Blade grinder
Encyclopedia
Blender
A blender is a kitchen appliance for chopping or liquefying food.Blender may also refer to:Media:* Blender , a music-themed magazine* Blender , a free and open-source software program for 3D modeling, animation, and rendering...
s (including immersion blender
Immersion blender
An immersion blender, or 'stick blender' is a kitchen appliance to blend ingredients or puree food in the container in which they are being prepared...
s), food processor
Food processor
A food processor is a kitchen appliance used to facilitate various repetitive tasks in the process of preparation of food. Today, the term almost always refers to an electric-motor-driven appliance, although there are some manual devices also referred to as "food processors".Food processors are...
s, some garbage disposal
Garbage disposal
A garbage disposal unit or waste disposal unit is a device, usually electrically powered, installed under a kitchen sink between the sink's drain and the trap which shreds food waste into pieces small enough—generally less than —to pass through plumbing.Garbage disposal units are widely used in...
s, and some coffee grinders. The terms "blade grinder" and "propeller grinder" are in popular use to distinguish the blade grinder type of coffee grinder from other types. Other consumer
Consumer
Consumer is a broad label for any individuals or households that use goods generated within the economy. The concept of a consumer occurs in different contexts, so that the usage and significance of the term may vary.-Economics and marketing:...
applications include rotary lawn mower
Lawn mower
A lawn mower is a machine that uses a revolving blade or blades to cut a lawn at an even length.Lawn mowers employing a blade that rotates about a vertical axis are known as rotary mowers, while those employing a blade assembly that rotates about a horizontal axis are known as cylinder or reel...
s.
Design
A blade grinder may be considered a type of hammermillHammermill
A hammermill is a machine whose purpose is to shred or crush aggregate material into smaller pieces. These machines have many sorts of applications in many industries, including:*Ethanol plants...
. A blade grinder resembles a meat grinder
Meat grinder
A meat grinder or meat mincer is a kitchen appliance for grinding, fine mincing or mixing raw or cooked meat, fish, vegetables or similar food. It replaces tools like the mincing knife, for example, which has been used to produce minced meat, filling etc. The producer puts the minced food into a...
in that both have propeller
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
-shaped cutting blades. However, meat grinders (and food mill
Food mill
A food mill is a food preparation utensil for mashing and sieving soft foods...
s) use a scissor cutting action as the blades rotate against a perforated metal plate. Meat grinder blades rotate at a much slower speed than blade grinders, which may may rotate at speeds as high as 20,000 to 30,000 rpm. Blade grinders also resemble industrial blade (propeller) mixers, which like meat grinders rotate at much slower speeds. Unlike blade grinders, these mixers do not alter (break, cut, shred, macerate, pulverize) the material being mixed. The high speed of rotation of blade grinders is necessary to achieve their cutting action. In a blender application, the high speed of rotation contributes to shearing
Shear stress
A shear stress, denoted \tau\, , is defined as the component of stress coplanar with a material cross section. Shear stress arises from the force vector component parallel to the cross section...
, which in turn contributes to aeration
Aeration
Aeration is the process by which air is circulated through, mixed with or dissolved in a liquid or substance.-Aeration of liquids:-Methods:Aeration of liquids is achieved by:...
and the formation of emulsion
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...
s. These are desirable qualities in many food preparations.
Coffee grinders
Special purpose coffee grinders usually are either blade grinders or burr grinders: blade grinders being less expensive and having additional uses, burr grinders giving a better quality of grind (see Coffee preparation#Grinding). Special purpose spice grinders usually are either blade grinders or mortar and pestleMortar and pestle
A mortar and pestle is a tool used to crush, grind, and mix solid substances . The pestle is a heavy bat-shaped object, the end of which is used for crushing and grinding. The mortar is a bowl, typically made of hard wood, ceramic or stone...
(or related tools).
Low cost coffee blade grinders for use in home kitchens frequently are difficult to clean. The Joy of Cooking
The Joy of Cooking
Joy of Cooking, often known as "The Joy of Cooking" is one of the United States' most-published cookbooks, and has been in print continuously since 1936 and with more than 18 million copies sold. It was privately published in 1931 by Irma S. Rombauer, a homemaker in St. Louis, Missouri, who was...
(1997 edition) suggests a blade grinder may be cleaned by grinding a few tablespoons of sugar then wiping it out. Another suggestion is to clean around the blade with a soft brush or a damp cloth. Because these blade grinders frequently are used for grinding both coffee beans and spices, cleaning them well is important to prevent unwanted transfer of flavors. Some people keep two blade grinders, one for coffee and the other for spices.
Blenders
Blenders are blade grinders designed specifically for use with wet ingredients. Blenders are popular tools for production of puréePurée
Purée and mash are general terms for cooked food, usually vegetables or legumes, that have been ground, pressed, blended, and/or sieved to the consistency of a soft creamy paste or thick liquid. Purées of specific foods are often known by specific names, e.g., mashed potatoes or apple sauce...
s and pastes, using both the cutting and shearing effects of high rpm blades.
History
Blade grinders are a 20th century innovation that followed the adaptation of propellers to small motorboatMotorboat
A motorboat is a boat which is powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the gearbox and the propeller in one portable unit.An inboard/outboard contains a hybrid of a...
s. Blade grinders exploit a feature of propellers that is undesirable in the propulsion systems of boats and airplanes: the higher the rpm, the more energy is spent in shearing and cutting rather than in pushing. Rotary lawn mowers were not developed until small engines became powerful enough to run the blades at a speed high enough to cut.
Commercial blender
Blender
A blender is a kitchen appliance for chopping or liquefying food.Blender may also refer to:Media:* Blender , a music-themed magazine* Blender , a free and open-source software program for 3D modeling, animation, and rendering...
s were developed in the 1920s. With increasing miniaturization of the electric motor, the first consumer blender, the Waring Blendor, was developed in the 1930s, and a canister blender, the Osterizer
Osterizer
Osterizer is a brand which has been used by Oster Manufacturing for its line of blenders since 1946. It is claimed to be the first mainstream brand of blender, though technically the Waring blender brand was introduced in 1937....
, entered the market in 1946. The first immersion blenders were patented in the 1950s.
See also
- BladeBladeA blade is that portion of a tool, weapon, or machine with a cutting edge and/or a pointed tip that is designed to cut and/or puncture, stab, slash, chop, slice, thrust, or scrape animate or inanimate surfaces or materials...
- CavitationCavitationCavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...
- ImpellerImpellerAn impeller is a rotor inside a tube or conduit used to increase the pressure and flow of a fluid.- Impellers in pumps :...
- Grinding machineGrinding machineA grinding machine, often shortened to grinder, is a machine tool used for grinding, which is a type of machining using an abrasive wheel as the cutting tool...
- Milling machineMilling machineA milling machine is a machine tool used to machine solid materials. Milling machines are often classed in two basic forms, horizontal and vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to room-sized machines...
- Mixer (cooking)Mixer (cooking)A mixer is a kitchen appliance intended for mixing, folding, beating, and whipping food ingredients. Mixers come in two major variations, hand mixers and stand mixers....