By using these heat exchangers, temperature difference between feed water and steam in each effect would be constant. Modelling and optimising single and multiple effect. The modelling, optimisation and control analyses of single and multiple effect. Optimization of a multiple effect evaporator system. Mass and enthalpy balance of a triple effect evaporator. Pdf detailed design of a single effect evaporator with thermal. A single effect evaporator is required to concentrate a solution from 10% solids to 30% solids at the rate of 250 kg of feed per hour. The case study is presented that multiple effect evaporator is has good overall steam economy instead of single evaporator. Multipleeffect evaporators maximize steam economy as vapor generated from one effect is used to drive another. In case of multipleeffect evaporation plants, the exhaust vapors from the product are used to heat the downstreamarranged evaporation effect so that the steam consumption will be reduced accordingly.
Pdf detailed design of a single effect evaporator with. The falling film evaporators can be single effect or multiple effects depending on the capacity. The configuration of a multiple effect system, as well as the setup of contracting methods, can optimize evaporator performance when dealing with high viscosity fluids. Design, modelling and simulation of multiple effect. This rate of heat transfer is the same as that obtained with a single effect operating between the same ultimate temperature levels.
Evaporators falling film evaporators manufacturer from. The latent heat of the vapor leaving in single effect evaporator is not. A multipleeffect evaporator, as defined in chemical engineering, is an apparatus for efficiently using the heat from steam to evaporate water. Thus, multipleeffect evaporation using n effects increases the steam.
Multiple effect evaporator is the combination of several sets single effect evaporator. Chapter 5 multiple effect evaporators 1 multiple effect evaporator in case of a single effect evaporator, the vapor leaving the equipment are discarded. F actors affecting evaporation, evaporators, film evaporators, single effect and multiple effect evaporators and mathematical problems on evaporation. A multiple effect evaporator system for concentrating a process liquid comprises. Types of evaporators open kettle or pan single effective evaporator multiple. To reduce energy consumption, water vapor from an evaporator is. Singleeffect evaporators are often used when the required capacity of operation is. Evaporators may be composed of one or more effects, where an effect is defined as one or more bodies operating at the same boiling temperature. Falling film evaporators can be operated with small temperature differences between the heating media and. A multipleeffect evaporator is an apparatus for efficiently using the heat from steam to evaporate water. Multiple effect evaporator control is a problem that has been widely reported in the pulp and sugar industries. Single effect evaporators are often used when the required capacity of operation is relatively small andor the cost of steam is relatively cheap compared to the evaporator cost.
Single effect evaporator calculations are pretty straight forward. This type of multipleeffect system is perfect for continuous. Comparison between single and multieffect evaporators for. Plate heat exchanger, how it works working principle hvac industrial engineering phx heat transfer. Detailed design of a single effect evaporator with thermal vapor re compression thesis pdf available march 2016 with 4,990 reads how we measure reads. Block diagram of a single effect in a multipleeffect evaporator 31 fig. Optimization of multiple effect evaporators designed for fruit juice. Pdf single and multiple effect evaporators pranavv. Thermal analysis on triple effect falling film evaporator. The modelling, optimisation and control analyses of single and multiple effect evaporators using aspen custom modeller acm is carried out to develop programs in different software packages for both. Heating steam cooling water deaeration vapour condensate heat. Project design document pdd title of the project activity tongaat hulett sugar refinery steam. The evaporation in each effect will be approximately 0.
Modelling and optimising single and multiple effect evaporators by. The heating steam loses its latent heat and condenses before it flows out of the tube bundle. A multipleeffect evaporator is an apparatus for efficiently using the heat from steam to. In a multipleeffect evaporator, water is boiled in a sequence of. Design and simulation of a multipleeffect evaporator. Tubular evaporators classification is based on the contact steps between the liquid feed to be evaporated and the heating tubes. Evaporators singleeffect evaporator multi effect evaporator pan evaporator naturalcirculation evaporator rising film evaporator falling film evaporator risingfalling evporator forced circulation evaporator. Brine is pumped in hot weather to reservoirs of 100,000 m2 in area to a. Our organization is one of the most prominent and leading supplier and manufacturer of multiple effect evaporators.
Single effect evaporation desalination processthe feed seawater mf is chemically treated and deaerated before beingpumped to the evaporator. Note, however, that the temperature difference from initial steam to the final condenser which was available for a single effect evaporator will be unchanged by inserting any. Psychrometrics psychrometric chart example1 psychrometric chart given dbt, wbt example2 psychrometric chart given dbt, rh. In the operation of a single effect evaporator the liquid feed passes once through heating tubes, steam emerges and leaves a liquid concentrate. Evaporation is the removal of solvent as vapor from a. However, for largecapacity operation, using more than one effect will markedly reduce steam costs. Calculations on evaporators can be carried out combining mass and energy balances with the principles of heat transfer. Performance ratio of the singleeffect distillation system. While the design criteria for evaporators are the same regardless of the industry involved, two questions always exist. In actual practice, the steam economy can vary widely because of differences in feed. Multiple effect evaporator mass and enthalpy balance. This concentrated liquids in a gentle and efficient man. The economy of a single effect evaporator is always less than 1. Evaporator problems require solution of the system material and energy balances with the accompanying property and heat transfer equations.
Evaporators are the largest heat users and major contributors to losses in sugar cane. With addition of each effect steam economy of the system also increases. Design and simulation of a multipleeffect evaporator using vapor bleeding. Heating is performed by passing steam inside the tube bundle. We are the leading manufacture and suppliers and service providers of multiple effect evaporators in the market. Condenser requirements are less for multiple effect evaporators. Evaporators singleeffect evaporator multieffect evaporator pan evaporator naturalcirculation evaporator rising film evaporator falling film evaporator risingfalling evporator forced circulation. The characteristic is to heat the next effect evaporator by used steam. Introduction, single and multiple effect operation, long tube vertical evaporators, agitatedfilm evaporators, evaporator capacity, bpe and duhrings rule. The use of multiple effects enables a large number of possible arrays depending on the vapor and liquid flows. Swenson thermal vapor recompression tvr evaporators use a thermocompressor to reduce the steam required per pound of evaporation. A multipleeffect evaporator, as defined in chemical engineering, is an apparatus for. The major advantage to andritz multipleeffect evaporators is the utilization of proven lamella heating surfaces for high efficiency and reliability.
The single effect evaporator uses rather more than 1 kg of steam to evaporate 1 kg of water. Concentrate product d 1a calandria plate heat exchanger 1b calandria vertical shellandtube. Evaporators are classified by the number of effects. In addition to the economy increase in multiple effect evaporation, a capacity variation would be expected. In a multipleeffect evaporator, vapor from one body heats. Forced circulation evaporators are optimally suited as crystallising evaporators for saline solutions. Single and multiple effective evaporator mee slideshare.
In the evaporator, the seawater fed in is heated to its boiling temperature and is partly evaporated by boiling. 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. This decoupling allows for the use of multiple effect evaporation, a far more efficient method of. Evaporators with direct heating the use of solar heat for the production of glaubers salt has been described by holland22,23. Hugot, construction of multiple effects, in handbook of cane sugar engineering, elsevier, 1972, pp. Multiple effect evaporators have higher economy but. There could be single effect evaporator or multiple effect evaporators. Thermal vapor recompression tvr evaporator swenson. In this way, the required energy for preheating the feed water will decrease.