Bubble cap trays feature a riser with a cap on top, allowing the vapor to flow through the rise and around the cap, coming into contact with the liquid as it. Report bubble cap tray please fill this form, we will try to respond as soon as possible. Turndown, a term for the decrease of efficiency due to low tray vapor velocity, is important to consider when using heat integrated distillation columns the images below show a sieve tray left, a valve tray center, and a bubble cap tray right. In bubble cap trays, vapor flowing up through the tower contacts the liquid by passing through bubble caps figure 6. The bubble caps were 3 in diameter with square openings. Large if froth is expected, also allow space for crawling 12 to 24. The liquid enters the bubble cap stage through a pipe coming from a tray just above the depicted bubble cap tray.
Some of the vapor condenses overflows the weir on the tray and falls down the column. Normag bubble cap tray with bubble cap over flow tube glass weir bubble cap tray column, 5stage bubble cap tray column, silvercoated with. The pressure drop for vapor flow from one tray to the next is designated h t and has the value that would be read from a manometer tapped to the vapor space of adjacent trays see figure 1 h t is segregated into the following resistances. Bubble cap trays are also flat and perforated but have fixed risers over the holes and multi design caps in the form of inverted cups over the risers. The limits of vapour loading required for a steady hydrodynamic tray operation are found. Bubble cap column is a bell shaped cap which is fixed on the top of a cylindrical risers through which the vapor passes the tray deck.
Each hole is provided with riser small, short pipes set into the tray or chimney with a cap over it. Because of their design, bubble cap trays cannot weep. Trays are supported in a vessel by means of support rings or beams. There it will be seen that the plate contains 27 bubble caps each 59 cm diameter arranged on a 14. Pdf masstransfer efficiency of a smallsize teflon bubblecap. The cap is mounted so that there is a space between riser and cap to allow the passage of vapor. Design and scaleup the design and scaleup of bubble columns have gained considerable attention in recent years due to complex hydrodynamics and its in. Distillation equipment, distillation trays, tray tower scube. In all types of impingementplate scrubbers, the scrubbing liquid flows across each plate and down the inside of the tower onto the plate below. Bubble cap design free download as powerpoint presentation. For bubble cap trays the gas flow path is very different compared to other tray. The cap is mounted so that there is a space between riser and cap to allow the passage for vapour.
They are usually equipped with slots to allow the passage of vapor. The vapour enters the tray, turns 90 degrees through the bubble cap and leaves the plate to rise upwards via the slots. Some components may be beams or stand alone beams may be included. Our design team is well experienced in tower rating and can select or advise you on the type of tray most suitable for the given conditions. All tray product designs have been proven products can also be. Another practical design for a stripping column is structured packing, in which thin corrugatedmetal sheets form triangular cross sections. Analyzing this flooding phenomenon and why it happens below its design specifications are one of the purposes for this thesis. Mtl can manufacture and supply you with all sizes of bubble caps and assemblies from 2 up through 6. A bubble cap tray has riser or chimney fitted over each hole, and a cap that covers the riser. Number of plates specify the number of bubble plates trays.
Reprinted from seader 1998 the column design allowed for variation in the feed point. Pdf distillation column tray hydraulics selection, sizing. Among them, sieve trays offer high capacity and efficiency, low pressure drop. Some of the alcohol in the liquid vaporizes creating a higher concentration of alcohol and rises further in the column where the process is repeated at the net bubble cap tray. Sulzer offers a standard cap for 3 and 4 and a slotted type for 6. Bubble cap riser or chimney fitted over each hole, and a cap that covers the riser.
Bubble cap trays for high turndown bubble cap trays are generally used for low liquid loads and have a very high turn down ratio. However, bubble cap trays are also more expensive and have a lower capacityhigher pressure drop than valve trays or sieve trays. Diameter ditentukan oleh hubungan yang dikorelasikanoleh faktorfaktor empiris. Most of the glycol dehydration contactors have 4 to 10 bubble cap trays with standard 24inch tray. A bubble cap tray is perforated flat plate which has a riser chimney over the holes covered with a cap.
Bubble cap trays are installed inside the column, as drawn in gure 3. The cap is mounted so that there is a space between riser and cap to allow the passage of vapour. Fractionation trays including sieve, round valve, rectangular valve and bubble cap trays just to name a few. Fluid velocity larger than ascending bubbles minimum width. Pdf currently distillation is the most commonly used separation purification technique in many. Bubble cap trays are generally used when no leakage is allowed.
Bubble cap trays also remain as an excellent defense mechanism against fouling. In bubble cap trays, vapor flowing up through the tower contacts the liquid by passing through bubble. Dry gas exits the top of the absorber tower and passes through the glycolgas heat exchanger to the gas outlet. It was learned that a twelveinch bubble cap column was. They are also used for low liquid loads and have a very high turndown ratio. We have little experience in the design of distillation columns and. Bubble cup geometries can either be defined directly or accessed via the database. In the lower part of gure 3, the bubble cap is seen from the side. Phd, pe, in surface production operations third edition, volume 2, 2014 6. The cap forces the vapor into the liquid sitting on top of the tray.
In this type of trays, gas strikes the cap and dispersed back to the liquid. In terms of capacity, however, they are slightly lower than valve or sieve trays. Regardless of the oem, we can manufacture most kinds of trays in any type of metallurgy from carbon steel to hastelloy b3, without sacrificing reliability or quality. Vapour rises through the chimney and is directed downward by the cap, finally discharging through slots in the cap, and finally bubbling through the. A cap is mounted over a riser in such a way that, a proper space for the passage of. Part 3 mechanical designs for tray performance sciencedirect. The performance of the column in relation to the process requirements dew point is determined by carefully selecting the following parameters. Quite similar to sieve tray, as high or higher than bubble cap tray from 50% up to 100% design rate varies with system and design criteria. Bubble cap trays a bubble cap tray has riser or chimney fitted over each hole, and a cap that covers the riser. Pdf design of distillation column for separating a.
