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A hot plate or hotplate is a heated flat surface on a stove or electric cooker on which food may be cooked, either built into an electric cooker or kitchen stove, or portable, plugged into an electric outlet.
Hot plates can also be used as a heat source in laboratories. [1] [2]
A hot plate or hotplate is a heated flat surface on a stove or electric cooker on which food may be cooked. [3] It comprises a heated top which is flat and usually circular, and may be made of metal, ceramic, or heat-resistant glass, with resistive wire forming a heating element fitted underneath and a thermostat to control the temperature. An electric current is passed through the wire, heating it; the thermostat controls the temperature the top reaches.
A hotplate may be a portable self-contained tabletop small appliance cooktop, or incorporated into an electric cooker or kitchen stove. [4] Portable hot plates are often used for food preparation, generally in locations where a full kitchen stove would not be convenient or practical.
Hotplates are used in laboratories, outside the domestic environment, mainly for heating, and possibly continuously stirring, liquids. [5]
In laboratory settings, hot plates are generally used to heat glassware or its contents. Some hot plates provide an integrated magnetic stirrer, allowing a heated liquid to be stirred automatically. In a student laboratory, hot plates are used because baths can be hazards if they spill, overheat or ignite because they have high thermal inertia (meaning they take a long time to cool down) and mantles can be very expensive and are designed for specific flask volumes.
Two alternative methods for heating glassware using a hotplate are available. One method is to suspend glassware slightly above the surface of the plate with no direct contact. This not only reduces the temperature of the glass, but it also slows down the rate of heat exchange and encourages even heating. This works well for low boiling point operations or when a heat source's minimum temperature is high. Another method, called a teepee setup because it looks a little like a tipi, is to suspend glassware above a plate and surround the flask by a skirt of tinfoil. The skirt should start at the neck of the flask and drape down to the surface of the plate, not touching the sides of the flask, but covering the majority of the plates surface. This method is for glassware to be heated at higher temperatures because the flask is warmed indirectly by the hot air collecting under the skirt and unlike simply suspending the glassware, this method is better protected from drafts. Both these methods are useful in a student laboratory as they are cheaper, effective, safe, and the user does not have to wait for a bath to cool down after use.
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Hot plates are widely used for many industrial applications. These hot plates vary in size from 2 to over 300 square centimetres.
Typical operating temperatures vary from 100 to 750°C (212 to 1382°F) and power requirements are usually in the 120 to 480 volt range. Most industrial hot plates will withstand a weight of more than 150 pounds.
Industrial hot plates which incorporate a porous heated plate are referred to as heated chucks. These plates, widely used in semiconductor manufacture, are used to heat thin sheets evenly by drawing the sheets firmly on the plate by suction.
Corrosion-resistant hotplates using special material and protective coatings are used in mining and related industries to heat samples of toxic chemicals.
Hot plates are widely used in the electronics industry as a method of soldering and desoldering components on circuit boards.
Hot plates with two heating surfaces are used to fuse plastic pipes, which may have a diameter exceeding 90 centimeters. The two pipes to be fused are pressed against the plate till the edges are soft. The plate is removed and the two pipes are pressed together and bonded. This process is called butt fusion. [6]
A wok is a deep round-bottomed cooking pan of Chinese origin. It is believed to be derived from the South Asian karahi. It is common in Greater China, and similar pans are found in parts of East, South and Southeast Asia, as well as being popular in other parts of the world.
Grilling is a form of cooking that involves heat applied to the surface of food, commonly from above, below or from the side. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat and vegetables quickly. Food to be grilled is cooked on a grill, using a cast iron/frying pan, or a grill pan.
The Aga Range Cooker is a Swedish range cooker. Invented and initially produced in Sweden, since 1957 most production has been located in the UK. In 2015, the British AGA Cooker manufacturing company, AGA Rangemaster Group, was acquired by the American corporation Middleby.
A griddle, in the UK typically referred to simply as a frying pan or flat top, is a cooking device consisting mainly of a broad, usually flat cooking surface. Nowadays it can be either a movable metal pan- or plate-like utensil, a flat heated cooking surface built onto a stove as a kitchen range, or a compact cooking machine with its own heating system attached to an integrated griddle acting as a cooktop.
