Hoffmann ring furnace
The Hoffmann ring furnace (short: ring furnace ) is a device for the effective continuous burning of bricks , lime and gypsum . It is named after the engineer Friedrich Eduard Hoffmann , who applied for a patent for it in 1859 . The ring kiln is the forerunner of the modern tunnel kiln as a continuous kiln . The ring oven was invented in Fürstenwalde as early as 1839 .
Working principle
The ring furnace consists of a large circle or oval with around 14 to 20 chambers in which a fire can be maintained independently of each other, which burns the dried bricks that are also in the chamber. After the burning process, the fire is allowed to go out in one chamber and the next chamber is filled with fuel. As a result, the fire moves once around the oval in about one to two weeks. By ventilating the chambers, the fired bricks heat the supply air for the fire, which in turn allows it to cool down more quickly, while the hot exhaust gases dry and preheat the blanks. Opposite the heated one are the coolest chambers. The finished bricks are removed here and the chamber is refilled.
Cross-section through a ring furnace, Hoffmann system, a combustion chamber, b dry storage
Top view of a circular ring furnace
Development and importance
In 1859, the royal master builder in Berlin, Friedrich Eduard Hoffmann, registered a patent in Prussia and Austria for the "invention of a ring-shaped furnace for the uninterrupted burning of all kinds of bricks , pottery, lime, plaster and the like". He applied for the patent together with Julius Albert Gottlieb Licht, City Planning Officer of Danzig . This is why these ovens were also called ring ovens according to the Hoffmann light system . Hoffmann was awarded a first prize (Grand Prix) for the patent at the Paris World Exhibition in 1867 . The trial sample for the patent was in Scholwin near Stettin . The patent was later revoked after it could be proven that the master bricklayer Arnold from Fürstenwalde had already invented the ring oven in 1839, but had not applied for a patent. In 1873 he became an honorary citizen of Fürstenwalde for his invention.
The ring kiln revolutionized the brick industry in the 19th century. For the first time, the continuous firing resulted in a consistent quality of the bricks, while the result in the previously common chamber kilns looked different after each firing. In addition, the ring kilns burned continuously day and night for the first time, which led to a surge in the need for workers, but at the same time enabled a previously unknown increase in brick production.
Since 1859 the image of the houses has changed from gray (reed and thatched roof , shrub, wood, clay walls ) to red ( roof tiles , brick house , less risk of fire ). Brick pipes enabled sewerage, as well as underground drainage and drainage of fields.
Today brick production is done by machine. A few ring kilns have been preserved and are protected as industrial monuments. The oldest still completely preserved Hoffmann type ring furnace in Germany is located in Großtreben in Saxony. It was built in 1861–65 and renovated from 2010 onwards. One of the last brickworks in Germany that still operates a ring kiln is the Rusch company in Drochtersen . In Austria, the Pottenbrunn brickworks still works with a ring kiln. However, they are still used in developing countries. In the Kathmandu valley in Nepal , for example, there are still over 90 ring furnaces in operation in 2009.
Round ring ovens
Principle scheme (1869)
The Eisenach brickworks Sältzer with the round Hoffmann ring furnace built in 1863, copper engraving from 1875
Ring furnace in Großtreben , oldest completely preserved ring furnace of Hoffmann design in Germany (built 1861–65)
Round ring furnace according to the Prussian system Hoffmann in Tochigi in Japan, built in 1889
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Rectangular ring ovens
Altglietzen brickworks
Zsoldos brick in Szentes , Hungary
Penna brickworks in Sicily
Oval ring ovens
Principle scheme
Sectional view, around 1900, decentralized chimney
Ring furnace in Wiesenburg- Reetz
Ring furnace in Willy-Spahn-Park in Hanover
Brick production in the oval ring kiln of the Grafschafter Krautfabrik
Detail pictures
Combustion chamber in the ring furnace Cathrinesminde with the rest of a partition wall, Denmark
Outside ring furnace Cathrinesminde
Ceiling of the Cathrinesminde ring furnace, covered openings for loading, rods to control the smoke outlets
Firing level on the furnace in Wiedenbrück (Eusterbrock brickworks)
Manual loading or unloading of a ring furnace
Preserved ring furnaces
Brandenburg
- Altglietzen , Chausseestrasse 60: Oblong, square ring kiln of the "Dampfziegelei Hietzig" on the Neuenhagen island in the Oderbruch
- Klausdorf , Pappelallee 1: on the grounds of the Märkischen Ziegel GmbH Klausdorf, ruins of a round (?) Ring furnace according to Hoffmann, from 1868?
