Design of multiple effect forcedcirculation evaporators and. Abstract the main goal behind this project is to treat highly generated tds, tss, bod, etc. The latent heat of the vapor leaving in single effect evaporator is not used but is discarded much of this latent heat, however, can be recovered and reused by employing a multiple effect evaporator, that is, vapor from one effect serves as the heating medium for the. The multipleeffect configuration combines two or more evaporator bodies to conserve steam, which is condensed in the firsteffect heat exchanger only. Design of triple effect evaporator developed by a program. Thermal vapor recompression tvr evaporator swenson technology. In such a system, the heat from the original steam fed into the system is reused in the. Figure 4 shows the mass flows in a threeeffect evaporator. In the operation of the multipleeffect evaporators there is a number of aspects which incide in. Calculation for multiple effect evaporator free download as word doc. Evaporation is an unit operation by which a solvent is evaporated from a solution by boiling the liquor in a suitable vessel and withdrawing the vapor, leaving a concentrated liquid residue. Hi friends, i would like to calculate the multilple 3 effect evaporator steam consumption. As result of calculations, it has been found that about 3.
The single effect evaporator uses rather more than 1 kg of steam to evaporate 1 kg of water. Possible methods to solve multiple effect problems several approaches can be used to solve the typical multiple effect evaporator homework problem. The characteristic is to heat the next effect evaporator by used steam produced from the front effect, so as to reduce energy consumption. Noniterative design of multiple effect evaporators using excel addins.
We design the triple effect evaporator such that the heating area in all the three effect is the same a 1 a 2 a 3 u 1. Pdf optimum design and operating conditions of multiple. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals. As with mechanical recompression, thermal recompression is more applicable to low boilingpoint rise liquids and low to moderate differential temperatures in the heat exchanger to. Multipleeffect evaporator design the design calculations required. May 21, 2016 evaporation is an unit operation by which a solvent is evaporated from a solution by boiling the liquor in a suitable vessel and withdrawing the vapor, leaving a concentrated liquid residue. In this method, the evaporator has one or two horizontal or vertical tube bundles representing the heating surface and contained in the lower part of a shell. In a multipleeffect evaporator, water is boiled in a sequence of vessels, each held at a lower pressure than the last. Design of multiple effect forcedcirculation evaporators. For a multiple effect evaporator system calculations, the values required to be obtained are i the area of the heating surface in each effect, ii the kg of steam per hour to be supplied, and. In case of multiple effect evaporation plants, the exhaust vapors from the product are used to heat the downstreamarranged evaporation effect so that the steam. This system is used in a singleeffect evaporator or in the first stage of a multipleeffect evaporator.
By means of heatbalance equations, calculate the evaporation in the first. Multiple effect 3 evaporator steam consumption calculation. Multiple effect evaporator is the combination of several sets single effect evaporator. Optimization of multiple effect evaporators designed for fruit juice. The maximum number of effects in a multipleeffect evaporator system is. This ability, together with our complete system design, allows us to. Multiple effect each individual effect will have a smaller temperature difference, thus high area of heating surfaces capital cost more costly operating cost steam economy, only required for the first effect 1 kg steam vaporizes 3 kg water small capacity but wasteful energy 1 kg steam vaporize 1 kg water. With addition of each effect steam economy of the system also increases. Evaporation technology gea engineering for a better world. Typically, multiple effect evaporator calculations require an iterative solution procedure because so many of the required properties, etc.
In particular, the system is used as a finishing evaporator to concentrate materials to high solids following a low solids multi effect or mvr film evaporator. Technical terms like falling film, forced circulation flash, and multiple effect can add to the confusion. A design steps first calculate of overall mass balance calculate of temperature in each effect byqu 1 a 1. In essence, the steam usage for the double effect with thermal recompression is comparable to that of a triple effect evaporator. All textbooks 3,4,5 that cover evaporation present a pencilandpaper iterative approach. These metrics are regularly updated to reflect usage leading up to the last few days. Lecture 7 evaporation universiti teknologi malaysia. In the evaporator, the seawater fed in is heated to its boiling temperature and is partly.
Water evaporated in the firsteffect vapor body is condensed in the secondeffect heat exchanger, which provides energy for evaporation in the secondeffect vapor body and so on for additional. Development of a new model for multiple effect evaporator system. Pdf design of heat integrated multiple effect evaporator. Jun 03, 20 discussing and analyzing the performance of single effect evaporation process. Its divided in to three category on the basis of feed direction. Unesco eolss sample chapters thermal desalination processes vol. If these differ appreciably from those assumed in step. Calculation methods for multipleeffect evaporators. Outlining features of various evaporator configurations2. Pdf an iterative procedure previously presented in the literature lambert et al. The use of this system requires that steam be available at high pressure, and low.
The double effect evaporator with thermal recompression requires 33% less steam than the conventional double effect. The multiple effect configuration combines two or more evaporator bodies to conserve steam, which is condensed in the first effect heat exchanger only. Design and simulation of a multipleeffect evaporator. Design and simulation of a multipleeffect evaporator using vapor bleeding. Construction and working of single effect evaporator pdf. Feed 3000 kghr, feed temperature 30 degc, intial tds 5%, final tds 30%, available steam pressure for tvr 6. Optimum design and operating conditions of multiple effect evaporators. This is to certify that the project entitled design and simulation of a multiple effect evaporator using vapor bleeding is an. Detailed design of a single effect evaporator with thermal vapor re compression thesis pdf available march 2016 with 5,033 reads how we measure reads. Scribd is the worlds largest social reading and publishing site. The rdg evaporator design, based on patented technologies, is ideal for multipleeffect systems, as each effect can be optimized for both vapor and fluid functional conditions to achieve optimum evaporation. A multiple effect evaporator is an equipment system for efficiently using the heat from steam to evaporate water. A singleeffect submerged tube system, which is shown in figure 1, was the first and simplest method used to desalt seawater in large quantities. A multipleeffect evaporator, as defined in chemical engineering, is an apparatus for efficiently using the heat from steam to evaporate water.
