SU1375660A1 - Method of burning gas in heating furnaces - Google Patents

Abstract

This invention relates to metallurgical heat engineering and can be used in heating furnaces and industrial zones that do not use gaseous fuels, for example, for the disposal of waste gases, including oxygen in the air. The goal is to intensify the combustion process and ensure complete combustion of the gas while reducing emissions of nitrogen oxides. According to the method of gas combustion, which includes supplying gas and air to the primary combustion zone with a catalytic layer, burning the gas-air mixture formed in this zone, feeding the secondary combustion zone of the combustion products and additional gas, the gas supply to the primary combustion zone is 25- 30%, and air, in the amount necessary for complete combustion of the entire gas, while in the secondary zone the combustion of gas with combustion products from the primary zone is carried out in a layer of crushed refractory. 2 Il. C (L

Description

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The invention relates to the section of metallurgical heat engineering and can be used in heating furnaces and industrial zones using gaseous fuels, for example, to dispose of waste gases containing oxygen in the air.

The aim of the invention is to intensify the combustion process and to ensure complete combustion of the gas while reducing emissions of nitrogen oxides.

Fig. I shows an oven, longitudinal section; figure 2 - section aa in fig ..

A device that implements the method of burning gas contains a heat-insulated body 1 with adjacent heat-insulated chambers 2. The body 1 is filled with a layer 3 of crushed refractory, the chamber 2 - a layer 4 of catalytic material. In the center of the housing 1, an opening 5 is made, in which a pipe 7 is supplied to the layer 3 of the primary gas with an annular gap 6. At the base of the chambers 2, holes 8 are made, by which the internal volume of chambers 2 is connected to the chamber 9 located under the bottom of the housing I. At the base of the chamber 9, the center hole 10 in which the tube 7 is tightly mounted holes 11, in which the air inlets 12 are tightly mounted. In the air supply nozzles 12 and the gas supply pipe 7, respectively, holes 13 and 14 are made in which tubes 15 are tightly mounted. stuffy mixture in chambers 2, the flow of gas through the tubes 15 is regulated by means of taps 17.

Example. Air at a pressure of 0.5 kPa through the nozzles 12 enters the chambers-2, where, mixing with the gas entering this zone through the tubes 15, it forms a gas-air mixture with an excess air ratio (CPS) in the range from 3.3 to 4, 0, Formed gas-air mixture burns in sing 4 of catalytic material. Excess air diluted with the formed combustion products enters chamber 9 through openings 8, from which through ring gap 6 enters crushed refractory layer 3, where, mixing with gas, it creates a gas-air mixture with a required excess air ratio and burns in this layer , he cracked his comforting end. The gas enters the device through pipe 7, from which one part of its flow enters the chambers 13 into the chambers, 2, and the other into the layer 3 of crushed refractories.

The temperatures developed in chambers 2 (up to 900 s) ensure the complete burnout of gas in the layer 4 of the catalytic material, heating the excess air. The supply to the combustion zone of the secondary combustion of heated air sharply intensifies the combustion process of the secondary gas, shortening the burnout time, thereby reducing nitrogen oxide emissions in this zone and creating powerful thermal radiation from the end face of the crushed refractory layer 3.

In addition, the reduction in emissions of nitrogen oxides formed in the primary combustion zones is explained by the temperatures developed in this zone, and in. the secondary combustion zone is the presence in it of combustion products formed in the primary combustion zone.

The device is ignited as follows.

Before igniting the device, the taps 17. The gas supply to chambers 2 is closed with, after which gas and air are supplied to the device, respectively, through pipe 7 and nozzles 12 and the gas-air mixture is ignited in a known manner in housing 1. Then, using ignition devices (not shown) installed in the ignition unit 4 in the openings 16 of the chambers 2, as the taps 17 are opened, the gas-air mixture is ignited in the chambers 2.

Shutting down the device that implements the method of burning gas is carried out by disconnecting the gas from the device and after cooling the layer 3 of crushed refractory material to 300 s - by turning off the air.

The supply of more than 30 gases to the layer of catalytic material leads to. increase in temperature in the catalyst bed, which can cause mechanical destruction of the catalytic

material or loss of its catalytic properties.

Submission of less than 25% of gas to the bed of catalytic material leads to unstable gas combustion in the primary combustion zones due to overcooling of the chambers.

The use of crushed refractories as a backfill chamber in the secondary combustion makes it possible, along with the intensive combustion of gas, to allow a high temperature regime in this chamber.

Claims (1)

Invention Formula A method of burning gas in heating furnaces, comprising supplying gas and air to the primary combustion zone with a catalytic bed, burning the gas-air mixture formed in this zone, feeding additional combustion gases to the secondary combustion zone, and in order to intensify combustion process and ensuring complete combustion of gas with a simultaneous reduction in emissions of nitrogen oxides, the gas is supplied to the primary combustion zone in an amount of 25–30%, and air is supplied in the amount necessary for complete burning all of the gas, while in the secondary zone the combustion of gas with combustion products from the primary zone is carried out in a layer of crushed fire abutment. /five 2