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Cataract (beam Engine)
A cataract was a speed governing device used for early single-acting beam engines, particularly atmospheric engines and Cornish engines. It was a kind of water clock. The cataract is distinctly different from the centrifugal governor, in that it does not control the speed of the engine's stroke, but rather the timing between strokes. Operation The typical installation of a house-built beam engine spanned four floors. The cylinder and the engine driver's usual working position were located in the 'bottom chamber', approximately at ground level. Above this were the 'middle chamber', with the cylinder top cover and 'top nozzle' (the upper valve chest), and above that the 'top chamber' or beam chamber. The cataracts were located in the lowest part of the engine house, in a chamber below the bottom chamber, along with the exhaust pipe. This space was awkward to access and not visited in normal operation. The valve gear (or 'working gear') of a Newcomen or Cornish engine is bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elsecar Newcomen Engine
Elsecar (, ) is a village in the Metropolitan Borough of Barnsley in South Yorkshire, England. It is near the villages of Jump and Wentworth and south of the town of Hoyland, south of Barnsley and north-east of Sheffield. Elsecar falls within the Barnsley MBC Ward of Hoyland Milton. Elsecar is unique as a name. It is thought to derive from the Old English personal name of ''Aelfsige'' (mentioned in Cartulary of Nostell Priory, 1259–66) and the Old Norse word kjarr, denoting a marsh or brushwood. From the late 18th century, Elsecar was transformed into an 'industrial estate village' for nearby Wentworth Woodhouse, with multiple collieries and two major ironworks.https://historicengland.org.uk/research/results/reports/6-2019 It is seen as one of the UK's first model villages and a precursor to Saltaire. A 1795 Newcomen steam engine at the Elsecar New Colliery is the oldest steam engine still in situ, anywhere in the world.https://historicengland.org.uk/listing/the-list/l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boulton And Watt
Boulton & Watt was an early British engineering and manufacturing firm in the business of designing and making marine and stationary steam engines. Founded in the English West Midlands around Birmingham in 1775 as a partnership between the English manufacturer Matthew Boulton and the Scottish engineer James Watt, the firm had a major role in the Industrial Revolution and grew to be a major producer of steam engines in the 19th century. The engine partnership The partnership was formed in 1775 to exploit Watt's patent for a steam engine with a separate condenser. This made much more efficient use of its fuel than the older Newcomen engine. Initially the business was based at the Soho Manufactory near Boulton's Soho House on the southern edge of the then-rural parish of Handsworth. However most of the components for their engines were made by others, for example the cylinders by John Wilkinson. In 1795, they began to make steam engines themselves at their Soho Foundr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Throttle Valve
A throttle is the mechanism by which fluid flow is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' has come to refer, informally, to any mechanism by which the power or speed of an engine is regulated, such as a car's accelerator pedal. What is often termed a ''throttle'' (in an aviation context) is also called a thrust lever, particularly for jet engine powered aircraft. For a steam locomotive, the valve which controls the steam is known as the regulator. Internal combustion engines In an internal combustion engine, the throttle is a means of controlling an engine's power by regulating the amount of fuel or air entering the engine. In a motor vehicle the control used by the driver to regulate power is sometimes called the throttle, accelerator, or gas pedal. For a gasoline engine, the throttle most commonly regulates the amount of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science Museum, London
The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and is one of the city's major tourist attractions, attracting 3.3 million visitors annually in 2019. Like other publicly funded national museums in the United Kingdom, the Science Museum does not charge visitors for admission, although visitors are requested to make a donation if they are able. Temporary exhibitions may incur an admission fee. It is one of the five museums in the Science Museum Group. Founding and history The museum was founded in 1857 under Bennet Woodcroft from the collection of the Royal Society of Arts and surplus items from the Great Exhibition as part of the South Kensington Museum, together with what is now the Victoria and Albert Museum. It included a collection of machinery which became the ''Museum of Patents'' in 1858, and the ''Patent Office Museum'' in 1863. This collection contained many of the most famous exhibits of what is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lap Engine
The Lap Engine is a beam engine designed by James Watt, built by Boulton and Watt in 1788. It is now preserved at the Science Museum, London. It is important as both an early example of a beam engine by Boulton and Watt, and also mainly as illustrating an important innovative step in their development for its ability to produce rotary motion. The engines name comes from its use in Matthew Boulton's Soho Manufactory, where it was used to drive a line of 43 polishing or lapping machines, used for the production of buttons and buckles. Innovations Watt did not invent the steam engine and there is no single 'Watt steam engine' as such. He developed a number of separate innovations, each of which improved the existing engines of the day, beginning with Newcomen's. The Lap Engine of 1788, also the Whitbread Engine (1785), represent survivors of the first engines to show all of Watt's major improvements in one. Parallel motion Rotative beam engines Sun and planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windmill
