CHAPTER VII HOUSEHOLD REFRIGERATING MACHINES (Part 5)

slow speed machine operating at forty strokes per minute, or eighty compressions. Poppet valves are used throughout — bakelite operating on brass seats, eliminating metal to metal contact with its attendant sticking. The bearings on the crank shaft and connecting rod are of hardened steel and amply large. The stuffing box is of the double gland stype. The compressor is lubricated automatically by the mineral oil which is formed when the refrigerant is expanded into the brine. The condenser is air cooled and consists of a hundred feet of ^-inch copper tubing. No forced draught is required over these coils to condense the refrigerant, therefore, the need for a fan is eliminated. 264 HOUSEHOLD REFRIGERATION The expansion valve is a simple device which runs into the brine within a few inches of the bottom of the tank. This valve releases the chloric ether into the brine from the high to low pressures. The expansion member of this mechanism is a sylphon bellows, which expands or contracts through verv narrow limits, thus eliminating or keeping adjustments to a minimum. I-IG. 125.— COMPLKTE SAXAT UNIT IXCLUDIXG CAl'.lNKT. The cooling tank, made of ' s-inch steel, occupies the space in the ice compartment of the refrigerator and con- tains the solution of calcium chloride brine and alcohol. The refrigerant is expanded directly into the brine causing an agi- tation which produces an even temperature throughout the brine and results in a constant crisp dry-cold in the refrigera- tor. A marked advantage of this system lies in the fact that the agitation resulting from the direct expansion of the refrig- erant into the brine produces an emulsion, which is equivalent to a medium grade mineral lubricating oil. This lubricant is formed in small but sufficient cj;uantities and is drawn back into the compressor and automatically solves the lubricating problem. The temperature control operates on a ten volt circuit ; a rela}^ mounted in a convenient location being used to reduce the voltage from the usual liome pressures. This arrangement COMPRESSION REFRIGERATING MACHINES 265 requires the mininuiin of attention. The thermostat is gov- erned by the temperature of the brine and can be set to operate accurately between small variations of temperature. Fig. 125 shows a complete unit including the cabinet. Fig. 126 shows the cabinet with vegetable storage space at bottom as arranged when tlie machine is located in the basement. ■Hi. 1J(.. SAXAT MKTAL CAIUXKI' W 111 1 ' Kl.KTA I'.l.K SIORAGE. Savage. — Fig. 127 shows the mercury refrigerating ma- chine made by the Savage Arms Corporation, Utica, New York, suitable for ice cream cabinet and household fields. Fig. 128 shows the machine with the condenser removed. This machine operates on a new system of mercur^ compres- sion. The screw pumj), invented by Archimedes about 250 B C, 266 HOUSEHOLD REFRIGERATION using mercury as the compressing fluid, is the basis of the design. Following are the most important advantages : There are no internal moving parts. There is no lubricant within the refrigerating cycle. FIG. 127.— SAVAGE MERCURY REFRIGERATING MACHINE. The drive is external to the refrigeration cycle, requiring no stuffing box or gland joint. The system is sealed by weld- ing, and is leak proof. The machine is exceptionally quiet in operation, due to purely rotary motion at relatively low speeds. Mercury compression, because of its inherent freedom from power losses, makes possible an exceedingly low power consumption per unit of refrigeration. COMPRESSION REFRIGERATING MACHINES 267 Excessive pressures cannot be generated, since the critical point of the mercury compressor is reached only a few pounds above the working ]:)ressure of the machine. It then blows back, short circuiting itself. FIG. 128.— SAVAGE MERCURY REFRIGERATING MACHINE WITH CONDENSER REMOVED. A force feed oiling system provides adequate lubrication to the four external bearings with oil storage capacity suf- ficient for many years of operation. An automatic temperature speed control gives the machine added refrigerating capacity as the room temperature rises. The machine automatically operates at the most efficient speed for all room temperatures, an exclusive feature. Service may be performed upon any mechanical or elec- trical part of the machine without disconnecting or disturbing the refrigeration system, and without losing any refrigerant. 