Misplaced Pages

#255744

61-564: Henninger Turm (Henninger Tower) was a grain storage silo located in the Sachsenhausen-Süd district of Frankfurt , Germany. It was built by Henninger Brewery (now part of the Binding Brewery/Radeberger Group ) and had a storage capacity of 16,000 tons of barley . The 120-metre (390 ft), 33-storey, reinforced concrete tower was designed by Karl Lieser and was built from 1959 to 1961. It

122-418: A chute into a wagon, wheelbarrow, or open pile. When closed, the forage continues past the opening and onward to other parts of the conveyor. Computer automation and a conveyor running the length of a feeding stall can permit the silage to be automatically dropped from above to each animal, with the amount dispensed customized for each location. Silos are hazardous, and people are killed or injured every year in

183-430: A considerable engineering analysis of the system. Flexible Silos are the most versatile and cost-effective solution for the storage of bulk powder and granules. Manufactured from trevira tissue, a tough non-toxic fabric, the silos can handle particle size down to 2 microns and can be pneumatically loaded without the need for a dust collector. The 45-degree fabric silo cone flexes freely when the product discharges, enabling

244-526: A disadvantage for items like chopped wood. The tower silo was invented by Franklin Hiram King . In Canada , Australia and the United States, many country towns or the larger farmers in grain-growing areas have groups of wooden or concrete tower silos, known as grain elevators , to collect grain from the surrounding towns and store and protect the grain for transport by train, truck or barge to

305-402: A fabric bag suspended within a rigid, structural frame. Polyester based fabrics are often used for fabrication of the bag material, with specific attention given to fabric pore size. Upper areas of silo fabric are often manufactured with slightly larger pore size, with the design intent of acting as a vent filter during silo filling. Some designs include metal thread within the fabric, providing

366-600: A fluid always give the static pressure value, the 'static' is often dropped. In the design and operation of aircraft , static pressure is the air pressure in the aircraft's static pressure system . The concept of pressure is central to the study of fluids. A pressure can be identified for every point in a body of fluid, regardless of whether the fluid is in motion. Pressure can be measured using an aneroid , Bourdon tube , mercury column, or various other methods. The concepts of total pressure and dynamic pressure arise from Bernoulli's equation and are significant in

427-643: A fluid flow field. In Aerodynamics , L.J. Clancy writes: "To distinguish it from the total and dynamic pressures, the actual pressure of the fluid, which is associated not with its motion but with its state, is often referred to as the static pressure, but where the term pressure alone is used it refers to this static pressure." Bernoulli's equation is foundational to the dynamics of incompressible fluids . In many fluid flow situations of interest, changes in elevation are insignificant and can be ignored. With this simplification, Bernoulli's equation for incompressible flows can be expressed as where: Every point in

488-418: A large comb -shaped tines to push forage into the bag. The forage is pushed in through a large opening, and as the teeth rotate back out, they pass between the comb tines. The cam-shaped auger teeth essentially wipe the forage off using the steel tines, keeping the forage in the bag. Before filling begins, the entire bag is placed onto the loader as a bunched-up tube folded back on itself in many layers to form

549-407: A large brake shoe pressure regulator, holding back two large winch drums on either side of the loader. Cables from the drum extend to the rear of the bag where a large mesh basket holds the rear end of the bag shut. To prevent molding and to assure an airtight seal during fermentation, the ends of the silo bag tube are gathered, folded, and tied shut to prevent oxygen from entering the bag. Removal of

610-420: A large heavy sheet of silo plastic which seals out oxygen and permits the entire pile to begin to ferment in the autumn. In the winter when animals must be kept indoors, the silo plastic is removed, the unloader is lowered down onto the top of the silage pile, and a hinged door is opened on the side of the silo to permit the silage to be blown out. There is an array of these access doors arranged vertically up

671-404: A need for the expression freestream static pressure . Gracey has written "The static pressure is the atmospheric pressure at the flight level of the aircraft". Gracey then refers to the air pressure at any point close to the aircraft as the local static pressure . The term (hydro)static pressure is sometimes used in fluid statics to refer to the pressure of a fluid at a nominated depth in

SECTION 10

#1732772589256

732-416: A plug, the forage needs to be forked out into an even layer around the unloader so that the unloader does not immediately dig into the pile and plug itself again. All during this process the farmer is standing on or near a machine that could easily kill them in seconds if it were to accidentally start up. This could happen if someone in the barn were to unknowingly switch on the unloading mechanism while someone

