EP2262583A2

EP2262583A2 - Device for removing fine-grained or dust-like solids from a container

Info

Publication number: EP2262583A2
Application number: EP09716242A
Authority: EP
Inventors: Eberhard Kuske; Stefan Hamel
Original assignee: Uhde GmbH
Current assignee: ThyssenKrupp Industrial Solutions AG
Priority date: 2008-03-05
Filing date: 2009-02-27
Publication date: 2010-12-22
Also published as: TW200944451A; KR20100138983A; MX2010009716A; RU2010140438A; WO2009109286A3; ZA201007040B; NZ587654A; AU2009221248A1; CN102083520A; RU2479344C2; DE102008012731A1; BRPI0908550A2; WO2009109286A2; CA2716997A1; US8430950B2; US20110296995A1; AU2009221248B2; UA102245C2; WO2009109286A4

Abstract

The invention relates to a device for removing fine-grained or dust-like solids from a container that is to be pressurised or that is pressurised. Said container is fitted with a double-walled removal cone or funnel. The aim of the invention is to avoid using, in particular, porous materials such as sinter metals or similar, whilst providing good conveying properties in the transfer funnel without reducing the size of the grain of the respective material. Particle-charged gas for conveying can be also used. This is achieved due to the fact that the gas outlet opening is larger than the largest particle of the removed solids and that said gas outlet openings (4) are provided with a tube support or gas supply channel (4a) extending into the inside of the annular chamber (6) and forming at least one angle having an imaginary horizontal plane and that the gas supply channel (4a) is part of a retaining device (12) for preventing solids from trickling into the annular chamber (6).

Description

"Apparatus for discharging fine-grained or dust-like solids from a container"

The invention is directed to a device for discharging fine-grained or dust-like solids from a container to be placed under overpressure or under overpressure of the type specified in the preamble of claim 1.

In the thermal conversion of solid fuels, such as a variety of coals, peat, hydrogenation residues, residues, waste, biomass and fly ash or a mixture of said substances under elevated pressure, there is a need, under normal pressure and ambient conditions stored feedstocks to the pressure level of the thermal Conversion to bring about a promotion in the pressure reactor. Possible thermal methods may be, for example, the pressure combustion or pressure gasification by the fluidized bed or air flow method.

This requires the promotion and intermediate storage of finely ground fuels. To bring the fuel to the pressure level of the reactor, it is usually used lock systems in which the fuel is placed in successively connected containers on pressure. The decisive criterion for operational safety is the reliable emptying of the containers even after they have been brought to high system pressures. In principle, to discharge very fine and fine-grained solids from a container, different approaches are possible:

In large, under atmospheric silos silos is often removed with mechanical devices, such as clearing arms, etc., the solid. Basically, the solid bed can be converted by gas supply against gravity in the fluidized bed state. The fluidized bed behaves then similar to a liquid and can leak through outlet openings, side nozzles, etc. The disadvantage is that large amounts of gas are needed. To make matters worse, that very fine particles can be very difficult to convert into a homogeneous vortex layer.

Another way to enable the solids discharge from a container, is to provide, taking into account the bulk material properties conical outlet geometries. The solids discharge from a cone out can be supported by adding gas via lances (US 5 129 766) or to the cone walls (CH 209 788). The amount of gas is usually less than the amount that would be required for fluidization, but sufficient to cancel the wall friction of the bulk material and / or to prevent local approaches to bridge formation. An air-permeable intermediate floor with elastic, self-closing valve nozzles is shown in DE 11 70 988.

The latter method is the preferred variant in the described gasification plants, where fine-grained fuel must be handled at both atmospheric and high pressures. Here, the required amount of gas is limited and dispensed with mechanical installations at the same time.

The prior art is to supply via porous elements gas in the outlet cone (US 2006/0013660 Al, US 4,941,779). The porous elements are preferably made of sintered metal, but may also consist of other porous media. The use of porous materials has some procedural and operational disadvantages: The permissible pore size is based on the solid to be handled or on its particle size distribution. The pore size can only be reduced to a reasonable level, which results from the desired retained particle size and Durchstömungsdruckverlustes. In practice, it can be stated that even with very small pore sizes, the porous medium becomes clogged over time. The reason for this is that the finely ground fuel to be handled has a particle size distribution in which even the finest particles are present, which can settle in the pores. In addition, abrasion effects of the fuel within the container and during handling lead to the formation of extremely fine particles which can potentially also clog the pores. Although it is attempted to counteract the clogging of the porous medium by giving up a permanent gas flow, the practice shows that this can only extend the life of the porous elements.

