RU2573031C2 - Device for providing several burners with fine-grained fuel - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry. Device contains discharge cone (1), equipped with gas-permeable wall parts (6, 6') and two leading to burners pipelines (15) for solid material discharge, with discharge cone (1) being also equipped with locking bottom (4, 22), which, at least, on certain parts is gas-permeable, with locking bottom (4, 22) having supply (17, 23) of fluidising agent.

EFFECT: invention makes it possible to reduce excessive quantities of gas and refuse from separate discharge cones on each pipeline of burner.

10 cl, 5 dwg

Description

The invention relates to a device for supplying several burners with fine-grained fuel of the type indicated in the restrictive part of Claim 1.

In the thermal conversion of solid fuels, such as, for example, various coals, peat, hydrogenation residues, by-products, waste, biomass and volatile dust or a mixture of these substances, at elevated pressure, it is necessary to bring the materials loaded under normal pressure and environmental conditions to thermal conversion pressure level in order to make it possible to feed into a pressurized reactor. Possible thermal methods can be, for example, pressure combustion or pressure gasification using fluidized bed or suspended flow methods.

Dosing of fine-grained fuel from the storage container for transportation to the burners is a prerequisite for the optimal operation of the gasifier.

Possibility of dosing consists in the fact that the contents of the storage container are fluidized in the same way as the fluidized bed (EP 0 626 196 A1 / DE 4108048 A1). This option has the disadvantage that, on the one hand, a greater amount of gas is required for fluidization, and on the other hand, the pressure at the outlet to the transport pipe is significantly determined by the properties of the fluidized bed. The state of fluidization and the thickness of the fluidized bed directly affect the outlet pressure. If we are talking about inhomogeneous, that is, for example, forming fluidization bubbles, then additional pressure and density fluctuations occur, which affect the outlet pressure and, thus, the output mass flow.

Another opportunity to make it possible to unload solid material from the container is to provide a conical geometry of the release, taking into account the properties of the bulk material. The release of solid material from the cone can be supported by the addition of gas through the walls of the housing or along the walls of the cone (US 2006/0013660, US 4941779), and the gas is supplied to the discharge cone through porous elements. The amount of gas is usually less than the amount that would be necessary for fluidization, but enough to eliminate friction against the walls of the bulk material and / or to prevent prerequisites for arch formation. Moreover, as described, the solid material is removed from the layer of bulk material (DE 102008012731 A1, DE 102008014475 A1).

By adding gas to the transport pipeline or a conical exit from the container directly at the beginning of the transport pipeline, it is attempted to establish a constant density of solid material as possible.

The latter method is the preferred option in the described gasification plants, in which fine-grained fuel should be processed both at atmospheric pressure and at elevated pressure. In this case, the required amount of gas as opposed to full fluidization is limited and at the same time they abandon mechanical embedded devices.

With large plant capacities, most often for each burner pipeline its own discharge cone is provided. At large flows of selection of solid material, the amount of gas supplied to ensure unloading through the cone is noticeably less, that the gas addition required to establish the density of transportation in a dense stream, that is, gas must be added to the solid material under the cone for further transportation in a dense stream. In addition, as a rule, additional gas is required in the container to maintain pressure.

The objective of the invention is to reduce the necessary excess amounts of gas and discard individual discharge cones for each burner pipe, without giving up the isolation of the burner pipelines.

This problem according to the invention is solved in a device for supplying several burners with fine-grained fuel from a storage container or hopper equipped with a discharge cone during the thermal conversion of solid fuel in a gasification reactor. The problem is solved due to the fact that the discharge cone, at least in individual sections, is equipped with a gas-permeable wall section and at least two solid material discharge pipelines leading to the burners, the discharge cone also having a closing bottom, which, at least in some sections , is gas permeable, and the closing bottom has a fluidizing means inlet.

The technical results achieved by the implementation of the invention are to reduce the required excess amounts of gas and to exclude separate discharge cones for each burner pipe, and also that the device proposed in the invention provides loosening of arches or blockades and allows adjusting the density of the transported mixture of gas and solid material in the required range of values. It is clear that the gas-permeable wall sections of the discharge cone positively affect the loosening of the fine-grained fuel to be transported, and at the same time several solid material pipelines leading to the respective burners can be loaded with fuel.

Embodiments of the invention follow from the dependent claims. In this case, first of all, it can be provided that the discharge pipes of the solid material in the cone are provided in the direction of gravity under the gas-permeable wall surfaces. Through these measures, it is ensured that each burner conduit can be loaded with suitably loosened fuel.

The execution of the wall of the cone can be carried out very diverse. One of the measures according to the invention is that the gas-permeable wall surfaces generally form a wall surface of a truncated cone-shaped discharge cone element.

To ensure a better installation and, if necessary, a better possibility of replacement in case of damage, the invention provides that the discharge cone is formed of several elements connected to each other, especially in the form of a truncated cone of elements.