A windmill is a structure that converts wind power into rotational energy using vanes called sails or blades, specifically to mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and other applications, in some parts of the English speaking world. The term wind engine is sometimes used to describe such devices. Windmills were used throughout the high medieval and early modern periods; the horizontal or panemone windmill first appeared in Persia during the 9th century, and the vertical windmill first appeared in northwestern Europe in the 12th century. Regarded as an icon of Dutch culture, there are approximately 1,000 windmills in the Netherlands today. Forerunners Wind-powered machines may have been known earlier, but there is no clear evidence of windmills before the 9th century. Hero of Alexandria (Heron) in first-century Roman Egypt described what appears to be a wind-driven wheel to power a machine.Dietrich Lohrmann, "Von der östli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watermill
A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills. One major way to classify watermills is by wheel orientation (vertical or horizontal), one powered by a vertical waterwheel through a gear mechanism, and the other equipped with a horizontal waterwheel without such a mechanism. The former type can be further divided, depending on where the water hits the wheel paddles, into undershot, overshot, breastshot and pitchback (backshot or reverse shot) waterwheel mills. Another way to classify water mills is by an essential trait about their location: tide mills ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kew Bridge Steam Museum
London Museum of Water & Steam is an independent museum founded in 1975 as the Kew Bridge Steam Museum. It was rebranded in early 2014 following a major investment project. Situated on the site of the old Kew Bridge Pumping Station in Brentford, near Kew Bridge on the River Thames in West London, England, the museum is centred on a collection of stationary water pumping steam engines dating from 1820 to 1910. It is the home of the world's largest collection of working Cornish engines, including the Grand Junction 90 inch, the largest such working engine in the world. The site is an anchor point on the European Route of Industrial Heritage (ERIH). The museum reopened on 22 March 2014. History Kew Bridge Pumping Station was originally opened in 1838 by the Grand Junction Waterworks Company, following a decision to close an earlier pumping station at Chelsea due to poor water quality. In the years up to 1944 the site expanded, ultimately housing six steam pumping engines as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closed-loop Control
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a desired state, while minimizing any ''delay'', ''overshoot'', or ''steady-state error'' and ensuring a level of control stability; often with the aim to achieve a degree of optimality. To do this, a controller with the requisite corrective behavior is required. This controller monitors the controlled process variable (PV), and compares it with the reference or set point (SP). The difference between actual and desired value of the process variable, called the ''error'' signal, or SP-PV error, is applied as feedback to generate a control action to bring the controlled process variable to the same value as the set point. Other aspects which are also studied are controllability and observability. Control theory is used in control system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-loop Control
In control theory, an open-loop controller, also called a non-feedback controller, is a control system in which the control action is independent of the "process output", which is the process variable that is being controlled."Feedback and control systems" - JJ Di Steffano, AR Stubberud, IJ Williams. Schaums outline series, McGraw-Hill 1967 It does not use feedback to determine if its output has achieved the desired goal of the input command or process setpoint. There are many open-loop controls, such as on/off switching of valves, machinery, lights, motors or heaters, where the control result is known to be approximately sufficient under normal conditions without the need for feedback. The advantage of using open-loop control in these cases is the reduction in component count and complexity. However, an open-loop system cannot correct any errors that it makes or correct for outside disturbances, and cannot engage in machine learning, unlike a closed-loop control system. Open- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Servomechanism
In control engineering a servomechanism, usually shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the action of a mechanism. On displacement-controlled applications, it usually includes a built-in encoder or other position feedback mechanism to ensure the output is achieving the desired effect. The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position, speed, attitude or any other measurable variables. For example, an automotive power window control is not a servomechanism, as there is no automatic feedback that controls position—the operator does this by observation. By contrast a car's cruise control uses closed-loop feedback, which classifies it as a servomechanism. Applications Position control A common type of servo provides ''position control''. Commonly, servos are electric, hydraulic, or pneumatic. They operate on the principle of negative feedback ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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