Patent GB-1402311-A (GB)
Title: Process for the washing of comestible materials
IPC: A23L5/10
Filed: 1972-01-19
Abstract: 1402311 Washing comestibles BLAW-KNOX FOOD & CHEMICAL EQUIPMENT Inc 19 Jan 1972 [21 Jan 1971] 2590/72 Heading A4C [Also in Divisions B2 and C1] Washing process: A process for washing a raw particulate comestible with water comprises passing the comestible through an elongate tube 56 having an upwardly extending portion in concurrent contact with a water stream to remove substances from the comestible therewith, and passing the substance-enriched water stream to a concentrating zone to separate it into a concentrated substance-enriched slurry and a substancelean water stream. Washing apparatus: Raw whole potatoes are introduced into a washer 12 where water from a line 14 removes soil &c. The potatoes are transferred to an abrasive peeler 20 and the peeled potatoes are sliced in a slicer 28. The sliced potatoes are conveyed to a blanching tank 32 where they gravitate through baffles 34 against a countercurrent of water from a line 40 flowing upwardly through perforated plates 36. Starch washed from the potatoes overflows a weir 38 and passes as starch slurry into a line 44. The slices are fed through an outlet 46 into the washing tube 56 in concurrent contact with wash water from lines 31 and 51. The slices pass to a shoot 58 and perforated conveyers 60, 66 to separate the slices from water and suspended solids and then into a deep-fat fryer 210. The separated water collects in a tank 62 together with fresh water from a line 64. Starch slurry from the tank 62 and the line 44 is combined and the mixture passes via a line 76 and a pump 80 to a hydrocyclone 86 where the slurry is separated into a concentrated starch slurry in a line 96 and a starch-lean stream in a line 88. The starch-lean stream is fed back via the line 51 to the washing tube 56 and constitutes the wash water. The concentrated slurry is settled in a plurality of tanks 98 from which the starch is removed through a line 101 using a cascade system. The blanching tank 32 may be bypassed by a line 31, in an alternative mode of operation. Cooking oil condenser: Recovery of oil vapour from the fryer 210 is accomplished in a condenser 110 having a fan 117 and coaxial tubes 118, 124 and 126. The tube 118 is closed at the top and communicates with the interior of the condenser 110 through a port 122 and the tube 124 is open at the top. The tube 126 is bent at its ends and passes through the tubes 118 and 124 in liquidtight manner. The condenser 110 has a vapour inlet 138, a mesh screen 140 and spray nozzles 142 fed with cold water from a line 166. The condensed oil and water settle at the bottom and the oil is siphoned off through the tube 126 while the water overflows through the port 122 and the tube 124 into a line 140. Water circuits: The water in the line 140 passes through a heat exchanger 142 where it heats the wash water before returning it to the washing tube 56. The water flowing out of the heat exchanger 142 may be divided between the lines 154, 158 and 150 to the washer 12 via line 14, a cooling tower 162 and to the washing tube 56 respectively. Water from the cooling tower 162 is pumped back to the condenser 110 and this part of the circuit may be a closed loop. Alternatively, the cooling water to the condenser 110 is fresh water and the washing water in the lines 14, 22 is used water in the line 148. The only other fresh water source is the line 64.