In yet another embodiment according to the invention, it can be provided that a truncated cone-shaped element with double walls with a gas-permeable inner wall of a ceramic-metal alloy, perforated sheet metal and the like, is directly correlated with the storage container for fine-grained fuel a similar design for the entire cone is known from the aforementioned US 2006/0013660.

In order to also facilitate and optimize the unloading of solid material, according to the invention it can also be provided that the pipelines for unloading the solid material have an angle directed in the direction of gravity downward of less than 90 ° relative to the vertical axis of the cone, and the possibility of such an implementation may consist in the fact that the pipelines unloading of solid material are located at right angles to the associated wall of the cone.

Depending on the fuel, it may be appropriate when a mixing device located inside is associated with the closing bottom. Such an internal mixing device has several advantages. It can serve to support fluidization by mechanical loosening, make it possible to homogenize a fluidized or loosened bed of solid material and help to reduce the bubbles that can form when the gas is supplied for fluidization.

In yet another embodiment, according to the invention, it is provided that the closing bottom and / or lower gravity discharge region of the discharge cone are provided with pipelines for supplying media, especially for loosening the solid material inside the cone. With this embodiment, additives can be metered into the fuel itself, that is, substances that affect the melting behavior of the ash, for example mineral, organic matter, as well as ash, slag and the like, and the slag can be recycled.

Other details, features and advantages of the invention follow from the following description, as well as from the figure. It is shown on:

FIG. 1 is a schematic sectional view of a discharge cone according to the invention,

FIG. 2 and FIG. 3 shows views in the direction of arrows II / III in FIG. 1 for two embodiments of the discharge cone, as well as

FIG. 4 and FIG. 5 - in FIG. 1 form two versions of the discharge cone.

Shown in FIG. 1, the discharge cone 1 from a technological point of view is preferably divided into segments and consists of an inner cone 2 forming a fluidization region, a solid material discharge region 3 and a cone bottom 4. The discharge cone according to the invention can also be made in the form of a structural part (not shown here), which has the properties according to the invention.

The fluidization region is formed from a sealed outer shell 5, an inner cone 2 located therein, a fluidizing means supply 7 and both connecting flanges 8a and 8b.

Through the connecting flange 8a, the discharge cone 1 is connected to a solid material container not shown in the figures. The wall of the inner cone 2 is made in the form of a permeable wall section 6 for fluidizing means, and the opening angle relative to the vertical or to the direction of gravity (arrow "g") is indicated by the angle α ₁ .

The fluidizing agent flowing through the inlet 7 of the fluidizing means (arrow 9) is distributed in the chamber 10 for distributing the fluidizing means formed between the outer shell 5 and the inner cone 2. From there, it flows through the correspondingly gas-permeable regions of the inner cone 2. The solid material (arrow 11) coming under the action of gravity from above into the discharge cone is loosened by the fluidized means on the inner cone 6 and flows into the solid material unloading zone 3 adjacent to the bottom of the fluidizing means zone 2.

Zone 3 of the discharge of solid material consists of both connecting flanges 12 and 13, the wall 14 of the cone with an opening angle α ₂ to the vertical and the pipeline 15 of the discharge of solid material. Through the connecting flange 12, the solid discharge zone 3 is connected to the connecting flange 8b of the fluidization zone of the discharge cone 1. The loosened solid material enters the solid discharge zone 3 and is discharged through the two shown in this embodiment, FIG. 1 pipe 15 discharge of solid material.

The opening angles α ₁ and α _{2 of the} corresponding walls of the cone have different values in order, for example, to vary the structural height of the discharge cone 1.

Through the connecting flange 13, the solid discharge zone 3 is connected to the connecting flange 16 of the bottom 4 of the cone. The bottom 4 of the cone has an additional supply 17 of fluidizing means. The fluidizing agent (arrow 9a) is introduced into the solid material unloading zone 3 through the gas distribution device 18 of the bottom 4 of the cone. The gas distribution device 18 in FIG. 1 is preferably shown as a centrally located nozzle, whereby the arches or blockages are loosened and the density of the transported gas / solid mixture can be set in the desired range.

The gas distribution device 18 can be made, for example, in the form of one or more porous elements in the bottom, a hole distributor, or a multi-nozzle device. Which of the options should be used is determined in a particular case to a large extent by the flow properties of the solid material to be transported.

In FIG. 2 shows a schematic view of an embodiment of the invention with three outlets for solid material discharge pipelines 15, centrally located in the bottom of the gas distribution device 18 and the inner cone 6, which in this example is completely formed from a material permeable to the fluidizing means. Through the connecting flange 8a, the discharge cone 1 is fixed to the outlet of the container through a threaded connection.

