CHAPTER VII HOUSEHOLD REFRIGERATING MACHINES (Part 1)

CHAPTER VII HOUSEHOLD REFRIGERATING MACHINES COMPRESSION TYPE Household Refrigerating Machines. — In this chapter, at- tention will be given tc) the general types and characteristic construction of a number t)f household compression refrigerat- ing machines. The makes of the various household refrigerat- ing machines which are described here have been selected promiscuousl}-, and represent the characteristic design of the different classes of machines. It does not include descrip- tions of all of the different kinds of household machines, since, at present, there are several hundred different concerns pro- ducing or developing machines of this type. FIG. .^7.— .\BSOPURE AIR-COOLED MECHANICAL UNIT. In the following, attention has been given to the mechan- ical design of the different parts of the compression type. Absopure. — Fig. Z'J shows a % hp. air-cooled mechanical unit used on the household machine manufactured by the Gen- 187 188 HOUSEHOLD REFRIGERATION FIG. 38.— SECTIONAL VIEW OF ABSOPURE COMPRESSOR. FIG. 39.— HALF-HORSEPOWER ABSOPURE CONDENSING UNIT FOR I€K CREAM CABINET. COMPRESSION REFRIGERATING MACHINES 189 eral Necessities Corporation of Detroit, Michigan. This ma- chine uses methyl chloride as the refrigerant. A sectional view of the compressor is shown in Fig. 38. The motor drives the compressor by means of a "V" type belt. The discharge valve is of a disk type. The shut-off valves are made of forged brass. FIG. 40.— TYPICAL ABSOPURE FREEZING UNIT I\ VARIOUS SIZE.S. The Yz hp. air-cooled mechanical unit is shown in Fig. 39. This is one of the condensing units used for ice cream cabinet work. The condensing unit is placed in a compartment which mav be fastened to the ice cream cabinet. 190 HOUSEHOLD REFRIGERATION Fig. 40 shows a typical freezing unit. These are made in sizes suitable for use in all types of household refrigerators. FIG. 41.— TYPICWL Ai?S01'LRE KEFKIGF.R.\TOR. Fig. 41 is a topical refrigerator in which the mechanism ma}- be installed as a complete self-contained unit. Audiffren. — Fig. 42 gives a sectional view of the household machine manufactured by the Audiffren Refrigerating Ma- chine Company of New York Cit}'. A view of a cabinet equip- ment with this machine is shown in Fig. 43. This machine has an enclosed sulphur dioxide compressor. All of the o])erating parts are sealed up within this revolving "dumbbell," consisting of two bronze bells on a hollow shaft. The Rotor consists of two hollow bronze bells connected by a hollow steel shaft. One bell containing the compressor also acts as the "condenser" ; in the other the liquid boils oiT under reduced pressure and this is the "evaporator" where in- tense cold is produced. The hollow shaft contains a tube through which the liquid refrigerant is carried from the con- COMPRESSION REFRIGERATING MACHINES 191 denser to the evaporator, and an annular space around the tube throug-h which the spent gas is drawn back by the com- pressor. Thus compressor, condensing surface, Hc[uid re- ceiver, oil separator, expansion valve and refrigerating sur- face are all represented in this hermetically sealed Rotor. The compressor rides on the shaft inside of the spherical bell, being held in an approximately vertical position against the turning of the Rotor by means of a heavy lead counter- weight. The compressor has two double acting, oscillating cylinders. The compressor pistons are driven by an eccen- tric secured to the shaft. SCOOP FOB SUPPLYING SO. TO DECANTING TAN ^ EQUALIZING CCCENTRC RE\Ol.Vt5l WFTM 5KAF CSaLLATINCCYLINDtR SUBMtRCEO REFRCERATING END PRESSUPC WITHIN DEPENDS ONTEMPERATURE SO.CMARCfD TMROUCH HCXLOV SHAf I KFORC FIG. 42.— SECTIONAL VIEW OF AUDIFFREN HOUSEHOLD MACHINE. As the Rotor revolves, this compressor, being held in posi- tion by the counterweight, draws gas from the evaporator, compresses and discharges it under pressure into the condenser bell within which the compressor is located. The condenser bell runs partly immersed in cooling water and the compressed gas is cooled and condenses on the inner walls of this bell. The operating pressure is about 50 pounds per square inch, varying with the cooling water temperature. The condensed refrigerant and the oil are held out against the shell of the condenser bell l^y centrifugal force and are finally caught by means oi a small scoop mounted on top of the frame of the compressor and poured down into a decanting cup where the oil is separated and poured back over the com- pressor cylinders to lubricate and cool them. The refrigerant is then passed by means of a float valve, which serves for an 192 HOUSEHOLD REFRIGERATION automatic "expansion valve," to the evaporator bell of the machine, again to boil off and continue its cycle. The evaporator is a simple bell providing a chamber for the liquid to evaporate and produce cold. The lubricant that reaches the cold end of the machine is automatically sepa- rated and returned to the condenser end through the cylinders, providing internal lubrication for the cylinders and the pistons. FIG. 43.