Details of the cap plate and bubble caps are presented in figures 2 and 3. Bubble caps and the like also prevent liquid from flowing down the perforations if the gas flow is reduced epa, 1998. Bubble cap design phases of matter chemical engineering. Apr 24, 2015 be removed from a water stream using air. Each tray had a diameter of approximately 14 and contained 18 bubble caps. Performance at specification quality falls off at lower rates. Each tray should be designed so as to give as efficient a contact between the vapour and liquid as possible, within reasonable economic limits. A tray consists of a metal plate having drilled or punched holes all over the plate. Bubble cap trays feature a riser with a cap on top, allowing the vapor to flow through the rise and around the cap, coming into contact with the. The vapor raises through the cap in the middle and is bubbled through the liquid on the stage. Alphatray design sheet tray configuration listed beloware the key tray design parameters which impact on column operation. Design handbooks fractionation tray design handbook. Column tray and packing design university of oklahoma.
The terms trays and plates are used interchangeably. Faktor yang mempengaruhi bubble cup dan perangkat sejenis, sieve dan perforated tray agak. The valve and bubble cap designs are often protected by patents, and thus the performance data are suppliedby the vendors. After specific pressure achieved by the vapors, the cap floats and it allows vapors to flow. Kochglitsch has the capability and experience to design and manufacture traditional tray configurations, such as. One way is to use tray towers, which include sieve trays, valve trays, and bubble cap trays. There are many types of tray designs, but the most common ones are. Usually not quite as high as bubble caps in region of design, but falls to unacceptable values below 60% design rate. The size of the cap tends to create hydraulic gradient across the deck and a high vapor side pressure drop. Determining the operation limits of two distillation columns. The desired contacting between vapor and liquid occurs as the vapor, flowing upwards through the perforations, comes into contact with the liquid flowing downwards through the perforations.
Applications include amine absorbers, regenerators and caustic towers. Amacs valve types bubble cap trays bubble cap trays are best suited for applications with low liquid ows andor high turndown ratios. Vapour rises through the chimney and is directed downward by the cap. Distillation principles chemical engineering, 200711, rvce. The methods used in design mode to determine column design parameters also are discussed in. On the operating principles, there are three common types of trays. Flooding calculations and distillation column sizing. Bubble cap tray bubble cap construction variations. The cap is mounted so that there is a space between riser and cap to.
Bubble cap tray hydraulics theory a schematic of a bubble cap tray is given in figure 1 of the schematics. Feb 25, 2015 bubble cap trays work well in high turndown applications because the orifices in the bubble caps are in the form of risers whose top opening is elevated significantly above the tray deck. Pdf design of distillation column for separating a mixture. Trays chemical engineering chemistry free 30day trial. Typical bubble cap trays used in industrial distillation columns an example of a very simple tray is a perforated tray. Each bubble cap assembly consists of a riser and a cap. This distillation column will make use of either bubble cap trays or sieve. We number the absorption section bubble cap trays from the top down as per the aspen convention. Bubble cap tray bubble cap trays are complex in structure. The vapor rising through the column passes up through the riser in the tray floor and then is. This article describes the procedure for designing an optimum sieve tray.
The numbers of flowpaths of liquid on tray are 1, 2, 3 or 4 as per liquid capacity requirement of column. Operational and economic assessment of distillation column. Active area or bubble area is the deck area of the tray which may either be perforated or fitted with valves or bubble caps and is the area available for vapourliquid contacting. To predict entrainment flooding, tray designers assume that. Rely on bubble caps for leak tight design bubble cap trays are generally used when minimal leakage is allowed. By specifying the free area, the number of bubble caps, the riser diameter, the gas velocity in the riser. In which the vapour passes up through short pipes, called risers, covered by a cap with a serrated edge, or slots. Introduction to the nox abatement process at rfaap. Special features how to design and optimize bubble cap. The modular design of the bubble cap tray column allows the combination with various types of condensers and evaporators, e.
The matrices includes sieve tray, valve tray and bubble cap tray. The cap column divert the vapor flow below the level of liquid on the tray deck where it is jetted into the liquid either through slots at the bottom of the cap or else between the skirt of the cap and the tray deck. Bubble cap tray the oldest widely used equilibriumstage plate is the bubble cap tray. What is the difference between bubble cap tray, sieve tray. Review bubble column reactors nigar kantarcia, fahir borakb, kutlu o. Leading tray technology reliability and performance. Pdf operational and economic assessment of distillation column. Allows for fabrication, installation, outofround tolerances. The tray types differ mainly in the way the vapor enters the liquid.
From a capacity viewpoint, a liquid rate greater than 6 gpm inch of weir weir loading, is the rate at which a higher number of flow paths should be considered. The particular tray selection and its design can materially affect the performance of a given distillation, absorption, or stripping system. Bubble cap are preferred over valve trays as they do not weep or drain at low gas flowrate, which gives higher turn down ratio. A similar procedurecan be applied in principle to the valve and bubble cap trays, provided critical performance data are available. Three principal types of crossflow tray are used, classified according to the method used to contact the vapour and liquid. Bubble cap trays use the tea cup style in industry today. The design of trays depends on the density, the rate of vapor and liquid through the tray.
198 256 1567 1640 1675 39 1204 281 1621 1314 390 1720 524 1321 1146 560 1564 1826 82 748 564 910 1495 1282 154