Humphrey pump

Humphrey pump
Humphrey pump
	The top of a Humphrey pump at the King George V pumping station in London
Classification	Gas-fueled liquid piston pump
Application	Water pumps for sewage, utility, irrigation and drydocks
Fuel source	Coal gas, Producer gas or Natural gas
Inventor	H. A. Humphrey
Invented	1909

Last updated February 21, 2024

The Humphrey pump is a large internal combustion gas-fueled liquid piston pump. The pump was invented by H. A. Humphrey and first presented in paper to the Institution of Mechanical Engineers on 19 November 1909.^[1]^[2]^[3] A pump capable of pumping 250,000 gallons per hour to a head of 35 feet was exhibited at the 1910 Brussels Exhibition, where it was awarded two Grands Prix, for both engines and pumps.^[4]

Operation

Humphrey's pump consists of a large U-shaped tube, filled with water. One end is sealed by a heavy cast iron, or steel, 'combustion head'. The combustion head contains the inlet and exhaust valves, the ignition source and withstands the pressure of the combustion chamber. Water enters the pump through sprung inlet valves below the combustion chamber. A distinctive feature of the Humphrey pump, compared to others, is that the water only has to flow through this single set of valves: there are no non-return outlet valves, only the inertia of the delivered water within the outlet pipe is used to control its flow. As there are no delivery valves opening and closing suddenly, the water flow changes smoothly, avoiding water hammer and the usual problems for this type of pump.^[1]

Combustible gas, mixed with air, is supplied into the combustion chamber and then fired by an electric spark. The force of the expanding gas drives water downwards from the combustion chamber and accelerates it along the delivery pipe. Once the chamber pressure drops to that of the inlet water, the delivered water is no longer being accelerated but the large mass of water in the long pipe continues to flow by its own inertia. This reduces the pressure in the chamber below atmospheric, which causes the inlet air and gas valves to open, drawing in fresh air as a scavenging effect. As the water begins to flow back down the U, this increases the chamber pressure and causes the exhaust valves to open.^[1]

Four-stroke and two-stroke cycles

H A Humphrey patented both four-stroke and two-stroke versions of his engine.^[5] The four-stroke design required mechanical interlocks to the inlet valves, so that the exhaust and scavenge valves open once during the cycle to allow scavenging of the exhaust, but not during the compression cycle afterwards. A two-stroke cycle was also possible, if adequate scavenging could be achieved. The air trapped within the combustion chamber of a Humphrey pump has two roles: both for combustion and also as an air spring to maintain the oscillating water column. As this spring action involves a large volume of air, relative to the minimal air needed for combustion, the air cools easily to below the ignition temperature to pre-ignite the next charge. There would still be a risk of inefficient four-stroking though, unless the scavenging is effective enough to sweep out the previous exhaust gases. This was done by using a tall, thin combustion chamber so that the combustion air remained roughly isolated from the majority of the chamber's air and so was scavenged through the exhaust valves first. There was no separate scavenge air valve.^[2]

A large amount of experimental work on the two-stroke version of the Humphrey engine was conducted by multiple companies in the hope of improving the type's efficiency and power density. In practice however it was impossible to prevent the incoming gas from mingling with the products from the previous combustion cycle resulting in the loss of gas through the exhaust valves.^[2]

The only 2-stroke Humphrey pump to enter service was a single example designed by A.P Steckel and installed at the Sun shipyard in Pennsylvania in 1925. All other commercial installations were of the 4-stroke type.^[5]

Limitations and advantages

The main limitation of the Humphrey pump is that it has no suction capacity, in fact it must be installed in a dry sump several meters below the supply level. Given the pump's physical size and the need to protect the equipment against flood events, this is no small engineering exercise, requiring (in the Cobdogla example) several thousand tons of concrete.^[6]

Its advantages however are: with no moving parts except for the dozens of spring-loaded inlet valves, it has low maintenance and high reliability.^[6] The Humphrey pump's efficiency was also good by the standards of the time. The demonstration pump exhibited at the Brussels exhibition was tested by Prof W.C Unwin in 1909^[5] and was found to require around 33% less fuel gas than would have been consumed had contemporary gas burning engines been used drive pumps moving the same amount of water to the same height.^[2]

Installed pumps

Ten Humphrey pumps are known to have been built for commercial service between 1912 and 1925:^[5]

King George V Reservoir, near Chingford in East London, had four Humphrey pumps installed when the pumping station was first constructed in 1912.^[7]^[8]^[9] Each pump was capable of pumping 40,000,000 gallons of water per day. A fifth, smaller, pump was added later.^[2] The pumps were built by Siemens at their facility in Stafford, England.^[5]

