CZ2012103A3 - Fluidization method of hot loose material and apparatus for making the same - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a method of continuously fluidizing a bulk, difficultly fluidizable material at high temperatures used in fluid transport and transportation and apparatus for carrying out this process. The hot bulk material to be transported is purged through the narrow and long streams of gaseous medium, which emanates from the gaps between the rods, resulting in fluidization, after a self-flowing entry into the fluid channel. The apparatus for carrying out the method comprises a fluid channel (1) internally provided with a plurality of rods (2) arranged side by side, including sterbins (3) therebetween. The rod assembly (2) divides the inner space of the fluid passage (1) into an upper space (4) for transporting fluidized bulk material (5) and to the lower space (6) interconnected with the upper space (4) by sterbin (3) through the bottom wall ( 7) the fluid channel (1) is provided with at least one gas medium inlet (8) and the top wall (9) of the fluid channel (1) is provided with at least one bulk material inlet (10). The invention finds its application in the heating and power industry for handling of ash in fluidized bed boilers, in cement production, in foundry, etc.

Description

Technical field /

The present invention solves a technical process for the permanent fluidization of bulk, difficult-to-fluidize material at high temperatures, which is used in fluid transport and transport, and an apparatus for carrying out the process.

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BACKGROUND OF THE INVENTION Transportation in bulk material piping systems at low or closed profile by local mixing of bulk materials with air, gas (hereinafter referred to as fluidization), while also reducing the specific gravity of the fluidized

Existing mean temperature methods are based on a suitable reduction of the friction between the pipe wall and the fluidized material and the material, as appropriate, as compared to the specific gravity of the bulk material to be transported.

Existing systems and equipment solve fluidization of loose at low and medium temperatures. The solidification of the bulk material is effected, in particular, by the use of a fluidizing fabric which forms the bottom in parts of either the horizontal conveyor trough or the silos. The technical problem is the temperature up to which 15C ^ C can be economically available, short term to and Kevlar are in part or storage to be fabric cloth, have an area of permanent

200 ° C. Special materials used. Commonly used and used as Aramid materials for continuous operation usable up to 250 ° C, short term up to 35 ° C.

AND

For higher temperatures, in some cases, steel, woven wire meshes treated or pressed or sintered ceramic materials are used. However, these materials are susceptible to clogging and clogging of small fluidization air passages through various grain shapes of the material to be conveyed, particularly when stopping the transport of fluidized material in the piping system.

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Metal fluid elements made of stainless pressed wires - usually with a diameter of 0.1

0.8 mm, but does not comply with deformations /

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/ under pressure at high temperatures from the weight of the material. These metal fluid elements made of stainless steel wires are worn very soon due to the small wire diameters and prevent material movement after twisting. Also, the gaps in these elements are irregular and curvilinear, the transported material adheres to the openings and clogs during cooling and heating.

Another possible grate construction is the use of ceramic porous materials. These generally meet temperature requirements, abrasion resistance requirements, but are fragile, susceptible to damage and destruction. The disadvantage is also their low permeability and their unsuitability for the transport of materials with higher grain size and also their high cost.

These materials also create a high resistance to fluidizing air, requiring the use of compressed air sources at pressures of 50 kPa and above, i.e. blowers and compressors. The known solutions generally consist of a pipeline into which, at its lower part, at certain distances from each other, i.e. not along its entire length, there are openings of compressed air inlets. However, experience from practical testing of this equipment has shown that these solutions do not exhibit the required properties for the transport of bulk hot materials and are unreliable or inoperable from an operational point of view.

SUMMARY OF THE INVENTION

The above drawbacks eliminate the method of fluidizing the hot bulk material of the present invention for conveying it in a ducted fluid channel having a closed profile in which the bulk material to be conveyed, after its gravity entry into the fluid channel, over its entire length, continuously and in a continuous manner. throughout its volume, blown through numerous, narrow and long • · · ·

35 ”gas streams located next to the medium, emerging from the gaps, longitudinally in the conveying direction and at the bottom of the fluid channel, thereby achieving transport along the rods along the entire length, by fluidizing the transported hot bulk material resulting in reduced specific gravity , its friction of the transport elongate body, increasing its fluidity by its longitudinal movement through the fluid channel. An essential part for the fluidization of the hot bulk material is the fluidization (grate), which is formed side by side, after the material being added, to the walls and hence the element element with a flow of 0.1 bars of heat resistant stainless steel along the length of the fluid channel. between which there is a small gap mm to 2.5 mm, chosen according to the material. Fluid element of grain size of loose guided, fluid channel or hot loose materials like ash,