268 HOUSEHOLD REFRIGERATION It is obvious that llu-ic can be no piston leakage, since each mercury piston seals itself in the helical passageway. Neither can there be an\ clearance or re-expansion loss, since each gas volume is pushed completely through from the low to the high pressure chamber. There is no internal wear. Fig. 129 is a typical cabinet for preserving ice cream. This cabinet is of angle iron frame construction with tongue and groove spruce flooring. FIG. 129.— SA'AGE ICE CREAM CABINET. Cork insulation is used and all joints flooded with sealing compound. Two thicknesses of waterproof paper are used as an additional ])r()tection against air leakage. The lining is of heavy gahanized sheet steel. 'J'lie top is of laminated wood, covered with non-C()rr()si\e metal. The sides are of black-enameled sheet steel, bound in by metal corner angles. The cabinets may be installed either as a unit with the compressor or as a remote system. In the latter case the com- pressor unit is generally installed in the basement or in some other convenient i)lace separate from the cabinet. Servel. — Figs. 130 and 131 shows the Model 21-A refrig- erating machine manufactured by the Servel Corpc^ration COMPRESSION REFRIGERATING MACHINES 269 whose main offices are at 51 Jiasl 42nd Street, New York City. Methyl Chloride is the refrigerant used in this system. The compressor, condenser, pressure control and ^ hp. motor are mounted on a pressed steel base. The 21-A is used in all complete Servel refrigerators, as well as all remote FIG. 130.--SERVEL MODEL 21-A REFRIGERATING UNIT. household installations. The compressor is of the vertical, twin cylinder, single acting, reciprocating type. It is free from vibration and practically noiseless. The bore is 1^ inch and the stroke 1^4 inch. The compressor runs at a comparatively low speed — 375 r.p.m. The drive is accomplished through a "V" belt. Both the inlet and outlet valves are flapper valves. 270 HOUSEHOLD REFRIGERATION Leakage around the compressor shaft is prevented by use of a special sylphon seal of the rotating type. The temperature control, Fig. 132, is accomplished by means of the action of the copper bellows connected to the low FIG. 131. -CUTAWAY VIEW OF SERVEL COMPRESSOR SHOWING MOVING PARTS AND SYLPHON PACKING. pressure side of the system. The inflation and deflation of the bellows operates a quick make and break switch, opening and closing the motor circuit, and is adjustable for different pres- COMPRESSION REFRIGERATING MACHINES 271 sure to give any desired temperature. A special feature of the control device is that it limits the pressure of the suction gas to the compressor at the time of start so that no overload is placed on the motor. FIG. 132.— SERVEL PRESSURE CONTROL CUT OPEN TO SHOW OPERATION' OF PISTON. The condenser is trombone shaped, cooled by two fans running in opposite directions. The four bladed fan on the motor pulley blows directly into and across the condenser. The large fan on the compressor flywheel draws the air out of the condenser. Exhaustive tests show^ conclusively that 272 HOUSEHOLD REFRIGERATION this arrangeincnt is superior to two fans operating in the same direction and materially reduces the head pressure where boxes are so located as to make air circulation difficult. The motor mounting- plate is of pressed steel and adapted to Gen- FIG. 133.— FLOAT VALVE, SER\EL REFRIC.ERATIXG IMT. era! Electric, Century, Emerson and Westinghouse motors. The adjusting (jf the motor for belt tension is controlled by one nut. making this a very simple operation. In the complete refrigerator the float valve is placed in the machine compartment. The sturdy construction of this float is clearly shown in Fig. 133. When sufficient liquid meth} 1 chloride has accumulated in the float it raises the ball, opens the needle valve and enters the expansion coils. A c\lin(h-ical screen is used as a strainer both on the inlet to the float and as a cage surrounding the needle valve. This prevents any foreign matter clogging the needle valve. All shutofl: valves are made from bronze forgings and are provided with caps which completely inclose the valve stem, thus eliminating leaks through the valve packing. Fig. 134 shows the Model S-7, suitable for the family of medium size, one of the three all steel models now being man- COMPRESSION REFRIGERATING MACHINES 273 ufactured by Servel. The other two models are the S-5, for the small family, and the S-10, suitable for the more preten- tious household. (Fig. 135 and 136.) -(. 134.