A fire piston, sometimes called a fire syringe or a slam rod fire starter, is a device of ancient Southeast Asian origin which is used to kindle fire. In Malay it is called "gobek api." It uses the principle of the heating of a gas (in this case air) by rapid and adiabatic compression to ignite a piece of tinder, which is then used to set light to kindling. [1]
A fire piston consists of a hollow cylinder sealed at one end and open at the other. Sizes range in length from 3 to 6 inches (7.5 to 15 cm) with a bore about 0.25 inch (6–7 mm) in diameter, to 10 to 14 inches (25 to 35 cm) with a bore about 0.5 inch (14 mm) in diameter. A piston with an airtight circular seal is fitted into the cylinder. A string packing lubricated with water or rubber gasket lubricated with grease is used to create an air-tight but slippery seal. At the end of the piston a small cavity is made, where tinder can be inserted without it being crushed during subsequent operations. The piston can be completely withdrawn from the cylinder for installation or removal of the tinder.
The piston (or cylinder) has a handle on the end to allow a firm grip to be applied to it, or a large enough surface area to strike it sharply without causing pain, while the cylinder (or piston) is braced or slammed against a hard surface. The compression of the air when the piston is quickly forced into the cylinder causes the interior temperature to rise sharply to over 400 °F (260 °C), the autoignition temperature of tinder. This is hot enough for the tinder in the piston face to ignite with a visible flash that can be seen, if the cylinder is made of translucent or transparent material. The piston is then quickly withdrawn, before the now-burning tinder depletes the available oxygen inside the cylinder. The smouldering tinder can then be removed from the face of the piston and transferred to a larger nest of tinder material. The ember is then fanned or blown upon vigorously to create a flame, at which time various stages of larger kindling can be added until built into a full-scale fire.
Ancient and modern versions of fire pistons have been made from wood, animal horns, antlers, bamboo, or metal. Today, fire pistons are commonly constructed from wood, metal, or plastic. Do-it-yourself designs have become available using wood dowels, PVC and copper pipe, and rubber O-rings, to build versions costing less than $2 USD each.[ citation needed ]
Rapid compression of a gas increases its pressure and its temperature at the same time. If this compression is done too slowly the heat will dissipate to the surroundings as the gas returns to thermal equilibrium with them. If the compression is done quickly enough, then there is no time for thermal equilibrium to be achieved. The absolute temperature of the gas can suddenly become much higher than that of its surroundings, increasing from the original room temperature of the gas to a temperature hot enough to set tinder alight. The air in the cylinder acts both as a source of heat and as an oxidizer for the tinder fuel.
The same principle is used in the diesel engine to ignite the fuel in the cylinder, eliminating the need for a spark plug as used in the gasoline engine. The principle of operation is closer to the hot bulb engine, an early antecedent to the diesel, since the fuel (tinder) is compressed with the gas, while in a diesel the fuel is injected when the gas is already compressed and at a high temperature.
Fire pistons have a compression ratio of about 25 to 1. This compares with about 20:1 for a modern diesel engine, and between 7:1 and 11.5:1 for a gasoline engine. The fire piston is made deliberately narrow so that unaided human strength can exert enough force to compress the air in the cylinder to its fullest extent. To achieve a high compression ratio, the final compressed volume of the tinder and air must be small relative to that of the length of the piston tube. These two factors together mean that only a tiny amount of tinder can be lit by a fire piston, but this can be sufficient to light other tinder, and in turn to light a larger fire.
Tinders that ignite at a very low temperature work best. Easily-combustible materials such as char cloth or amadou work well as tinder, and can also hold an ember. By contrast, cotton fibers ignite at 455 °F (235 °C) and will flash brightly but do not hold an ember. The bright flash of light is sometimes sufficient for demonstration purposes, but will not start a persistent fire.
The construction of a hand-operated pump, such as an ordinary bicycle pump, is very similar except that the pump also has valves and a hose to deliver compressed air as an output. In the case of the pump, the heating of the compressed air is an undesired side effect. In both fire piston and pumps, the mechanism and lubricants must be chosen to resist high peak temperatures and pressures.