Porous material inevitably has a lower strength (than comparable solid material) and may therefore only be operated with gas so that a maximum allowable pressure drop over the porous material is not exceeded. Improper handling or unsecured pressure rises during operation can therefore lead to destruction of the porous material.

Another procedural disadvantage is that porous materials may only be charged with particle-free gas. It is not possible, e.g. to use gas generated from container depressions and particle-contaminated gas, since the porous materials would clog up from the gas feed side.

The processing of the porous material in conjunction with The steels used in classic tank construction requires special manufacturing skills and experience, especially in the case of high-quality welding of, for example, sintered metals.

The object of the invention is, in particular the use of porous materials, such as sintered metals od. Like. to avoid providing good conveying properties in the transfer funnel without limiting the grain sizes of the respective material, with particle-laden gas can be used for the promotion.

With a Vorrichtun of the type described, this object is achieved according to the invention characterized

- That the gas outlet openings are larger than the largest particles of the solid to be discharged and

- That the gas outlet openings are provided with a projecting into the interior of the annular space, at least one angle with an imaginary horizontal plane having gas supply channel and

- That the gas supply channel is part of a retaining device for preventing the Einrieseins of solid in the annulus.

The provision of provided with respective short gas supply channels gas outlet openings in the interior of the funnel, wherein the gas used for this purpose is blown from a surrounding the funnel annulus, leading to a number of design and operational advantages. Thus, it is possible with simple means to be able to adapt both the gas inlet directions in the hopper to the respective requirements, also the introduction of the gas required for conveying into the annulus means the possibility of optimal homogenization of the gas distribution, a resuspension of the gas distribution and the gas u. like. more. It is also advantageous that the gas supply channel is part of a retaining element for preventing the Einrieseins of solid in the annulus. The retaining element may be provided on a single gas supply channel or may be equipped with a plurality of gas supply channels.

Embodiments of the invention will become apparent from the dependent claims. It can be provided in particular that the annular space-side effective end of the gas supply channel in the direction of gravity above or below the outlet opening of the gas supply channel is in the hopper, which in particular substantially prevents solids from passing through the openings in the funnel wall to the outside, in particular in the Annular space for gas supply.

In order to optimize the gas inlet and at the same time to additionally prevent the return of solids, it can be provided that each retaining element is provided with gas distribution openings or gas inlet openings situated in the direction of gravity above the gas outlet openings. The retaining elements can be designed annular or cross-sectionally angular.

On the one hand, to achieve a favorable gas distribution and, on the other hand, to ensure that any sedimented solid can be whirled up and conveyed back into the hopper via the conveying gas, it is provided that the injection of the gas into the annular space at the bottom effective soil in one direction, preferably tangentially, takes place, which leads to a vortex-like flow in the annulus and to a Aufwirbelung possibly there located solid particles.

In a further embodiment, it can be provided that the Ring space is equipped at least with a double bottom to form a lower part of the annular space in the direction of gravity is equipped with at least one gas supply and one or a plurality of gas outlet nozzles on the inner annular space floor.

A further variant according to the invention is that the annular space is divided by a plurality of floors in annulus segments, each segment is assigned at least one distributed over the circumference plurality of gas outlet openings and at least one gas supply.

Another variant may be that the gas supply is made via ring lines at the bottom of the respective annular space.

If, as the invention also provides in a further embodiment, gas supply slots instead of approximately circular gas outlet openings provided, these slots may be similar to the gas outlet openings arranged in horizontal rows on the handling of the funnel, possibly offset from each other, the slot design can be provided so that, for example the slot forms an exit angle to the horizontal against the force of gravity or in the direction of the force of gravity, subliminal slot configurations being possible with different media to be conveyed.

The invention also provides a method using a device with the preamble feature of claim 1, characterized in that it is acted upon by a gas supply of the effective bottom space of the annulus formed by the double-walled funnel so that in the annulus a possibly located there solids fugitive dust forms billowing flow, wherein via gas outlet openings with angular gas supply channels, the fluidized gas is injected into the inner funnel at an angle to the direction of gravity.

