OVEN CALERO, MAITZULO-BESABI (Iriondo, 2008) lime production at small scale.
The development of lime from limestone melted in furnaces called calciners, is a technique that has been practiced from time immemorial until well into the first third of the twentieth century.
Following the dictionary, we find the application of lime kiln for both the stone quarry to the kilns where it is melted, reserving to the operator the name of liming. While, however, is widespread tobacco industry either voice or liming to refer to the oven where the cooking is materialized.
Lime is a material whose use represents a diverse and broad range of applications, was used as flux in metallurgical operations, such as pottery, crucibles for many temperature, dehydration and drying fluid spaces and various products ; in sugar processing, manufacture of potash, ammonia, chloride of lime and hydraulic lime, as well as tanning and treatment of the salt in obtaining soda lime that much emphasis had since the nineteenth century until decades on the job as an agent absorbing carbon dioxide (CO2) in the development of physiological studies in construction and also in medicine where he had a great significance as an antiseptic and pests and infectious diseases such as cholera and typhus and also was used as an inhibitor of putrefaction of water. In past centuries the health regulations required to be covered with lime corpses of dead people and animals and disinfect infectious diseases in epidemic situations fecal material by the same procedure.
Perhaps the most ancient and widespread use of lime mortar is to produce or mortar to construct solid buildings, stone and mortar . To that end properties were used to regain strength in contact with carbon dioxide from the air in a symmetrical process of obtaining, for thousands of years. Was also used in a long list of agricultural and domestic uses. Even today, some laws, like the Navarro Regional Decree, provide for the use of lime in their health-funeral rules.
The slaked lime, diluted in water, is what constitutes the slurry, which has traditionally been used in whitewash the walls of houses. The lime is a strong base, which absorbs intensity of carbon dioxide from the air, covered with a white film of carbonate of lime. This is what happens when you let it dry after spreading lime on the wall, this film has a white dial and is impervious to rain.
are precisely the domestic and agricultural purposes, of all those, which give rise to the use of lime and consequently to the proliferation of these small and primitive stoves in rural areas of our peoples.
can easily understand that the production of lime, and thus the abundance of the furnace is on, if it prevails in the rock environment limestone, but also occurs when the adverse and favorable geology is the lack of lime, as in the geographic area that surrounds the massif Aia - Five villas, represented by primary rocks and Paleozoic granite or slate. In Irun, given the circumstance described above, and the point of greatest concentration of lime "seven" gives geologically scarce space in the limestone, distributed in an area represented by the conglomerate at the base of industries and Triassic red sandstone. We refer to the environment and the farmsteads Meaker Meaker Goikoa Beko, where we could barely find the race with a small outbreak limestone. What makes us think that the lack of a subject, does not prevent the production of it derivative, but it facilitates the transport of it.
Ovens
The lime kilns are stone buildings, erected inside for calcining limestone materials in order to obtain quicklime. Its exterior shape is generally cylindrical or truncated-pyramid, with rare exceptions oval or square, like that of San Anton in Goizueta. This geometric exception, however, is more common in Vizcaya. The interiors are always cylindrical, The most common are three to four meters high and two in diameter, providing the Cuba of stew, an interior capacity of around 6 cubic meters. There are also known, type "French", or high Cuba, whose length is around six or seven meters, but with a smaller diameter, about one meter, to improve the draft, making them less common but with sufficient examples, as we have seen in the town of Urnieta and Leiza.
Generally this is not an exempt building, but part of its structure is usually embedded in the hillside or taking advantage of a slope, providing a portion of its volume below ground level, occupying release the rest outside. This lift is made of stone, like the liner, in some cases, there is even, which feature an elegant front of masonry received, as in the case of the tobacco industry's singular Maitzulo in Urnieta, at the foot of Mount Adarra.
His most significant parts are formed by the upper mouth or blast furnace, which is charging, the Cuba of cooked and the front on which are the arc discharge outlet, which gives access to home and on the basis of it, is the channel through which distilled lime-living and ashtray. In some stairs, mainly in Guipuzcoa, the arc of the discharge is focused in front of two counters oblique to the work being provided them in a small cupboard carved in the wall. The top of the lift, where the upper mouth, generally tends to narrow the diameter providing the right shot. The entrance arch to the home is usually a simple structure, semicircular or segmental, but we also find elegant representations splayed towards the interior, especially when the structure is determined by thick walls, a case in point would be the oven Alduncin at Goizueta.
The Home
is the inside bottom of the oven, is provided with a strong metal grill on which to perform fire. This is prepared by placing logs piled in the center cone-shaped hole, putting in interiory inside the gorse, which burns with a flame easy, always arranged so as to facilitate the combustion through the flue, where the home base has adequate fuel layer, which draws up the grill and temperature, we proceed to the furnace load shedding in the upper mouth of the blast furnace alternating layers of limestone pebbles and cut into logs, the most valued of these are called stumps , which are the base of trees is a land after harvesting. Have the burden through Cuba's cooked, so you run the right shot from the arc to home base upper opening so that air flow will help raise the temperature of roasting or melting of around between 820 º and 900 º. When considered "mounted" the oven it is then on, start the procedure after three to five days, when the fire reaches the top of the oven, indicating the end of the roasting process. This system is called single or intermittent production. There is also the so-called continuous production, consisting of continuous recharge, when, as the lime is evacuated through the channel of bleeding, pour new alternating layers of limestone and fuel for the blast furnace, the color of smoke indicates an expert liming whether to add wood or stone. This continuous production process is carried out only in the type furnaces called "fance" where his high Cuba and its small diameter, around a meter, facilitated the operation.
Obtaining
lime Quicklime is produced by calcining limestone in these special ovens called Calero, where the stone is subjected to a temperature of around 900 º.
The raw material is limestone is a sedimentary rock, consisting of chemical and mineralogical by carbonates, mainly calcium and magnesium, the formula is: CaMg (CO3) 2. The process causes the following reaction:
limestone + heat = carbon dioxide +
lime CaCO3 + CO2 + heat = CaO
Calcium carbonate + heat = carbon dioxide + calcium oxide
Lime living is very caustic and has a great affinity for water, for which contact is transformed into hydroxide, with great development of heat during the process.
Quicklime is killed, mixing it with water, obtaining the slaked lime or hydrated lime, this extinction environment produces a 30-50% contribution of water to form carbon hydroxide Ca (OH) 2:
Quicklime + Water + heat =
lime CaO + H2O = Ca (OH) 2 + heat
Calcium oxide + Water = carbon + heat hydroxide
Lime is a natural product, whose use has been very important in the past, as it is currently an important issue in our daily lives. As indicated above, the oldest and most widespread use has been the preparation of mortar or plaster, used in building construction, building on the property that the scale has to purchase very hard to make contact with air.
The slaked lime, slightly soluble in water, mixed with sand and water to make mortar. A lime and a sand . Once applied to the mortar, lime recovers CO2 out of the atmosphere and becomes calcium carbonate again (which is known as set), recovering their original strength and returning the water absorbed in the shutdown process. This is the reaction that occurs:
calcium hydroxide (slaked lime) + Carbon dioxide + water = calcium carbonate
Ca (OH) 2 + CO2 = CaCO3 + H2O
Regionally, some ovens for their most significant conservation level structural or architectural elegance, we have found in the municipal Urnieta, Arano, Leiza, Goizueta and Oiartzun. In Irun, we recorded a total of 30 units, among which include: those of Gorroaga, Mendiola and Altzubide. RICARDO
Berodia Gordejuela. 2008