— VIEW OF CABINET EQUIPPED WITH AUDIFFREN MACHINE. The temperature and pressure in the condenser will, ob- viously, be dependent upon the temperature of the condensing w^ater. Consequently the position assumed by the compressor under the control of the counterweight will be dependent upon the temperature of the condensing water. If the supply of condensing water gives out so that the temperature rises above the normal operating limit, the counterweight will finally rise to the horizontal position and any increase in pressure beyond this point will cause the counterweight to revolve with the machine, so that no increase of pressure beyond that for which COMPRESSION REFRIGERATING MACHINES 193 the counterweight is designed can be caused by the operation of the machine. This acts as a safety device absolutely pro- tecting the machine from dangerous pressures as a result of failure of condensing water. Until the law of gravity fails, this machine is absolutely safe. To freeze ice, the ice cans are placed directly in the brine tank. To cool refrigerators, this cold brine is circulated through pipe coils placed in the refrigerators. frPICAl. ARRAIMSEMENT AUDIFFREN REFRIGERATING SYSTEM V/ITM COLO ROOM AMD PAMTRV REFRIGERATOR FIG. 44. Fig. 44 shows a typical arrangement for cooling a large cold room, a pantry refrigerator and an ice making plant. A circulating brine system is used. During the last 15 years many systems similar to this have been used for large resi- dences and country estates. Autofrigor. — This machine, Fig. 45, is manufactured by Esher Wyss & Company of Zurich, Switzerland. The refrigerant is methyl chloride. The compressor "5" is double-acting, operating at motor speed. Gas from the suc- tion chamber "6" is compressed into the pressure chamber 194 HOUSEHOLD REFRIGERATION "7." The compressed gas then passes through the vertical pipe to the high pressure gas chamber ''8" and into the annular space surrounding the chamber. The condensed liquid col- lects in chamber "9." The gas is condensed by circulating water which enters by connection "H" and leaves by outlet "12." Nozzle "13" is used in place of an expansion valve to the evaporator "R." Abb. 2 Abb. 3 FIG. 45.— AUTOFRIGOR. The motor "M" has its rotor "3" enclosed by a steel shell "4," which seals the gas chamber "8." This machine is man- ufactured in several sizes. Brunswick-Kroeschell. — Fig. 46 shows one of the small self-contained units made by the Brunswick-Kroeschell Com- pany of New Brunswick, New Jersey, who have been making household refrigerating machines continuously for more than 25 years. Self-contained units are supplied for full automatic control, semi-automatic or manual operation. COMPRESSION REFRIGERATING MACHINES 195 The ammonia or carbon dioxide system can be supplied for either direct expansion of the refrigerant or cooling through brine circulation. FIG. 46.— SMALL SELF-CONTAINED BRUNSWICK-KROESCHELL UNIT. Fig. 47 shows a large self-contained unit. This consists of a compression side, electric motor with its starting equip- FIG. 47.— LARGE SELF-CONTAINED BRUNSWICK-KROESCHELL UNIT. ment, special power transmission for short center operations, and interconnection for ammonia, water and electric supply; 196 HOUSEHOLD REFRIGERATION these are all mounted on a cast iron pedestal and intercon- nected ready for service. The compressor is of the enclosed, vertical, single acting type. Splash lubrication is used. The condenser is of the shell and tube multi-pass type. Removable heads permit convenient cleaning of the condenser tubes when required in cases where the water leaves a sedi- FIG. 48. -BRUNSWICK-KROESCHELL RESIDENCE INSTALLATION, INCLUDING ICE-MAKING SET. ment. The shells are of ample size for the combined purpose of service as condenser and ammonia receiver. Fig. 48 shows a typical residence installation including an ice-making set. Carbondale. — Fig. 49 shows a self-contained unit made by the Carbondale Machine Company, Carbondale, Pa. Am- monia is the refrigerant used. The compressor is of the vertical, single-acting type. Worthington feather valves are used in the compressor. The cylinder is ground and honed to size. All the bearings are of the die cast type and are interchangeable. COMPRESSION REFRIGERATING MACHINES 197 The condenser is of the horizontal, tubular type with re- movable heads and straig-ht tubes, making" it conveniently cleaned and inspected. The water passes through seamless drawn steel tubes, which are expanded into forge welded heads. FIG. 49.