Under certain circumstances, several cones can be arranged on a container. Furthermore, it may have manufacturing advantages to provide several cones possibly different size in series.

Further advantages, details and embodiments of the invention will become apparent from the following description and from the drawing. This shows in

1 shows a partial cross section through a discharge cone of a non-illustrated solid containing container,

1a and 1b modified embodiments of the Austragskonusses,

Fig. 2 shows a further modified embodiment of the Austragskonusses and in the

3a and 3b additional embodiments of the Austragskonusses each in the representation of FIG. 1.

The discharge cone 1 shown in Fig. 1 is designed double-walled. In the annular space 6, which is located between the inner wall 7, outer wall 5, intermediate bottom 9 and upper flange, gas is supplied. Gas is first introduced into the underfloor space 10 via a gas feed connection and line 8. leads, which is located between the inner wall 7, outer wall 5, intermediate bottom 9 and lower flange. The gas is distributed from there via nozzles 11 located in the intermediate bottom 9 into the annular space 6. Preferably, the nozzles 11 are aligned parallel to the intermediate bottom 9 and employed tangentially, so that adjusts a swirling gas flow in the annular space 6. By injecting the gas with increased speed and twist as well as by the high turbulence, it is possible to stir up deposited fine solid particles and to guide them with the gas flow into the bed. The underbody space 10 serves to distribute the gas to the nozzles 11, wherein the intermediate bottom 9 simultaneously provides a flat surface from which deposited dust particles can be removed by the gas flow.

The variant shown in FIG. 1 with intermediate bottom 9, nozzles 11 and bottom space 10 is particularly advantageous when it comes to bulk material with larger particle diameters, which require a high speed and as undisturbed flow to raise from the ground. In the case of fine to dusty bulk material, structurally simple variants of the gas supply can be used in the annular space, which are shown in Figs. Ia and Ib.

In Fig. Ia, the gas supply takes place directly over the gas supply nozzle 8, at the end in the annular space 6, a Umlenkdüse 15 is provided to give the incoming gas a tangential orientation, wherein a gas supply nozzle 8 may be provided with Umlenkdüse multiple. A further variant of the gas supply is shown in Fig. Ib, in which via the gas supply port 8 gas a ring line 16 is fed, which is located in the annular space 6. From the ring line 16, the gas is injected via nozzles 17 in a preferably tangential direction in the annular space 6. From- Direction of the nozzles 11,15,17 preferably takes place tangentially and horizontally (with respect to the gravitational field), but may also be directed in deviating from the tangent up to 45 ° in the radial direction and / or up to 45 ° from the horizontal upwards.

The gas supply openings 4 with their gas supply channels 4a according to the invention are designed so that they are considerably larger than the largest particle diameter of the solid, for example at least three times larger than the largest particle diameter. The gas supply openings 4 are provided in the annular space 6 with a retaining device 12, which has the task of retaining backflowing solid.

A preferred embodiment of this retaining device 12 is shown in FIG. The restraint device may therefore consist of an easy-to-manufacture ring which is turned off at an angle so that it has surface contact with the conical inner wall 7. The annular design also has the advantage that an outer surface can be turned off at any angle to the vertical, so that in a simple manner any angled holes can be performed simultaneously by retaining device 12 and inner wall 7. As a result, the gas supply opening 4 can be designed with arbitrary angles of attack on a very simple production technology, whereby the retention of the solid is favored (see, for example, detail in FIG. 1). The annular design of the retaining device 12 makes it possible to install a larger number of holes on the circumference and to provide holes in several rings over the height on several levels, in FIGS. 1 and 2, three levels for gas supply openings 4 are exemplified. The annular restraints 12 also reinforce the conical inner wall 7. Another possibility of the design is outlined in FIG. The gas supply openings 4 are here for example designed as slots, which may also be angled to the horizontal, as the holes (see sections a to c in Fig. 2). The retaining device 12 is here alternatively mounted, for example, as an angled plate behind the gas supply openings 4.

