Ballast Tray Design Manual Bulletin No 4900 International

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GOVERNMENT OF ANDHRA PRADESHSCHEDULE OF RATESAS PERA.P. REVISED STANDARD DATAFOR THE YEAR 2012-2013(Effective from 1st June, 2012)BOARD OF CHIEF ENGINEERSMASTER INDEXSl.No.DescriptionPage No.From To1Part –I (Irrigation & CAD Works) & Part – IV (PublicHealth Work Items)1 1382 Part-II (Road & Bridges) 1 313 Part – III (Buildings) 1 2664 Annexure (Seigniorage Charges) 1 5GOVERNMENT OF ANDHRA PRADESHPART-I&PART-IVSCHEDULE OF RATESAS PERA.P.

REVISED STANDARD DATAFOR THE YEAR 2012-2013(Effective from 1st June, 2012)BOARD OF CHIEF ENGINEERSOffice of the Engineer-in-Chief(I.W.)I & CAD Dept., Errum manzil, Hyderabad.Procs.No.ENC/IW/P&M/EE3/DEE10/5/AE/13305/12/Vol-34, dt:09.7.2012.Sub: Schedule of Rates as per Revised Standard Data for the year 2012-13 – Irrigation &CAD works (part-1) and Drinking water supply schemes (part-4) - approved-Printing & Communication of SoRs – Reg.Ref: 1. G.O.Ms.No.49, I & CAD (PW: Reforms) Dept., dt.2-3-2009.2. E-in-C (PH) Lr.No.146/T1/SoR/20 dt.3. Commissioner, lab our department rates down loaded from Net.4. Minutes of B.O.CE’s meeting for Schedule of Rates held on dt.14-6-2012.-o0o-The Government have approved Revised Standard Data vide ref 1stcited. The Schedule ofRates as per A.P.

Revised Standard Data for the year 2012-13 is approved based on the following.The Engineer-in-Chief, Public health Department has furnished draft rates for PublicHealth Work Items and Public Health materials vide ref 2ndcited.The ENC(R&B) Department and ENC (P.R) Department have not furnished theSoR as per A.P.Revised Standard Data.For Irrigation & CAD Work Items, the regional Superintending Engineers of IrrigationCircles of Hyderabad, Chittoor & Dowlaiswaram in charge of Telangana, Rayalaseema and Andhraregions respectively have submitted the draft basic rates of materials. The SuperintendingEngineer, Mechanical Circle, Hyderabad has furnished draft rates of mechanical and workshopitems.

FIELD OF THE INVENTIONThe invention relates to the design and construction of vapor-liquid contacting apparatus. The invention therefore relates to apparatus used within gas scrubbing columns or fractional distillation columns to, for example, perform separations of volatile chemical compounds. The invention specifically relates to apparatus used as fractional distillation or contacting trays. PRIOR ARTVapor-liquid contacting trays are used in gas scrubbing or treating columns to remove a specific contaminant such as hydrogen sulfide. One specific type of vapor-liquid contacting tray is the fractional distillation tray.

These trays are widely employed in the hydrocarbon processing, chemical, and petrochemical industries. Accordingly, a large amount of research, development, and creative thinking has been devoted to providing improved vapor-liquid contacting trays and especially fractionation trays. Entire texts are devoted to the subject. Fractionation tray development has therefore provided many variations in contacting area structure, downcomer design, and overall tray structure.U.S. 3,410,540 issued to W. Bruckert is believed pertinent for its showing of the structure of a prior art 'multiple downcomer' tray employing the highly distinctive downcomer design similar to that employed in the subject tray. This reference illustrates alternative downcomer designs and possible variations for sealing the downcomer outlet.

5 shows serpentine bracing means located within the downcomers (column 14, line 17).The use of 'anti-jump' baffles located above the inlet to downcomer is known in the art as illustrated by FIG. 10 in the ballast tray design manual issued by Glitsch Incorporated (Bulletin No. 4900-fourth edition, copyright 1974).U.S. 4,028,191 issued to N. Scott is believed pertinent for its showing of a fractionation tray design in which vertical baffles descend from the lower surface of an upper fractionation tray. The baffles are employed on a cross-flow tray and oriented perpendicular to liquid flow across the tray. The baffles do not extend downward to the upper surface of the next lower tray.Most trays have circular perforations evenly distributed across the contacting surface (decking) of the tray.

These allow the rising vapor to flow straight upward from the tray's surface. A smaller subset of fractional distillation trays utilize mechanical means such as small 'slot' in the tray surface for directing the vapor in a specified direction as it passes upward through the contacting area of the tray.U.S. 3,282,576 to W. Bruckert et al. Is believed pertinent for its showing of a cross flow tray having a receiving pan and a bubble promoting device. The reference also teaches that slots may be placed across the surface of a sieve-type liquid gas contacting tray to promote the flow of liquid across the tray without the aid of liquid gradients.

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3,417,975 to B. Williams et al. Is believed pertinent for its teaching of other variations in fractionation tray design such as variations in the tray or deck active area surface material.

Ballast Tray Design Manual Bulletin No 4900 International Parts

In this reference, the deck portion of the tray comprises both circular perforations and also flow directing slots. 1-5 of this reference illustrate tray deck materials and perforation types which may be employed in the subject invention.U.S. 4,499,035 issued to R. Kirkpatrick et al. Is believed pertinent for its showing of the provision of froth initiation or bubble-promoting means at the liquid entrance to the tray deck area from the inlet downcomer.

Ballast Tray Design Manual Bulletin No 4900 International Truck

This reference appears to employ conventional downcomers and seal pans and provides a description of alternative designs for these tray elements. BRIEF SUMMARY OF THE INVENTIONThe invention is an improved multiple downcomer contacting tray, as opposed to the more widely used cross-flow tray, which provides highly stable performance during disturbances in fluid flow such as would be caused by lateral movement. In the invention three types of fluid baffles are located within the downcomers or upon the upper surface of the tray. Bubble-promoting devices are spread across the tray and located on the periphery of the tray.