Material of steel bars of abrasive resistance, p

350 ° C to 800 ° C.

according to corrosion and transported stainless steel or is placed on containers, sand transported bottom, horizontally by which etc. at temperatures from is chosen are transported according to temperature and with regard to the material properties. Material steel. The profile of the bars can be triangular is also chosen with loose fireproof square, rectangular, whereby the specific profile of transported bulk material and needs are at certain intervals fixed to each other in the shape of grates and these bodies fluidized with their own supply

The advantages of this solution are usually circular or trapezoidal with respect to the fluid transport characteristics. The bars connected by crossbars to the grate are either fixedly attached to the elongate trough or inserted into the fluid cassette of the gaseous medium.

. are as follows:

fluid material resistance high temperature abrasion resistance of the fluid element according to the selected element

- clogging and fouling resistance, self-cleaning ability

- low pressure loss, allowing the use of air or other medium with an overpressure of 5 kPa according to the technology used, especially the sources of compressed air.

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Clarification of drawings

Giant. Fig. 1 shows a device for carrying out a method of fluidizing hot bulk material - a fluid channel having an angular profile; Fig. 2 shows a cross-section of a fluidized bed of a rectangular profile; 11a shows a cross section through a fluid channel of a circular profile.

DETAILED DESCRIPTION OF THE INVENTION

Example 1 (see Figures 1 and 2).

1 / An example relates to the transport of hot sand at a temperature of 400 ° C from a furnace to a refrigeration plant by a fluid path. The hot sand falls from the furnace bed by gravity to one end of a square or rectangular fluid channel located horizontally or with an inclination of 15 °.

The fluid channel 1 of square profile (see FIG. 1) is provided with a system of bars 2 juxtaposed and separated from each other by slots 2. The system of bars 2 divides the inner space of the fluid channel 1 into an upper space 4 for transporting the fluidized bulk material. and to the lower space 6 communicating with the upper space 4 by slots 2, wherein the lower wall 2.5 '* 7 of the fluid channel 1 is provided with at least one gas medium inlet 8 and the upper or front wall 9 of the fluid channel 1 is provided with a bulk material inlet 10. 1, the angular profile (see Fig. 2) shows that the diameter of the upper chamber 4 for conveyance of fluidized particulate material 30 2 ^e j significantly larger than the diameter of the lower chamber 6 to which is supplied pressurized gaseous meduim e.g. air or another suitable gas. The set of bars 2 consists (in Fig. 2) of bars of the same, circular profile, whereby the bar profiles may, in other cases, be angular, triangular, trapezoidal, etc. f.

After certain cross-members, a grate 12 with increased rigidity and greater dimensional stability is achieved.

The function of the described device is as follows:

From a container (not shown) positioned above the bulk material inlet 10, the hot bulk material is moved through the bulk material inlet 10 into the upper space of the square-shaped fluid channel 1 horizontally or inclined up to 15 ° due to gravity.

Here, the hot bulk material is mixed with a pressurized gaseous medium which flows from the lower space 6 of the fluid channel 1 through slits 3 in the rod system 6 into the upper space 4 of the fluid channel

1. Mixing the hot bulk material with the gaseous medium causes it to become fluidized, thereby forming a fluidized layer which is characterized by a reduced specific gravity of the bulk material / gaseous medium mixture, reduced by friction with the inner walls of the fluid channel.

Gravitational pressure of hot and flowing through the fluid channel of the first bulk material entering the feed

2 (/ of the fluid channel χ or in combination thereof with the formation of the fluidized bulk material 10 into the upper space 7, in the material 5, causes longitudinal displacement of the fluidized material 5 through the fluid channel 1. By suitable selection of the rod profile 2.

and the size and shape of the slots 2 is achieved by a continuous flow of the fluidized material through the fluid channel 1 as well as by the restoration of the flow after its possible interruption.