793-418: A processor or to an export port. In bumper crop times, the excess grain is stored in piles without silos or bins, causing considerable losses. Concrete stave silos are constructed from small precast concrete blocks with ridged grooves along each edge that lock them together into a high strength shell. Concrete is much stronger in compression than tension , so the silo is reinforced with steel hoops encircling

854-489: A relatively large stock of wheat was preserved in some hundreds of pits (silos) cut in the rock. A single silo stored from 60 to 80 tons of wheat, which, with proper precautions, kept in good condition for four years or more. The first modern silo, a wooden and upright one filled with grain , was invented and built in 1873 in Spring Grove, Illinois by Fred Hatch of McHenry County, Illinois , US. Forage silo filling

915-437: A small position error in the instruments' indicated altitude and airspeed. A designer's objective in locating the static port is to minimize the resulting position error across the aircraft's operating range of weight and airspeed. Many authors describe the atmospheric pressure at the altitude at which the aircraft is flying as the freestream static pressure . At least one author takes a different approach in order to avoid

976-471: A static conductive path from the surface of the fabric to ground. The frame of a fabric silo is typically constructed of steel . Fabric silos are an attractive option because of their relative low cost compared to conventional silos. However, when fabric silos are used to store granular or particulate combustible materials, conventional practices prescribed by established industry consensus standards addressing combustible dust hazards can not be applied without

1037-402: A steadily flowing fluid, regardless of the fluid speed at that point, has its own static pressure P {\displaystyle P} , dynamic pressure q {\displaystyle q} , and total pressure P 0 {\displaystyle P_{0}} . Static pressure and dynamic pressure are likely to vary significantly throughout the fluid but total pressure

1098-409: A thick pile of plastic. Because the plastic is minimally elastic, the loader mechanism filling chute is slightly smaller than the final size of the bag, to accommodate this stack of plastic around the mouth of the loader. The plastic slowly unfurls itself around the edges of the loader as the tube is filled. The contents of the silo bag are under pressure as it is filled, with the pressure controlled by

1159-534: A traveling sled driven from the PTO of a tractor left in neutral and which is gradually pushed forward as the bag is filled. The steering of the tractor controls the direction of bag placement as it fills, but bags are normally laid in a straight line. The bag is loaded using the same forage harvesting methods as the tower, but the forage wagon must be moved progressively forward with the bag loader. The loader uses an array of rotating cam-shaped spiraled teeth associated with

1220-578: A wide variety of polyethylene plastics. The silos are light weight and make for great small scale storage for farmers with livestock and grain operations. The light weight design and cost effective materials make plastic silos a great alternative to traditional steel bins. Unlike fabric silos, which "tend to be prone to grain rot and pests which have left many farmers frustrated", plastic silos are more safe and secure, keeping grain fresh and unspoiled. They can be designed to be stationary hopper bottom bins or portable pallet bins. Fabric silos are constructed of

1281-461: Is aircraft whose maximum speed will be less than about 30% of the speed of sound . As a consequence of the widespread understanding of the term static pressure in relation to Bernoulli's equation, many authors in the field of fluid dynamics also use static pressure rather than pressure in applications not directly related to Bernoulli's equation . The British Standards Institution , in its Standard Glossary of Aeronautical Terms , gives

SECTION 20

#1732772589256

1342-455: Is constant along each streamline. In irrotational flow , total pressure is the same on all streamlines and is therefore constant throughout the flow. The simplified form of Bernoulli's equation can be summarised in the following memorable word equation: This simplified form of Bernoulli's equation is fundamental to an understanding of the design and operation of ships, low speed aircraft, and airspeed indicators for low speed aircraft – that

1403-413: Is immune to atmospheric pressure changes over time. Instead, the silo structure is open to the atmosphere but outside air is separated from internal air by large impermeable bags sealed to the silo breather openings. In the warmth of the day when the silo is heated by the sun, the gas trapped inside the silo expands and the bags "breathe out" and collapse. At night the silo cools, the air inside contracts and

1464-401: Is in the silo working on the unloader. Often, when unloading grain from an auger or other opening at the bottom of the silo, another worker will be atop the grain "walking it down", to ensure an even flow of grain out of the silo. Sometimes unstable pockets in the grain will collapse beneath the worker doing the walking; this is called grain entrapment as the worker can be completely sunk into

1525-413: Is performed using a forage harvester which may either be self-propelled with an engine and driver's cab, or towed behind a tractor that supplies power through a PTO . The harvester contains a drum-shaped series of cutting knives which shear the fibrous plant material into small pieces no more than an inch long, to facilitate mechanized blowing and transport via augers. The finely chopped plant material

