MX2010007999A - Continuous kiln. - Google Patents

Abstract

A continuous kiln (1) for products, having a duct (2') with at least one lateral wall (2); conveying means (3) for feeding the products inside the duct (2'); and a number of firing assemblies arranged successively along the duct (2') and having at least one burner (4; 400); respective exhaust means (5, 6, 8), for the exhaust gas of the burner (4; 400), arranged so that the exhaust gas flows crosswise to the travelling direction of the products along the duct (2'); at least one respective pressure sensor (120) inside the duct (2'); and respective combustion supporter supply means (40) connected to the pressure sensor (120) to adjust combustion supporter supply to the burner (4; 400) as a function of the pressure detected by the pressure sensor (120).

Description

CONTINUOUS OVEN TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for baking a product.

BACKGROUND OF THE INVENTION Furnaces comprising a rectangular duct equipped with burners are known to be necessary for baking.

Furnaces of this type are used for baking ceramics, such as tiles, furniture, etc.

The term "ceramics" is intended to mean products formed by compressing powder of oldeados with liquid clay. Both can or not. product placement, in turn defines or bakes the given product.

The temperature of the pattern normally of the furnace admission in the direction of the product, and reaches a maximum (d ° C) along the middle part of the duct.

For example, GB-A-1075596 discloses a ceramic pipeline, comprising a pipeline; a nsportadora to feed the products den to, * and oriented burner assemblies verti ued on each side of the conveyor belt for the purpose of baking.

A major drawback of continuous ovens described is the difficulty of regulating the temperature of the various baking chambers, which is a negative effect on the operation of the oven.

That is, the temperatures in the adjacent sides, thus polluting the clean gas.

GB-A-2261059 discloses a duct furnace, comprising a duct; a transp band to feed the products inside the pipeline; adjacent sets that define sections of the horizontal vertical walls of the to above as well as below the raiser; and gas ejection openings well formed in the longitudinal walls facing and facing the burners. The hot gas ejection openings are placed to form a hot gas jet that is parallel to the direction of displacement products. For each section, the furnace is also located at the top of the ipated section with a damper to adjust the pressure of the section, alternatively, to admit or eject the lawnmower to feed the den to products. The furnace is divided into several eccenically, seven) separate baking chambers equipped with burners and ejection openings produced by the burners; and the duct pressure differs from one baking chamber to another.

Objectives of the invention None of the above solutions ensure gas ejected in each of the chambers of operation without alterations, and therefore not my one baking chamber to another, thus making a temperature pattern with an independent gradi perature easily controllable. baked and another.

Another equally important drawback is the expulsion gas. specific purification process to eliminate c polluting substance, increasing in great me year of the purification equipment and the cost of opera no.

In addition, steam is generated in the various furnaces during the baking process, and discharged.

It should be avoided that this steam is given to generate acidic liquids which, in fact, are harmful both to the product and to the structure of the furnace itself.

Steam is generated mainly in the low temperature, that is, in the admission, of the after that in the middle sections of températ a, the only water released is that which forms the product, and is released in quantities in the first few sections. of the admission of the portion of an oven and a baking method, vindicated in the independent claims to preferably in one of the claims directly or indirectly of the dependent claims.

Brief description of the figures Two preferred non-limiting modalities will be described as an example with appended references, wherein: Figure 1 shows a longitudinal section of a continuous roller furnace according to the first embodiment of the invention; Figure 2 shows a cross section of line II-II in Figure 1; Figure 3 shows a horizontal section of line III-III in Figure 1, showing that Figure 7 shows a graph of rable by the invention; the axis and the temperature in ° C, and the axis x the length of the furnace; Figure 8 shows a transverse regenerative cut in Figure 4.

Detailed description of the invention The number (1) in Figures 1 to 3 indicates either a continuous furnace for products, which is purchased (21), and a conveyor belt (3) for products within the pipeline (2 ·).

The conveyor belt (3) comprises a motorized illos (3).

The duct (2 ') comprises two, respectively vertical, opposite walls (2).

Each side wall (2) of the duct (21 ipated, above and below the burner (4) is associated with respective mmatics (40) (Figure 3) to supply the combustion (in particular, air) necessary the burner (4), and with the respective fuel pump (41).

