properties of the feed to an evaporator cannot exhibit unusual problems. However, as the liquor is concentrated, can drastically change the properties of the solution. Density and viscosity may increase with solid content until the heat transfer performance is decreased or the solution becomes saturated. Boiling continues a saturated solution can cause form crystals which often must be removed to avoid deficiencies or soil surface heat transfer. The boiling point of a solution increases significantly as is concentrated.
Some materials can foam during steaming. Stable Foams may cause excessive swipes. Foaming may be caused by gases dissolved in liquor, from a loss of air under the level of the liquid and the presence of surfactants or finely divided particles in liquor. Many antifoaming agents can be used effectively. Foams can be suppressed by operating at low levels of liquids, mechanically or hydraulic methods.
many chemicals are compromised when heated to moderate temperatures for relatively short time. When the evaporation of those materials, special techniques are needed to control the characteristics of the time/temperature evaporator system.
Salting refers to the growth of a matter that a solubility increases with increasing temperature on surfaces evaporator. Can be reduced or eliminated by keeping the evaporation of liquid in close or frequent contacts with a large surface area of solid crystallized.
scale is growth or deposition on the surfaces of insoluble or heating has a solubility that decreases with increasing temperature. It may also derive from a chemical reaction in the evaporator. Both in scale and salting liquids usually best are handled in a rotary evaporator not based on boiling for operation.
Fouling is the formation of deposits several meeting rooms or scale. They may be due to corrosion, solids entering feed or deposits formed by side heating medium.
Corrosion might influence the selection of the type of evaporator because expensive building materials indicate evaporators offering high rates of heat transfer. Corrosion and erosion are often more serious in evaporators compared to other types of equipment for the high speed of liquid and vapor, the frequent presence of suspended solids and concentrations requests.
quality may require holdup low and high temperatures. Low-holduptime requirements may eliminate the application of certain types of evaporator. Quality of the product may also dictate special building materials.
Other properties of Fluid
other smooth property must be considered. These include: heat solution, toxicity, explosion hazards, radioactivity and ease of cleaning. Salting, resizing and dirty the result steadily heat transfer speed, until the evaporator must be shut down and cleaned. Some deposits can be difficult and costly to remove.?