Fire pistons were invented by Southeast Asians (probably the Austronesian peoples). Their use was mostly concentrated in the Austronesian regions, particularly in the Malay Peninsula, the Philippines, Borneo, Sumatra, Java, some of the islands east of Java including Flores, and in Madagascar. They are also found in Burma, Thailand, and Laos in Mainland Southeast Asia, as well as parts of Yunnan and in Japan. [3] [4] [5] [6]
Fire pistons in Southeast Asia were variously constructed of bamboo, wood, metal, ivory, bone, and horn. The main tube was typically around 3.25 in (8.3 cm) long and 0.5 in (1.3 cm) in diameter, with a bore size around 0.375 in (0.95 cm). [7] The end of the tube usually flared out into a small cavity used for holding tinder. [2] The tinder used was typically obtained from the leaf bases of palm trees and rattan vines and were usually stored in a tinder box carried along with the piston. They were reported to be known as lek phai tok in Thai; and gobek api in Malay (literally "fire mortar and pestle). [8]
The antiquity of the fire piston in Southeast Asia is unknown, but it definitely pre-dated the Austronesian colonization of Madagascar (c. 100-500 AD). It was one of the early definite proofs linking Madagascar with a Southeast Asian origin. [6]
The principles governing fire pistons were also used to construct Southeast Asian piston bellows with bamboo. These piston bellows could pump sufficient air into a furnace to produce temperatures high enough to melt metal, which led to the independent development of sophisticated bronze and iron metallurgy in Southeast Asia starting at around 1500 BC. Particularly in the development of bronze gongs (e.g. from the Dong Son culture) that were then exported in the ancient maritime trade networks of Southeast Asia. [6] [9] These piston-bellows reached as far as Madagascar prior to European contact. [10] The bamboo piston-bellows technology was also adopted early by the Chinese, replacing the indigenous Chinese leather-bellows technology completely. [6] [11]
Whether the European fire pistons were influenced by the Southeast Asian fire pistons was a matter of debate. But Balfour (1908) and Fox (1969) have demonstrated convincingly that the European fire pistons were independently discovered via air guns. Fox, however, tries to argue that the Southeast Asian fire pistons were introduced from Europe, but this is rejected as unconvincing by other scholars. The presence of derivative piston-bellows technology and the existence of fire pistons even in isolated and widely separated cultures, like the Kachin of northern Burma and the Igorot of highland Luzon, makes it definitely known that Southeast Asian fire pistons existed long before the European versions. [4] [10]
Despite the independent invention of European fire pistons, it was the Southeast Asian fire pistons that inspired Rudolf Diesel in his creation of the diesel engine at around 1892, not the European versions (which had largely been replaced by matches by the late 19th century). Diesel was a student of the inventor Carl von Linde. He acquired the idea of the internal combustion engine after he witnessed Linde light a cigarette with a fire piston. This fire piston was acquired by Linde from Southeast Asia during a lecture in Penang. [5] [12] [13]
The first known documented fire piston in the West was made in 1745 by the Abbot Agostino Ruffo of Verona, Italy, who was making a pair of air guns for the king of Portugal, John V. While Ruffo was testing a gun's air pump for leaks by plugging its outlet with a scrap of wood, he noticed that, after he had pressurized the pump, the wood had been scorched. Subsequently, he found that tinder was ignited by the pump. Ruffo made an apparatus to study the phenomenon further, [14] but his invention was not popularized.
It is recorded that the first fire piston made its wider debut in front of scientists in 1802, [15] and it was patented in 1807 simultaneously in both England and France. [16] Fire pistons, or "fire syringes" as they were called then, enjoyed a brief period of popularity in parts of Europe during the early nineteenth century, until being displaced by the friction match invented in 1826. [17]
In the US, descriptions have been published for many years. [18] [19] [20]
The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values.
The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is called a compression-ignition engine. This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine or a gas engine.
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder.
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common features of all types. The main types are: the internal combustion engine, used extensively in motor vehicles; the steam engine, the mainstay of the Industrial Revolution; and the Stirling engine for niche applications. Internal combustion engines are further classified in two ways: either a spark-ignition (SI) engine, where the spark plug initiates the combustion; or a compression-ignition (CI) engine, where the air within the cylinder is compressed, thus heating it, so that the heated air ignites fuel that is injected then or earlier.
In engineering, the Miller cycle is a thermodynamic cycle used in a type of internal combustion engine. The Miller cycle was patented by Ralph Miller, an American engineer, U.S. patent 2,817,322 dated Dec 24, 1957. The engine may be two- or four-stroke and may be run on diesel fuel, gases, or dual fuel. It uses a supercharger or a turbocharger to offset the performance loss of the Atkinson cycle.