For example, if steam is available at 220f 104c, then the last effect boiling temperature is 120f 49c. By means of rate equations, calculate the surface required. Geawiegand has substantially contributed to the development of evaporation technology. Pdf detailed design of a single effect evaporator with. The vapor from the first effect m v1 becomes the heating source for the second effect m s2. This is to certify that the project entitled design and simulation of a multiple effect evaporator using vapor bleeding is an original work done by monalishanayak, roll no. Koko, 1987 for the design of multipleeffect evaporator systems with. In an evaporator handling an aqueous salt solution, the overall coef. Multipleeffect each individual effect will have a smaller temperature difference, thus high area of heating surfaces capital cost more costly operating cost steam economy, only required for the first effect 1 kg steam vaporizes 3 kg water small capacity but wasteful energy 1 kg steam vaporize 1. Citations are the number of other articles citing this article, calculated by crossref and updated daily. F k and saturated steam at t s enters the heatexchange section. This concentrated liquids in a gentle and efficient manner in a way unparalleled in its time. Discussing and analyzing the performance of single effect evaporation process. Vapour flows and heat transfer areas are calculated.
In any evaporation operation, the major process cost is the steam consumed. In case of multipleeffect evaporation plants, the exhaust vapors from the product are used to heat the downstreamarranged evaporation effect so. National institute of technology, rourkela department of chemical engineering, national institute of technology, rourkela. Multiple effect evaporator, evaporator selection, design 1. The problems associated with a multiple effect evaporator system are that it is an energy intensive system and therefore any measure to reduce the energy consumption by reducing the steam consumption will help in improving the profitability of the plant. Calculations on evaporators can be carried out combining mass and energy balances with the principles of heat transfer. This is possible because the second effects boiling temperature has been lowered to 68c at 29 kpa. This arrangement of reusing vapor latent heat is called multipleeffect evaporation. The heat capacity of the liquid solution is calculated from. Online calculations for multiple effect evaporators for the sugar industry. Singleeffect evaporators a simplified diagram of a singlestage or singleeffect evap orator is given in fig.
Noniterative design of multiple effect evaporators. Because the boiling point of water decreases as pressure. Selecting the best evaporator for a given application can sometimes be a confusing and even intimidating task. The first wiegand evaporator, built in 1908, was a patented multipleeffect circulation evaporator. Pdf on mar 12, 2016, widitha samarakoon and others published detailed design of a single effect evaporator with thermal vapor re compression find, read and cite all the research you need on.
Noniterative design of multiple effect evaporators using. Evaporation is the removal of solvent as vapor from a solution. Investigation of multiple effect evaporator design. Calculation for multiple effect evaporator evaporation. A thermocompressor is normally used on a singleeffect evaporator or on the first effect of a double or tripleeffect evaporator to reduce energy consumption. Multiple effect evaporatorpptx free download as powerpoint presentation ppt pptx, pdf file pdf, text file txt or view presentation slides online scribd is process modelling and optimization of design parameters in. Thermal vapor recompression tvr evaporator swenson. Multiple effect 3 evaporator steam consumption calculation posted in process heat transfer. Design calculations for multipleeffect evaporators. Evaporators come in many different shapes and sizes. Milk condensing in vacuum pan uses high amount of steam to evaporate water. Principles and pressure drop calculation in multiple. Water evaporated in the first effect vapor body is condensed in the second effect heat exchanger, which provides energy for evaporation in the second effect vapor body and so on for additional.
The design calculations required for a multipleeffect evaporator are complex enough to provide a real challenge for implementation using a spreadsheet. Construction and working of single effect evaporator pdf download. The apv forced circulation evaporator system is designed for the evaporation of liquids containing high concentrations of solids. In a multiple effect evaporator, water is boiled in a sequence of vessels, each held at a lower pressure than the last. There could be single effect evaporator or multiple effect evaporators.
Fortunately, the overall approach is basically the same for the majority of problems, requiring only minor adjustments to compensate for problem quirks. The case study is presented that multiple effect evaporator is has good overall steam economy instead of single evaporator. Mist flow conditions should be avoided because poor heat. Pdf a simplified and generalized method to size multipleeffect. Ii design of multiple effect forcedcirculation evaporators and crystallization systems u. Multipleeffect evaporator, evaporator selection, design 1. Multiple effect evaporator is used for steam economy. The utility model discloses a multipleeffect evaporation waste water treatment system which comprises at least seven effect evaporators in series connection, wherein an air outlet of each effect evaporator is connected with a separator, an air outlet of each effect separator is connected with a. Optimization of a multiple effect evaporator system. A multipleeffect evaporator is an equipment system for efficiently using the heat from steam to evaporate water. Take standard vertical short tube evaporator calendria type data.
437 83 772 1410 717 1114 1106 382 472 10 1313 186 13 1089 1492 279 1466 521 397 898 1395 291 883 1188 124 513 502 1344 1001 349 13 1184 363