A heat exchanger is a device for transferring heat between two fluids, such as liquids, gases, or vapours, of different temperatures. Depending on the type of heat exchanger being used, the heat is transferred from gas to gas, liquid to liquid, or liquid to liquid through a solid separator, which prevents mixing of the fluids or direct fluid contact. HEAT EXCHANGER FOR SHELLS AND TUBE The Shell-and-Tube heat exchanger transfers heat between fluids passing through tubes and fluids within a shell vessel surrounding the tubes. With tubes inside the shell, fluids that are more viscous or containing more particles can be processed than with a plate and frame heat exchanger.
FRAME AND PLATE HEAT EXCHANGER Corrugated parallel plates are separated from each other by gaskets that control the alternating flow of hot and cold fluid over the surface of the plates. By tightening bolts, a frame plate and a pressure plate compress gasketed plates together. Two upper bars and a lower guiding bar suspend the gasketed plates and the pressure plate. By removing or adding plates, it is easy to clean and change the capacity of this device. As heat transfers from the warmer to the cooler channel, hot and cold media flow in alternate channels with processed fluids. Carbon mechanical seals, carbon flushed/aseptic seals, hard face seals and hard face flushed/aseptic seals are available. Suitable materials will be selected for special applications.
HEAT EXCHANGER FOR SCRAPED SURFACE Applications involving highly viscous and/or sticky products require heat transfer. Because the blades on scraped surface heat exchangers prevent the product from settling on the interior surfaces, they are the best choice for heat transfer in those applications. In order to ensure uniform heat transfer to the product, blades inside the product channel remove product from the channel walls. The scraping blades are made from a variety of materials to meet different processing requirements, and are designed specifically for gentle product handling to avoid compromising product quality and consistency. Scraped surface exchangers can be mounted vertically or horizontally. Inside, an electric motor turns a rotor fitted with scraping blades.
Typical scraped surface heat exchanger applications include: – There are viscous products such as ketchup, mayonnaise, hummus, peanut butter, puddings, salad dressings, bread dough, gelatine, baby food, skin lotions, and shampoos. – Heat-sensitive produce: Egg products, fruit purées, cream cheeses, and fishmeal. – The following products crystallise and phase change: coffee/tea extracts, icings and frostings, sugar concentrates, margarines, shortening, spreads, gelatine broth, lard, fondant, beer and wine. – Meat, poultry, pet foods, jams, preserves, and rice puddings constitute particulate products. – Caramel, cheese sauces, processed cheese, gums, gelatine, mascara, and toothpaste are sticky products.