RU2752939C1 - Device for reducing emissions of carbon monoxide and nitrogen oxide when utilizing solid waste by incineration - Google Patents

Abstract

FIELD: solid waste processing.

SUBSTANCE: invention relates to the field of processing solid waste (SW) by incineration. The effect is achieved by the fact that the device for reducing emissions of carbon monoxide (CO) and nitrogen oxide (NO) during the disposal of solid waste by burning in an electrostatic field includes two electrodes placed in the combustion zone, while one electrode is a grate, insulated with ceramic inserts, for incineration of solid waste, and the other electrode is made in the form of a rod made of heat-resistant steel and placed in a ceramic insulator. A constant potential difference of up to 3 kV is supplied between the electrodes, which contributes to an increase in the combustion temperature and a change in the thermal decomposition of solid waste.

EFFECT: increased temperature in the combustion chamber is ensured, as a result the composition of the products of thermal decomposition changes and the completeness of combustion increases.

1 cl, 1 dwg

Description

The invention relates to the field of processing solid waste (MSW) by incineration

One of the components of MSW are products made of polymeric materials that, when burned, emit substances hazardous to the environment [Mazurin I. M., Ponurovskaya V. V., Kolotukhin S. P. Ecological dead end from waste incineration and possible ways to overcome it // Electronic scientific publication Almanac Space and Time. - 2018. - T. 16. - No. 3-4.].

The known method [patent for invention RU 2694268. Method of intensification and control of the flame. IPC F23C 99/00. Application No. 2018104632 dated 06.02.2018, publ. 07/11/2019 in bul. No. 20], which allows the use of a uniform electric field created by two ring electrodes as a combustion catalyst to reduce CO and NO emissions, but it was developed for the combustion of gas mixtures. The disadvantages of this method include the following:

The chosen configuration of the electrodes creates a uniform electric field, the strength of which depends very much on the distance between the electrodes at a given potential difference. The stated effective value of the influence intensity of 100 kV / m assumes, at a distance between the annular electrodes of one meter, the supply of a potential difference of 100 kV. This fact indicates the need for expensive equipment and high requirements for work safety.

The ring-ring electrode configuration does not allow the creation of an electric field in the melt zone during polymer combustion. In this case, it is the integral imposition of an electrostatic field on the combustion area of polymers, according to studies, leads to a significant increase in the combustion temperature [Reshetnikov S.M., Pozolotin A.P., Zyryanov I.A. University named after Academician SP Korolev (National Research University). - 2013. - No. 3-1 (41)], combustion efficiency up to 15% [Zyryanov IA et al. Possibility of reducing the toxicity of gaseous emissions from power plants by the effect of an electrostatic field on the fossil fuel combustion zone // Theoretical and Applied Ecology. - 2019. - No. 1. - S. 88-93].

The technical result of the proposed technical solution is to increase the temperature in the combustion chamber, as a result of which the composition of thermal decomposition products changes and the completeness of combustion increases.

The technical result is achieved by the fact that the device for reducing emissions of carbon monoxide (CO) and nitrogen oxide (NO) during the disposal of solid waste by burning in an electrostatic field includes two electrodes placed in the combustion zone, while one electrode is a grate, insulated with ceramic inserts. grate for incineration of solid waste, and the other electrode is made in the form of a rod made of heat-resistant steel and placed in a ceramic insulator. In this case, a constant potential difference of up to 3 kV is supplied between the electrodes, which contributes to an increase in the combustion temperature and a change in the thermal decomposition of solid waste.

The device works as follows.

In the combustion chamber of any type of boiler plant that burns solid waste on a grate to reduce CO and NO emissions, an electrode system is placed (see Figure). Electrode 1 is made of heat-resistant steel (it is possible to use grades 12X18H10T, 08X18H10T, etc.) and is placed in a ceramic insulator 2. Electrode 3 is a grate isolated from the boiler body by ceramic inserts 4 (examples of materials for insulator 2 and inserts 4: MKS- 72, KS-95, etc.), on which the elements of solid waste for incineration are placed 5. DC voltage up to 3 kV is supplied to the electrodes from source 6, using high-voltage wires 7. Electrode 1 is connected to the negative pole of the source, electrode 3 - to the positive pole. This system differs from the one set forth in the patent RU 2694268 in that it allows creating an electrostatic field in all areas of polymer combustion, has a significant effect on the growth of the combustion temperature (up to 150 K) and thermal decomposition processes, which at different rates of polymer heating give different decomposition products [ Reshetnikov S. M., Reshetnikov I. S. Anatomy of combustion // Moscow, NGSS. - 2014. - No. 247c. ISBN. - P. 987] and does not require the use of high (100 kV) voltage.

The principle of operation of the invention is as follows: an electrostatic field is created between the electrode 1 and 3, the intensity of which is maximum at the electrode 1 and is uniform at the electrode 3. There are excess charges (positive and negative) in the polymer flame [Reshetnikov S.M. Features of combustion of polymers in an electrostatic field [Text] / SM Reshetnikov., IA Zyryanov., AP Pozolotin // Izvestiya SFedU. Technical sciences, Taganrog, 2013. - No. 8. S.30-36]. From the side of the electric field, the Coulomb force (F = qE) acts on the charged particles, which leads to their movement, as a result of which the shape of the flame changes and the combustion temperature of the pyrolysis products of the k-phase rises. An increase in temperature leads to an increase in the heat flux into the k-phase, as a result of which there are changes in the composition of the gasification products. The processes described above lead to a decrease in CO emissions, see Table 1 (the results were obtained on a model plant simulating the combustion conditions described above).

, от разности потенциалов между электродамиTable 1. Dependences of the total concentrations of CO / NO emissions during combustion, referred to the mass of burned fuel

, from the potential difference between the electrodes

burned sample \ potential difference 0 kV 3 kV polystyrene (CO emissions) 3980 3680 polypropylene (CO emissions) 2960 870 SKD-2 (CO emissions) 2420 1670 SKD-2 (NO emissions) 250 95

Claims (1)

A device for reducing emissions of carbon monoxide and nitrogen oxide during the disposal of solid waste by incineration in an electrostatic field, which includes two electrodes placed in the combustion zone, characterized in that one electrode is a grate for solid waste incineration insulated with ceramic inserts, and the other electrode is made in the form of a heat-resistant steel rod and placed in a ceramic insulator.

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