an elongated, generally rectangular plastic member having a cavity defined by a pair of side panels and a pair of end panels. One end panel has a pair of opposed, outwardly-facing, L-shaped flanges, and the other end panel has a pair of opposed, inwardly-facing slots sized and shaped to matingly receive the L-shaped flanges. Two or more forms may be interconnected in an end-to-end fashion by inserting the L-shaped flanges of one form into the L-shaped slots of a second form. A plurality of holes are provided on the end panels of the forms to permit concrete to be distributed monolithically between adjacent forms and to accommodate the placement of horizontal reinforcement bars.

Abstract: A portable dance floor formed from the interconnection and interlocking of multiple dance sections each of which dance sections is formed from a dance substrate generally of plywood, wherein each dance section is supported off the ground. Dance sections interlock at the junction of four such sections, on the underside thereof into a main connector plate, and which sections interconnect along the interfacing sides of any two abutting sections by a spline disposed in a slot formed of aligned half slots. Transition members having an inclined plane to ease the change in elevation may be provided and may be interconnected in a similar manner to adjacent dance sections.

Abstract: A lightweight roofing shingle or tile having an elongated body with top and bottom surfaces that taper lengthwise of the body as provided by beveling of underside ribs. The shingle or tile has a composition consisting of expanded perlite, Portland cement, and an ingredient or ingredients selected from the group consisting of pumice and expanded shale, all ingredients being mixed particulate form, hydrated and cured.

Abstract: A prefabricated sleeper reduces labor costs associated with installing an anchored, resilient hardwood floor system. The prefabricated sleeper includes an elongated channel, pads located along the channel and an elongated nailing strip supported on the pads within the channel. A plurality of vertical access holes extend through the nailing strip. The pads are removed laterally from the access holes. The access holes enable a fastening gun to be inserted therein and into direct contact with the bottom of the channel to facilitate driving of fasteners through the bottom of the channel and directly into a base below. This prefabricated sleeper is formed by milling an elongated wooden strip to a desired T-shape and then drilling access holes therethrough. Pads are then stapled to the enlarged end of the T-shape, away from the access holes. An elongated sheet of steel is then rolled around the pads and the sides of the nailing strip to form a C-shaped channel thereabout.

Abstract: Apparatus for applying twist ties comprises structure for receiving the open end of the film wrapper of a bakery product; structure for severing the leading end from a length of ribbon to form a twist tie; and structure for twisting the twist tie around the end of the film wrapper, thereby closing same. A naked loaf detector and a hook jam detector are provided. All operations of the apparatus are controlled by a programmable logic controller.

Abstract: The conveying arm is composed of a first lower portion by which products assembled for wrapping are restrained, and a supporting upper portion embodied integrally with the first, which affords two slots occupying the full width of the arm as measured transversely to the conveying direction and designed to couple with two respective rails; the first such slot is located in and accessible from the face of the upper portion directed toward the products, and functions as a sliding bearing, whilst the second slot is located to the rear of the first. The arm is fashioned in a deformable material and its deformability enhanced by a narrow extension of the rear slot, in such a way that the upper portion can be locked to and released from the rail swiftly by applying a corresponding force parallel to the conveying direction.

Abstract: A method for wrapping an item wherein a plurality of sheets of material are connected into a pad of material. The sheets of material in the pad are organized into even numbered sheets of material and odd numbered sheets of material with each odd numbered sheet of material being disposed between a pair of even numbered sheets of material. A portion of each of the odd numbered sheets of material extends beyond the even numbered sheet of material disposed thereon to facilitate the removal of the sheets of material from the pad. The sheet of material is wrapped about the item.

Abstract: A band applicator for applying a band about a sheet of material disposed about a pot to provide a decorative cover for the pot. The band applicator includes a pot frame having a pot opening and a band holder configured to releasably hold a plurality of bands. The sheet of material is extended about the outer peripheral surface of the pot, and the pot with the sheet of material disposed thereabout is disposed in a pot receiving space in the pot frame. The pot frame holds the sheet of material positioned about the pot. A band is removed from the band holder and disposed about the sheet of material and pot for cooperating to hold the sheet of material positioned about the pot.

Abstract: A band applicator for applying a band about a sheet of material disposed about a pot to provide a decorative cover for the pot. The band applicator includes a pot frame having a pot opening and a band holder configured to releasably hold a plurality of bands. The sheet of material is extended about the outer peripheral surface of the pot, and the pot with the sheet of material disposed thereabout is disposed in a pot receiving space in the pot frame. The pot frame holds the sheet of material positioned about the pot. A band is removed from the band holder and disposed about the sheet of material and pot for cooperating to hold the sheet of material positioned about the pot.

