Drying systems show a considerable variation, depending on the nature of the industry in which it is used. Firstly, you must be knowing that drying essentially differs from evaporation. Particularly food products need to be dehydrated using various methods. This application finds its use primarily in the food industry. |
This includes milk and other dairy products, coffee surrogates, coffee, flavours, creamers, spices, herbs, vegetables and fruits. In some uses when correctly done, the process ensures that the shape of the food is retained. Further, drying also decreases the bulk weight of the products.
Different Types Of Drying Systems And Their Applications Here are some of the common types of drying systems, that are used in various industries.
Fluidized Bed Dryers (Food & Pharma) In this type of dryer, an air stream flowing upward is used to suspend the food materials against gravity. Besides, a horizontal air-flow is also used to make the food pass through the dryer. Therefore, the heat transfer takes place between air and the food material. Mostly, the transfer takes place through convection. The solid particles, that are fluidized, behave like liquids, and it is not possible to convey them. The velocity of air varies with the density and size of the particles. This process is effective during both drying and cooling processes.For pharmaceutical industry fan, static pressure is always on the higher side.This process is required for food and pharma both.
Spray Dryers Here, the product to be dried has to be suspended in the air. The liquid is converted to a mist or fog-like material. In the drying chamber, the atomized liquid gets exposed to a heated air-flow in a drying chamber. The flow of solid materials and air may be in a counterflow or parallel direction. The evaporation of moisture takes place fast. This process is ideal for materials that get damaged due to their exposure to heat. The solid materials can be recovered in the form of a powder, that consists of hollow, fine and spherical particles.
Drying systems used in various industries largely depend on the nature of water content present. It may be vapour, water or ice. Other factors like humidity and cross-ventilation also come into the play. In order to lower the chance of bacterial growth, the items need to be dehydrated.This process is applicable for food process industries.In this process, Exhaust fan (ID Fan) and supply fan (FD Fan) is required.Exhaust fan needs to handle some dusts which is sticky in nature and corrosive also. That is why we need to take care about the blade profile of the impeller and material of construction. Stainless Steel is mainly used as a primary material of construction for both ID & FD application. We need to take utmost care about the inside surface finish of these fans because mostly these fans handle food product, milk powder etc.in this application exhaust fans need to have gas tight construction with sealing arrangement, machined flange etc. No spot welding is acceptable inside the casing. We need to adhere to full welding inside the casing. It needs to be smooth, uniform. No black marks and under cuts are acceptable.
The static pressure in these type of fans is in the range of 1200 mmwg-1800 mmwg. The fans should be develop that much static pressure at a given volume requirement.In few cases fan handles fine dust particles and our impeller design is suitable for the same.
Reitz India has set a benchmark to deliver high quality fans for heavy duty industries which can work at precise operating conditions like high temperatures and pressures. Reitz offer idealistic Centrifugal Fans and Centrifugal blowers design that can be used in all large scale process industries like cement, iron & steel, power plants, fertilizers/ chemicals and more.
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