In FIG. 3 shows, as in FIG. 2, a schematic view of an example embodiment of the invention, with the difference that the inner cone 6 ′ is provided with material permeable to the fluidizing agent only on individual segments. If only the flow properties of the material to be transported allow this, then due to the reduced surface, the supplied amount of gas can be further reduced.

In one preferred embodiment, the impermeable regions of the inner cone 6 are made of steel or stainless steel and are joined to permeable surfaces consisting of a sintered metal alloy, for example by means of welded joints. Moreover, the fluidization zones located only on separate segments are preferably located directly above the outlets of the solid material discharge pipelines 15 to ensure a stable material supply.

Furthermore, in this preferred arrangement, the non-fluidized regions lie respectively opposite the fluidized regions, so that the risk of blocking due to arching can be minimized. Thus, by manufacturing segments of the inner cone 6 from a material impermeable to fluidizing means, the gas flow can be further reduced without damaging the discharge.

In FIG. 4 and FIG. 5 shows two variants of the device according to the invention, the functionally identical elements having the same reference signs.

In the embodiment of FIG. 1-3 in FIG. 4, an agitator 19 is further shown in the solid material unloading region 3 ′, the drive shaft 20 of which is passed through a shaft seal 21 through a flange bottom 22 that is mounted on the flange 13. In addition, gas inlets 23 are provided, which, for example, are equipped with a nozzle 24 to ensure optimal gas distribution. It can also be made by means of an open pipe in the form of a typical bell-shaped nozzle for a fluidized bed or as a porous material.

In FIG. 5 shows an embodiment in which, for example, an additive can be mixed in, for which the solid material discharge area 3 is equipped with a pipe 25 for supplying solid material. The supply of solid material is indicated by arrow 26. The supply of solid material may be more favorable when the supply, as shown in FIG. 5, is located in the area of the stirrer 19.

Of course, the described embodiments of the invention can be changed in many respects without deviating from the main idea. So, both the solid material unloading pipe 15 and the solid material loading pipe 25 can be located in different places and in different quantities, depending on the design, the gas supply pipes can also be double-walled in order to supply solid material in the center, and from the side of the outer wall is gas.

LIST OF REFERENCE NUMBERS

1 discharge cone

2 fluidization area

3 solid material discharge area

4 cone bottom

5 outer shell

6, 6 ′ gas-permeable wall section (inner cone)

7 fluidizing fluid supply

8a, 8b connecting flange

9, 9a arrow

10 fluidizing medium distribution chamber

11 arrow

12 connecting flange

13 connecting flange

14 cone wall

15 solid material discharge pipe

16 connecting flange

17 fluidization supply

18 gas distribution device

19 stirrer

20 drive shaft

21 shaft seal

22 trailing bottom

23 gas supply

24 nozzle

"g" direction of gravity

Claims (10)

1. A device for supplying several burners with fine-grained fuel from a storage container during the thermal conversion of solid fuel in a gasification reactor, the storage container being equipped with a discharge cone, characterized in that the discharge cone (1) is equipped with a gas-permeable wall section (at least in some sections) ( 6, 6 ′) and at least two solid material discharge pipes (15) leading to the burners, the discharge cone (1) also having a closing bottom (4, 22), which is at least e in sections, is gas permeable, the closing bottom (4, 22) has an inlet (17, 23) of fluidizing means. 2. The device according to p. 1, characterized in that the pipelines (15) for unloading the solid material are provided in the cone (1) in the direction of gravity under the gas-permeable wall section (6). 3. The device according to claim 1, characterized in that the gas-permeable wall sections (6) as a whole form the wall surface of the discharge cone element (2) made in the form of a truncated cone (1). 4. The device according to claim 2, characterized in that the gas-permeable wall sections (6) as a whole form the wall surface of the discharge cone element (2) made in the form of a truncated cone (1). 5. The device according to one of the preceding paragraphs, characterized in that the discharge cone (1) is formed of several elements connected to each other (2, 3, 4), primarily made in the form of a truncated cone of elements. 6. The device according to one of paragraphs. 1-4, characterized in that a double-walled element made in the form of a truncated cone with a gas-permeable wall section (6) of a ceramic-metal alloy, perforated sheet metal is directly correlated with the storage container for fine-grained fuel. 7. The device according to one of paragraphs. 1-4, characterized in that the pipelines (15) for unloading solid material are located on the cone under an angle less than 90 ° directed in the direction of gravity downward relative to the vertical axis. 8. The device according to claim 7, characterized in that the pipelines (15) for unloading the solid material are located at right angles to the associated wall (14) of the cone. 9. The device according to claim 1, characterized in that the mixing device (19) located inside is associated with the closing bottom (22). 10. The device according to claim 1 or 9, characterized in that the closing bottom (22) and / or located in the direction (g) of gravity, the lower region of the discharge cone (1) is equipped with pipelines (23, 25) for supplying media, especially for loosening solid material inside a cone or for feeding additives.

Images