A single 66" diameter pump was installed at Del Rio, Texas in 1914.^[10] This was constructed by the Humphrey Gas Pump Co. of Syracuse, NY, who had licensed the Humphrey patents.^[5]

A single Humphrey pump was installed at a Sewage works in Southend-on-Sea, England during 1914. The pump had head of 65 ft at a capacity of 198,000 gallons per day. Construction works started for a second pump but was cancelled in 1915.^[5]

Two pumps, each rated at 1,500,000 imperial gallons (6.8 Ml) per hour^[6] (36,000,000 imperial gallons (160 Ml) per day), were installed at Cobdogla, on the Murray River in Australia, from 1923. These were constructed by William Beardmore and Company in Glasgow and shipped out to Australia for assembly.^[11]^[12]

A 36" cylinder bore Humphrey pump was installed at Chester, Pennsylvania in 1927 by the Sun Shipbuilding and Dry Dock Company. The pump was used in dry dock operations and also for experimental purposes. It was designed as a 2-stroke engine to operate in a range of head from 20 to 150 ft (6 to 46 m). The engine was installed in a 18 ft 6 (5.6 m) diameter and 50 ft (15.25 m) deep steel caisson, about 40 ft below the Delaware river. Air was supplied to the engine at this depth through a compressor. The pump underwent endurance tests 8 hrs a day in 1925 – 27 before switching to 24 hrs a day with water at head of 150 ft for weeks in 1928.^[5]

Proposed installations

A very large drainage and irrigation plant for Egypt was also considered in 1914.^[13] Construction of this was disrupted, owing to the outbreak of World War I. It was originally to use eighteen pumps, each delivering 100,000,000 gallons per day to a head of 20 feet.^[1]^[14] Each pump chamber was to be 8 ft 8 in in diameter and 14 ft high. Final construction would have used ten pumps, five by Beardmore's and five by the Italian division of Brown Boveri.^[13]

Similar pumps

A similar pump, the Joy pump, was also described at around the same time. This was much smaller, around six inches in diameter rather than six feet, and also had much smaller water pipe connections to it. This reduced water mass also reduced the compression ratio available in the combustion chamber, leading to reduced efficiency. The pump's ability to work with a suction lift of a few feet, rather than needing to be submerged like the Humphrey pump, was a convenience though. This pump was thought to have some application for small-scale or portable tasks, where its convenience outweighed efficiency.^[15]

Surviving examples

The Chingford pumps were replaced by electric pumps in the 1960s, although three of the pumps remain in situ.^[16]

Cobdogla's pumps ran from 1927 to 1965. In 1985 one was restored as a working example and was awarded an IMechE Engineering Heritage Award.^[17]

The construction of a working model of a Humphrey pump was completed in 2008 and the model was demonstrated at various open days at UK museums.^[16]

Gallery

Inlet valve section,
Cobdogla
Inside valve section,
Cobdogla

Related Research Articles

The diesel engine, named after 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.

<span class="mw-page-title-main">Two-stroke engine</span> Internal combustion engine type

A two-strokeengine is a type of internal combustion engine that completes a power cycle with two strokes of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust functions occurring at the same time.

An opposed-piston engine is a piston engine in which each cylinder has a piston at both ends, and no cylinder head. Petrol and diesel opposed-piston engines have been used mostly in large-scale applications such as ships, military tanks, and factories. Current manufacturers of opposed-piston engines include Cummins, Achates Power and Fairbanks-Morse Defense (FMDefense).

The Brayton cycle is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. The original Brayton Ready Motor used a piston compressor and piston expander, but modern gas turbine engines and airbreathing jet engines also follow the Brayton cycle. Although the cycle is usually run as an open system, it is conventionally assumed for the purposes of thermodynamic analysis that the exhaust gases are reused in the intake, enabling analysis as a closed system.

A pumpjack is the overground drive for a reciprocating piston pump in an oil well.

Volumetric efficiency (VE) in internal combustion engine engineering is defined as the ratio of the equivalent volume of the fresh air drawn into the cylinder during the intake stroke to the volume of the cylinder itself. The term is also used in other engineering contexts, such as hydraulic pumps and electronic components.

<span class="mw-page-title-main">CVCC</span> Reduced-emissions engine by Honda

CVCC, or Compound Vortex Controlled Combustion, is an internal combustion engine technology developed and trademarked by the Honda Motor Company.

William Hall Barnett is described as a 'founder' in his 1836 patent, and an 'ironfounder' in his 1838 patent, and later as an engineer and gas engineer, working in Brighton, UK. He worked for many years for the Brighton and Hove General Gas Company. He was born in Bradford and died in Brighton.

In automotive engineering, an exhaust manifold collects the exhaust gases from multiple cylinders into one pipe. The word manifold comes from the Old English word manigfeald and refers to the folding together of multiple inputs and outputs.

