HU189956B - Method for operating self-burning continuous furnace and continuous furnace for carrying out the method - Google Patents

Abstract

Method and device for operating a self-burning tunnel furnace with the aim of replacing high-grade energy carriers with unrefined ones, the burnable components contained in the charge material in this connection introducing the entire heat quantity required for the burning process, the calcining loss being minimised by its complete burning out and a selective control of the burning curve being made possible and the quality of the products being improved by porosisation. …<??>This is achieved by: … … - drawing off the smoke gas at a high temperature from the burning-off zone and mixing with cooling as well as fresh air and the injection, offset on both sides, into the preheater for the controllable heating and subsequent drying of the material … - injection of combustion air at high speed variably over the entire burning-off zone as well as action with ballast air and selective smoke-gas extraction for controlling the temperature in the burning-off zone … - closure of the preheater with a furnace door and a burning duct slide. … …<IMAGE>…

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for operating a self-contained tunnel furnace and to a method for firing a preheated ceramic mold, wherein the ceramic mold contains sufficient combustible components for the firing process.

Tunnel furnaces are known in which flue gases containing a relatively high percentage of unburned substances produced during combustion are recycled and subsequently burned in the combustion zone. Since these gases need to be heated to the combustion temperature, fuel consumption is significantly increased. In the case of tunnels and furnaces without primary fuel inlet, gases are known in the known manner which do not burn immediately and are fed into an additional firing zone. This solution is technically risky.

No. 27 07 510. The disclosure in the GDR discloses a solution in which the insert is preheated by direct air preheated air to a defined combustion temperature and then burned in a combustion zone without temperature equalization by means of a furnace cross-section and without reliable control of the ignition and combustion of combustible components.

The solution requires a high level of equipment investment and therefore the process cannot be completed by retrofitting older equipment. The technical feasibility of the solution has not yet been demonstrated in practice.

The object of the invention is to replace high-value energy sources with less valuable energy sources in the operation of tunnel furnaces, while reducing specific heat consumption, and improving quality, in particular by fully burning combustible components, improving working conditions and reducing the production of harmful substances.

The object of the present invention has been solved by suctioning the flue gas generated during combustion in the combustion zone along the entire length of the combustion zone through a flue gas collecting line, mixing the cooling air with fresh air and blowing in and out heats below the ignition temperature, then cooled flue gas is led from the preheating zone through the exhaust duct and fan to the chimney, and the combustion air is variably incinerated through the entire combustion zone to balance the liner, ignite and completely burn the combustion gas, We control ballast air to control heating and when the combustion temperature is too high.

According to the invention, it is preferred to measure the oxygen content of the gas in the combustion zone by means of a probe and to keep it at the minimum concentration required by adding air to ensure explosion protection. It is also advantageous to lead to the removal of harmful substances, vi, relatively high concentration cuvettes and high temperatures.

The invention will be described in more detail with reference to the drawing. In the drawing:,

Fig. 1 shows an example of an algae furnace according to the invention. a top view of an embodiment thereof;

Figure 2 is a sectional view taken through the preheat zone of the solution shown in Figure 1;

Figure 3 is a cross-sectional view of the same solution over a burning zone.

As shown in FIG. 1, a portion of the flue gas 1 is mixed with hot air 2 and fresh air 3 in a mixing chamber 4 and then passed through a nozzle system 5 and a fan 6 to a preheating zone 7. In the preheating zone 7 there are nozzles 9 distributed on both sides at the height of the wagon ceiling 8, through which a mixture of 100-150 ° C flows in. The 150 ° C inlet temperature is regarded as a maximum to prevent the pressurized energy carriers from burning in the preheating zone 7. Due to the relatively high blowing rate no further circulation is required. The exhaust air is supplied to the flue gas fans 11 through two exhaust manifolds 10. The 7 live: pasture zones are separated from 12 burning zones by 13 burner channel latches. An oven door 14 is provided at the entrance of the preheating zone 7.

