DD154945A3 - METHOD AND DEVICE FOR REMOVING FLUID SLUDGE - Google Patents

Abstract

The invention relates to a method and a device for the extraction of liquid slag in the gasification of dusty or stubborn fuels. The object of the invention is the gasification of pulverulent or stubborn fuels with oxygen or a free-oxygen-containing gasification agent in a reactor such that at the lower end of the reaction space for the course of the gasification reactions at temperatures above the melting point of the ash / slag an undisturbed slag discharge optionally together with the hot raw gas is guaranteed in a cooling and Granulierteil the Schlackeablaufoeffnung. According to the invention, the Schlackeablaufoeffnung is provided with a heated molded block of electrically conductive material and heated by energy saving means of an induction coil of the molded block.

Description

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Title of the invention

"Process and apparatus for extracting liquid slag

Field of application of the invention

The invention relates to a method and apparatus for extracting liquid slag in order to be able to reliably remove the slags produced in certain technologies of the gasification of dusty or lumpy fuels with oxygen or air in the liquid state from the process _o

Such gasification processes are used in the production of heating gases, synthesis gases, reducing gas or town gas or "mixed components of town gas,"

Characteristic of the known technical solutions In the gas production technology, the gasification of dusty or lumpy fuels with a mixture of oxygen and water vapor or air as a flame reaction in the flying cloud or in a fixed bed is known. Bei'der gasification pulverized fuels and modern methods of gasification lumpy fuel, the reaction at such temperatures that the mineral components of the coal produced as Bchmelzflüssige slag. "Especially _then? When the gasification is carried out under increased pressure, there is the difficult technical Task to run the gasification reactor so that the Schlakkenfluß dominated and the slag from 'the system

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It can be carried out safely ", technical solutions are customary in which the molten slag is granulated and cooled in water within the reactor and suspended in water suspended from the pressure system as granules. The design of the Hüssig slag is responsible for the serviceability of such reactors Outflow from the hot part of the reactor, the reaction chamber in the strict sense, in the cooling and granulation crucial

The GDR exclusion pate 119 266 describes a reactor for the pulverization of pulverized coal under pressure, the reaction space of which consists of a water-exposed tube wall construction protected by a layer of refractory mass. _Q For the discharge of the liquid slag into the granulation part, there is a central opening in the bottom of the reaction space provided, the contours are formed by the correspondingly shaped pipe wall construction with ramming mass-Besehichtung _o The bottom of the Reaktionsräumes is slightly inclined towards the Schlackenabflußöffnung. The opening is provided with a sharp slag drip edge.

A similar solution is known in principle for a gasification plant operating slightly above the atmospheric pressure, where the upper edge of the central slag opening is soaked in a dam, so that the slag at the bottom of the reaction space becomes "% byproduct" and 5 "4" the dam overflows (üllmann's encyclopedia of Industrial Chemistry, 3rd edition, volume 1o, page 416, 1958) It is further known to transfer liquid slag and hot gas through a bottom opening with drip together in a cool room, see, _o B. Meunier , "Gasification of Solid Fuels," Weinheim / Bergstraße, 1962, page 453,

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Finally, DT-OS 2 325 2o4 describes a reactor for the pulverization of pulverized coal under pressure, in which hot gas and liquid slag are withdrawn together via a central opening in the bottom of the reaction space down, with a dam bath through a dam around the central opening is maintained at the bottom of the reaction chamber _o

Operating experience in such systems show a high susceptibility to the solidification of slag in the outlet opening in response to certain technological conditions, especially during startup and shutdown, which can lead to disturbances and hazards. Therefore, it was attempted to greatly overheat the slag by special employment der, Β the coal dust burner or by additionally operated with gas Aufheizbrenner near the drain. The consequences are an increased gasification requirement, high additional fuel demand and thus a deteriorated gasification efficiency as well as a heavy wear of the reactor lining in the lower area. "When using gas burners. Extensive, complicated technological equipment is necessary to clean, compress and the part of the production gas Feed reactor again. _O

Object of the invention

The object of the invention is to develop a method and an apparatus for the safe and continuous operation of plants for the gasification of fuels with liquid slag removal in order to avoid clogging by slag additives and to ensure a steady slag discharge. This increases the operational safety and availability. At the same time, the wear should. the lining and the burner are lowered »

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The object of the invention is the gasification of pulverulent or lumpy fuels with oxygen or a free-gasification agent in a reactor such that at the lower end of the reaction space for the course of the gasification reactions at temperatures above the melting point of the ash / slag 'a undisturbed slag effluent, if appropriate together with the hot raw gas, is ensured in a cooling and granulating part of the slag discharge opening. "

According to the invention, the stated object is achieved in that the reaction space down the final, preferably centrally located annular slag outlet opening is provided with a heated molded block of electrically conductive material. As an electrically conductive material are mixtures of carbon, ceramic materials, SiC, SiJ ^, SiONp u.a. used in varying proportions "

By a suitable energy supply by means of an induction coil, the shaped stone is heated, for which purpose the following technical solution was selected:

According to Figure 1, a device is arranged in the lower part of a Vergasungsrealctors, which represents a slag outlet opening. Form stone, a water-cooled induction coil embedded in insulating concrete and a metallic water tank, on the inner surface of which shielding plates made of copper are applied, consists of '.'

