Tray supports, weights

Tray support weights Include downcomer bolting bars as well. 

Mineral wool/cement board—Perforated and solid sheet metal and ladder-type cable trays can be completely enclosed with 1 in (25 mm) minimum thickness mineral wool/cement board panels, or equivalent. The panels should be secured with stainless steel screw and stainless steel bands in (19 mm) wide by 0.02 in (0.5 mm) thick, located no more than 18 in (450 mm) apart. In freezing climates the fireproofing panels should be given a weatherproof coat of paint. The structural strength of the metal cable tray should be adequate to support the weight of the fireproofing. 

Weight. Tray towers usually weigh less than packed towers, saving on the cost of foundations, supports, and column shell. 

Since cartridge trays are not fixed to support rings (like normal trays) they can be easily uplifted. Kitterman (2066) shows that the weight of the trays does little to resist uplift. The pressure drop sufficient to uplift a bundle is set by the shell friction, and this can be small. Uplifting has been troublesome on many occasions. In one... 

Design Loads Trays, pans, drawoff boxes, or similar internals, shall be designed using a corroded thickness, to support their own weight plus the following live loads ... 

In doing batch-drying experiments, certain precautions should be observed to obtain usable data under conditions that closely resemble those to be used in the large-scale operations. The sample should not be too small in weight and should be supported in a tray or frame similar to the large-scale one. The ratio of drying to nondrying surface (insulated surface) and the bed depth should be similar. The velocity,... 

The use of a factor of three times the dead weight capacity with respect to normal acceptance criteria is apphcable to cable trays with ductile supports (which permit large lateral movements without failure). 

If the vessel does not contain internal attachments, such as trays which support liquid, but consists only of the shell insulation, the heads, and minor attachments such as manholes, nozzles, and sts on, the additional load may be estimated as approximaici) cqua to 18% of the weight of a. steel sliHI. or as shmvn i>y Ncliion (139),... 

Mechanical stability without supporting devices. Solutions that dispense with battery trays (saving cost and weight) are especially advantageous. 

If the steam is at higher pressure than the process (which is frequently the case) and if one of the reboiler tubes develops a leak, steam will enter the process and flow up the distillation column. Given that the water has a much lower molecular weight than most chemicals that are being distilled, the volumetric flow of gas up the column can be so large that the trays or packing in the column are lifted up off their supports and seriously damaged. 

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