In order to prevent exhaust air from escaping, a slight lack of pressure is maintained in the preheating zone 7. This requires a relatively dense car park and furnace locking mechanism to avoid harmful air entry.

The combustion zone 12 of the napkin 80 to 120 C in a preheated 15 ° is heated to firing temperature until smooth, while the total energy demand of the firing zone of the cover blank _x zelőanyagtartalma lung. Preferably, burners 16 are provided in the furnace wall which, in the event of a malfunction, such as low fuel content of the insert 15, failure of the pusher, fan failure, etc., will be activated. The signal for switching the burners 16 on or off is received when the set values for the furnace temperature are exceeded or exceeded.

The combustion supply system comprises a fan 17 and a nozzle system 18 located in the combustion chamber 12. The amount of air to be drawn in, and hence the number and configuration of the nozzles, will depend on the air factor selected, which is, according to the invention, between 13 and 2. The system shall be dimensioned such that the exit velocities are approximately 100 m / s. In the combustion chamber 12, a plurality of registers 19 are variably arranged, each of which registers 19 may be shifted towards the end of the preheating zone 7 or the firing zone 12, according to 3-5 changes. The combustion air is set depending on the power output.

In the event of exceeding the required upper temperature threshold, ballast air 21 is supplied to the firing zone 12, which is preferably passed through a separate Duct 22 through the furnace wall, the amount of which depends on the degree of deviation from the temperature threshold. The desired threshold is reached, the valve closes and the fan 23 ^to 21 left-air coffee stop.

“Since the pressure in the firing zone 12 is constantly changing due to the variable supply of air, it is kept constant by the control mechanism arranged in the flue gas system. The flue gas 1 is sucked out through an outlet duct 24, and the exhaust gas collecting duct 25 is routed not on the bottom of the furnace, but on both sides of the furnace beside the outlet ducts 24. The outlet ducts 24 can be individually controlled by means of throttles. The temperature of the flue gas 1 is measured and regulated so that when an upper threshold is exceeded, a heat exchanger 26 is connected to the flue gas stream.

The cooling zone 27 is separated from the combustion zone 12 by an air outlet 28 and by pressure control.

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Absorbents 29 are provided in the flue gas collection lines 25 for the selection of harmful substances.

Claims (3)

Claims A method for operating a combustion tunnel furnace, wherein the tunnel furnace comprises a preheating zone, a combustion zone, and a cooling zone, characterized in that the flue gas (1) formed during combustion in the combustion zone (12) along the entire length of the combustion zone (12) ), mixed with cooling air (2) and fresh air (3) and blown into the preheating zone (7) by blending it bilaterally, thereby drying the insert (15) in a transverse stream and heating it below the threshold or ignition temperature (1). ) from the preheating zone (7) to the chimney via the downpipe (10) and the fan (11), and the combustion air to vary the high velocity through the entire combustion zone (12) to equalize the temperature of the insert, to ignite and completely burn the combustion gas The air is supplied to and fed to the food zone (12) to control heating or, in the event of an excessively high combustion temperature, ballast air (21). Method according to claim 1, characterized in that the oxygen content of the gas in the combustion zone (12) is measured by a probe and maintained at a minimum concentration by adding air to provide an explosion g. Method according to claim 1 or 2, characterized in that the harmful substances formed at relatively high concentrations and at high temperatures are introduced into an absorber (29). 10 4. Tunnel furnace as shown in Figures 1-3. A method according to any one of claims 1 to 4, characterized in that the preheating zone (7) is separated from the combustion zone (12) by a combustion duct latch (13) and an oven door (14) is arranged at the inlet of the preheating zone (7); at the height of the car platform (8), split nozzles (20) are mounted on both sides, and the combustion air supply system is implemented by a plurality of registers (19) associated with 3-5 nozzles (20) and connected to a fan (17) ) Preferably, 20 are arranged along the entire length of the combustion zone (12), and flue gas collection lines (25) provided on both sides with an outlet duct (24), wherein a heat exchanger (26) is connected to the flue gas collection lines (25).