DE1608669B1 - PROCEDURE FOR THE PERIODIC ACTIVATION OF A REDUCTION PHASE WHEN OPERATING OIL OR GAS FIRED CERAMIC TUNNEL STOVES - Google Patents

Description

In the area α of the abscissa, all burners 7 and 8 run at their normal output, which is set at 100% on the associated ordinate.

During the pushing process b , all burners 7 and 8 are switched off and the combustion air is throttled to 20%, for example.

During the subsequent reduction phase c , the normal burners 7 with low power, z. B. 20%, switched on, the draft remains at the set throttled value of 20%, while the additional burner 8 with multiple power, of at least about 500%, run.

After the end of the reduction phase c , both the normal burners 7 and the additional burners 8 get their normal output of 100% again. At the same time, during a short phase d, the air throughput is increased by blowing in additional air through the cyclone 11 of the individual burners 7 and 8, but at least the additional burner 8, for example to about 120%. Phases b and c can optionally be interchanged.

During the following normal work phase e , the furnace runs again with normal operating values until the start of the following sliding process.

Copy 1 sheet of drawings

Claims (2)

1 2 In the drawing, exemplary embodiments are presented, namely Fig. 1 shows a schematic partial section through 1. Method for periodically switching on a device equipped according to the invention a reduction phase when operating 5 tunnel kilns with oil, or gas-fired ceramic tunnel kiln, FIG. 2 an example of a working diagram, characterized in that the tunnel furnace 1, indicated schematically, has during the of the reduction phase (c in Fig. 2) a group of additional vaults 2 provided at the end in the combustion zone in the usual way in the cover of the combustion zone with several rows of burners spaced from one another with at least about five times the length 3, 4, S, etc. of Poking holes 6. Each row has the capacity of the other burners and, as a rule, several adjacent burners. In order to such high-making required einLeistung is switched purely reducing working phase of the Erfinringerung the air throughput, that too can switch practically at the end of the combustion zone receive an oxygen-free reducing atmosphere 15 further series X provided by Schürlöchern that is. has a group of additional burners 8. These 2. The method according to claim 1, characterized GE additional burner 8 have a multiple power indicates that following the reduction compared to the other burners 7, z. B. the fifth phase (c in Fig. 2) the air throughput up to ten times, and also such a wide (d in Fig. 2) is temporarily increased. ao control range that they can easily be used with the lower power of the normal burner 7 can be operated. The burner 7 and 8 are useful for oil heating known per se electromagnetic metering 25 injection pumps 10, which with each pulse The invention relates to a method for injecting precisely dosed quantities of oil and odic switching on of a reduction phase when using a device for introducing in Operation of ceramics fired with oil or gas, wide adjustable additional air quantities by means of Tunnel furnace. a cyclone 11 and a subsequent mixing To achieve certain technical properties 30 chamber 12 are provided. In addition, the fiery and color effects of the material to be fired, albeit appropriately by means of a spherical shell 13 on the only briefly, a completely reducing atmosphere stovetop 14 stored to the cheapest needed to be able to adjust the duration of the penetration depth and angle of inclination, and by means of is determined by the respective ceramic material. a clamp 15 also axially displaceable. The activation of such a completely 35 If a work phase with a completely reducing work phase could be activated in an atmosphere with a decorating tunnel furnace, this will not be realized or only incompletely realized. proceeded so that at the beginning of the next sliding is known per se, when burning ceramic materials process the fan or chimney draft z. B. to make the degree of reduction controllable. Known to be throttled to 20% and all burners 7 and 8 are also switched on at the tunnel furnace at the end of the combustion zone 40. After the end of the sliding so-called cover burners to shield the process, the normal burners 7 are to be provided in the burning and cooling zones. These cover holes 3, 4, 5 are only switched on to such an extent that burners have to operate with a higher excess of gas; the temperature in the individual zones will not die off and therefore also generate a reduction. The additional burners 8 in the last stoke-piercing atmosphere. 45 row X, on the other hand, are However, in order to achieve the desired shielding so that a complete reduction effect can be achieved here, they must be operated continuously with their high decorative, i.e. practically oxygen-free, atmosphere. As a result, is obtained. The duration of this work phase will depend on the material, the penetration depth, and the possibly controllable reduction that cannot be achieved if the furnace continues to run normally. 50 desired color effect or the like determined, but in all this is enough with the invention to achieve the common a few minutes,
the desired burning effects are absolutely necessary. Then the fan or chimney Rather, to solve the problem, a continuous pull has to be raised again to the normal value, and a thorough reduction has to be avoided. The and all burners 7 as well as the additional burner 8 invention achieve this in a simple manner in that 55 are switched to normal power. In addition, during the reduction phase a group of additional burners provided at the end of the reduction period shortly after the combustion zone can be used, preferably in all burner groups, few burners with at least about five times the output but in the group of auxiliary burners 8, over stiffness of the other burners and one Corresponding to the cyclone 11, larger amounts of additional air are injected with a large control range with a sharp reduction in the 60 sen in order to switch the afterburning of the air throughput to such a high power, reduction zone of the additional burner 8 to achieve a practically oxygen-free reducing the unburned fuel.
Atmosphere is maintained. To explain the working diagram of FIG. 2 Following the reduction, the following is expedient: They are drawn one on top of the other
phase the air throughput temporarily increased, at 6 _{5 the} ^^ _{the normal burner 7 at τ} for example so that at least em part of the burner with a device for blowing in larger quantities ^of the additional burner 8 at Π, is provided with additional air. the operation of the furnace air at IH.