— CARBOXDALE REFRK .KKA i l.NG IMT. The one ton unit is driven by a three horse power motor at 265 r.p.m. when operated at standard suction and dis- charge pressures. The same machine is rated at two tons when operated at 530 r.p.m. by a five hp. motor. This ma- chine has a vertical compressor of 3j/j inch diameter and 3^ inch stroke. The unit is equipped with the following automatic dexices : Automatic starting panel. High pressure cut out switch. Ammonia pressure water control valve. Automatic expansion valve, with strainer. The high pressure cut out is arranged with hand reset, so that in case it acts, the machine will not start itself until the 198 HOUSEHOLD REFRIGERATION cause for the high ammonia pressure is determined and cor- rected. The thermostat operates at full voltage and is fitted for two connecting wires. The thermostat is very accurate, and with a properly designed room, or box, the temperature may be held within a few degrees of the desired temperature. The water regulating vahe is mounted on the front end of the condenser. It is of the pressure actuated type and con- trols the flow of water by the ammonia pressure of the con- denser. When the ammonia pressure drops, the flow of water ceases; and as it rises, the flow is increased, thus obtaining maximum economy in the use of water. The ammonia connections, both to this \ alve and to the high pressure cut out, are short and protected by other parts of this unit. Valves are provided in both connections, so that the appliance can be removed for repairs or adjustment. The automatic expansion \alve is of the spring and dia- phram controlled type, selected for the service that it has given hundreds of users, and of a type that will operate satisfactorily under the most adverse conditions. Champion. — The Champion Electric leer is made by the Champion Electric Company of St. Louis, Missouri, a division of the Champion Shoe Machinery Com pan v. FIG. 5U.— ••JUNIOR" .MODEL, CHAMPION ELECTRIC ICER COMPRESSION REFRIGERATING MACHINES 199 Fig. 50 shows the Junior Model. This compressor is of the single cylinder reciprocating type. A belt drive is used. FIG. .SI.— CHAMPION COOLING UNIT. The cylinder block is lined with tool steel bushing hardened and ground. The pistons are semi-steel equipped with two piston rings. The crankshaft is drop forged in one piece. FIG. 52.— "SENIOR" MODEL, CHAMPION ELECTRIC ICER. Large eccentric bearings are used which are of semi-steel. Model No. 6 Junior Compressor has 1^^ inch diameter cylin- der, 1% inch stroke, and operates at 500 r.p.m. Model No. 8 200 HOUSEHOLD REFRIGERATION Junior compressor has 1^ inch diameter cylinder, 1^/4 inch stroke, and operates at 500 r.p.m. The condenser consists of a double coil of V^ inch co])]>er tubing". Natural air circulation is used for cooling the con- denser. FIG. S3.— CHAMPION "SENIOR" MODEL WITH COOLING i:NIT INSTALLED. The automatic control is of the adjustalde pressure ty])e on the suction line. The motor is 1/6 hp. and is of the induction-repulsion type. Fig. 51 shows the cooling unit which operates on the COMPRESSION REFRIGERATING MACHINES 201 flooded system. This uses 'direct expansion in open type coils. The refrigerant is sulphur dioxide. Fig. 52 shows the Senior Model which consists of a two- cylinder reciprocating type compressor geardriven. The ^ hp. motor drives the compressor by means of completely enclosed gears. The gear drive consists of a composition pinion on the motor shaft, driving a helical cut semi-steel gear on crank shaft. All moving parts are enclosed and run in oil. The compressor has a 1^ inch bore, 1-^^ inch stroke, and operates at 500 r.p.m. The condenser, automatic control and cooling units are sim- ilar in type to those used on the Junior Model. Fig. 53 show^s the Senior Model and cooling unit complete with the cabinet. Chilrite. — This machine, Fig. 54 is made by the Narragan- sett Machine Company in I'awtucket, R. I. FIG. 54.