A boiler is a closed vessel in which fluid is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation.
A chiller is a machine that removes heat from a liquid coolant via a vapor-compression, adsorption refrigeration, or absorption refrigeration cycles. This liquid can then be circulated through a heat exchanger to cool equipment, or another process stream. As a necessary by-product, refrigeration creates waste heat that must be exhausted to ambience, or for greater efficiency, recovered for heating purposes. Vapor compression chillers may use any of a number of different types of compressors. Most common today are the hermetic scroll, semi-hermetic screw, or centrifugal compressors. The condensing side of the chiller can be either air or water cooled. Even when liquid cooled, the chiller is often cooled by an induced or forced draft cooling tower. Absorption and adsorption chillers require a heat source to function.
A fire-tube boiler is a type of boiler in which hot gases pass from a fire through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam.
A high pressure watertube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which boils water in the steam-generating tubes. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam.
A thermal power station is a type of power station in which heat energy is converted to electrical energy. In a steam-generating cycle heat is used to boil water in a large pressure vessel to produce high-pressure steam, which drives a steam turbine connected to an electrical generator. The low-pressure exhaust from the turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate more high pressure steam. This is known as a Rankine cycle.
Thermosiphon is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. Thermosiphoning is used for circulation of liquids and volatile gases in heating and cooling applications such as heat pumps, water heaters, boilers and furnaces. Thermosiphoning also occurs across air temperature gradients such as those utilized in a wood fire chimney or solar chimney.
The steam-electric power station is a power station in which the electric generator is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser. The greatest variation in the design of steam-electric power plants is due to the different fuel sources.
A steam generator is a type of boiler used to produce steam for climate control and potable water heating in railroad passenger cars. The output of a railroad steam generator is low pressure, saturated steam that is passed through a system of pipes and conduits throughout the length of the train.
Economizers, or economisers (UK), are mechanical devices intended to reduce energy consumption, or to perform useful function such as preheating a fluid. The term economizer is used for other purposes as well. Boiler, power plant, heating, refrigeration, ventilating, and air conditioning (HVAC) uses are discussed in this article. In simple terms, an economizer is a heat exchanger.
An evaporator is a device used to turn the liquid form of a chemical substance, such as water, into a vapor.
A steam drum is a standard feature of a water-tube boiler. It is a reservoir of water/steam at the top end of the water tubes. The drum stores the steam generated in the water tubes and acts as a phase-separator for the steam/water mixture. The difference in densities between hot and cold water helps in the accumulation of the "hotter"-water/and saturated-steam into the steam-drum.
A boiler or steam generator is a device used to create steam by applying heat energy to water. Although the definitions are somewhat flexible, it can be said that older steam generators were commonly termed boilers and worked at low to medium pressure but, at pressures above this, it is more usual to speak of a steam generator.
In chemical engineering, a vapor–liquid separator is a device used to separate a vapor–liquid mixture into its constituent phases. It can be a vertical or horizontal vessel, and can act as a 2-phase or 3-phase separator.
Boilers for generating steam or hot water have been designed in countless shapes, sizes and configurations. An extensive terminology has evolved to describe their common features. This glossary provides definitions for these terms.
Three-drum boilers are a class of water-tube boiler used to generate steam, typically to power ships. They are compact and of high evaporative power, factors that encourage this use. Other boiler designs may be more efficient, although bulkier, and so the three-drum pattern was rare as a land-based stationary boiler.
A monotube steam generator is a type of steam generator consisting of a single tube, usually in a multi-layer spiral, that forms a once-through steam generator (OTSG). The first of these was the Herreshoff steam generator of 1873.
A high-pressure steam locomotive is a steam locomotive with a boiler that operates at pressures well above what would be considered normal for other locomotives. In the later years of steam, boiler pressures were typically 200 to 250 psi. High-pressure locomotives can be considered to start at 350 psi (2.41 MPa), when special construction techniques become necessary, but some had boilers that operated at over 1,500 psi (10.34 MPa).
A steam generator is a form of low water-content boiler, similar to a flash steam boiler. The usual construction is as a spiral coil of water-tube, arranged as a single, or monotube, coil. Circulation is once-through and pumped under pressure, as a forced-circulation boiler. The narrow-tube construction, without any large-diameter drums or tanks, means that they are safe from the effects of explosion, even if worked at high pressures. The pump flowrate is adjustable, according to the quantity of steam required at that time. The burner output is throttled to maintain a constant working temperature. The burner output required varies according to the quantity of water being evaporated: this can be either adjusted by open-loop control according to the pump throughput, or by a closed-loop control to maintain the measured temperature.
A LaMont boiler is a type of forced circulation water-tube boiler in which the boiler water is circulated through an external pump through long closely spaced tubes of small diameter. The mechanical pump is employed in order to have an adequate and positive circulation in steam and hot water boilers.
Circulation evaporators are a type of evaporating unit designed to separate mixtures unable to be evaporated by a conventional evaporating unit. Circulation evaporation incorporates the use of both heat exchangers and flash separation units in conjunction with circulation of the solvent in order to remove liquid mixtures without conventional boiling. There are two types of Circulation Evaporation; Natural Circulation Evaporators and Forced Circulation Evaporators, both of which are still currently used in industry today, although forced Circulation systems, which have a circulation pump as opposed to natural systems with no driving force, have a much wider range of appropriate uses.
