Detailed design of a single effect evaporator with thermal vapor re compression thesis pdf available. Multiple effect evaporator evaporation boiling free. The vapour evolved from the product in the first effect can be used as the heating medium for the next effect, which operates at a lower boiling. In our sugar industry the solvent is juice, heat is supplied. For a multiple effect evaporator system calculations, the values required to be obtained are. W 1 evaporation rate in first effect w 2 evaporation rate in second effect w 3 evaporation rate in the third effect w 1 w 2 w 3 12. The utility model discloses a multiple effect 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. This generates a simpler set of equations and substantially reduces the computational cost. For a multiple effect evaporator system calculations, the. Multiple effect evaporator mass and enthalpy balance. Vapour flows and heat transfer areas are calculated. Multiple effect distillation or multi effect distillation med is a distillation process often used for sea water desalination. In doing calculations for a triple effect evaporator system, the values to be obtained are usually the area of the heating surface in each effect, the kg of steam per hour to. Pdf single and multiple effect evaporators pranavv.
Fr multiple effect evaporation linkedin slideshare. For example, if steam is available at 220f 104c, then the last effect boiling temperature is 120f 49c. Density of liquid 10 wt% glycerol 1019 kgm3 density of water vapour pmrt. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals.
Desai page the energy consumption to evaporate an aqueous solution is fairly significant. The latent heat of the vapor leaving in single effect evaporator is not used but is discarded. Sep 16, 2016 the single effect evaporator uses rather more than 1 kg of steam to evaporate 1 kg of water. Teaching multiple effect evaporation in the junior year of the chemical engineering curriculum reinforces and integrates k ey topics from the sophomore year such as mass and energy balances, structured problem solving, and stea m table calculations. Selection from transport processes and separation process principles includes unit operations fourth edition book. For the love of physics walter lewin may 16, 2011 duration. Triple effect evaporator engineering spreadsheets eng. Given that evaporation is a separation system, the presence of three different fluids is found. Abstract the main goal behind this project is to treat highly generated tds, tss, bod, etc. Its divided in to three category on the basis of feed direction.
Fortunately, the overall approach is basically the same for the majority of problems, requiring only minor adjustments to compensate for problem quirks. Such calculations are also deemed effective in determining the effect of the operating variables on the characteristics of a stage. A multiple effect evaporator, as defined in chemical engineering, is an apparatus for efficiently using the heat from steam to evaporate water. Triple effect evaporator engineering spreadsheets engtips. Single effect evaporation is simple but fails to utilize the steam effectively, while multiple effect. In a double effect evaporator, the vapor product off the first effect is used to provide energy for a second vaporization unit. The single effect evaporator uses rather more than 1 kg of steam to evaporate 1 kg of water. Please enjoy this animation and model to do some basic calculations. Calculations for multiple effect evaporators make use of material balances, heat balances and capacity equations. Optimization of a multiple effect evaporator system ethesis.
The milk is pumped from a balance tank 1 to the pasteurizer 2, where it is pasteurized and heated to a temperature slightly above the boiling point of the first evaporator effect. Calculations on evaporators can be carried out combining mass and energy balances with the principles of heat transfer. The heating medium normally is high pressure steam or oil. In each stage the feed water is heated by steam in tubes, usually by spraying saline water onto th. A multipleeffect evaporator is an apparatus for efficiently using the heat from steam to evaporate water. Mauhay, romariz morquianos, almira belle nopre, frederick group iii che5102 outline introduction multiple effect evaporator working principle uses advantages and disadvantages.
Using a thermocompressor together with a multiple effect unit optimizes the energy balance. Calculation for multiple effect evaporator evaporation heat transfer. Methods of feeding forward feed backward feed mixed feed parallel feed. Multiple effect 3 evaporator steam consumption calculation posted in process heat transfer. 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. Single effect evaporator calculations are pretty straight forward.