Surprisingly, it has been found that a certain ratio between the supplied electrical energy and the sensible energy (heat) of the exiting production gas and the slag must be ensured in order to secure a continuous slag process. This ratio ranges from 1: 10 to 1: 2oo , preferably between 1: 1000 to 1: 200, where

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tions to the chemical-physical properties of the slag. If this ratio is undershot, the solidification and thus the growth up to the clogging of the slag discharge opening occur; if the ratio is exceeded, the slag film runs off too quickly, it can lead to overheating and thermal destruction of the molded block. Furthermore, it has been found that only a limited frequency range of the induction current is suitable for securing a continuous slag process, which is between 500 and 10 000 Hz, preferably between 2 4oo and 8000 Hz. It was found that in the proposed frequency range, the electrically conductive, liquid slag layer is also heated inductively _o

A further arrangement according to FIG. 2, which shows the principle of incorporating the necessary equipment for inductive heating of the slag outlet opening of a gasification reactor, consists of a slag outlet opening, an induction coil surrounding it, a passage of the electrical supply into the pressure space, a capacitor battery ,, the medium frequency generator and the two pressure measuring points.

The circuit arrangement of Figure 3 shows the two Druckmeßs'tellen, two shut-off valves, the differential pressure transmitter, the power supply, the control amplifier and the field winding. The devices shown in Figures 1, 2 and 3 operate as follows during operation of the reactor:

In the working area of the reactor, a mixture of produced gas and liquid slag _P passes through the outlet opening and thus through the shaped brick.

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is heated, in the ferry operation of the reactor through the induction coil, which forms the load circuit for the middle frequency generator together with the capacitor group heats, The electrical connection of the water-cooled induction coil made of copper via the implementation of the electrical supply into the pressure chamber in the pressurized reactor _O

With the help of the two pressure receiver, a value is determined at the differential pressure transmitter, which drives an amplifier, the output signal according to the amount of the impending differential pressure, the excitation of the center frequency he convincing he influenced s,

The control mechanism of the variant shown in Figure 3 functions in such a way that increases the increase in the differential pressure at the transmitter, whereby a cross-sectional reduction in the stone of the slag outlet opening is signaled by an increase of slag parts, the excitation for the middle frequency generator and thus the molded block on the induction coil more Energy is supplied _o This causes an increase in temperature in the brick, the slag starts to melt and the cross-section for the discharge of gas and slag is increased again. As a result of the differential pressure decreasing at the transmitter due to the increase in cross-section, the excitation for the medium-frequency generator is weakened and thus reduces the energy input into the shaped brick,

The invention will be explained with reference to the following embodiment:

In a pilot plant for the gasification of pulverized fuels, coal dust in an amount of 8o ~ 12o kg / h corresponding to an amount of energy of -

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1.6 _# 1o - 2.4 · 1 kJ / h via appropriate burner introduced into the reaction RAM of a reactor For thermal protection of the pressure-carrying shell is a cooling pipe screen with applied ramming mass. At the bottom of the reactor is a Schlackeabflußöffnung, pass through the liquid slag and gasification gas via an electrically heated molded block 2 in the cooling and Granulierteil. Gas and slag are quenched after exiting the .Schlackeabflußöffnung by injected water, whereupon the slag settles in a water bath and. Is withdrawn through an opening * The gas is discharged through a Rohgasaustritts truncated The amount of raw gas generated is 3oo m ί _ο ΪΤ « / η, the .with a temperature of ·] 4oo - leaves the reaction chamber 1 7oo ⁰ C over the molded brick 2 ·. The sensible energy (heat) of the raw gas is about 6,7 ₀ Ιο- ³ - 7,2 ♦ 1ο- ⁵ kJ / h _o To ensure the slag discharge, an electric power to heat the stone was 1-25 KW accordingly

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an energy quantity of 3,6 "1o - 9o _o 1o kJ / h installed. The ratio between electrical energy and the .sensible energy (heat) of the gas generated in the experimental operation was to achieve favorable, continuous operating conditions at 1: 1oo to 1: 2oo "It was possible by a differential pressure-controlled control similar to Figure 3, the electrical energy process-related irregular or periodically. It turned out that according to the experimental conditions the frequency of the electric current had to be adjusted to 8,000 Hz »

Claims (1)

♦ * ö · * 24199 Invention claim. A process for Vergasung.staubförmiger or lumpy fuels under pressure, preferably at pressures between 5 and 5o bar containing by partial oxidation with oxygen or a free-oxygen gasification agents at gasification temperatures lower than the melting point of fuel ash, preferably 5o "2oo ⁰ C and slagging followed by cooling and granulation, the slag vent alone or together with the hot. Gasification gas can be carried out, characterized in that the arranged at the bottom of the reaction space Schlackeabflußöffnung is inductively heated by an electrical in.ittelfrequenten current, wherein the ratio between the supplied electrical energy and the sensible energy (heat) of production gas and slag between 1: 1c to 1 ': 2oo, preferably 1: 1oo to 1: 2oo, is » 2 "method according to item 1, characterized in that the frequency of Indulctionsstromes between 5oo and 10o ooo Hz, preferably between 2 4oo and 8oooo Hz. o Method according to items 1 and 2, characterized in that the frequency of the induction current is selected so that the electrically conductive .Schlackeschicht is also heated inductively. 2 24199 4β method according to item 1 to 3, characterized in that the heating of the Eormsteines time-limited or »
periodically " 5-, process according to point 1 to 4, -, characterized in that at simultaneous discharge of slag and production gas, the slag deposit in the Schlackeabflußöffnung by a differential pressure measurement with measuring points before and after the slag outlet is measured, and the ratio of the supply of electrical
Energy and the sensible energy (heat) of the production gas is controlled so that the slag residue melts β 6. Apparatus for carrying out the method according to
Points 1 to 5 », characterized in that the
Reaction space closing down, preferably
centrally arranged annular slag-opening (1) with a heated shaped block (2) made of electrical ' Conductive material is equipped and the device part for energy input from a in insulating concrete (3) embedded water-cooled induction sink (4), with metallic water tank (5) _; on the shielding plates (6) are made of copper, consists ,, Dazu_.iL $ eiten drawings