- Werder- Glindow , Brickworks Museum Glindow : Hoffmann's ring kiln still active at times, guided tours through the inactive kiln possible
- Wiesenburg- Reetz: oval ring kiln from the Reetz brickworks
- Zehdenick - Mildenberg , Museum Ziegeleipark Mildenberg : oval ring kiln, not before 1887
Mecklenburg-Western Pomerania
- Petrol : Hoffmann ring furnace of the "Ziegelei Petrol" from 1907/08, in operation until 1990, the only preserved ring furnace in Mecklenburg-Western Pomerania
Lower Saxony
- Bremervörde- Bevern , Malstedter Straße 38: preserved oval ring kiln from the Pape brickworks
- Drochtersen : active ring furnace of the still working company Rusch
- Hanover- Ahlem , Willy-Spahn-Park : oval ring furnace system Hoffmann, from 1925
- Krummhorn- Uttum : Ring kiln of the old brickworks in Uttum, from 1898
- Sehnde: Ceramic hut , ring furnace from around 1900, demolition planned since 2013
- Westerholt Brickwork Museum
North Rhine-Westphalia
- Düsseldorf- Ludenberg : ruins of an oval ring kiln (formerly Sassen brickworks), restored, 19th century
- Location (Lippe) , brickworks museum Location : Hoffmannscher Ringofen, from 1909
- Rheda- Wiedenbrück : Oven of the former Eusterbrock brickworks, 1865–70?
- Viersen : Süchtelner Straße 188 (on the Alte Süchtelner Landstraße), rectangular ring oven
Rhineland-Palatinate
- Mainz-Bretzenheim : old brickworks , ring kiln from 1904 with half-timbered superstructure
Saxony
- Geithain -Sommerhof, Am Kalkweg 10: partially restored round ring kiln system Hoffmann and Licht, based on a Prussian patent from 1858 (of the former lime works Heinrich Bauch), commissioned on July 20, 1869, in 1870 the Saxon King Johann visited the building here on a visit to Geithain Ring oven, oldest partially preserved Hoffmann ring oven in Saxony, used until 1910 (partial demolition), preserved without chimney, restored; and the remains of two ovens near Geithain train station
- Großtreben-Zwethau : allegedly the oldest preserved ring furnace in Europe in Großtreben, oldest completely preserved ring furnace of Hoffmann design in Germany (built 1861–65)
Saxony-Anhalt
- Elbe- Parey : round ring oven after Hoffmann und Licht from 1885, ruinous
Denmark
- southwest of Broager , Cathrinesminde Brickworks Museum : Ring kiln preserved from 1892, operated until 1968
- Nivå near Fredensborg
Great Britain
- Prestongrange Colliery , Prestongrange Industrial Heritage Museum with ring kilns and coal mine, Scotland
Italy
- between Sampieri and Villagio Portosalvo in Sicily : Penna brick kiln ("Fornace Penna"), square oven, ruin
Austria
- Gänserndorf : oval ring oven
- Neubau-Kreuzstetten , round ring furnace
- Pottenbrunn : active ring kiln in the Pottenbrunn brickworks
Hungary
- Szentes : former brick factory Zsoldos
Asia
- Nogi Town, Tochigi : round ring furnace according to the Hoffmann system, built in 1889, formerly Shimotsuke Brickyard Co. Ltd., Japan
- Kaohsiung City, Sanmin District: Long Kiln, formerly Tangrong Brick Factory, Taiwan
Trivia
In the play Der Lohndrücker , which deals with the production conditions in the GDR immediately after the Second World War, Heiner Müller sets the plot around a ring oven that is to be repaired while the plant is still in operation.
Individual evidence
- ↑ 725 Years of Fürstenwalde page 3, right column, 4th paragraph (pdf, 1.9 MB)
- ↑ State Office for Monument Preservation Saxony: The rich Saxon monument landscape. Selected funding projects . Dresden 2014, pp. 16/17
- ↑ Internet site of the Pottenbrunn brickworks ( memento of the original from October 15, 2014 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Brandenburg State Office for Monument Preservation and State Archaeological Museum (ed.): List of monuments of the State of Brandenburg, district of Märkisch-Oderland , Zossen 2019, ID number 09180215
- ↑ Information board on the stove at Gasthof Sommerhof, Geithain, Am Kalkweg 10, Saxony, 2020
- ↑ Ring oven in Geithain-Sommerhof