Multiple effect evaporator, evaporator selection, design 1. Multiple effect evaporator is the combination of several sets single effect evaporator. With addition of each effect steam economy of the system also increases. As a side benefit, teaching multiple effect evaporation allow s the opportunity to. The process inside and andritz evaporator relies on a free flow falling film of liquor over the surface of the lamella. However, using the falling film technique, it is feasible to have as many as 10 or more effects. Feed 3000 kghr, feed temperature 30 degc, intial tds 5%, final tds 30%, available steam pressure for tvr 6. The characteristic is to heat the next effect evaporator by used steam produced from the front effect, so as to reduce energy consumption. In the evaporator, the seawater fed in is heated to its boiling temperature and is partly. This type of multiple effect system is perfect for continuous feed applications, as fluids are progressively reduced in each effect to final concentration discharge. The stripper is part of the multiple effect evaporator system.
Capacity and economy equipment description calculation method for multiple. Pdf a simplified and generalized method to size multiple. Dynamic simulation of multiple effect evaporators in paper. Evaporators are classified by the number of effects. Made by faculty at the university of colorado boulder department of chemical and. If necessary, new boiling point rise values can be incorporated. Multiple effect evaporators generally have several evaporator effects which are arranged serially according to the operating temperature. Heat transfer area is nearly equal for each effect. Solution of multiple effect evaporator problems pdf free download.
Triple effect evaporator bpeirson structural 25 oct 03 15. In a single effect evaporator, steam provides energy for vaporization and the vapor product is condensed and removed from the system. A simplified and generalized method to size multipleeffect evaporator systems with any feed scheme conference paper pdf available august 2005 with 5,144 reads how we measure reads. 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. Design and simulation of a multipleeffect evaporator. Evaporation of the solvent takes place as the thin film moves down the evaporator wall. In such a system, the heat from the original steam fed into the system is reused in the successive effects. Design and simulation of a multipleeffect evaporator using vapor bleeding. Multiple effect evaporator evaporation boiling free 30. Lecture 7 evaporation presented by muhammad abbas ahmad zaini, phd japan ceng uk. Design calculations for multipleeffect evaporators. Heat and mass balances in the evaporator components.
Multiple effect evaporators the theory is that if two evaporators are connected in series, the second effect can operate at a higher vacuum and therefore at a lower temperature than the first. Evaporation is the removal of solvent as vapor from a. Desai page 12 this brings a saving in the steam cost, but at the same time, the cost of material and installation of the evaporator system increases because of the large number of effects involved. Multiple effect evaporator having a multistage flash evaporator and adapted for making fresh water from feed water, and more particularly to a single casing multiple effect evaporator. Modeling and simulation of multiple effect evaporator system ethesis. This arrangement of reusing vapor latent heat is called multiple effect evaporation. Multiple effect evaporators maximize steam economy as vapor generated from one effect is used to drive another. Jan 15, 2017 multiple effect evaporator problem guided by prof. The object of evaporation may be to concentrate a solution containing the desired product or to recover the solvent. The governing equations of these models are nonlinear in nature.
In a multipleeffect evaporator, water is boiled in a sequence of vessels, each held at a lower pressure than the last. Introduction in evaporation of solutions in a single effect evaporator, a major cost is the cost of the steam used to evaporate the water. Figure 4 shows the mass flows in a three effect evaporator. In an evaporator handling an aqueous salt solution, the overall coef. Sep 04, 2015 mass and enthalpy balance of a triple effect evaporator. For optimum cost the maximum number of effects in a multiple effect evaporator usually. As result of calculations, it has been found that about 3. Lecture 7 evaporation universiti teknologi malaysia. Calculates the heat transfer area for a single effect evaporator that is used to concentrate a salt solution. Multiple effect evaporator is useful when desired concentration of. 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. However, much of this latent heat can be recovered and reused by employing multipleeffect evaporators. 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. There could be single effect evaporator or multiple effect evaporators.