— SERVEL AIJ^STEEL REFRIGERATOR FOR ^rEFlT^^T SIZED FAMILY. The cabinets are constructed of especially selected "Armco" Ingot Iron carefully lead-coated as a positive pro- tection against rust. The metal shell is given an application of oil base primer coat, after which this coat is slowly and carefully baked on under a low temperature, pr(iducing a 274 HOUSEHOLD REFRIGERATION finish which will neither peel nor scale. Next, several coats of surfacer and two coats of genuine Du Pont White Duco Lacquer are applied and allowed to air dry. The slow process of air drying, while it creates an additional factory cost, pro- FIG. 13S.— SERVEL ALL-STEEL REFRIGERATOR F(^R SMALL lA.MlLi' ISL, duces a much better appearing and more lasting finish than can ever be expected under artificial or forced drying. The porcelian liners are of the box type, and are so con- structed, with double lock flanges, that bolt holes or screw holes are entirely eliminated except those required for tank and shelf supports. This produces an absolutely sanitary liner and eliminates all chance of flaking of the porcelain finish, due COMPRESSION REFRIGERATING MACHINES 275 to uneven strain such as results from the use of screws or bolts. The chilling units are of tinned copper and have front FIG. 136.— SERVEL ALL-STEEL REFRIGERATOR FOR LARGE SIZED FAMILY. panels and ice-cube-tray fronts of genuine porcelain. Each ice-cube-tray holds 12 cubes. The insulation is pure compressed corkboard thoroughly impregnated with hydrolene, 1^-inch thick on top and sides 276 HOUSEHOLD REFRIGERATION on the S-5, 2-inch thick top and sides on the S-7 and S-10: with a 3-inch bottom thickness on all models. All seams in tlie C()rkl:)oard arc filled with Hydrolene. \^ater])roof paper is then aj^plied over the corkboard as added FIG. 137.— SERVEL SEMI-COMMERCIAL REFRIGERATING UNIT. seal against air leaks. An air space of 34"^i'ich to 3^-inch is used between the outer metal shell and the insulation sur- rounding the liner. The semi-commercial machines are shown in Figs. 137 COMPRESSION REFRIGERATING MACHINES 277 and 138. The 15-A is ])articularly ada])ted for ice cream cabi- nets and low temperature work. The rated capacity of the FIG. 138.— SERVEL SEMI-COMMERCIAL REFRIGERATING UNIT. 15-A is 350 lbs. The 18-A has a rated capacity of 300 lbs., and is used on large household or small commercial boxes. Socold. — Fig. 139 shows the compressor unit used in the electric refrigerator manufactured by the Socold Refrigerat- ing Corporation of Boston, Massachusetts. The refrigerant used is sulphur dioxide. The compressor has two vertical cylinders. The pistons arc driven by connecting rods operated by a walking beam. The drive shaft oscillates on an arc of 12 to 15 degrees each side of center at slow speed. A plate of special metal seals against a shoulder on this shaft. Thus the wear on the pack- ing is very slight. The discharge valves are in the cylinder head and are made of three monel discs. The suction valves are single parts in the cylinder walls. 278 HOUSEHOLD REFRIGERATION The condenser consists of a coil of one tube mounted on the same base with the compressor. Forced air cooling is obtained by a fan in front of the motor and in the compressor drive wheel. FIG 139.— SOCOLD REFRIGERATING UNIT. m FIG. 140.— SOCOLD FROST UNIT OF HEAVY SEMI-STEEL CONSTRUCTION. COMPRESSION REFRIGERATING MACHINES 279 Fig. 140 shows the frost unit which is of heavy galvanized semi-steel construction and operates on the direct expansion system. An expansion valve of single construction is used to reduce the pressure of the liquid refrigerant. FIG. 141.— SOCOLD TYPICAL STEEL CABINET. A Mercoid thermostat is used for temperature control. It is responsive to the temperature of the frost unit and not by temperature of the food compartments, which issues a con- stant supply of ice cubes without making seasonal adjust- ments necessary. The thermostat is set to maintain a tem- perature in the frost unit of from 20 to 24 degrees F. This 280 HOUSEHOLD REFRIGERATION produces a temperature of from 45 to 50 degrees F. in the food compartment. Fig-. 141 and 142 show typical steel cabinets. The construction provides one air and moisture tight steel ^^sss^UBsaa, zz-ji %ss^msm FIG. 14: -SOCOLD STEEL CABINET SHOWING REFRIGERATING AND FROST UNITS INSTALLED. case inside another which will not permit the penetration of moisture and odors into the insulation. -Balsam-wool is used to insulate the cabinets. This ma- terial is manufactured from the fibers of northern coniferous woods. The process is somewhat similar to that employed in COMPRESSION REFRIGERATING MACHINES 281 pulp making, as the wood is first reduced by mechanical means and then chemically treated so the wood fibers are separated from one another. The individual fibers are fine, hairlikc, hol- low tubes, and at this stage