1586-427: Is then blown by the harvester into a forage wagon which contains an automatic unloading system. Tower forage filling is typically performed with a silo blower which is a very large fan with paddle-shaped blades. Material is fed into a vibrating hopper and is pushed into the blower using a spinning spiral auger . There is commonly a water connection on the blower to add moisture to the plant matter being blown into

1647-422: Is typically lowered only a half-inch or so at a time by the operator, and the unloader picks up only a small amount of material until the winch cable has become taut and the unloader is not picking up any more material. The operator then lowers the unloader another half-inch or so and the process repeats. If lowered too far, the unloader can pull up much more material than it can handle, which can overflow and plug up

1708-410: Is typically much shorter than a silo, and is typically used for holding dry matter such as cement or grain. Grain is often dried in a grain dryer before being stored in the bin. Bins may be round or square, but round bins tend to empty more easily due to a lack of corners for the stored material to become wedged and encrusted. The stored material may be powdered, as seed kernels, or as cob corn. Due to

1769-594: The United States . The shaped is based on natural shape formed when piling solids. The dome is made of prefabricated wood panels with shingles installed on a circular reinforced concrete base. Open canopy entrance allows for front end loaders to fill and retrieve easily. These are usually found along major highway or key primary roads. Plastic silos, also known as hopper bottom tanks, are manufactured through various processes such as: injection molding , rotational molding, and blow molding . They are constructed using

1830-476: The slipform and Jumpform concrete silos being the larger diameter and taller silos. They can be made of many materials. Wood staves, concrete staves, cast concrete, and steel panels have all been used, and have varying cost, durability, and airtightness tradeoffs. Silos storing grain, cement and woodchips are typically unloaded with air slides or augers. Silos can be unloaded into rail cars, trucks or conveyors. Tower silos containing silage are usually unloaded from

1891-400: The air pressure varies slightly at different positions around the aircraft's exterior, so designers must select the static ports' locations carefully. Wherever they are located, the air pressure that the ports observe will generally be affected by the aircraft's instantaneous angle of attack . The difference between that observed pressure and the actual atmospheric pressure (at altitude) causes

Henninger Turm - Misplaced Pages Continue

1952-427: The amount of material to be stored. They are packed using a machine made for the purpose, and sealed on both ends. They are unloaded using a tractor and loader or skid-steer loader . The bag is discarded in sections as it is torn off. Bag silos require little capital investment. They can be used as a temporary measure when growth or harvest conditions require more space, though some farms use them every year. A bin

2013-412: The bag loader can be hazardous to bystanders since the pressure must be released and the rear end allowed to collapse onto the ground. A silo unloader specifically refers to a special cylindrical rotating forage pickup device used inside a single tower silo. The main operating component of the silo unloader is suspended in the silo from a steel cable on a pulley that is mounted in the top-center of

2074-482: The bags "breathe in" and expand again. While the iconic blue Harvestore low-oxygen silos were once very common, the speed of its unloader mechanism was not able to match the output rates of modern bunker silos, and this type of silo went into decline. Unloader repair expenses also severely hurt the Harvestore reputation, because the unloader feed mechanism is located in the bottom of the silo under tons of silage. In

2135-416: The blower, outlet spout, and the unloader tube, resulting in a time-wasting process of having to climb up the silo to clear the blockages. Once silage has entered the conveyor system, it can be handled by either manual or automatic distribution systems. The simplest manual distribution system uses a sliding metal platform under the pickup channel. When slid open, the forage drops through the open hole and down

2196-400: The blower. The farmer must continually move around in this highly hazardous environment of spinning shafts and high-speed conveyors to check material flows and adjust speeds, and to start and stop all the equipment between loads. Preparation for filling a silo requires winching the unloader to the top, and any remaining forage at the base that the unloader could not pick up must be removed from

2257-418: The contents in a low-oxygen atmosphere at all times, to keep the fermented contents in a high quality state, and to prevent mold and decay, as may occur in the top layers of a stave silo or bunker. Low-oxygen silos are only opened directly to the atmosphere during the initial forage loading, and even the unloader chute is sealed against air infiltration. It would be expensive to design such a huge structure that

2318-833: The dry nature of the stored material, it tends to be lighter than silage and can be more easily handled by under-floor grain unloaders. To facilitate drying after harvesting, some grain bins contain a hollow perforated or screened central shaft to permit easier air infiltration into the stored grain. There are different types of cement silos such as the low-level mobile silo and the static upright cement silo, which are used to hold and discharge cement and other powder materials such as pulverised fuel ash (PFA). The low-level silos are fully mobile with capacities from 100 to 750 tons. They are simple to transport and are easy to set up on site. These mobile silos generally come equipped with an electronic weighing system with digital display and printer. This allows any quantity of cement or powder discharged from