These four relationships are the basis of all the alternative methods which can be used for performing calculations on multiple effect evaporators. Usually there is double effect evaporator, three effect evaporator or. The first stage acts as a steam generator for the second which acts as a condenser to the first and so on 4. Evaporator design consists of three principal elements. View homework help calculations of multiple effect evaporator. It is the operation which is used for concentration of solution. Evaporation is the removal of solvent as vapor from a solution. Calculations for multiple effect evaporators make use of material balances, heat. The overall heat transfer coefficients u i are assumed to be known. Hi friends, i would like to calculate the multilple 3 effect evaporator steam consumption.
This system is used in a singleeffect evaporator or in the first stage of a multipleeffect evaporator. Scribd is the worlds largest social reading and publishing site. Multiple effect evaporators are applied to concentrate fruit juices and other solutions. Vacuum condensate product out feed steam steam figure 4 apv evaporator hndbook 12600 11. Noniterative design of multiple effect evaporators. Therefore the average area per effect of the evaporator is 232 m2. It must be admitted, however, that the present method is also one of the approximate calculations, because it comprizes errors on drawing and the assumption that the heat requirement in the first effect of the n effects evaporator is 1n of that of the single effect evaporator, having the same amount of product liquor as that of the n effects. In multiple effect evaporator, steam is used only in the first effect 3. Calculation for multiple effect evaporator free download as word doc.
In a typical multiple effect evaporator homework problem figure 1 the feed condit ions and flow rate f are given. A high temperature heating medium generally is necessary to obtain a reasonable evaporation rate since the. These metrics are regularly updated to reflect usage leading up to the last few days. Pdf a simplified and generalized method to size multipleeffect. The multipleeffect evaporator was invented by the africanamerican engineer norbert. 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. Balachandran on enhancement of evaporator steam economy of large scale sugar industry in ethiopia. 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. Optimization of a multiple effect evaporator system. Noniterative design of multiple effect evaporators using. A thesis on design of heat integrated multiple effect evaporator system submitted by ghoshna jyoti 210ch1201 for the partial fulfillment of master of technology under esteemed guidance of dr.
Multiple effect 3 evaporator steam consumption calculation. Configuration screen of multipleeffect evaporation visualbasic application. Jul 05, 2019 abstract the main goal behind this project is to treat highly generated tds, tss, bod, etc. The vapor from the first effect m v1 becomes the heating source for the second effect m s2. The steam consumption of the evaporator unit can be. The utility model discloses a multiple effect 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 heat. Online calculations for multiple effect evaporators for the sugar industry. Hence, the temperature drops at in a multiple effect evaporator are.
These are forward feed multi effect evaporator, backward feed multi effect evaporator, mixed feed multi effect evaporator and parallel feed multiple effect evaporator. A multiple effect evaporator is design to cut down the steam consumption by different operating strategies like feed, condensate and product flashing, vapor compression, vapor bleeding, feed and steam splitting and using an optimal feed flow sequence. Shabina khanam may2012 department of chemical engineering national institute of technology rourkela, orissa. Take standard vertical short tube evaporator calendria type data. This method of reverse feed is advantageous when the fresh feed is cold, since a. The use of this system requires that steam be available at high pressure, and low. Feeding of multiple effect evaporator multiple effect evaporator divided in to four categories on the basis of feed direction as shown figure 25. Pdf detailed design of a single effect evaporator with. Typically, multiple effect evaporator calculations require an iterative solution procedure because so many of the required properties, 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. Thermal analysis on triple effect falling film evaporator. Design of triple effect evaporator developed by a program. Citations are the number of other articles citing this article, calculated by crossref and updated daily. Jun 14, 2009 noniterative design of multiple effect evaporators using excel add ins.
1033 1429 1375 810 1595 1019 12 1411 240 425 645 1216 877 720 1505 1289 1544 166 732 1179 18 1256 1247 760 547 534 1494 451 1385 384 1430 1620 925 1150 1274 999 9 822 370 1394 108 675 206 311