Abstract: The present invention comprises a device and method for feeding a cut loose-leaf material such as, for example tobacco, from a weight scale; dropping the tobacco into a hopper; compressing the tobacco into the desired size, shape, and density; and packaging the loose-leaf tobacco product. Packaging is accomplished by wrapping an inner foil and overwrap label around an arbor on a rotating arbor wheel. The package is constructed in various stages as the arbor wheel rotates to various positions. The inner foil is fed and wrapped around the arbor without extending the foil below the body of the package so that the foil does not form a bottom end. The foil extends above the body of the package and is folded to form a top end. An outer label having a sufficient length to extend past the top and bottom of the arbor is overwrapped about the foil innerwrap. The overwrap label extending past the bottom of the arbor is folded and glued over the foil innerwrap to form a top end to the package.

Abstract: An apparatus for packaging granular materials, wherein the granular material flows vertically through various components, wherein the apparatus comprises a frame, a plurality of servo driven packaging payout means, a plurality of packaging material alignment means, granular material filler means, sealing means, and severing means. The apparatus further comprises a computer controlled coordination means for controlling and coordinating the operations performed by the components of the apparatus.

Abstract: A container providing selective access to stored objects consists of a plurality of cells for storing objects and a mechanism for causing the cells to open and close in accordance with a control pattern that specifies the cells that are to be opened and the cells that are to be closed. A user, by selecting an appropriate control pattern gains access to those cells in which he has an immediate interest. The user may quickly gain access to other combinations of cells simply by selecting other control patterns.

Abstract: An improved hinge assembly for a vacuum packaging machine is designed to pivotally connect a stainless steel tub in the machine to a sealing lid. The lid is equipped with a pair of the hinge assemblies, with each hinge assembly including a stationary hinge plate which is positioned beneath a rear, overhanging lip of the tub. A pair of pins are spaced apart and extend outward from each hinge plate and into and through an arcuate slot in a movable hinge block which is, in turn, connected to the lid. The hinge block is designed to move relative to the hinge plate along a path dictated by the arcuate slot and the pins, with the pins acting as respective stops for the movement. A gas spring is pivotally connected between the rear surface of the machine and each hinge block, with the hinge blocks including different mounting points to vary the effectiveness of the springs.

Abstract: A method and apparatus for forming one or more longitudinal creases in a web of material. The web is formed into a tube in a vertical form, fill and seal apparatus, and then passed over an internal guide. A pair of pinch rolls are located adjacent the guide, and a portion of the web is directed between the pinch rolls to crease the film as it is advanced. Direction of the film between the pinch rolls is accomplished by a pair of protrusions extending from the internal guide on opposite sides of the pinch rolls. The thus-creased tube is then passed over opposite, spaced forming plates at the bottom of the guide and then tucked and sealed.

Abstract: A hay roll bagging system for bagging a number of hay rolls as have been cut, harvested and dried in a hay field into a plastic sleeve that, is maintained in a stretched state during bagging and then tighten around each hay roll, which sleeve is tied at its ends forming a container. The system is preferably mounted onto a wheeled trailer to be moved into the hay field and includes a cradle structure to receive each hay roll, in turn, and includes a ram for urging a hay roll end off of the craddle and through a collapsing ring. The collapsing ring of the invention is mounted to the trailer across a craddle rear end and is formed to have, in an erected state, a greater diameter than that of a hay roll. The ring receives a folded plastic sleeve therearound when the ring is in a collapsed state.

Abstract: An electronic control system for controlling and displaying the status of the location of a combine harvesting head is disclosed herein. The system includes transducers for monitoring the position of the harvesting head relative to the combine, the location of the head relative to the surface upon which the combine is operating, and the force at which the surface is supporting the head. The system also includes a control unit coupled to the transducers and an electronic display located with the operator cab of combine. Depending upon the configuration of the control unit, the control unit samples the transducer signals to apply display signals to the display. In response to the display signals, the display can produce human-readable characters representative of the status of the head as monitored by the transducers.