are saturated with chemicals that render them non-inflammable and proof against decay. These fibers are handled by air and felted into a fleecx mat lujund together with cement. An imp(_)rtant feature of this mat is that its fibers extend in all three cubical dimensions, with the result that the blanket is remarkably light in weight and con- tains millions of dead-air cells. To increase the mechanical strength of the fibrous Ijlanket. a layer of water-proofed Kraft ])aper is cemented to each side of the blanket with asi^halt. This method of applying the liner does away with stitching and leaves the surface of the material impervious to water and air. The cold storage type of balsam-wool is particularlx adapted for these small boxes because it is easily fitted in around the corners, is odorless either wet or dry, and will not support mildew or mold. A complete line of cabinets in por- celain or white baked enamel are manufactured. Universal Refrigerating Machine. — Fig. 143 shows the household compressor unit manufactured by the Unixersal Ice Machine Company of Detroit. The refrigerant used is ammonia. A y^ hp. motor drives the comjjressor by means of a 'A'" type leather belt and idler pulley. The compressor has a special type aluminum piston, designed to assure good lubrication and eliminate wear on the sides of the cylinders. Disc plate suction and discharge valves are used. These are located in tlie head of the compressor and are easily ac- cessible. The cylinder head is water jacketed. Metallic pack- ing is used on the compressor crankshaft. The condenser is made of a double spiral coil with welded ends. Water flows through the inner coil. Utility Refrigerating Unit. — Fig. 144 shows the mechanical unit used in the Utility Electric Refrigerator which is manu- factured at Adrian. Michigan b}- the Utility Compressor Com- pany. It is reported this company is now out of business. 282 HOUSEHOLD REFRIGERATION IO?60 FIG. 143.— UNIVERSAL KEFRIGERATIXG MACHINE. The electric motor and pump are enclosed in the dome at the right, hermetically sealed. This eliminates a packing gland for the shaft of the compressor. The thermostat and the cooling coils, which absorb the heat from the atmosphere in the refrigerator are situated in the chamber at the left. The condenser is of the radiator t} pe and is located behind the dome and coil chamber. This condenser is air-cooled. The complete mechanical unit is interchangeable and easily removed from the cabinet. In case service is required, it is claimed that the complete mechanical unit can be removed and another put in place in COMPRESSION REFRIGERATING MACHINES 283 fifteen minutes. This eliminates the need of mechanics work- ing on repairs in the home. The small door is for the ice freezing chamber. FIG. 144.— UTILITY REFRIGERATING UNIT. The mechanical unit is placed in the upper part of a special cabinet. The cabinets are of white porcelain or natural wood exteriors. A one-piece porcelain lining is used. The cabinets are seventy inches high, thirty-eight inches wide, and twenty- three inches deep. Ward. — Fig. 145 shows the condensing system of the household refrigerating machine made by the Ward Electric Refrigerator Corporation of Buchanan, Michigan. FIG. 145.— WARD HOUSEHOLD REFRIGERATING SYSTEM. 284 HOUSEHOLD REFRIGERATION A ^i hp- motor drives the compressor by means of a "V" type belt. The condenser consists of a coil of copper tubing. Air is forced over the condenser b- a fan on the motor shaft. FIG. 146." A\AKD EN'APOKATI XG SYSTEM. Fig. 146 shows a ty])ical evaporating s}stcm consisting of a brine tank. exi)ansion valve and necessar' connections. The thermostat control is mounted on the brine tank. i;! ^^ =&^*%i ^« FIG. 147.— SMOWIXG SPLIT-VALVE CONNECTIONS, W.\RD REFRTGER. ATING SYSTEM. The system is connected together by means of tubing con- taining split-valves on each end as in Fig. 147. This arrange- COMPRESSION REFRIGERATING MACHINES 285 inent eliminates the need to dehydrate, pull a vacuum or charge the machine when making an installation. The valves on each end of the tubing are shut off when charged at the factory and after dealer has connected up same with machine, they are then turned on by a ratchet wrench which operates on the end of each valve and thus the dealer does not lose the charge when installing unit. ^1' 4|» *--SiS- ^ FIG. 148.— WARD STEEL HOUSEHOLD CABINET. One of the cabinets is shown in Fig. 148. The cabinet has a steel exterior and is insulated with corkboard. Various sizes and types of cabinets can be supplied. 286 HOUSEHOLD REFRIGERATION Warner. — Fig. 149 and 150 show compressor