FI78245C - FOERFARANDE OCH APPARAT FOER AVSKILJNING AV EN TYNGRE PARTIKELFRAKTION UR EN PARTIKELBLANDNING. - Google Patents

Description

78245

A method and apparatus for separating a heavier particle fraction from a solid particle mixture.

For example, an apparatus for particulate fractionation and particulate matter is used.

The present invention is directed to a method for separating a heavier particle fraction from a solid particle mixture.

The present invention also relates to an apparatus for separating a heavier particle fraction from a solid particle mixture.

It is known to divide particle mixtures into fractions according to particle size, for example by sieving using different density screens. It is also known to facilitate the screening process by causing the screen or particles to be screened to vibrate. It is also known to divide particle mixtures into different fractions by means of an oscillating, inclined surface. In this case, the particle mixture is generally led to an open inclined surface, where the vibration causes the heavier particles to flow downwards and the light particles to travel upwards, respectively. Classifiers of this type are disclosed in U.S. Pat. No. 3,473,657 and EP 223,639.

However, particle fractionators 2 78245 of the type mentioned above are not suitable for separating very fine solids or those which tend to clog the screens. In addition, highly dusty or dirty solid mixtures, such as carbon-ash mixtures, cannot be classified in open screens.

Carburettors always leave fine material with the gas, the so-called fly ash and among it fine unburned coal. To improve efficiency, non-combustible carbon should be returned to the carburetor. The fine material can most often be separated from the product gas, for example with a secondary cyclone, and returned to the carburetor. But still, the ash itself must be able to be removed from the system in some way. If the ash can be removed from the system without containing significant amounts of carbon, the efficiency of the plant will increase substantially. Separation of ash and carbon with cyclone separators is remarkably complicated and expensive.

It is an object of the present invention to provide a simpler and better method and apparatus for separating a heavier particle fraction from a solid particle mixture. It is a further object to provide an apparatus and method which are particularly suitable for the continuous classification of hot finely divided materials.

The method according to the invention is essentially characterized in that the particulate mixture to be classified is passed as an upward flow in a substantially vertical chamber and subjected to vibration or vibration motion in the chamber. particles accumulate, solid particles are removed.

The device according to the invention is characterized in that it comprises a substantially vertical chamber with an inlet for the particle mixture, a first outlet at the bottom of the chamber for a heavier particle fraction and a second outlet at the top of the chamber for a lighter fraction and means for vibrating or vibrating the particle stream. The vertical chamber is preferably formed from the central part of the knee fitted in the tube, from the lower part of which heavier particles can be removed.

The invention will now be described in more detail with reference to the accompanying drawings, in which

Figure 1 shows a classifier according to the invention

Figure 2 shows a schematic diagram of an application of a classifier according to the invention.

Figure 1 shows a classifier 3 connected between pipes 1 and 2. The classifier forms a knee between pipes 1 and 2. From the tube 1, a solid particle mixture, such as an ash-carbon mixture, is led through the inlet opening 4 to a vertical chamber 5. Means 6 and 7 cause vibration in the particle mixture in the chamber. As a result of the vibration, the heavier ash fraction tends to flow to the lower part of the chamber and the light carbon fraction tends to rise to the upper part of the chamber. The lighter fraction containing less ash exits the chamber through the outlet 8 into the pipe 2. The knee is fitted to the pipes 1 and 2 by means of flexible sealing and bellows members 10 and 11 which prevent dust from penetrating the knee and vibrations from passing through the pipes into other structures. continuously or, if necessary, through the opening 9.