Abstract: A mower unit having a bevel gear mechanism includes an input shaft extending substantially horizontally; a first bevel gear mounted on the input shaft; an output shaft extending substantially vertically; a second bevel gear meshed with the first bevel gear and mounted on one end of the output shaft; a blade mounted on the other end of the output shaft; a blade housing coveting the blade and defining an opening for receiving the output shaft; a beating holder rotatably supporting the output shaft; a bevel gear case containing the first and second bevel gears; and a pair of fight and left support stays connected to the bevel gear case for mounting the bevel gear case to the blade housing. The bearing holder and support stays are interconnected by reamer bolts, with the blade housing interposed between flange surfaces formed on the beating holder and flange surfaces formed on the support stays.

Abstract: A compact nut harvesting apparatus for collecting and separating out pecan nuts from the debris from the surface of the ground. The nuts are separated from the debris using two converging non-parallel air streams. The nuts are gleaned from the ground by a series of rotating fingers that throw the nuts and accompanying debris into a trough containing a rotating screw-shaped auger. The auger carries the nuts and debris along the trough to a side exit area. A fan blows a stream of air along the trough to help carry away some of the debris as the nuts are carried towards the exit. At the exit area, another stream of air moving upwardly from a second fan meets the debris. The debris is forced out through a chimney with a lateral air port, and the heavier nuts fall onto a conveyer located below the exit area. A series of spaced apart and slanting bars are located at the lower end of the chimney and conveyer to direct the fallen nuts towards the conveyer belt.

Abstract: A lawn mower is provided which has one or more rotatable wheels on one side of the mower shroud enabling the mower to cut grass at the edge of gardens and around obstructions.

Abstract: A mower deck is convertible between a discharge configuration wherein grass clippings are discharged from the deck and a mulching configuration wherein grass clippings are mulched within the deck. The deck has a housing with a discharge port for discharging grass clippings from the housing when the deck is in the discharge configuration. Spindles are rotatably mounted to the housing and coupled to a drive mechanism. A cutting blade is attached to each spindle. A removable shroud can be attached to and removed from the housing. The mulching configuration of the deck corresponds to when the removable shroud is attached to the housing and the discharge configuration of the deck corresponds to when the removable shroud is detached from the housing. A fixed shroud is attached to the housing and partially enshrouds the cutting path of the cutting blade.

Abstract: A plant structure having three floors with first and second ringless spinning apparatuses located on the first floor and with vertical sliver feed tubes extending from the first and second ringless spinning apparatuses respectively to the second floor for feeding a sliver through the sliver feed tube to the first ringless spinning apparatus and to the third floor for feeding sliver from a can thereof to said second ringless spinning apparatus.

Abstract: A system for bonding alternate S and Z twist plied yarn. The system bonds the plied yarns as they move in a path through the process and permits balanced expansion of the yarn while preventing lateral movement out of the path. The bonding of the yarn strands while plied together, forms a bond characterized by a dense region of filaments adhesively joined together where one of the strands overlaps another strand, followed by a less dense region along the one strand where fewer filaments are adhesively joined, followed by another dense region.

Abstract: A fiber opening device for use in a discontinuous spinning process. The opening device includes an opening roller rotatably mounted about an axis and having a cylindrical working surface which extends around the axis. Opening elements are provided around the working surface. A space is defined between an axially outermost fiber opening element and an adjacent outer edge of the cylindrical working surface. A pressure reduction opening is provided for reducing pressure in or around that space. The pressure reduction opening is arranged to urge fibers into engagement with the working surface.

Abstract: A chain structure for bicycles is composed of a series of inner chain plates, outer chain plates, rollers, and pins. Each inner plate has three arcuate peripheries at respective ends and slanting surfaces along one side of the arcuate peripheries. Each outer plate has also three arcuate peripheries at respective ends and slanting surfaces along one side of the arcuate peripheries. The slanting surfaces of the inner chain plates and outer chain plates are adapted to facilitate engagement of sprocket teeth with the chain plate.

Abstract: A method of establishing part-load operation is proposed for a turbine group. This gas turbine group consists essentially of a compressor unit (1), of an HP combustion chamber (4) downstream of the compressor unit (1), of an HP turbine (5) downstream of this HP combustion chamber (4), of an LP combustion chamber (8) operating by self-ignition and arranged downstream of the HP turbine (5), the hot gases (10) of which LP combustion chamber (8) being admitted to an LP turbine (11). The temperature at outlet from the HP turbine (5) remains essentially the same due to the reduction of the fuel quantity in the LP combustion chamber (8) to zero. Furthermore, the fuel quantity of the HP combustion chamber (4) remains approximately constant during the reduction of the fuel quantity in the LP combustion chamber (8) so that the temperature at inlet to the HP turbine (5) likewise remains constant.