<span class="mw-page-title-main">Reed valve</span> Type of check valve

Reed valves are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face. Modern versions often consist of flexible metal or composite materials.

Crossley, based in Manchester, United Kingdom, was a pioneering company in the production of internal combustion engines. Since 1988, it has been part of the Rolls-Royce Power Engineering group.

In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block.

<span class="mw-page-title-main">Crankcase ventilation system</span> System to relieve pressure in a combustion engines crankcase

A crankcase ventilation system (CVS) removes unwanted gases from the crankcase of an internal combustion engine. The system usually consists of a tube, a one-way valve and a vacuum source.

The term six-stroke engine has been applied to a number of alternative internal combustion engine designs that attempt to improve on traditional two-stroke and four-stroke engines. Claimed advantages may include increased fuel efficiency, reduced mechanical complexity, and/or reduced emissions. These engines can be divided into two groups based on the number of pistons that contribute to the six strokes.

Scavenging is the process of replacing the exhaust gas in a cylinder of an internal combustion engine with the fresh air/fuel mixture for the next cycle. If scavenging is incomplete, the remaining exhaust gases can cause improper combustion for the next cycle, leading to reduced power output.

Internal combustion engines come in a wide variety of types, but have certain family resemblances, and thus share many common types of components.

A total-loss oiling system is an engine lubrication system whereby oil is introduced into the engine, and then either burned or ejected overboard. Now rare in four-stroke engines, total loss oiling is still used in many two-stroke engines.

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, transforming chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.

References

1 2 3 4 5 Wimperis, Harry Egerton (1915). "The Gas Engine". The Internal Combustion Engine (2nd ed.). New York: D. Van Nostrand Company. pp. 113–117.
1 2 3 4 5 6 McLaughlan, James Ivey (1931). "The Humphrey Pump and the Installation of Two Sixty-Six Inch Units at Cobdogla, River Murray" (PDF). Trans. Inst. Engineers of Australia. XII: 413–426.
↑ Humphrey, Herbert A. (19 November 1909). "An Internal-Combustion Pump, and other applications of a new Principal". Proc. Inst. Mech. Eng. 77: 1075–1200. doi:10.1243/PIME_PROC_1909_077_019_02.
↑ "The Humphrey Pump at the Brussels Exhibition". Engineering. 22 July 1910. Archived from the original on 12 October 2018. Retrieved 12 April 2021.
1 2 3 4 5 6 7 8 9 Smith, Dennis (10 February 1971). "The Humphrey Pump and its inventor". Transactions of the Newcomen Society. London, United Kingdom: Science Museum.
1 2 3 Mack, David (2003). Irrigation Settlement: Some historical aspects in South Australia on the River Murray 1838–1978. Cobdogla, South Australia 5346: Cobdogla Irrigation and Steam Museum. p. 252.{{cite book}}: CS1 maint: location (link)
↑ "The New Reservoir at Chingford, No I". The Engineer . 14 March 1913.
↑ "The New Reservoir at Chingford, No II". The Engineer . 21 March 1913.
↑ "The New Reservoir at Chingford, No III". The Engineer . 28 March 1913.
↑ "A Humphrey Direct-Acting Explosion Pump for Irrigation Service at Del Rio, Texas". Engineering News. 72 (16). 15 October 1914. Archived from the original on 14 October 2016. Retrieved 12 April 2021.
↑ South Australia Water (1913). Cobdogla Humphrey Pumps (Photograph). Flickr.
↑ "Big Works at Cobdogla: Preparing to Instal Gigantic Humphrey Pump". Murray Pioneer and Australian River Record . Renmark, SA: National Library of Australia. 21 December 1923. p. 5. Retrieved 12 April 2021.
1 2 "The Largest Pumping Plant in the World: a Great Humphrey Engine Pumping Plant for Land Drainage in Egypt". Engineering News. 72 (2). 9 July 1914. Archived from the original on 15 October 2016. Retrieved 12 April 2021.
↑ "Internal Combustion Pumping Plant". Internal Combustion Engineering. 24 June 1914.
↑ Kennedy, Rankin (1912). The Book of Modern Engines & Power Generators. Vol. V. Caxton. pp. 15–16.
1 2 Wells, Don (September 2012). "A Model Humphrey Pump". Archived from the original on 23 March 2018. Retrieved 12 April 2021.
↑ "The Humphrey Pump". Energy 21. Archived from the original on 12 January 2020. Retrieved 12 April 2021.

External links

Cobdogla Irrigation and Steam Museum, South Australia
South Australia Water. Cobdogla Humphrey Pumps. Flickr . Retrieved 12 April 2021.