Example 2 (see Fig. 3)

Example 2 relates to an optimal solution for conveying hot 30 coarse-grained ash with a grain size of 0.3 mm to 4 mm and a bulk density

1300 kg / m ³ , at a temperature of 700 ° C from the fluidized bed boiler to the cooling device or its recirculation by fluid way. In this case (see Fig. 3), the fluid channel 1 is formed by a tube of circular cross-section with a diameter of 300 mm. At the bottom of the fluid channel 1, at its bottom 35, along its entire length, there is a cut-out 13 in which the

The fluid cassettes 14 comprising in the upper trapezoidal cross-section of the material, with slots 3, of mm, are incorporated, wherein the system of bars 2 of the fire-retardant rod 2 is crossbars 11, thereby stiffness and larger dimensional fluid media 8.

shows the designated parts are at certain distances is achieved by creating stability. Into a grid with a height of 0.2

4.5 mm of interconnected grate 12 to the raised bottom wall Ί, each inlet of the gaseous circular profile (see FIG.

The fluid channel of the cartridge 14 is at least incorporated

Cross-section through the fluid channel 1 that the clearance of the upper space 4, for transporting the fluidized bulk, is significantly greater than the clearance of the lower space 6, respectively, with the fluid cassettes 14 into which the

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1, a gaseous medium, for example compressed air or other suitable gas, is supplied in this material 5. The set of bars 2 consists (in Fig. 4) of bars of the same, circular profile, whereby the profiles of the bars can, in other cases, be angular, triangular, trapezoidal, etc. , depending in particular on the grain size and bulk density of the transported material.

The operation of the described apparatus is as follows: Hot ash or sand (hereinafter referred to as "hot, loose material") falls from the bottom of the furnace bed by gravity and (see Fig. 3) enters at one end frontally into a fluid channel 1 of circular cross section horizontally or inclined to 15 °. Due to gravity, the hot, free-flowing material finds itself in the upper space of the 4th fluid channel 1 of circular cross-section. Here, the hot bulk material is mixed with compressed air or other suitable gas at a pressure of 15 kPa, which flows from the lower space of it, the fluid cassette 14, through the slots in the rod assembly 6 to the upper space 4 of the fluid channel 1. By mixing the hot bulk material with the gaseous medium, the hot bulk material is fluidized to form a fluidized layer which, with the gaseous medium, reduced friction with the inner walls of the fluid channel and the fluid flow capability 1, in this case characterized by reduced bulk density. material speed 0.3 m / s. The gravitational pressure of the hot bulk material entering the fluid passage 1 and its upper space 4, respectively, in combination with the formation of the fluidized material 5, causes longitudinal displacement of the fluidized material 5X through the fluid channel 1, in the described example at 10 m to the outlet. By suitable selection of the profile of the rods 2 and the size and shape of the slots 3, a continuous flow of the fluidized material 5 through the fluid channel 1 as well as a restoration of the flow of the fluidized material 5 after its possible interruption is achieved.

Industrial applicability

The method and apparatus according to the invention find application in heating and M power plants in handling of bed ash in fluidized bed boilers, in cement production, in foundry, etc.

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Patent No. 122 of the Czech Republic 106 A / 6> 2 00 8 < 7399130 &lt; 7399130 &lt; tb &gt;

Claims (5)

PATENT CLAIMS 1. A method of fluidizing bulk materials, in particular hot materials, for conveying them in fluid channels of a duct having a closed profile, characterized in that the material, after gravity entering the fluid channel, is continuously blown through its entire length of the fluid channel. flow of gaseous medium. 2. The method of claim 1 wherein the gaseous medium is air, inert gas or flue gas. Device for carrying out the method according to claim 1, characterized in that the fluid channel (1) is provided internally with a plurality of bars (2) arranged parallel to one another, longitudinally in the material transport direction and along the length of the fluid channel (1). the rods forming the rod assembly (2), provided with crossbars (11) firmly connected to its individual rods in the form of a grate (12), are separated from each other by slots (3), the rod assembly (2) dividing the inner space of the fluid channel (1) into an upper space (4) for transporting the fluidized bulk material (5) and a lower space (6) connected to the upper space (4) with slots of the fluidized bed provided with at least one gas inlet (8) and an upper wall (9) of the fluid channel (1) it is provided with at least one supply of bulk material (10). Device according to claim 3, characterized in that it is fluidized 3 (/ z \ channel (1) is a square profile. Device according to claim 3, characterized in that the fluid channel (1) is of an oval profile.