PT94193B - CYLONE TYPE SEPARATOR WITH WATER COOLED WALLS - Google Patents

Abstract

Separator/cyclone consisting of a series of parallel tubes. In one zone, the tubes form a cylinder, in another they curve radially inwards so as to form the top of the cyclone, and in the base they curve to form the collector. The water passes through the tubes, cooling the separator.

Description

WATER COOLED WALLS - STEAM

DESCRIPTIVE MEMORY

J Background of the Invention

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This invention relates to a cyclone separator, in particular, a separator for separating solid fuel particles from gases discharged from a combustion system or the like.

Conventional cyclone separators usually have a collector attached to the lower end to collect the solid particles from the separator. The separator and the

The collector has, in general, a monolithic outer wall of an abrasion resistant and insulating refractory material so that the outer surface is kept relatively cold. Typically, these walls are formed by an outer metallic shell and two insulated insulating refractory materials to prevent the outer surface from reaching high temperatures and reducing heat losses.

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However, in order to obtain adequate insulation, these layers must be relatively thick, which means that the separator and collector have a high volume, weight and cost, requiring relatively long start-up and closing times and well controlled so that there is no fragmentation of the refractory. In addition, the outer metallic surface of these devices cannot be completely isolated from the outside as this would raise its temperature to about 1500 ° F which is much higher than the maximum temperature tolerable by the metallic surface.

Most conventional cyclone separators still require distribution networks covered by refractories that are relatively expensive and high temperature expansion joints between the reactor and the cyclone and between this and the heat recovery section, which are quite sophisticated and expensive. In addition, conventional separators built in the above manner require relatively long heating times before they can be put in line with other equipment in order to eliminate the early fragmentation of the refractory walls, which is inconvenient and increases the cost of the process. There is also another type of cyclone separator that may need an independent network of tubes at the top, which again makes its cost more expensive.

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summary

The object of the present invention is, therefore, a cyclone separator in which heat losses are reduced and the need for internal insulation with a refractory is minimized.

A cyclone separator of the above type is also the object of this invention for which the volume, weight and cost of the separator are much lower than that of conventional separators,

A cyclone separator of the above type is also the object of the present invention, for which the needs of distribution networks covered by refractories and high temperature expansion joints between the reactor and the cyclone and between this and the heat recovery section are minimized , which are quite expensive.

A cyclone separator of the above type is also the object of the present invention, formed by heat exchange tubes covering the conical, cylindrical and roof sections of the separator so that the circulation of the mixture of steam and water in the tubes can be maintained through an external pump or without it in the case of a naturally circulating boiler.

In order to fulfill these and other objectives, the separator of the present invention consists of a cylinder, a roof and a collecting section which are formed by a series of tubes arranged parallel to each other. At the ends of the tubes, there are ring heads for the passage of cooling water, or steam, through the tubes. An inner cylinder inside the separator cylinder forms an annular space in which the mixture of gases and solid particles is received with the objective of separating the solid particles from the gases by centrifugal forces. The solid particles fall into the collector section a of the separator to be discarded or recycled, while the gases pass, upwards through the separator, to an external heat recovery equipment.

Brief Description of the Drawings of the Figures

The above brief description, as well as other purposes, characteristics and advantages of the present invention, is presented in more detail for the preferred arrangement, but by no means less illustrative according to the present invention in conjunction with the attached figures: Figure 1 diagram of the cyclone separator of the present invention showing a part of the tubes that form the outer cylinder, and Figure 2 cross section along line 2-2 of Figure 1.

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Preferred Arrangement Description

When referring to figure 1, number 2 refers, in general, to the cyclone separator of the present invention which includes an upper section forming the roof 4, a lower collecting section 6 with a conical shape and an intermediate cylindrical section 8, a head in ring 12 y placed on

I lower part of the collecting section 6 and a ring head 14 already placed above the roof 4. y

Each of sections 4, 6 and 8 are formed by a group of tubes 20 arranged around the separator 2 in a continuous and spaced manner, parallel to each other, connected at the lower ends of the ring 12 and at the ends!

I greater than ring 14. '

The cylindrical section 8 differs from an inlet 24 which gives access to the interior of the cylinder, and which can be formed by bending a part of the tubes 20 out of the plane of the cylindrical section 8 as shown in more detail in US Patent No. 4.74 37.337 granted to the applicant of the present invention and whose mention is made for reference.

The roof section 4 is formed by bending the tubes 20 radially inward to a certain angle marked by 20a, and then upwards by an angle marked by 20b.

Inside the cylindrical section 8 there is a tube, or barrel, 28, formed by a solid metallic material, for example stainless steel, which has an upper part that extends above the roof section 4. The tube 26 extends to slightly below the constriction formed by the folded pipe portions 20a and 20b. Between the outer surface of the tube 26 and the inner surface of the cylindrical section 8, there is an annular zone 28, for the reasons described below.