Figure 2 shows a preferred embodiment of a classifier according to the invention. After the flow-through cyclone 13, a secondary cyclone 14 is arranged in the circulating bed carburetor 12, which separates most of the very fine solid particles remaining in the gas. From the bottom cone 15 of the secondary cyclone, the particles are led back to the carburetor through tubes 1 and 2 from the orifice 16. The particles separated in the secondary cyclone contain for the most part fine unburned carbon, but also ash-reacted ash. The ash is removed from the carburetor mainly through the ash removal pipe 17 at the bottom of the carburetor 4 78245. Through the opening in the bottom of the carburetor, ash particles larger than 1 mm and somewhat smaller particles are mainly removed. This results in the formation of a suspension in the carburetor containing a large number of particles larger than 100, which is advantageous in order to obtain a circulating suspension of the carburetor sufficiently dense. Very small ash particles <100 μm pass through the flow cyclone 13. The secondary cyclone is again able to separate particles of 10 to 100 μm.

A knee 5 is arranged in the pipe 1 after the bottom cone 15 of the secondary cyclone, which acts as a classifier. The center of the knee forms a vertical chamber 3, which is connected to means, e.g. electrically operated devices, which cause the mixture of particles flowing in the chamber to vibrate. Surprisingly, it has been found that since the carbon particles are lighter than the ash, it is thus possible to distinguish the heavier ash particles therein from the stream of particles consisting mainly of carbon. The lighter carbon particles tend to move upward faster in the vibrating suspension than the heavy ash particles. The ash particles accumulate at the lowest point of the knee and can be easily removed from there continuously or intermittently through 9.

By the method described above, particles of the same size but different specific gravity can be separated from each other. Fluidization, which has also been used to classify particles, is not required in this method, but can, of course, be used to enhance classification if required.

The invention is not intended to be limited to the embodiment described above, but various embodiments are possible within the scope of the inventive idea defined by the claims.

Claims (10)

A method for separating a heavier particle fraction from a solid particle mixture, characterized in that - the particle mixture is passed in an upward flow in a substantially vertical chamber, - the particle mixture is vibrated or vibrated particles are removed from the lower part of the chamber where the heavier particle fraction accumulates. A method according to claim 1, characterized in that - the particle mixture is made to flow in a substantially vertical chamber formed in the middle of the knee fitted in the tube and in that - heavier particles are removed from the lower part of the knee. A method according to claim 1 or 2, characterized in that - hot solid particles above 600 ° C separated from the gas leaving the circulating bed gasifier are made to flow through a substantially vertical chamber, - heavier ash particles are removed from the lower part of the chamber, and back to the carburetor. A method according to claim 1, characterized in that the particle mixture is subjected to a lateral vibration or vibration motion. 6 78245 Device for separating a heavier particle fraction from a solid particle mixture, characterized in that the device comprises a substantially vertical chamber (3) with an inlet (4) for the particle mixture, a first outlet (9) at the lower end of the chamber for a heavier particle fraction and a second outlet at the upper chamber for the particle fraction and means (6,7) for subjecting the particle stream to vibration or vibration motion. Device according to claim 5, characterized in that - the vertical chamber (3) is formed by a central part (3) of a knee (5) arranged between two tubes (1,2), the chamber inlet (4) being formed in the lower part of the chamber and connected upwards the lower end of the directed tube (1) and the second outlet (8) of the chamber are formed at the upper end of the chamber and connected to the upper end of the second downward tube (2), and - the first outlet (9) of the chamber is arranged substantially at the lowest point of the knee (5). Device according to Claim 6, characterized in that the inlet and outlet openings (4,8) of the chamber are connected to the pipes (1, 2) by flexible seals (10, 11). Device according to Claim 5, characterized in that means (6, 7) are arranged at the upper and lower ends of the chamber for producing lateral or transverse vibration. Device according to Claim 5 or 6, characterized in that - the vertical chamber (3) or the elbow (5) is arranged in the carburettor (12) in a return pipe (1,2) which connects a particle separator (13, 14) arranged in the carburettor. a bottom cone (15) and a particle return port (16) fitted to the bottom of the carburetor to separate the fine ash from the fine carbonaceous material to be recovered. 7 78245 Device according to Claim 9, characterized in that a knee (5) is arranged in the circulating bed carburettor between the secondary cyclone (14) of the return pipe (1,2) and the carburettor to separate the fine carbon from the fly ash before returning the material to the lower part of the carburettor. > β 78245