DD291340A5 - PROCESS FOR THE PREPARATION OF ASH SLAG MIXTURES - Google Patents

Abstract

The invention relates to the treatment and the hydraulic transport of ash-slag mixtures obtained in the pressure gasification of spiky or dusty coals, especially when using high-fiber fuels. The essence of the invention is that the coarse slag is subjected to pressure waves in the water bath under operating pressure and thereby undergoes comminution and rendering, so that the hydraulic transportability of the ash-slag-water mixture is economically and safely possible, so that upstream or downstream mechanical acting comminution aggregates can be omitted. The field of application are preferably compressed gas plants, in which, due to the process, transport-difficult ashes occur. {Ash preparation; Ash-slag mixtures; crushing; hydraulic solids transport; Pressure gasification of spiky or dusty coal}

Description

For this 1 page drawing

Field of application of the invention

The field of application of the invention are pressurized generators of coal-pressure gasification, in particular dust and fixed-bed gasification of hard coal and lignite cartilage and / or briquettes in which process-related solid gasification residues, especially transport-difficult ash-slag mixtures.

Characteristic of the known state of the art

The hitherto known and practiced technology (DD-WP 110511) of ash removal in the coal-pressure gasification of solid fuels in a fixed bed by means of modules assembly grate, ash sluice, ash pit, scraper chain, crusher and subsequent hydraulic rinsing. This open deashing technology has the following disadvantages:

- poor working and living conditions with high cleaning costs due to the open technology,

- high wear of all mechanical assemblies for relaxation, promotion and refraction,

- high energy expenditure for refraction and promotion,

- insufficient treatment leads to faults in the hydraulic disposal system.

In the inventions CS PS 124440, DD-WP 116259 and DE-OS 2455127 only solid fine-grained residues can be disposed of. In case of accruing coarse slag fails the system or the proposed solution.

In the patents DD-WP 210925, DD-WP 210927, DD-WP 210296, DD-WP 210297 a high expenditure on equipment is required and the treatment and transport of the coarse slag with conventional wear-intensive methods and units.

The mentioned has the disadvantage of an open transport technology.

The patent DD-WP 271707 has Jen decisive disadvantage that no constant delivery ratios can be set and mechanical crushers high wear intensity are used, which must be pressure-tight. According to DD-WP 249710 only eligible or treated ash-slag mixtures can be disposed of. Refraction in the device is excluded.

In DE-OS 2606039, the patent DD 245441 and US 4463686 there is a mechanical refraction in the closed system.

The mechanical crushers have to be made non-pressure-tight, which causes a high expenditure on equipment and thus high costs. Availability under such wear-intensive conditions is low.

Object of the invention

The aim of the invention is a low-cost, low-wear, mechanically trouble-free and safe disposal of difficult to transport ash-slag mixtures that arise in the coal gasification, especially when using ballastreicher fuels, while avoiding heavy physical work by significantly improved work, life and maintenance conditions.

Essence of the invention The task is to transport difficult ash-slag mixtures with slag sizes up to '000 mm 0, especially in the Coal pressure gasification incurred under certain process conditions and when using ballastreicher fuels, so

To prepare that a low-wear and continuous hydraulic transport in closed systems even over longer distances is possible.

According to the invention the object is achieved in that in the downstream pressure vessels of the gasification reactor, for. B. Ash sluice or flood space, the fine ash is separated from the coarse fraction under operating pressure. At the same time the

coarse fraction of ash-slag mixture depending on the slag content greater than 10mm quasi-continuous

Pressure waves exposed by electrical discharges with a pulse strength up to 2OkJ and a pulse density of 2-10 Pulses per minute are generated in a water bath and cause a moistening and / or crushing. Due to the specific mineral structure of the demineralized slag occurs in the subsequent hydraulic Transport another crushing of the slag. The hydraulic transport of the crushed slag is possible both together with the fine ash and separately. Hydraulically effective is the joint transport of coarse and fine ash. With material use of certain Fractions (eg in the construction industry) offer a separate transport. The advantages of this invention are

in the absence of wear-intensive mechanical breaking devices,

in reducing the wear of the subsequent disposal system,

- in the increase of generator availability,

- securing a transport-favorable solid-water mixture,

- in the elimination of heavy physical work during repair and maintenance work,

- reduction of disposal costs,

- Increasing safety and improving working and living conditions for staff.

Ausführungsbelspiol The invention is intended below an Ausführungsbeispie! to be explained with a drawing.

Due to the geometric dimensions of the central tube 4 and the annular gap 5, the majority of the injected water occurs due to the different pressure losses in the central tube 4 and in the annular gap 5 of at the top of the central tube 4 a.

Upon entry of the ash-slag mixture through the nozzle 6 takes place due to the countercurrent of the injected water and the introduced ash-slag mixture, a classification of the fine and coarse fraction of the injected slag-ash mixture.

The direct entry of the slag-ash mixture into the central tube 4 is prevented by a distributor cone 7 arranged above the central tube 4.

Depending on the speed of the upwardly flowing water, the fines of the slag-ash mixture is entrained upward and enters the Zentralrorir 4 and then flows in the central tube 4 down in the direction of the slag-ash mixture-water outlet nozzle. 8

The coarse fraction of the slag-ash mixture sinks outside the central tube 4 down, where it collects in the annular gap 5 and is subjected to comminution by means of pressure waves generated by electrical discharges in the water bath through the pulse generator 9.

Thereafter, below the central tube 4, the mixing of the previously deposited fine fraction with the fractional coarse fraction of the slag-ash mixture. The hydromechanical removal of the slag-ash mixture takes place in a known manner. The water level 10 is adjusted by a gas cushion depending on the pressure loss of the slag-ash-mixture-water disposal system.

Claims (6)

1. A process for the treatment of ash-slag mixtures obtained in the coal-pressure gasification with the use of lumpy or dust-like fuels in downstream tanks, are difficult to process and disposed of in closed systems with simultaneous crushing, characterized in that the crushing of the slag depending on Slag content greater than 10mm in a container by high-energy pressure waves, which are generated by electrical discharges in a water bath with a pulse count of less than 10 power sound pulses per minute and a crushing energy to 2OkJ per power sound pulse occurs. 2. The method according to claim 1, characterized in that the crushing takes place under operating pressure. 3. The method according to claim 1, characterized in that the crushing takes place in pressureless containers. 4. The method according to claim 1, characterized in that the ash-slag mixture 0 to 30 mm diameter before the slag is crushed larger than 30 mm and disposed of together with the crushed slag. 5. The method according to claim 1, characterized in that before the crushing of the slag larger 30mn removed ash-slag mixture is disposed 0-30 mm separate from the crushed slag. 6. The method according to claim 1, characterized in that the energy of e: ougten pressure waves are transmitted to mechanical components that cause the crushing.