Liquid-gas contact tray

Claim 2

In a circular edged liquid-gas contacting tray of the slotted sieve-type for effecting intimate contact between rising vapor and liquid flowing across the tray in a diverging-converging pattern from a liquid inlet at one outer edge to a liquid discharge at an opposite outer edge in which a multiplicity of band members are provided with main flat top and bottom surfaces and arranged with outer edges of adjacent band members contiguously positioned transverse to liquid path and a plurality of fixed size openings uniformly distributed across such band members and extending therethrough with walls normal to said main flat top and bottom surfaces for gas flow, and a plurality of elevated portions formed form said band members across said surfaces each with an upper surface raised from said main flat top surface having a front leading edge separated from said main flat top surface to form an elongated slot opening therewith of greater width than height, the raised upper surface being inclined to said main flat top surface and having a back edge integral with such surface and each elevated portion being spaced from adjacent elevated portions by said main flat top surface entirely surrounding such elevated portion, and each elevated portion being oriented with its back edge upstream of its slot opening with respect to the liquid flow path, the improvement comprising: at least two adjacent band members with a first upstream band member having relatively lower slot density across said surfaces and a second downstream band member having relatively higher slot density across said surfaces, the band member with a downstream edge at said liquid outlet having the highest slot density of all band members, and the average slot densities upstream and downstream the tray transverse centerline being such that lambda 2/ lambda 1 is greater than 1 and less than 5 where lambda is defined by the equation lambda fs Cs/fs Cs + fp Cp where fs total area of the slot openings expressed as a fraction of the active portion of a particular tray part fp total area of the normal fixed size openings expressed as a fraction of the active portion of the same tray part Cs orifice coefficient of the slots Cp orifice coefficient of the normal fixed size openings, and where lambda is the tray part upstream of the tray transverse centerline and lambda 2 is the tray part downstream of the tray transverse centerline.

Claim 3

A tray according to claim 1 in which lambda 2/ lambda 1 is between 1.2 and 2.5

Claim 4

A tray according to claim 1 in which lambda for the band member with its downstream edge at the lquid outlet is less than 0.3.

Claim 5

A tray according to claim 1 in which lambda for the band member with its downstream edge at the liquid outlet is less than 0.2.

Claim 6

A tray according to claim 1 in which the tray diameter is greater than 10 feet and with at least three band members having progressively higher slot densities in the direction of the liquid flow path.

Claim 7

A tray according to claim 1 of the parallel flow type with a center baffle extending from edge to edge of said tray along the diameter thereof so as to divide the tray into two equal parts; liquid inlet means at the edge of one tray part immediately adjacent a first end of said center baffle for flow thereacross, and liquid outLet means immediately adjacent a second end of said center baffle at the opposite edge of said one tray part; liquid inlet means at the edge of the other tray part immediately adjacent said second end of said center baffle for flow thereacross in the opposite direction to the liquid path across said one tray part, and liquid outlet means immediately adjacent said first end of said center baffle at the opposite edge of said other tray part; and band members immediately downstream said liquid inlet members of said one and other tray parts having only said fixed size openings and not having said slot openings.

Claim 8

A tray according to claim 1 in which at least some of the slot openings in the tray part downstream the tray transverse centerline are angularly oriented with respect to and toward the tray diametral streamline such that: (a) the slot angle of individual slots increases in the transverse direction to the liquid flow path from the diametral streamline to the tray outer edge, (b) the slot angle of individual slots also increases in the longitudinal direction of the liquid flow path to the liquid outlet, and (c) the slot angle of individual slots immediately adjacent said liquid outlet and the tray active surface outer edge at the point of intersection with said liquid outlet is within 20* of the angle formed by a tangent line at said point of intersection and said diametral streamline, and represents the maximum slot angle on said tray; less than 15* slot angle of said slot openings in the tray part upstream the tray transverse centerline and away from the diametral streamline; and a longitudinal part of said tray containing the diametral streamline and extending from the liquid inlet to the liquid outlet having 0* slot angle.

