Introduction Flashcards
What is an Air-moving device (AMD)?
A revolving, wheel-type, mechanical device used to move air for drying or aeration. An AMD includes the wheel or blade assembly, mounting structure, and casing, but may or may not include a power source.
What is Aeration?
The purposeful movement of air at a low rate through a product to maintain or improve product quality. Air flow rates usually do not exceed 0.08 cubic meters per minute per cubic meter of product through a dry product and 0.80 cubic meters per minute per cubic meter of product through a wet product.
What is Ambient temperature?
The temperature of the surrounding air.
What does ‘Approved’ refer to?
‘Approved’ or ‘approved-type’ refers to listing by a recognized testing agency or laboratory.
What is Available heat?
In drying a harvested crop, the quantity of heat in air that can be utilized in evaporating water from the product.
What is a Batch?
A quantity of a harvested crop put into a bin or container on a repetitive basis specifically for treatment, such as drying.
What is Blending?
The process of mixing two or more different products together to obtain desired food ratios, or mixing different quantities of the same product with different moisture contents to obtain a final mass with a uniform moisture content.
What is a Bushel?
One bushel by volume equals 1.25 cubic feet. One dry bushel is defined by government grain standards as a standard unit for trading at a specific moisture (e.g. 56 pounds at 15.5 percent w.b. for number 2 corn). A wet bushel is the weight of wet grain which when dried will give one dried bushel.
What is Casing?
The outer enclosure surrounding the entire heat exchanger and confining the air being heated.
What is Combustible material?
Combustible refers to a material or structure that can burn. It is a relative term; some materials may burn under certain conditions but not others.
What is Conduction?
Transmission through or by means of a conductor, distinguished in the case of heat from convection and radiation.
What is Control in the context of drying?
Any component of a dryer, or dryer heat source, designed to affect or limit any normal or abnormal condition of the drying operation.
What is Convection?
Transference of heat or electricity by moving masses of matter, caused by differences in density or by electrically charged particles across a spark gap.
What is a Cooling stage?
The time required to move a cooling zone entirely through the product mass.
What is a Cooling zone?
That portion of the product mass in storage where the product temperature of the crop is falling during aeration.
What is Cubic meters per minute (CFM)?
Volumetric measure of quantity of flow. CFM is the most common customary measure.
What is Curing?
A form of conditioning as opposed to simple drying in which a chemical change occurs to prepare the crop for storage or use.
What is a cycling burner?
A type of operation wherein the application of maximum heat is periodic, such as cycling between high fire and low fire, high fire and constant pilot, or cycling from high fire to off, then restarted to high fire by constant or intermittent ignition.
What is dehydration?
The rapid removal of moisture, usually to a very low level.
What is the depth factor (Df) in drying?
A depth which would contain enough product that, if all the theoretical heat available for drying could be used, it would all dry to equilibrium in a period of time equal to the time required for the fully exposed product to dry halfway to equilibrium.
What is a dryer?
A unit which provides the conditions for removing moisture from a product.
What is a batch dryer?
Any dryer wherein the product to be dried is placed in the dryer, the complete drying or drying and cooling operation performed, and then removed for storage or further processing. Usually self-contained, comprising a drying compartment, either horizontal or vertical.
What is a circulating dryer?
A batch dryer equipped to circulate or mix the product during the drying and cooling period.
What is a concurrent flow dryer?
A type of continuous flow dryer wherein the product being dried moves in the same direction as the drying air. Sometimes referred to as parallel flow.
