Patent GB-726805-A (GB)
Title: Improvements in or relating to the deaeration of viscose
IPC: D01F2/08
Filed: 1952-09-29
Abstract: <PICT:0726805/IV (a)/1> <PICT:0726805/IV (a)/2> Viscose is deaerated by introducing it into an inner chamber until it reaches a level somewhat below the top while simultaneously or subsequently reducing the pressure in a closed outer chamber surrounding and covering the upper portion of the inner chamber until the viscose boils, and allowing the foam thereby formed to flow over the top of the inner chamber or through an opening in a cover of the inner chamber into the outer chamber.  As shown in Fig. 1, viscose is continuously introduced through a conduit 1 into an inner chamber 3 while an outer chamber enclosing the inner chamber is evacuated through a conduit 2. A layer of foam formed by the boiling of the viscose in the chamber 3 continuously flows over the wall of the chamber 3 and via an annular space 4 between the chamber 3 and the wall of the outer chamber to a barometric discharge pipe 5, about 11 metres long, provided at the bottom with a pump (not shown).  The deaerated viscose is continuously removed from the inner chamber 3 through a conduit 6, which may also be a barometric discharge pipe provided at the bottom with a pump.  As shown in Fig. 2, the viscose discharged into the inner chamber 3 from the inlet conduit 1 passes over a horizontal corrugated plate 7 surrounding the mouth of the inlet conduit. The greater part of the foam is formed on this plate, due to the large surface area offered by the viscose when flowing over it. The excess foam enters the annular space 4 between the inner and outer chambers through an opening 8 in the cover of the inner chamber.  The inner chamber 3 may be provided with a vertical overflow pipe projecting through the bottom of the chamber and maintaining the viscose in the chamber at a constant level.  The continuous removal of foam enables the viscose to be rapidly deaerated without the deposition of films of coagulated viscose on the upper walls of the deaerator. Specification 726,804 and U.S.A. Specification 2,355,057 are referred to.ALSO:<PICT:0726805/III/1> <PICT:0726805/III/2> A liquid, such as viscose (see Group IV (a)) is de-aerated by introducing it into an inner chamber until it reaches a level somewhat below the top while simultaneously or subsequently reducing the pressure in a closed outer chamber surrounding and covering the upper portion of the inner chamber until the liquid boils, and allowing the foam thereby formed to flow over the top of the inner chamber wall or through an opening in a cover of the inner chamber into the outer chamber.  As shown in Fig. 1, the liquid is continuously introduced through a conduit 1 into an inner chamber 3, while an outer chamber is evacuated through a conduit 2.  A layer of foam formed by the boiling of the liquid in the chamber 3 continuously flows over the wall of the chamber 3 and via an annular space 4 between the chamber 3 and the wall of the outer chamber to a barometric discharge pipe 5, about 11 metres long, provided at the bottom with a pump (not shown).  The de-aerated liquid is continually removed from the inner chamber 3 through a conduit 6 which may also be a barometric discharge pipe provided at the bottom with a pump.  As shown in Fig. 2, the liquid discharged into the inner chamber 3 from the inlet conduit 1 passes over a horizontal corrugated plate 7 surrounding the mouth of the inlet conduit.  The greater part of the foam is formed on this plate, due to the large surface area offered by the liquid when flowing over it. The excess foam enters the annular space 4 between the inner and outer chambers through an opening 8 in the cover of the inner chamber.  The inner chamber 3 may be provided with a vertical overflow pipe projecting through the bottom of the chamber and maintaining the liquid in the chamber at a constant level.  The continuous removal of foam enables liquids containing dissolved solids to be rapidly de-aerated without formation of deposits on the upper walls of the apparatus. Specification 726,804 and U.S.A. Specification 2,355,057 are referred to.