Claim 9

A tray according to claim 7 in which the slot angle of all slot openings in the tray part upstream the tray transverse centerline is 0*.

Claim 10

In a circular edged liquid-gas contacting tray of the slotted sieve-type for effecting intimate contact between rising vapor and liquid flowing across the tray in a diverging-converging pattern from a liquid inlet at one outer edge to a liquid discharge at an opposite outer edge in which a multiplicity of band members are provided with main flat top and bottom surfaces and arranged with outer edges of adjacent band members contiguously positioned transverse to liquid path and a plurality of fixed size openings uniformly distributed across such band members and extending therethrough with walls normal to said main flat top and bottom surfaces for gas flow, and a plurality of elevated portions formed from said band members across said surfaces each with an upper surface raised from said main flat top surface having a front leading edge separated from said main flat top surface to form an elongated slot opening therewith of greater width than height, the raised upper surface being inclined to said main flat top surface and having a back edge integral with such surface and each elevated portion being spaced from adjacent elevated portions by said main flat top surface entirely surrounding such elevated portion, and each elevated portion being oriented with its back edge upstream of its slot opening with respect to the liquid flow path, the improvement comprising: angular orientation of at least some of said slot openings in the tray part downstream the tray transverse centerline and with respect to and toward the tray diametral streamline such that: (a) the slot angle of individual slots increases in the transverse direction to the liquid flow path from the diametral streamline to the tray outer edge, (b) the slot angle of individual slots also increase in the longitudinal direction of the liquid flow path to the liquid outlet, and (c) the slot angle of individual slots immediately adjacent said liquid outlet and the tray surface outer edge at the point of intersection with said liquid outlet is within 20* of the angle formed by a tangent line at said poInt of intersection and said diametral streamline, and represents the maximum slot angle on said tray; less than 15* slot angle of said slot openings in the tray part upstream the tray transverse centerline and away from the diametral streamline; and a longitudinal part of said tray containing the diametral streamline and extending from the liquid inlet to the liquid outlet having 0 degree slot angle.

Claim 11

In a circular edged liquid-gas contacting tray of the slotted sieve-type for effecting intimate contact between rising vapor and liquid flowing across the tray in a diverging-converging pattern from a liquid inlet at one outer edge to a liquid discharge at an opposite outer edge in which a multiplicity of band members are provided with main flat top and bottom surfaces and arranged with outer edges of adjacent band members contiguously positioned transverse to liquid path and a plurality of fixed size openings uniformly distributed across such band members and extending therethrough with walls normal to said main flat top and bottom surfaces for gas flow, and a plurality of elevated portions formed from said band members across said surfaces each with an upper surface raised from said main flat top surface having a front leading edge separated from said main flat top surface to form an elongated slot opening therewith of greater width than height, the raised upper surface being inclined to said main flat top surface and having a back edge integral with such surface and each elevated portion being spaced from adjacent elevated portions by said main flat top surface entirely surrounding such elevated portion, and each elevated portion being oriented with its back edge upstream of its slot opening with respect to the liquid flow path, the improvement comprising: angular orientation of at least some of said slot openings in the tray part downstream the tray transverse centerline and with respect to and toward the tray diametral streamline such that: (a) the slot angle of individual slots increases in the transverse direction to the liquid flow path from the diametral streamline to the tray outer edge, (b) the slot angle of individual slots also increase in the longitudinal direction of the liquid flow path to the liquid outlet, and (c) the slot angle of individual slots immediately adjacent said liquid outlet and the tray surface outer edge at the point of intersection with said liquid outlet is within 20* of the angle formed by a tangent line at said poInt of intersection and said diametral streamline, and represents the maximum slot angle on said tray; less than 15* slot angle of said slot openings in the tray part upstream the tray transverse centerline and away from the diametral streamline; and a longitudinal part of said tray containing the diametral streamline and extending from the liquid inlet to the liquid outlet having 0 degree slot angle.

Claim 12

A tray according to claim 9 in which the slot angle of all slot openings in the tray part upstream the tray transverse centerline is 0* .