Furthermore, in the advantageous embodiment, a gas distributor device 13 is provided, which covers the side of the retaining device 12 facing the annular space 6. The gas distributor device 13 is itself provided with gas inlet openings. Each retaining device 12, either in annular form (FIG. 1) or in angular form (FIG. 2), is assigned a defined number of gas supply openings 4. The main task of the gas distributor device 13 during operation is to accomplish the gas distribution to the gas supply openings associated with the individual restraint devices. For this purpose, the pressure loss of each gas distributor device 13 can be adjusted by a suitable choice of the inflow opening 14. Thus, a uniform distribution to all gas supply openings can be achieved or targeted the gas supply to each restraint device can be adjusted with the associated gas supply openings. This can be done in a simple way e.g. the different pressure conditions, which result from different heights of the gas supply openings in the cone, be taken into account.

If an amount of gas distribution of this type is required which can only be achieved by adjusting the pressure loss of the gas distributor device 13, there is also the option of two further separating plates 9 ', 9 "for forming a second underbody space 10' with separate gas supply 8 ', nozzles 11 'Insert (see Fig. 3). The second gas supply 8 'and the second annular space 6' is spatially from first annulus 6 separated and both gas feeds can be acted upon with individual gas. In addition, the distribution of gas, for example, from a common supply line to both gas chambers 6,6 'can be adjusted by means of pinholes on the gas supply pipe 8,8'.

Another way to vary the amount of gas above the cone height in a container is to switch two or more of the devices according to the invention on top of each other (not shown). The diameters at the transition point must be adjusted so that the inner walls seamlessly follow the cone angle.

Of course, the invention is not limited to the above embodiment, but can be modified in many ways without departing from the spirit.

Claims

Claims:

1. A device for discharging fine-grained or dust-like solid from a container to be pressurized or under overpressure, wherein the container is equipped with a double-walled discharge cone (1) or -trich- ter, with at least one gas supply (8) in the annular space (6) formed by the double-walled funnels, wherein the funnel wall (7) facing the funnel interior is provided with gas outlet openings (4), characterized

- That the gas outlet openings (4) are larger than the largest particles of the solid to be discharged and

- That the gas outlet openings (4) with a in the interior of the annular space (6) projecting, at least one angle with an imaginary horizontal plane having pipe socket or gas supply channel (4a) are provided and

- That the gas supply channel (4a) is part of a retaining device (12) for preventing the Einrieseins of solid in the annular space (6).

2. Apparatus according to claim 1, characterized in that the annular space-side effective end of the gas supply channel (4a) in the direction of gravity above or below the outlet opening (4b) of the gas supply channel (4a) is in the hopper.

3. Apparatus according to claim 1 or 2, characterized in that one or more retaining devices (12) with one or more gas supply channels (4a) is provided.

4. Apparatus according to claim 2 or 3, characterized in that each retaining device (12) in the direction of gravity above the gas outlet openings (4) lying Gasverteil- or gas inlet openings (14) is provided, wherein the Gasverteil- or gas inlet openings (14) Have diameter larger than the particle diameter.

5. Device according to one of the preceding claims, characterized in that the injection of the gas into the annular space (6) at the bottom effective bottom (9,9 ') in a direction, preferably tangentially, takes place, which leads to a vortex-like flow in the annulus ( 6) and leads to a Aufwirbelung possibly there located solid particles.

6. Device according to one of the preceding claims, characterized in that the annular space (6) is equipped with at least one double bottom (9, 9 ') for forming a lower part annular space in the direction of gravity (6) with at least one gas supply and one or a plurality of gas outlet nozzles (11) is equipped on the inner annulus floor.

7. Device according to one of the preceding claims, characterized in that the annular space is divided by a plurality of bottoms (9, 9 ', 9 ") in annulus segments, each segment at least one distributed over the circumference plurality of gas outlet openings and at least one gas supply (8,8 ') is assigned.

8. Device according to one of the preceding claims, characterized in that ring lines (15, 15 ') are provided in the annular space (6) for supplying gas into the annular space.

9. Device according to one of the preceding claims, characterized in that the outlet openings in the funnel wall (7) are designed as slots (Fig. 2), wherein the length of the slots may be less than 50% of the circumferential length of the funnel wall.

10. A method using a device according to claim 1, characterized in that via a gas supply of the effective bottom space of the annulus formed by the double-walled funnel is acted upon such that in the annulus a possibly located there solids aufwirbelnde flow forms, via gas outlet openings in the Angle standing gas supply channels the fluidized gas is injected into the inner funnel at an angle to the direction of gravity.