Patent GB-801621-A (GB)
Title: Method and apparatus for forecasting and controlling atmospheric conditions in storage compartments
IPC: B63J2/08
Filed: 1954-10-05
Abstract: 801,621. Air conditioning. COLVIN, O. D. Oct. 5, 1954 [Oct. 12, 1953], No. 28687/54. Class 137 The dew-point temperature of the atmosphere within a storage copartment, e.g. a ship's hold, is controlled to prevent condensation, by plotting regularly or continuously in the form of tracks upon a chart, having common tine - temperature coordinates, the out-of-doors or weather dewpoint temperatures and the storage compartment dew-point temperatures and, according to the positions or trends of the heads of the tracks, recirculating the atmosphere within the compartment, or ventilating the compartment with outside air. The recirculation would, in general, be effected when the compartment drew-point is below the weather dew-point, and ventilation would be effected when the compartment dew-point is the higher. Fig. 1 shows a ship's hold divided into sections 10d, 10e, 10f by decks, and vertical conduits 35, 45 with horizontal branches 36, 37, 38 and 46, 47, 48 for delivering air into the hold and withdrawing it therefrom, by means of fans 43, 51, when the flap valves 39, 50 are vertical,- and for recirculating the air in the hold when the valve 39, 50 are horizontal, in which position the open ends 40, 49 of the condits 35. 45 are blanked off and passages 54, 53a are opened to the conduits. The tracks are drawn upon a chart 26 which is on rollers 27, 28 operated by time-means 29, a type-wheel 31 having embossed on its periphery a number of symbols, one for each of the factors to be delineated as tracks upon the chart. For example, the symbols may be the letters W, T, C, D denoting weather dew-point, weather dry bulb temperature, cargo dry bulb temperature and dehumidifier-air dewpoint temperature when a supply means 14 for dehumidified air is provided; and the numbers 1, 2, 3, 4 denoting dew-point temperatures in holds 1, 2, 3, 4 respectively. The type wheel is capable, under the influence of control means 32, of axial movement as shown by arrow 33, radial movement as shown by arrow 34, and a rotary movement to alter the symbol to be applied to the chart. In the example shown, with eight symbols, a sensing apparatus is operated at 15 second intervals, so that each symbol is printed on the chart once in two minutes. The control means 32 is operated by sensing means comprising a weather dry bulb thermometer 15, a humidity sensitive means 16 such as is described in Specification 555,303 [Group XX] for measuring weather dew-point and similar sensing means 17, 18, 19a, 23, 24 for influencing the control means 32 according to conditions existing in the storage space or spaces. From observation of the tracks on the chart 26, decisions may quickly be made as to what, if any, change in humidity conditions is required in any hold, and such decisions are implemented by pressing a button or buttons 55, 56, 61, 59 on a panel 41, such buttons activating circuits for operating flap valves 39, 50, 60, and fan motors 43, 51. The track printing means may be modified by having separate pens, closely arranged so as to be separated as little as possible as regards the time ordinate of the chart, for each characteristic to be delineated. The chart may be a rotary circular one, and the pens may be oscillated about the axis of the control means instead of, as in Fig. 1, being reciprocated along the arrow 33. The invention may be used for inducing artificially the deposition of sweat upon the cargo where this is desirable.