A stratified charge engine describes a certain type of internal combustion engine, usually spark ignition (SI) engine that can be used in trucks, automobiles, portable and stationary equipment. The term "stratified charge" refers to the working fluids and fuel vapors entering the cylinder. Usually the fuel is injected into the cylinder or enters as a fuel rich vapor where a spark or other means are used to initiate ignition where the fuel rich zone interacts with the air to promote complete combustion. A stratified charge can allow for slightly higher compression ratios without "knock," and leaner air/fuel ratio than in conventional internal combustion engines.
A four-strokeengine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed:
In spark-ignition internal combustion engines, knocking occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignited by the spark plug, but when one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel–air charge is meant to be ignited by the spark plug only, and at a precise point in the piston's stroke. Knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive.
An air compressor is a machine that takes ambient air from the surroundings and discharges it at a higher pressure. It is an application of a gas compressor and a pneumatic device that converts mechanical power into potential energy stored in compressed air, which has many uses. A common application is to compress air into a storage tank, for immediate or later use. When the delivery pressure reaches its set upper limit, the compressor is shut off, or the excess air is released through an overpressure valve. The compressed air is stored in the tank until it is needed. The pressure energy provided by the compressed air can be used for a variety of applications such as pneumatic tools as it is released. When tank pressure reaches its lower limit, the air compressor turns on again and re-pressurizes the tank. A compressor is different from a pump because it works on a gas, while pumps work on a liquid.
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed. It has many applications, in particular blowing on a fire to supply it with air.
The Brayton cycle, also known as the Joule cycle, is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. It is characterized by isentropic compression and expansion, and isobaric heat addition and rejection, though practical engines have adiabatic rather than isentropic steps.
Sir Dugald Clerk KBE, LLD FRS was a Scottish engineer who designed the world's first successful two-stroke engine in 1878 and patented it in England in 1881. He was a graduate of Anderson's University in Glasgow, and Yorkshire College, Leeds. He formed the intellectual property firm with George Croydon Marks, called Marks & Clerk. He was knighted on 24 August 1917.
Dieseling or engine run-on is a condition that can occur in spark-plug-ignited, gasoline-powered internal combustion engines, whereby the engine keeps running for a short period after being turned off, drawing fuel through the carburetor, into the engine and igniting it without a spark.
This timeline of heat engine technology describes how heat engines have been known since antiquity but have been made into increasingly useful devices since the 17th century as a better understanding of the processes involved was gained. A heat engine is any system that converts heat to mechanical energy, which can then be used to do mechanical work.They continue to be developed today.
The hot-bulb engine, also known as a semi-diesel or Akroyd engine, is a type of internal combustion engine in which fuel ignites by coming in contact with a red-hot metal surface inside a bulb, followed by the introduction of air (oxygen) compressed into the hot-bulb chamber by the rising piston. There is some ignition when the fuel is introduced, but it quickly uses up the available oxygen in the bulb. Vigorous ignition takes place only when sufficient oxygen is supplied to the hot-bulb chamber on the compression stroke of the engine.
Engine efficiency of thermal engines is the relationship between the total energy contained in the fuel, and the amount of energy used to perform useful work. There are two classifications of thermal engines-
Internal combustion engines date back to between the 10th and 13th centuries, when the first rocket engines were invented in China. Following the first commercial steam engine by Thomas Savery in 1698, various efforts were made during the 18th century to develop equivalent internal combustion engines. In 1791, the English inventor John Barber patented a gas turbine. In 1794, Thomas Mead patented a gas engine. Also in 1794, Robert Street patented an internal-combustion engine, which was also the first to use liquid fuel (petroleum) and built an engine around that time. In 1798, John Stevens designed the first American internal combustion engine. In 1807, French engineers Nicéphore and Claude Niépce ran a prototype internal combustion engine, using controlled dust explosions, the Pyréolophore. This engine powered a boat on the river in France. The same year, the Swiss engineer François Isaac de Rivaz built and patented a hydrogen and oxygen-powered internal-combustion engine. Fitted to a crude four-wheeled wagon, François Isaac de Rivaz first drove it 100 metres in 1813, thus making history as the first car-like vehicle known to have been powered by an internal-combustion engine.
Internal combustion engines come in a wide variety of types, but have certain family resemblances, and thus share many common types of components.
A booster pump is a machine which increases the pressure of a fluid. It may be used with liquids or gases, and the construction details vary depending on the fluid. A gas booster is similar to a gas compressor, but generally a simpler mechanism which often has only a single stage of compression, and is used to increase pressure of a gas already above ambient pressure. Two-stage boosters are also made. Boosters may be used for increasing gas pressure, transferring high pressure gas, charging gas cylinders and scavenging.
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance. This process transforms chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.