Abstract: A fuel control system for a gas turbine engine having a staged combustor includes apparatus and methods to operate the combustor during pilot operation, staged operation, and transition between the two modes of operation. Various construction details are developed which provide a fuel control having a switch with built in hysteresis for determining the transition points between operating modes. In one embodiment, the combustor is switched from pilot to staged operation at a thrust level greater than the thrust level at which the combustor is switched from staged to pilot operation. During transitions between operating modes, the changes in fuel flows are limited by a plurality of rate limits to prevent combustor fuel spikes and blow-outs from occurring. During engine starts, the fuel lines to the main combustor are pre-filled to provide responsiveness during the transition from pilot to staged operation.

Abstract: In a gas turbine, a linear stem extends through a diffuser and a combustor cowl into a sleeve that is attached to the swirler in such a way that the sleeve can move relative to the swirler but is supported on the swirler. The stem slides into the sleeve and contains a fuel nozzle that supplies fuel through a sleeve outlet to a swirler inlet.

Abstract: The present invention provides a cooling apparatus with two spaced apart walls, one of which is a coolable wall, having a cooling flowpath between them wherein the cooling flowpath is converging in the direction of the cooling flow. In one embodiment the coolable wall is an afterburner cooling liner that includes a film cooling means on the hot side of the liner. Another embodiment provides a corrugated or wavy wall afterburner cooling liner wherein each wave includes a forward facing surface, from crest to trough of the wave in the direction of the hot gas flow, and an aft facing surface, from trough to crest. A high density pattern of multi-hole film cooling holes is disposed on the hotter of the two surfaces and a lower density pattern on the cooler one.

Abstract: A multi-stage honeycomb heater includes: at least two honeycomb heaters electrically connected with each other and disposed along a stream of fluid; the two honeycomb heaters including furthest upstream honeycomb heater and a an adjacent honeycomb heater which is adjacent to and downstream of the furthest upstream honeycomb heater; each of the two honeycomb heaters having an electrically conductive honeycomb structure the honeycomb structure of the upstream honeycomb heater having slits for adjusting its electrical resistance and/or element for adjusting heat capacity of the honeycomb structure so that the ratio of applied power to heat capacity of the furthest upstream honeycomb heater is larger than the ratio of applied power to heat capacity of the adjacent honeycomb heater. Thus the upstream heater and the downstream heater can give similar temperature increases without a temperature distribution along a flow direction during the engine warm-up.

Abstract: A catalytic converter comprises two catalytic matrices 10, 12, 14 mounted in a common housing and spaced from one another by an afterburner chamber 16. An igniter 22 is arranged in the afterburner chamber 16 near the first matrix 12 and a flame guard 18 is arranged upstream of and in close proximity to the igniter 22. The flame guard 18 comprises at least one elongate narrow strip spanning the combustion chamber which acts to spread the base of the flame across the width of the chamber 16 so as to enable the flame to spread in a shorter distance across the exhaust gases before reaching the second matrix 14.

Abstract: A torque converter having an impeller, turbine, and stator each formed of interconnecting upper and lower members, and a method for producing the same. The upper and lower members each include a number of spaced apart blades disposed about a central axis. Preferably, the corresponding upper and lower members are die cast with blades spaced apart at twice the distance desired in the completed assembly. When the upper and lower members are interconnected, their blades nest such that each member provides every other blade of the assembled component.

Abstract: A hydraulic fluid reservoir contains an extensible bladder which has its exterior exposed to the fluid and its interior vented to the exterior of the reservoir. The interior of the bladder is sealed from the hydraulic fluid in the reservoir. Depletion of the fluid from the reservoir results in distension of the bladder and replenishing the fluid to the reservoir collapses the bladder. The bladder is pleated and a tie-rod which holds the reservoir together extends through the bladder.

Abstract: In a gas turbine combustion chamber, which consists of an inlet zone (1) with injection, an ignition delay zone (2), a reaction zone (3), a burn-out zone (4) and a transition zone (5) to the turbine, the reaction zone (3) has a cross-section which increases in such a way that the gas dynamics of the combustion process can take place at constant pressure or constant Mach number. By this means, the total pressure loss and the combustion chamber length necessary for the combustion are reduced and this is reflected in an improvement to the efficiency and the output.