2379-634: The efficient flow of hard to handle products such as sugar, flour, calcium carbonate etc., minimally assisted by a small vibrator fitted to the discharge transition. The trevira tissue is able to breathe, preventing condensation from forming on its internal walls. This eliminates lumping and caking of the product. With sizes ranging from 2m to over 1000m , Rigid Silos cover an extreme range of applications and they can be constructed from various materials. Rigid silos can be provided with more than one vertical partition to compartmentalize it for different grades of product. The 5th millennium BC site of Tel Tsaf in

2440-592: The event of cutter chain breakage, it can cost up to US$ 10,000 to perform repairs. The silo may need to be partially or completely emptied by alternate means, to unbury the broken unloader and retrieve broken components lost in the silage at the bottom of the structure. In 2005 the Harvestore company recognized these issues and worked to develop new unloaders with double the flow rate of previous models to stay competitive with bunkers, and with far greater unloader chain strength. They are now also using load sensing soft-start variable frequency drive motor controllers to reduce

2501-413: The floor of the silo. This job requires that the farmer work directly underneath a machine weighing several tons suspended fifty feet or more overhead from a small steel cable. Should the unloader fall, the farmer will likely be killed instantly. Unloading also poses its own special hazards, due to the requirement that the farmer regularly climb the silo to close an upper door and open a lower door, moving

Henninger Turm - Misplaced Pages Continue

2562-416: The following definition: An aircraft's static pressure system is the key input to its altimeter and, along with the pitot pressure system , also drives the airspeed indicator . The static pressure system is open to the aircraft's exterior through a small opening called the static port , which allows sensing the ambient atmospheric pressure at the altitude at which the aircraft is flying. In flight,

2623-507: The grain within seconds. Entrapment can also occur in moving grain, or when workers clear large clumps of grain that have become stuck on the side of the silo. This often results in death by suffocation . Static pressure In fluid mechanics the term static pressure refers to a term in Bernoulli's equation written words as static pressure + dynamic pressure = total pressure . Since pressure measurements at any single point in

2684-543: The likelihood of mechanism breakage, and to control the feeder sweep arm movement. Bunker silos are trenches, usually with concrete walls, that are filled and packed using tractors and loaders. The filled trench is covered with a plastic tarp to make it airtight. These silos are usually unloaded with a tractor and loader. They are inexpensive and especially well suited to very large operations. Bag silos are heavy plastic tubes, usually around 8 to 12 ft (2.4 to 3.6 m) in diameter, and of variable length as required for

2745-418: The process of filling and maintaining them. The machinery used is dangerous, and workers can fall from a tower silo's ladder or work platform. Several fires have occurred over the years. Filling a silo requires parking two tractors very close to each other, both running at full power and with live PTO shafts , one powering the silo blower and the other powering a forage wagon unloading fresh-cut forage into

2806-414: The roof of the silo. The vertical positioning of the unloader is controlled by an electric winch on the exterior of the silo. For the summer filling of a tower silo, the unloader is winched as high as possible to the top of the silo and put into a parking position. The silo is filled with a silo blower , which is literally a very large fan that blows a large volume of pressurized air up a 10-inch tube on

2867-405: The side of the silo, with an unloading tube next to the doors that has a series of removable covers down the side of the tube. The unloader tube and access doors are normally covered with a large U-shaped shield mounted on the silo, to protect the farmer from wind, snow, and rain while working on the silo. The silo unloader mechanism consists of a pair of counter-rotating toothed augers which rip up

2928-403: The side of the silo. A small amount of water is introduced into the air stream during filling to help lubricate the filling tube. A small adjustable nozzle at the top, controlled by a handle at the base of the silo directs the silage to fall into the silo on the near, middle, or far side, to facilitate evenly layered loading. Once completely filled, the top of the exposed silage pile is covered with

2989-425: The silo blower attached to the silo at all times to use it when necessary to ventilate the silo with fresh air, or to have a dedicated electric fan system to blow fresh air into the silo, before anyone attempts to enter it. In the event that the unloader mechanism becomes plugged, the farmer must climb the silo and directly stand on the unloader, reaching into the blower spout to dig out the soft silage. After clearing

3050-607: The silo to be controlled and also provides an accurate indication of what remains inside the silo. The static upright silos have capacities from 200 to 800 tons. These are considered a low-maintenance option for the storage of cement or other powders. Cement silos can be used in conjunction with bin-fed batching plants . Sand and salt for winter road maintenance are stored in conical dome-shaped (clear truss roof) silos. These are more common in North America , namely in Canada and

