CONFIDENTIAL REPORT 2G-9C
S59
     
 
FORMER GERMAN SUBMARINE TYPE IXC
  
 
 
 
REFRIGERATION
  
     
 
SUMMARY
  
     
          The IXC German Submarine has a limited amount of refrigeration capacity.  The only refrigerated space provided is that in the small galley refrigerator.  The unit is no larger then a domestic refrigerator, and is not adequate in terms of US vessel practice.  
     
     
     
     
     
     
     
     
     
     
     
     
     
     
 
July, 1946
 
 
 
 
PORTSMOUTH NAVAL SHIPYARD, PORTSMOUTH, N. H.
 
     
 
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9C-S59
     
  1.  General Description  
          A comparatively small refrigeration unit is installed on the port side of the pantry.  It consists of an icebox normally kept between 35-39°F. and a small ice cuber capable of making 13.2 lbs of ice per day.  The compressor, its motor and the condenser are on a common bed plate on top of the ice box.  Two sets of cooling coils, one rated at 250 Kg cal/hr (.0826 tons) and the other at 85 KG cals.hr (.0281 tons), are set in series within the ice box.  
          The ice box has a wooden frame and is built of sheet metal on the sides, top and bottom and of aluminum on the rear.  Aluminum foil and "Torfat" (a granulated cork compound) are used for insulation between the wood and metal.  The outside dimensions of the ice box are 41.5 x 51.2 x 53.1 ins.  
          Freon is used as the cooling agent in a more or less standard refrigerant cycle.  The path of freon through the cycle is as follows:  
          1.  Compressed in the compressor  
          2.  Cooled and liquefied in an air cooled condenser  
          3.  Settles into freon collecting tank  
          4.  Passes through freon strainer and h.p. side of a small freon heat exchanger where it is further cooled by the low pressure freon.  
          5.  Enters the thermo - controlled expansion valve where it expands to vapor.  
          6.  Passes through the largest set of cooling coils and then through a second smaller set.  
          7.  Flows through the l.p. side of the freon heat exchanger and then passes to the suction side of the compressor.  
          Low and high pressure cut out switches are installed in the compressor motor circuit.  The former is activated by the suction pressure at the compressor and the latter by the pressure in the collecting tank.  
     
 
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9C-S59
     
          The units within the circuit are of standard design and in most cases do not represent the latest developments.  The compressor has two single acting pistons and is air cooled.  A rather complicated shaft seal is used wherein oil pressure greater than the suction pressure of the freon is used to prevent freon leakage out along the shaft.  An obsolete type of thermostatically controlled expansion valve is used.  Regulation of valve setting is controlled through the medium of expanding bellows, whereas on better designs, diaphragms are used.  
     
  2.  Individual Components  
          a.  Compressor  
 
 
Compressor
Motor
Volts
110
170
RPM
345
430
KW        
Capacity (tons) .0826 at cooling coil temp. of +5°F and cooling air temp. of 86°F.        
 
          b.  Cooling Coils  
 
 
Main
Auxiliary
Rating .0826 Tons refrig. with temp diff. of 31°F and 13.2 lbs ice per day .029 tons refrig. with temp. diff. of 31°F.
 
     
  3.  Conclusions  
          The refrigeration system on the IXC submarines is not considered adequate for extended patrols.  No cold storage box was installed and the capacity of provision stowage ice box is small for the relatively large crew carried on the vessel.  The refrigerant cycle is standard in nature and offers nothing of particular interest.  
     
 
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