Holddown plate

As indicated above, packed column internals include hqiiid distributors, packing support plates, redistributors (as needed), and holddown plates (to prevent movement of packing under flow conditions). Costs of these internals for columns with random packing are given in Fig. 14-80, based on early 1976 prices, and a Marshall and Swift cost index of 460. 

FIG. 14-80 Cost of internal devices for columns containing dumped packings, a) Holddown plates and support plates, (h) Redistributors, (c) Liquid distributors. [Pikulik and Diaz, Cbem. Eng., 84(21), 106 (Oct. 10, 1977).]... 

Place the sandwich in the IR salt plate holder and cover it with a holddown plate. 

Open area of holddown plate = 30 percent (Answer 40 percent x 70 percent X 30 percent = 8.4 percent.)... 

As a result, the tower flooded above the holddown plate. To fix this problem, the packing holddown was dropped 15 in below the chimney, orifice plate, distributor. As a result, the tower fractionated properly. 

Holddown plates and support plates, h) Redistributors. [PikuUk and Diaz, Tower wall thickness, mm... 

Packed columns, c/s column with c/s Raschig rings including support trays, holddown plates, distributor and redistributor trays including column with some nozzles but no access holes. FOB cost 28000 at the product of (column height, m) (diameter, m) = 2.8 with n = 0.65 for the range 0.5-2.8 m and n = 0.9 for the range 2.8-85. L-i-M = 2.9. L/M = 0. 4. 

The metallic internal structures are composed of the core vessel, upper and lower support plates, holddown plates and a positioning plate. They provide support and housing to the ceramic internal structures and also transmit the mechanical loads coming from the fuel pebble bed and the ceramic internals to the reactor pressure vessel. 15CrMoR is selected as the material for most metallic core internal structures. The total weight of the metallic core internals is about 72.5 t. 

In the first molding step, half of the fluoroplastie resin was charged into the mold. Next, the bearer and core assembly was set in the mold. Then the other half of the resin was dispensed into the mold. The holddown plate was used to compress the eontents of the cavity while the mold was heated to a temperature above the melting point of the fluoroplastie resin. After eool-ing, the part can be removed and maehined to the required specifications. 

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