3111-422: The silo. The blower may be driven by an electric motor but it is more common to use a spare tractor instead. A large slow-moving conveyor chain underneath the silage in the forage wagon moves the pile towards the front, where rows of rotating teeth break up the pile and drop it onto a high-speed transverse conveyor that pours the silage out the side of the wagon into the blower hopper. Silo bags are filled using

SECTION 50

#1732772589256

3172-652: The southern Levant contain the earliest known silos. Archaeological ruins and ancient texts show that silos were used in ancient Greece as far back as the late 8th century BC; the term silo is derived from the Greek σιρός ( siros ), "pit for holding grain". The silo pit, as it has been termed, has been a favorite way of storing grain from time immemorial in Asia. In Turkey and Persia, insurance agents bought stores of wheat or barley whilst comparatively cheap, and store it in hidden pits against seasons of dearth. In Malta

3233-429: The study of all fluid flows. These two pressures are not pressures in the usual sense - they cannot be measured using a pressure sensor . To avoid potential ambiguity when referring to pressure in fluid dynamics, many authors use the term static pressure to distinguish it from total pressure and dynamic pressure ; the term static pressure is identical to the term pressure , and can be identified for every point in

3294-426: The surface of the silage and pull it towards the center of the unloader. The toothed augers rotate in a circle around the center hub, evenly chewing the silage off the surface of the pile. In the center, a large blower assembly picks up the silage and blows it out the silo door, where the silage falls by gravity down the unloader tube to the bottom of the silo, typically into an automated conveyor system. The unloader

3355-482: The top but become progressively more closely spaced towards the bottom to prevent seams from opening and the contents leaking out. Concrete stave silos are built from common components designed for high strength and long life. They have the flexibility to have their height increased according to the needs of the farm and purchasing power of the farmer, or to be completely disassembled and reinstalled somewhere else if no longer needed. Low-oxygen silos are designed to keep

3416-410: The top of the pile, originally by hand using a silage fork—which has many more tines than the common pitchfork; 12 vs 4—and in modern times using mechanical unloaders. Bottom silo unloaders are utilized at times, but have problems with difficulty of repair. An advantage of tower silos is that the silage tends to pack well due to its own weight, except in the top few feet. However, this may be

3477-426: The tower and compressing the staves into a tight ring. The vertical stacks are held together by intermeshing of the ends of the staves by a short distance around the perimeter of each layer, and hoops which are tightened directly across the stave edges. The static pressure of the material inside the silo pressing outward on the staves increases towards the bottom of the silo, so the hoops can be spaced wide apart near

3538-412: The unloader chute from door to door in the process. The fermentation of the silage produces methane gas which over time will outgas and displace the oxygen in the top of the silo. A farmer directly entering a silo without any other precautions can be asphyxiated by the methane, knocked unconscious, and silently suffocate to death before anyone else knows what has happened. It is either necessary to leave

3599-936: Was conceived by the architects Meixner Schlüter Wendt . Whereas both the contours and the side facing the city are strongly reminiscent of the original appearance of the old silo , the three other sides clearly indicate the new building's function as a residential tower. It contains 209 luxury apartments. The cornerstone for this project was laid in June 2014 and the tower was completed in summer 2017. Storage silo Silos are commonly used for bulk storage of grain, coal , cement , carbon black , woodchips , food products and sawdust . Three types of silos are in widespread use today: tower silos, bunker silos, and bag silos. Silos are used in agriculture to store fermented feed known as silage . Storage silos are cylindrical structures, typically 10 to 90 ft (3 to 27 m) in diameter and 30 to 275 ft (10 to 90 m) in height with

3660-460: Was held on 1 May, the course circling the tower multiple times. In November 2012, it was announced that Henninger Turm would be demolished because it was too costly and uneconomic for renovation. Demolition began in January 2013 and was completed by the end of the year. On its site a new 140-metre-tall (460 ft) residential tower was built. Being inspired by the former Henninger Turm, the design

3721-511: Was inaugurated on 18 May 1961. It was demolished in 2013. Until 1974 it was the tallest building in Frankfurt, and it remained the tallest storage silo in the world until its demolition. On top of the building was a barrel-like pod which contained a viewing platform and a revolving restaurant (originally two). In October 2002, the tower was closed to the public. From 1961 to 2008, the annual professional cycling race Rund um den Henninger-Turm

SECTION 60

#1732772589256
#255744