— CHILRITE REFRIGERATING UNIT. The compressor is of the multi-stage rotary gear ty[)e and uses sulphur dioxide as the refrigerant. The condenser con- sists of a coil of finned tubing. The cooling unit is of the dry system- consisting of a coil connected with an expansion valve and submerged in a tinned copper tank filled with alcohol and water. In some installa- tions the tank is dispensed with and the open coil system is used. 202 HOUSEHOLD REFRIGERATION The temperature is controlled by an immersion type of thermostat of the tilting tube variety. The machine is made in three sizes using 34. Ya and Yz hp. motors and is adaj^ted to operate with any standard make of cabinet. Climax. — Fig. 55 shows the self-contained refrigerating unit manufactured by the Climax Engineering Company of Clinton, Iowa. The refrigerant used is methvl chloride. cli:max refrigerating umt. The condenser, comi)ressor and motor are all mounted on the same base. The compressor is direct connected to the electric motor. A rotary type of compressor is used, consist- ing of only three moving parts. The rotating element oper- ates on bronze bearings submerged in oil, tints providing posi- tive lubrication. The refrigerating unit is made in four different sizes: Model Model G Model F Model E Model D Motor % hp. % hp. K3 hp. K' hp. Weight 86 lbs. 127 lbs. 204 lbs. 224 lbs. Ue -Melting Effect 75 lbs. 150 lbs. 300 lbs. 500 lbs. The condenser is of the radiator type and is mounted under the l^ase. The air is drawn through the radiator and does dou- COMPRESSION REFRIGERATING MACHINES 203 ble duty by being blown against the compressor case. A float valve is used for the liquid control. The operation of this unit is controlled by a thermostat or pressure control and is entirely automatic. Coldmaker. — In Fig. 56 is illustrated the Coldmaker house- hold refrigerating machine manufactured in Toledo, Ohio. The machine is installed in the basement or other out of the way place and the cooling coils are installed in the ice compartment of anv box. FIG. 56.— COLDMAKER REFRIGERATING MACHINE. Coldmaker consists of a water cooled ammonia system of automatic refrigeration. The comi)ressor is motor driven by means of a flat leather belt. The compressor has two cylinders, 1^4 inches in diam- eter by 1^^ inch stroke made of a semi-steel casting. Suc- tion port openings are located near the center of the cylinders. The pistons have long ports on each side to admit the suction gas. The suction valve is located in the upper end of the piston. The top end of the piston has four piston rings 204 HOUSEHOLD REFRIGERATION and the lower end three rings. The wrist pins arc made of nickel steel. The eccentrics are made of gray iron castings and are cast integral at an angle of 180°. They are shrunk and pinned to the shaft. The shaft is made of forged steel and is ground to size after the eccentrics have been shrunk on. The discharge valves are made of nickel steel, light in weight, and cup shaped. They give full area opening of the cylinder and permit the compressor to handle saturated gas or liquid without endangering the safet}^ of the machine. The suction valves, located in the head of the pistons, are made of nickel steel. They have a large suction area and op- erate with a minimum lift. Both suction and discharge valves are provided with springs to hold the valves snugly to seats when the pressure is released. The end plates containing the shaft bearings are made of semi-steel, bored and reamed accurately, and fitted with die cast bearings. The stuffing box is provided with an oil gland, or ring, with soft packing on both sides. The gland has a direct con- nection with an oil reservoir, entirely separate from the oil in the crank case. This in realit}', forms an oil storage in the center of the stuffing box, which keeps the packing soft and resilient, and effectively seals the stuffing box so that no gas can get past this oil seal. A threaded packing nut or gland forms the outer end of the stuffing box proper. The rings are made of soft, close grained gray iron. Each ring is cast individually and the inner surface is left unfinished to give toughness and resiliency to the ring. The rings are cast eccentric. The cylinder heads are made of semi-steel. The discharge port is located in the cylinder head. The water jacket sur- rounds the compressor, condenser and liquid receiver. Any leak which might occur will be absorbed by the water. The condenser is made of extra heavy ^2 inch steel pipe bent to shape and surrounding the compressor cylinders. Some advantages of the water jacket surrounding the com- pressor, condenser and liquid receiver are: COMPRESSION REFRIGERATING MACHINES 205 1. It absolutely assures splendid operating conditions for the compressor,