KR19980043364A - Inner Circulating Fluidized Bed Gasification Reactor with Bottom Perforated Draft Tube - Google Patents

Abstract

The present invention relates to an internal circulating fluidized bed gasification reactor having a bottom perforated draft tube. More specifically, the present invention is installed in close contact with the draft pipe formed in the lower hole of the reactor injection plate to generate a high calorific value of gas, and at the same time to install a sloped steam injection plate at the bottom of the reactor of the annulus part It relates to an internal circulating fluidized bed gasification reactor that facilitates solid particle movement. By using the gasifier of the present invention, it is possible to generate gas of high calorific value while maintaining the circulation characteristics of the fluidized bed particles.

Description

Inner Circulating Fluidized Bed Gasification Reactor with Bottom Perforated Draft Tube

The present invention relates to an internal circulating fluidized bed gasification reactor having a bottom perforated draft tube. More specifically, the present invention is installed in close contact with the draft pipe formed in the lower hole of the reactor injection plate to generate a high calorific value of gas, and at the same time to install a sloped steam injection plate at the bottom of the reactor of the annulus part It relates to an internal circulating fluidized bed gasification reactor that facilitates solid particle movement.

In general, fluidized bed gasifiers have been used in many chemical processes, such as alternative energy development and waste disposal, in energy conversion and energy recovery processes associated with gasification of coal, sludge or waste polymers and waste tires, and extensive research has been conducted. Is going on. Fluidized bed gasifiers have a consistent yield and composition of gasification product gases due to better heat transfer characteristics and uniform temperature distribution in the reactor compared to many other types of gasifiers. It has the same flow, so it is easy to process solids and has many advantages.

The gasification reactor using such a fluidized bed is mainly intended to obtain calorie gas as a product of solid treatment. Gasification reactors and processes have been researched and developed.

Among them, a gasification reactor using an internal circulation fluidized bed and a gasification process using the same are disclosed in detail in South African Patent No. 857,717. In other words, the inner circulating fluidized bed gasification reactor divides the fluidized bed into two parts by inserting a draft tube into the fluidized bed, and injects them at different fluidizing gas velocities. Allowing the material to flow downward allowed internal circulation in the fluidized bed.

Referring to FIG. 1 attached to the conventional inner circulation fluidized bed gasifier, the conventional inner circulation fluidized bed gasifier is a draft pipe 11 for largely inducing an internal circulation flow, and an air or oxygen injection portion 24 to the draft pipe. ), And a hood 22 for separating gas from the draft tube and the annulus portion.

However, the conventional internal circulating fluidized bed gasification reactor separates the draft tube and the reactor injection portion from the bottom of the reactor so as to induce the smooth circulation of the solid, which causes some of the air or oxygen injected into the draft tube to anneal. As it flows into the russ portion, the calorific value of the gasification product gas is lowered. In addition, the conventional internal circulation fluidized bed gasification reactor has the disadvantage that the injection of steam is not injected from the bottom of the reactor, but rather is injected at the upper part, the smooth movement of the solid particles at the bottom of the injection is limited, industrial scale There was a limit to being used as.

Therefore, in order to solve the problems of the related art described above, it is necessary to develop a gasifier with improved internal circulation characteristics.

Accordingly, the present inventors have made intensive research to solve the above problems, and as a result, the draft tube formed at the bottom of the hole is installed in close contact with the reactor injection plate in the inner circulating fluidized bed, whereby the reactor is an annular part of air or oxygen. By blocking the flow of gas to generate a high calorific value gas at the same time by installing a sloped steam injection distribution plate at the bottom of the reactor, while maintaining the circulation characteristics of the fluidized bed particles, it is confirmed that the solid particle movement of the annulus portion is smooth, The invention was completed.

After all, it is an object of the present invention to provide an internal circulating fluidized bed gasifier with improved flow of air or oxygen and water vapor which are reaction gases.

1 is a schematic diagram schematically showing a conventional internal circulation fluidized bed gasifier.

2 is a schematic diagram schematically showing the inner circulating fluidized bed gasifier of the present invention.

3 is a graph showing a comparison between the solid circulation rates of the inner circulating fluidized bed gasifier of the present invention and the conventional inner circulating fluidized bed gasifier.

4 is a graph showing the generated gas calorific value of the inner circulating fluidized bed gasifier of the present invention, a general fluidized bed gasifier and a conventional inner circulating fluidized bed gasifier.