The burners (4) on the transp band on each side wall (2) are staggered to the burners (4) below the carrier (3) on the same side wall (2), with respect to the burners (4) on the wall is (2). And, on each side of and on a buffer level (4), ejection openings (5) are formed generated by the burners (4).

Each burner (4) and the respective opening are located in opposite side walls (2); rtura (5) is oriented directly towards the corresponding one so that the gas of e no (1).

If each of the sets of three burners (4) (as in the trad), two are located above and one below conveyor (3), or vice versa.

The burners (4) in each set of may be a number other than three.

The burners (4) in each set constitute an array of adjacent burners (4).

The furnace 1 described comprises the par) extending between an upper wall of) and a conveyor belt (3), and between a pipeline side (21) and the conveyor belt (ies are dimensioned to leave only the fuel to allow Pass the transp band and the products on it.

In the example shown, the items taminants of the gas before it is expul erior.

Each bake assembly comprises 1 stack (6).

A battery (9) is located in the inlet (2 ') to expel the gas produced by the pump, comprising a suction fan (10).

The partitions (11) preferably placed to separate the baking assemblies.

At least one temperature sensor (12 minus one pressure sensor (120) (Figure 2) within each bake set The temperature (12) is located in the area inside) occupied by the burner (4) of the arrangement of adjacent qu.

. The furnace 1 also comprises a trolley (13), which is connected and receives fuel (in particular, the pump (41)) to supply fuel to the burner (4) as a temperature detected by the temperature sensor.

During actual use, the sensor preserves the current pressure value in conjunction with baking (either continuously, at predetermined intervals). The current pressure Pcurrent is transmitted to the troll (13), which compares it with a prfrence value Pref set in the installation step 1. In a preferred variation, the pr preference value is slightly higher than the ospic More specifically, the pressure den to (2 ·) is maintained between 101331 and 101334 Pa (Pref If the absolute difference between the current pressure PCurrent and the pressure value of the adjacent bake sets, increase the supply of the support directly to each burner (4) as a function of the current pressure PCUrrent- In other words , by adjusting the combustion supply for each burner (4) as a pressure of each set of bake determined pressure sensor (120), essentially having a uniform pressure in the duct (21).

The control unit (13) is taughty to adjust the combustion support (4) as a function of the pressure value detected by the pressure sensor (1 together with relative baking, so that it runs along the length of the duct (2 ') inside a ran (in particular, 6 Pa) on either side of the reference source Pref «In some modalities, The reference pressure value Pref is to all bake assemblies.

The control unit (13) is designed to supply the combustion support to each of the bake sets (more specifically, designer (4)) independently, as a function detected by the ective pressure sensor.

By adjusting the pressure gradient, the same pressure, equal to the pressure value of re, can be maintained in all non-length duct assemblies (2 '), and the gas can be prevented from migrating from a preset bake assembly. an adjacent one with lower pressure.

Tests show that, when the duct pressure (2 ·) is essentially uniform within the previous range), and the ejection gas During actual use, the temperature sensor determines the current temperature value of the bake set ( either continually ernatively, at predetermined intervals). The current temperature Tcurrent is transmitted for conti- nuity (13), which compares it with a tem- perature value Ti_tgt established in installation stage 1.

If the absolute difference between the current temperature and the temperature value Ti tgt exceeds a tolerance value of at least 3 ° C, and advantageously 1 ° C) established in the installation stage, the unit transmits a signal to the supply means (the pump (41)). The amble temperature of baking can be controlled independently of the adjacent baking assemblies, increase. The control unit (13) is taughty to adjust the supply of fuel to burner (4) as a function of that tempered by the sensor (12) of the assembly. The temperature of the baking temperature within a range of 1 ° C) on each side of the temperature value Ti tgt- The target temperature value Ti_tgt var baking set y, in one variation pr enta from the ejection admission firing assemblies.

More specifically, the control unit designed to adjust the combustion supply to one of the bake sets (more specific burner (4)) independently, as a temperature sensed by the temperature sensor (13) for all the the furnace (1), or the unit of) comprises several units of controllers) separate or with a few modalities comprise a trailing unit for each baking set. Other central control units for each conjugate: one for controlling the supply means (pump (41)), and the others for controls of supply of combustion support (40)). Other embodiments comprise a central control for each burner (4); in which central control unit is connected to the sen- sor and pressure (12) and (120) of the fuel assembly, and is designed to control the fuel supply (pump (41)) and the combustion support supply (respective pneumatic burner means (4).