Abstract: A thermoelectric cooler for cooling a sample of hot, continuously flowing gas involves a mechanical heat flow path passing from the flowing gas through a heat-exchanging tube channeling the gas, a heat-conductive block housing the tube, a thermoelectric element having a cold side abutting the block, a heat sink abutting a hot side of the thermoelectric element, and cooling air streams passing through slots in the heat sink. The heat sink is a unibody, jointless metallic body having relatively thin fins defining the slots. A high pressure blower drives turbulent air streams through the slots of the heat sink, and a thermal switch is disposed on the heat sink near the hot side of the thermoelectric element.

Abstract: An apparatus for compressing/expanding a working gas (compression/expansion apparatus), including: a cylinder; a piston for compressing/expanding said working gas in a working space (front space) of said cylinder; a crank mechanism connected with a piston rod of said piston via an oil seal; a crank chamber for housing therein said crank mechanism and communicating with said cylinder via said oil seal, said apparatus comprising: a first tube allowing for a unidirectional flow of the working gas from said crank chamber to said front space in said cylinder, said first tube having therein an oil filter and a first check valve; and a second tube allowing for a unidirectional flow of the working gas from said front space to a second space (rear space) behind said piston in said cylinder, said second tube having therein a second check valve.

Abstract: A Vuilleumier heat pump comprises a high temperature section and a low temperature section. The high temperature section includes a high temperature chamber heated by a combustion unit, and a high temperature heat exchanger. The low temperature heat section includes a low temperature chamber and a low temperature heat exchanger. During a room-cooling mode, the high and low temperature heat exchangers are connected to outdoor and indoor heat exchangers, respectively. During a room-heating mode, the high temperature heat exchanger is connected to the indoor heat exchanger, and the low temperature heat exchanger is connected to an auxiliary heat exchanger which transmits heat from the combustion unit to the low temperature heat exchanger.

Abstract: A pumping system for pumping fluids at sub-ambient temperatures where the pumping fluid, after it has been used for its analytical application, is expanded such that the energy of expansion of the pumping fluid can be employed for cooling the pump head or pumping fluid prior to pumping.

Abstract: An apparatus for dispensing a cryogenic liquid includes means for focusing a beam of energy, eg. laser energy from a source onto the liquid cryogen as it passes through an outlet from a cryogenic liquid container.

Abstract: An automated fueling facility allows untrained persons to safely dispense homogeneous phase liquid methane from a cryogenic storage tank into a motor vehicle. The fueling facility automatically maintains pressure on the liquid methane within a predetermined safe operating range using methane gas trapped in the cryogenic storage tank. The pressure on the liquid methane is at least set equal to a set pressure equal to the sum of the saturation pressure of the liquid methane plus an additional amount to help to ensure that it remains in a fully saturated condition after exposure to any pressure losses as the fluid enters the pump. A pump is cooled by placing it in the storage tank and circulating liquid methane through the pump and back into the storage tank. A dispenser, including nozzle for connecting to a motor vehicle, is cooled by circulating liquid through the nozzle and back to the storage tank through a receptacle on the dispenser to which the nozzle is connected.

Abstract: The invention relates to a cryopump operated with a refrigerator, having a housing, having an inlet valve, having heatable pumping surfaces and having a backing pump connected to the pump interior; to be able to regenerate the cryopump quickly by executing the removal of the condensed gases at a high pressure, it is proposed that it is equipped with a line for the precipitates to be removed and that is provided with a regeneration valve.

Abstract: The lower-most temperature of the thermal mass in a chilled water stratified storage tank is lowered without reducing its density by the addition of sodium nitrite and sodium nitrate, alone or in combination, preserving thermal stratification so that both warm and chilled water may be stored in the tank, a benefit not previously obtained without the use of chemicals damaging to the environment. A 7% solution of sodium nitrite and sodium nitrate in a 2 to 1 ratio lowers the freezing point of the cooling water to -3.75.degree. C. (25.25.degree. F.) yet still permits the chilled water to stratify in the storage tank.

Abstract: A refrigeration system of the type having an economizer cycle is provided with a null cycle, in addition to heating and cooling cycles, without shutting a compressor prime mover down, to preserve air flow in a conditioned space. First, second and third controllable valves respectively: (1) select main and auxiliary condensers, (2) open and close a liquid line, and (3) open and close a line which provides a warm liquid to an economizer heat exchanger. The valves are controlled in at least one predetermined open/close pattern during a null cycle, and preferably in a plurality of selectable predetermined open/close patterns, to provide a null cycle at any instant which substantially matches the net heat gain or loss taking place in the conditioned space. Thus, the temperature of the served space will be more apt to remain in a null temperature range close to set point, providing smoother and more accurate control over the temperature of the conditioned space for longer shelf life of perishables stored therein.