Explanation of symbols on the main parts of the drawings

10: inner circulating fluidized bed gasifier 11, 12: draft pipe

14: steam injection unit 15: steam injection jet plate

22: off-gas separation hood 24: air or oxygen injection unit

25: air or oxygen injection dispersion plate 26: layered material

30: water vapor generator 40: air or oxygen generator

50: solid sample feeder

Hereinafter, the internal circulation fluidized bed gasifier of the present invention will be described in detail with reference to FIG. As shown in FIG. 2, the inner circulating fluidized bed gasifier 10 of the present invention includes a draft tube 12, a steam injection dispersion plate 15, an air or oxygen injection dispersion plate 25, and a hood 22 which is a gas separator. In the inner circulating fluidized bed gasifier, the bottom perforated draft tube (12) to improve the flow characteristics of the reactor fluid of the inner circulating fluidized bed and the inclined steam injection dispersion plate (15) to provide smooth movement of the solid particles. ).

In the above, the lower perforated draft tube is installed in close contact with the reactor injection distribution plate to block the flow of air or oxygen to the annulus portion, the perforated hole in the diameter is about 15 to 40% of the diameter of the draft tube As a corresponding magnitude | size, it is preferable that it is about 4-8 pieces. In addition, the inclined steam injection dispersion plate is preferably installed to be inclined 45 to 60 ° to the bottom surface of the reactor.

By using the above-described dispersion plate form, it shows the effect of blocking the flow of air or oxygen injected into the draft tube to the annulus, and also does not interfere with the solid circulation since the injection line of water vapor is not required in the annular portion. The device is simple.

When the reactor is applied to the gasification reaction, air or oxygen is injected into the draft tube at a flow rate at which a bubble layer or slagging layer is formed, and water vapor is injected at a flow rate near the minimum fluidization rate to the annular part, thereby moving the bed. Is formed to cause internal circulation. In addition, in the draft tube, a combustion reaction, which is exothermic, occurs, and the heat of consumption of the water vapor gasification reaction, which is an endothermic reaction in the annular part, is supplied to thereby supply necessary heat of the gasification reaction. The gasification product is separated into the larynx of the annulus portion, and this product gas separation device seeks to be separated from the combustion reaction product in the draft tube, thereby improving the quality of the gasification product gas to obtain a middle calorific gas. The off-gas separation hood may be installed on top of the draft tube or the annulus portion.

Hereinafter, the effects of using the present invention gasifier will be described.

In order to compare the solid circulation rate of the internal circulating fluidized bed gasifier having the bottom perforated draft tube according to the present invention and the degree of flow of the reaction gas to the draft tube and the annulus, sand of 300 micro particle size was used as a layer material. The solid circulation rate was measured (see FIG. 3), and the concentration of carbon dioxide in the air used as the reactor gas was investigated by measuring the concentration of carbon dioxide into the draft tube and the annulus. (See Figure 4.)

As shown in FIG. 3, in the internal circulating fluidized bed gasifier of the present invention, the same solid circulation rate as that of the conventional internal circulating fluidized bed gasifier can be obtained by adjusting appropriate operating conditions. At this time, the flow of the reactive gas injected into the draft tube to the annulus showed an effect of decreasing from about 6 to about 11% to about 1%. As a result of applying this phenomenon directly to the coal gasification reaction, the internal circulating fluidized bed gasifier of the present invention under the same experimental conditions as shown in FIG. 4 shows a conventional internal circulating fluidized bed gasifier having a general fluidized bed gasifier or a draft tube type (see : It was found that the calorific value of the generated gas was much higher than that of South African Patent No. 857,717).

As described in detail above, the internal circulating fluidized bed gasifier of the present invention introduces a draft tube of the bottom perforated in close contact with the reactor gas injection plate and an inclined steam injection plate installed at the bottom of the reactor, thereby maintaining the circulation characteristics of the fluidized bed particles. In addition, the flow of the reactor gas in the annulus portion is improved to produce a high calorific value gas.

Claims (4)

In an internal circulating fluidized bed gasifier having a hood, a draft tube, a steam injection dispersion plate, an air or oxygen injection dispersion plate, and a gas separator, A bottom perforated draft tube for improving the reactor flow characteristics of the inner circulating fluidized bed and a sloped steam injection dispersion plate for providing smooth movement of the solid particles. Internal circulating fluidized bed gasifier. The method of claim 1, The lower perforated draft pipe is installed in close contact with the air or oxygen injection dispersion plate Internal circulating fluidized bed gasifier. The method according to claim 1 or 2, The holes perforated in the draft tube have a diameter corresponding to 15 to 40% of the diameter of the draft tube, and are characterized by four to eight. Internal circulating fluidized bed gasifier. The method of claim 1, The inclined vapor injection dispersion plate is installed on the bottom of the gasifier so as to be inclined 45 to 60 ° with respect to the bottom surface Internal circulating fluidized bed gasifier.