Figures 4 to 6, differs from the first used so-called regenerative burners (400) instead of standard burners (4).

As is known, burners are widely used, increasing the efficiency of fuel consumption.

As more clearly shown in the regenerative fixture (400) is a flame burner comprises combustion gas supply means a channel having an X axis. The burner (400) ignites a support supply means of (con) comprising a tubular (annular) conduit with X axis; and means for ejecting gas from eject a tubular (annular) coaxial conduit with which it has an opening for expulsion gas ortante take into account that, also in this mode in the opposite direction, which is preca en en heat of the gas flow of expulsion, to be cured with the fuel.

In Figures 4 to 6, the parts below relate to the first modal using the same reference numbers.

In a preferred embodiment, the furnace (1) stack (9) near the intake section of the du to expel the gas produced by the furnace (1).

Figure 7 shows a graph of rable by the invention in a furnace (1) co ras between the admission and the expulsion.

The left end of the graph of ica the admission, and the right end the expulsion to (2 ·).

Clearly, the changes can be made as described without thereby moving away

Claims (1)

1. Claims 1. A continuous furnace (1) for produc 1 comprises: a duct (2 ') having at least one side (2); transportation means (3) for food products inside the duct (21); Y several baking assemblies di- sively along the duct (21) and yielding at least one burner (4; 400); The continuous furnace which is characterized as a baking set comprises: respective ejection means (5) to the burner ejection gas (4; 400), so that the gas expelling the burner. {e) crosswise to the direction of travel of the products along the duct (2). '); the pressure sensor (120). 2. A continuous oven according to the claim wherein each baking set comprises a respective temperature (12) to determine the temperature of the baking set; and fueling means (41) to supply fuel to the 400), which are connected to the temperature (12) to adjust the supply as a function of the temperature detected by the temperature (12). 3. A continuous furnace according to a preceding claim, which comprises a control (13) connected to each pressure sensor set to control the combustion supply means (40) as a function of the pressure d of each pressure sensor (120), for keep the tro of a range of 3 Pa along the pipeline (2 ') 6. A continuous furnace according to any preceding vindications, which comprises by partition (11) located between two sets of acentes, designed to allow the passage of the p vitar the flow of expulsion gas between the adjacent baking c. 7. A continuous furnace according to a previous vindication, wherein the burner is fixed to the side wall (2) of the duct (2 '), d its combustion flame is directed in d to the direction of displacement of the prod 8. A continuous furnace according to an earlier claim, wherein each baking unit comprises several burners placed on opposite sides of the transducer means (3). 9. A continuous furnace according to a Ejecting devices (5, 6, 8) by the support of comb fuel supply means (40, ally by an additional ejection pile (9). 11. A method for baking a product comprises the steps of: Feed the product inside a tinuo (1) - transport the product inside a du to bake the product; Y remove the product once mentioned through the pipeline (21); the method is characterized in that the furnace is as claimed in one of claims O; and the method comprises a step of adjusting the each bake set, and in the course of ingesting the combustion support to each burner (bake assembly is set as a function to calculate the difference between the current version (PCUrrent) and a value pressure of re f); Y adjust the supply of the burner to each burner (4; 400) independently or to other bake sets and as a function between the current pressure value (Occurrence of reference pressure (Pref) ... 13. A method according to claim 12 of adjusting the pressure comprises adjusting the combustion support to each mats (4; 400) when the absolute difference or current pressure (Pcurrent) and the preferential value (Pref) exceeds a first tolerance value. 14. A method according to one of claims 13, wherein the step of adjusting the pressure is the supply of fuel to each burner (baking set is set as a function of the respective detected baking set of temperature (12). 16. A method according to claim 1 comprises, for each of the sets of additional h steps of: to establish, in a stage of insining, a target temperature value (take in the baking set to achieve a given baking; determine the temperature value rrent) by means of the temperature sensor; calculate the difference between the current temperature (TCUrrent) and the temperature value (Ti_tgt); Y