| 摘要 |
<p>1,017,013. Cooling liquids. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. Jan. 28, 1964 [Jan. 31, 1963], No. 3586/64. Heading F4H. Apparatus for maintaining a liquid at a constant temperature or density comprises a thermo-electrically cooled contact member which at said predetermined temperature or density is immersed to a predetermined depth in the liquid and is so arranged that deviation in the liquid temperature or density cause the contact member to be immersed to a greater or lesser degree to extract greater or lesser amounts of heat from the liquid. As shown, water in a flask 3 is maintained at freezing point by a pivotally mounted member 7 on which a thermo-electric cooling device 11 is mounted, the hot junctions of device 11 being connected to heat-dissipating fins 14. As ice forms on the lower part of the member 7 the latter is pivoted anticlockwise to reduce the area of contact between the member and the water and thus to reduce the rate of heat withdrawal. This rate is further reduced by a member 13 secured to member 7 which projects from the apparatus when member 7 is raised and absorbs heat from the ambient air. In one modification (Fig. 2, not shown) the thermoelectric device is fixed and contact between it and the member 7 is broken when the latter rises. In another modification (Figs. 3 and 4, not shown) the member 7 is in contact with the fixed device 11 via a mercury bath, the area of contact between the mercury and the member 7 being progressively reduced as the latter is raised. The lower end of the member 7 may be hollow and filled with the liquid to be cooled.</p> |