As can be seen from Figure 2, tubes 20 are arranged with a certain spacing, with fins 30 which run from top to bottom being welded to them between adjacent tubes. The formed structure is placed between an interior refractory material 32 and an exterior insulating material 34. The refractory material 32 can be a relatively thin layer of a high conductivity refractory and the insulating material can be any usual insulating material.

A naturally circulating steam barrel 40 is connected, via tube 42 and branches 42a and 42b, to the upper ring 14. A descending tube 44 and branches 44a and 44b connect barrel 40 to the lower ring 12. Thus water from the barrel is transported by the downward tube 44 to the ring 12 by gravity and passes upwards from this ring through the tubes 20 by convection) ·

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natural, as described below.

It is assumed that the separator 2 of the present invention is part of a boiler system that includes a fluidized bed reactor, or similar Cinexistent in the figuresj placed in the vicinity of the separator. In operation, inlet 24 receives hot gases from the reactor which hold a certain amount of solid particles from the fluidized bed fuel. The inlet 24 is constructed so that the gases containing the particulate material enter in a direction close to the direction tangent to the chamber 28, thus circulating around the chamber. The suspended solid particles are therefore projected, by centrifugal forces, against the inner wall of the cylindrical section 8 where they accumulate and fall by gravity in the collector 6. The remaining gases in the chamber 28, relatively clean, are prevented by the roof 4 of they come out from the top, so they do it from the bottom of the tube 26. The gases pass through the tube 26 before being led through the top of the tube to external equipment for further processing.

Water or steam is passed from keg 40 through tubes 44, 44a and 44b to the lower ring 12 from which it goes upward through convection through tubes 20 through collecting section 6, cylindrical section 8 and the roof 4. The heated water or steam passes to the upper ring and, through tubes 42a, 42b and 42, back to the barrel

40, The water thus keeps the separator 2 at a relatively low temperature.

A number of advantages result from the arrangement of the present invention. For example, heat losses are reduced and the need for internal refractory insulation is reduced.

In addition, the volume, weight, and cost of the separator of the present invention is much less than that of conventional separators. The need for distribution networks covered by refractories and high temperature expansion joints between the reactor and the cyclone and between this and the heat recovery section, which are quite expensive, is also minimized. The need for an additional network of tubes at the top of the separator is also eliminated.

It is clear that changes can be made to what has been described above without departing from the scope of the present invention. For example, the inner tube 26 can be formed by tubes with water passing through it in a similar way to that used in separator 2 and this tube can be connected to the circuit that includes the barrel 40. Or, a forced circulation system can be used in place of the natural circulation system described above, in which case a pump 50 would be placed on line 44 receiving the fluid from the barrel 40 and pumping it through branches 44a and 44b and tubes 20.

Other modifications, alterations and substitutions are implied in the previous description and in certain conditions even some parts of the invention, even if employed without the corresponding use of the other parts. It is therefore appropriate that the appended claims are constructed loosely and in a manner consistent with the scope of the invention.

Claims (9)

R_e_I_Y_I_n_d_i_ç_a_ç_o_e_s 1- A cyclone separator, characterized by the fact that it comprises a series of tubes arranged in circumference, parallel to each other, folded at the top radially to form the top of the cyclone, and curved at the bottom so as to form a section collecting cone, a ring connected to at least one of the ends of each of the said tubes, and the means for delivering water or steam to said ring, so that water or steam circulates through said tubes, in order to cool said outer cylinder. 2- A separator, as claimed in claim 1, -9fc · ΐ, ι Si characterized by the fact that it also comprises an inner cylinder coaxial with said tubes, extending out of said top of the cyclone, so as to form an annular space to receive said gases and solids forming an outlet for said gases . 3- A separator, as claimed in claim 1, characterized by the fact that it also comprises means for receiving, through a tangential entry, in said ring chamber, the gases containing the solid particles, and directing them against the interior wall of the said cylinder, in order to separate the solid particles from the gases, by centrifugal forces, the separated gases being removed through said inner cylinder, and the separated solids removed by the base of said outer cylinder, to be discarded or recycled. A separator, as claimed in claim 1, characterized in that said tubes are spaced apart, in a certain relationship. A separator, as claimed in claim 4, characterized in that it further comprises blades joining adjacent tubes to form a structure capable of containing gases. 6- A separator, as claimed in claim 1, characterized in that it also comprises refractory means over the entire inner surface of said tubes, and the insulation around the outer surface of said tubes -10 tubes. 7. A separator as claimed in claim 1, characterized in that the said circulation means comprise a steam drum and the means for connecting said drum to said connecting ring, and to the other end of each of said tubes, for circulation of water and steam, through said steam drum and said tubes. 8. A separator as claimed in claim 7, characterized in that the water and the said steam circulate through said tubes and steam drum, by natural circulation. A separator as claimed in claim 7, characterized in that it further comprises the means for pumping said water and steam through said tubes and steam drum.