W' 



ICE MACHINES 



FOR FLORISTS 



To keep pace with the times in the face of keen competition, we must 

 increase our efficiency. We must not only produce hetter goods, hut we 

 must also insure ourselves against depreciation in the value of these products 

 during their marketing process. Failing to do this, we cease to progress. 



ECHANICAL refrigeration 

 has been made possible by 

 the fact that certain gases, 

 chief among them anhy- 

 drous ammonia, carbon 

 dioxide and methyl chlo- 

 ride, when subjected to ab- 

 normal pressure, can be 

 transformed from their 

 original or gaseous state 

 to a liquid consistency and will remain 

 in this state as long as the pressure is 

 maintained. This fact, however, would 

 be of little value in itself if it were not 

 for the fact that when the pressure is 

 released, the liquid product evaporates 

 immediately, producing an intense cold 

 in the surrounding atmos- 

 phere. This method of re- 



frigeration would be an 

 expensive one if a new sup- 

 ply of the refrigerant were 

 necessary each time that an 

 evaporation took place, but 

 upon experimentation it 

 was found that these gases 

 could be compressed into a 

 liquid state and allowed to 

 evaporate with the same re- 

 sults an infinite number of 

 times without deterioration 

 or loss, as long as the con- 

 tainers were kept air-tight. 



flowing over the condenser in turn ab- 

 sorbs heat which the gas picked up on 

 its previous round, thus making the 

 liquid substance ready for its second 

 trip. From the condenser the liquified 

 gas collects in a storage drum, or re- 

 ceiver, from which it is permitted to 

 escape into the expansion coils at a 

 greatly reduced pressure, as low as fif- 

 teen pounds per square inch. These ex- 

 pansion coils are placed in the top of 

 the various refrigerating boxes which it 

 is desired to cool and are equipped with 

 valves, both automatic and hand, in case 

 the thermostatic control is attached, 

 which allow the liquified gas to expand 

 gradually from the receiver into the ex- 



How Machine Works. 



If any one of these gases 

 is compressed to a liquid 

 state, stored in a container 

 and allowed to escape grad- 

 ually, it will absorb heat 

 and can be used over and 

 over again, it being only 

 necessary to remove the 

 heat which has been ab- 

 sorbed. With these facts in 

 mind, it will be readily un- 

 derstood that it is only nec- 

 essary to provide machinery which will 

 accomplish these transformations in or- 

 der to have a refrigerator in which a 

 temperature as low as 18 degrees above 

 zero, or even less, can be maintained for 

 almost any length of time. Such a 

 machine is made self-regulating by 

 attaching a thermostatic control. 



An ice machine consists of a com- 

 pressor, driven by an electric motor or 

 any form of power found most conven- 

 ient or economical at the place of instal- 

 lation, which compresses the gas into a 

 container, called a condenser, under 

 pressures varying with the kinds of gas 

 used as the refrigerant, over which a 

 constant stream of cold water flows. 

 The pressure is sufficient to transform 

 the gas into a liquid state and the water 



Occasional references in these columns 

 to mechanical refrigeration and the best 

 types of ice machines for florists have been 

 followed by numerous inquiries on this 

 subject from subscribers. To provide 

 answers to them and to furnish other inter- 

 ested readers with full information on the 

 subject, a careful study has been made by 

 a member of The Review staff, the results 

 of which are here set forth. The facts 

 stated by florists using ice machines are 

 allowed to speak for themselves. 



coils, a material with the greatest heat- 

 conducting properties is used, in order 

 that the greatest amount of heat can 

 be absorbed in the least possible time 

 by the refrigerant. 



The thermostatic or automatic control 

 has been made possible by the discovery 

 that certain metals respond readily to 

 temperature changes, expanding or con- 

 tracting as they become warmer or 

 colder. By using a metal which responds 

 readily to slight temperature changes, a 

 small switch has been perfected which 

 is placed within the cooling box, and 

 any slight variation of the temperature 

 in one direction or the other causes this 

 piece of metal to expand or contract, 

 thus opening or closing the 

 switch, which, in turn, con- 

 trols the expansion valve, 

 either opening or closing it, 

 allowing more of the re- 

 frigerant to pass into the 

 expansion coils if the box is 

 becoming too warm, or stop- 

 ping the flow entirely in 

 case the temperature in the 

 box goes too low. The sup- 

 ply of water which flows 

 over the condenser is also 

 regulated automatically in 

 the same manner, with the 

 exception that, in this case, 

 air pressure controls the 

 water valve instead of the 

 expanding and contracting 

 metal mentioned above. 



Two Systems. 



pansion coils, where evaporation takes 

 place and where the heat from the air 

 surrounding these coils is absorbed. 



This expansion valve is so regulated 

 that, with the compressor running, the 

 ]iressurc in the refrigerator coils will be 

 sufficiently low to produce the desired 

 degree of temperature. After the re- 

 frigerant is completely vaporized — that 

 is, returns to its gaseous state — due to 

 the reduced pressure and addition of 

 heat absorbed in the refrigerator coils, 

 the gas passes to the compressor, which 

 forces it hack into the condenser. 



Oil traps are also provided to catch 

 the small amount of oil that may by 

 chance creep past the piston rings of 

 the compressor and into the condenser. 

 In the construction of the expansion 



There are two distinct 

 methods of mechanical re- 

 frigeration. The method 

 described above is known 

 as the direct system of re- 

 frigeration. It is called the 

 direct system because the 

 expansion coils are placed 

 directly within the box to be cooled; 

 these coils are not only within the 

 box itself, but are also directly above 

 the contents of the box. Herein lies 

 a disadvantage in the direct system, 

 because there is ever present the 

 possibility of a leak in the ammonia 

 pipes, and should such a leak occur, the 

 ammonia would ruin the contents of 

 the box if they were exposed, as in the 

 case of flowers in vases. Whore carbon 

 dioxide (carbonic acid gas) is used as a 

 refrigerant, this possibility is obviated 

 because carbon dioxide has not the inju- 

 rious properties of ammonia gas. 



The second system of mechanical re- 

 frigeration is known as the indirect 

 method. In the indirect method the 

 same apparatus and principles are em- 