A clothes iron is a small appliance that, when heated, is used to press clothes to remove wrinkles and unwanted creases. Domestic irons generally range in operating temperature from between 121 °C (250 °F) to 182 °C (360 °F). It is named for the metal (iron) of which the device was historically made, and the use of it is generally called ironing, the final step in the process of laundering clothes.
A rice cooker or rice steamer is an automated kitchen appliance designed to boil or steam rice. It consists of a heat source, a cooking bowl, and a thermostat. The thermostat measures the temperature of the cooking bowl and controls the heat. Complex, high-tech rice cookers may have more sensors and other components, and may be multipurpose.
An oven is a tool that is used to expose materials to a hot environment. Ovens contain a hollow chamber and provide a means of heating the chamber in a controlled way. In use since antiquity, they have been used to accomplish a wide variety of tasks requiring controlled heating. Because they are used for a variety of purposes, there are many different types of ovens. These types differ depending on their intended purpose and based upon how they generate heat.
A stove or range is a device that generates heat inside or on top of the device, for -local heating or cooking. Stoves can be powered with many fuels, such as natural gas, electricity, gasoline, wood, and coal.
A kitchen stove, often called simply a stove or a cooker, is a kitchen appliance designed for the purpose of cooking food. Kitchen stoves rely on the application of direct heat for the cooking process and may also contain an oven, used for baking. "Cookstoves" are heated by burning wood or charcoal; "gas stoves" are heated by gas; and "electric stoves" by electricity. A stove with a built-in cooktop is also called a range.
Induction cooking is a cooking process using direct electrical induction heating of cooking vessels, rather than relying on indirect radiation, convection, or thermal conduction. Induction cooking allows high power and very rapid increases in temperature to be achieved: changes in heat settings are instantaneous.
An electric stove, electric cooker or electric range is a stove with an integrated electrical heating device to cook and bake. Electric stoves became popular as replacements for solid-fuel stoves which required more labor to operate and maintain. Some modern stoves come in a unit with built-in extractor hoods.
Electric heating is a process in which electrical energy is converted directly to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.
A cooktop, stovetop or hob, is a device commonly used for cooking that is commonly found in kitchens and used to apply heat to the base of pans or pots. Cooktops are often found integrated with an oven into a kitchen stove but may also be standalone devices. Cooktops are commonly powered by gas or electricity, although oil or other fuels are sometimes used.
A blech is a metal sheet used by many observant Jews to cover stovetop burners on Shabbos, as part of the precautions taken to avoid violating the halachic prohibition against cooking on the Sabbath.
A heating mantle, or isomantle, is a piece of laboratory equipment used to apply heat to containers, as an alternative to other forms of heated bath. In contrast to other heating devices, such as hotplates or Bunsen burners, glassware containers may be placed in direct contact with the heating mantle without substantially increasing the risk of the glassware shattering, because the heating element of a heating mantle is insulated from the container so as to prevent excessive temperature gradients. Heating mantles may have various forms. In a common arrangement, electric wires are embedded within a strip of fabric that can be wrapped around a flask. The current supplied to the device, and hence the temperature achieved, is regulated by a rheostat. This type of heating mantle is quite useful for maintaining an intended temperature within a separatory funnel, for example, after the contents of a reaction have been removed from a primary heat source.
Cooker may refer to several types of cooking appliances and devices used for cooking foods.
Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another for the purpose of space heating.
A thermal cooker, or a vacuum flask cooker, is a cooking device that uses thermal insulation to retain heat and cook food without the continuous use of fuel or other heat source. It is a modern implementation of a haybox, which uses hay or straw to insulate a cooking pot.
A bachelor griller, mini oven or mini kitchen is a countertop kitchen appliance about the size of a microwave oven but which can instead grill, bake, broil or roast food. It generally incorporates one or two heating elements at the top and bottom of the appliance, has one or two hobs on the cooktop, or a ceramic hotplate, and may incorporate a rotisserie.
