BRPI0805325A2 - Gas-solid suspension reverse cyclic separator and separation method - Google Patents

Abstract

REVERSE CYCLEIC SEPARATOR SUSPENSION SUSPENSION AND SEPARATION METHOD. A gas-solid suspension cyclonic separator is described which comprises a cyclonic chamber with at least one inlet at its top, one solids outlet at its bottom, and two outlet portions of gas fractions, one tube being attached at the bottom. upper pipe and the other pipe fixed at the bottom and with an inner diameter in the range of 1% to 5% of the upper pipe diameter. Also described is the separation method using said cyclonic separator, which makes it possible to stabilize the vorticial flow of the suspension.

Description

CYCLONIC SEPARATOR REVERSE SUSPENSION GAS-SOLID SEPARATION METHOD

FIELD OF INVENTION

The present invention finds its field of application among equipment and methods for separating solid particles from gas-solid suspensions, more particularly among cyclonic separators, where it provides a tangential force component to the gas-solid suspension.

BACKGROUND OF THE INVENTION

Cyclonic separators in different constructional forms are employed in a number of equipment to separate impurities contained in gaseous fluids, such as solid particles or dust, deliquid droplets or the like.

Such equipment is also widely used for separation and removal of air particles or process gases. They are also used as chemical reactor, heat exchanger, for drying granular materials and oil combustion. In oil refineries, they are used to ensure the continuity of the process to obtain products, retaining catalyst and preventing their emission to the atmosphere, avoiding loss and polluting effect, in order to ensure the continuity of the process. The high applicability of cyclonic separators is due to their low operating cost and easy maintenance, as well as their ability to withstand severe temperature and pressure conditions.

Cyclonic separators can be used in several arrangements, in series or in parallel. In some processes, all of the gaseous fluid produced, which will hereinafter be referred to as the solid gas suspension, passes through the separator. In other processes, cyclonic separators may be used as part of the exhaust gas cleaning system.

The particles are separated by a gas-solid suspension centrifugation process. This phenomenon occurs with the induction of a flow-flow within the cyclonic separator due to the significant tangential force component with which the suspension enters the cyclic chamber, which is generally conical-cylindrical in shape. Being larger than gases, solid particles are more likely to remain in the trajectory perpendicular to the vorticial flow due to the centrifugal force, and thus collide with the chamber walls. With collisions, the particles slow down and tend to separate from the flow, falling towards the bottom of the chamber from which they are drawn. The separated gas is drawn through the cyclone outlet tube after a few turns through the chamber and a sharp angle curve toward the upper outlet tube.

Gas-solid suspension cyclonic separators are generally reverse flow type, which are the most traditional for this type of separation. However, unidirectional flow cyclones are also used, especially in applications where the concentration of solids in the suspension is low.

In reverse flow cyclones, the gas outlet tube, usually called a vortex or finder, is fixed and located at the top of the cyclone. During operation there is a need for the full reversal of the vorticial flow of the gas to be aspirated through the outlet pipe.

In unidirectional flow cyclones, also known by the English term "uniflow", the gas outlet tube is located at the bottom of the cyclonic separator, so there is no need for reversal of the vorticial flow.

The unidirectional flow separator has a separation zone length less than that of a reverse flow separator, which is why the unidirectional flow separator is effective only in gas-solid suspensions with low solid concentrations.

Although the reverse flow separator separation zone is larger, it is known that the flow reversal zone is the region where the greatest loss of cyclonic separator collection efficiency occurs due to the instability existing at the flow reversal apex, which is the time when Vorticial flow is reversed from descending to ascending, resulting in lateral displacements of vorticial flow, which causes dragging of previously separated solids and erosion in the walls of the cyclonic separator.

U.S. Patent 4,238,210 discloses a unidirectional cyclonic separator comprising an inner duct forming a flow path common to the central body provided with externally extended vorticialy flow generating propellers. The duct is surrounded by a collecting chamber and the propellers have collecting ends and channels that open through the duct wall into the collecting chamber. Downstream vorticial flow generating propellers are transverse output slits in relation to the gas flow.

As with other unidirectional cyclonic separators, this equipment is only effective for low solids suspensions.

Patent application PI0803051-0, owned by the applicant, discloses a cyclonic separator and a gas-solid separation method with two reverse flow sequential separation zones, in which part of the gas of the high solid concentration gas-solid suspension is separated, and a subsequent unidirectional flow separation zone in which the other portion of the suspension gas, with low desolate concentration, is separated.

The cyclonic separator is provided with two outlet tubes, one axially fixed at the top and one axially fixed at the bottom, respectively generating the reverse-flow and unidirectional separation zones.

The equipment and method described below is an alternative that has advantages for the separation of gas-solid suspensions using reverse flow cyclones over devices and methods known in the art as it avoids the problems of loss of efficiency and erosion in the region. vorticial flow reversal from descending to ascending.

SUMMARY OF THE INVENTION

This invention relates to a solid gas suspension cyclonic separator and a separation method wherein said separator comprises a cyclonic chamber (1) with at least one inlet (11a), an annular space (13) for collecting separate particles and one tube (2) fixed axially to the upper part of the cyclonic chamber (1) and one tube (3) fixed axially to the lower part of the chamber (1) and with an internal diameter in the range of 1% to 5% of the internal diameter of the upper tube (2), both tubes extending axially into the chamber (1).

The gas-solid separation method using the above described separator comprises the steps of admitting the gas-solid suspension into the chamber (1) through the inlet (11a), providing the gas-solid suspension with a tangential force component to separate asuspension; suction the separated gas through the pipe (2) and the pipe (3) simultaneously; remove through the annular space (13) the separated solid particles.

In the present method a gas fraction of greater than 95% is aspirated by the upper pipe (2), the complementary fraction being drawn by the lower pipe (3) in order to maintain the reversal apex inside the pipe (3) and stabilize the ascending vorticial flow, since the descending flow is stabilized by the cyclonic chamber wall (1).

BRIEF DESCRIPTION OF THE FIGURE

The characteristics of the gas-solid cyclonic suspension separator and separation method, object of the present invention will be better understood from the detailed description, associated with the figure below, which is an integral part of this report.

FIGURE 1 presents a perspective representation with the gas-solid suspension cyclonic separator cutter in a two-way configuration, as well as a schematic representation of the separation method using the cyclonic separator.

DETAILED DESCRIPTION OF THE INVENTION

The present invention discloses a solid-gas suspension cyclonic separator and a separation method in a configuration wherein the separator is capable of maintaining the stability of the upward vorticial flow during the separation process.

The cyclonic separator, object of this invention comprises a cyclonic chamber (1) with at least one inlet (11a), an annular space (13) for collecting separate particles and two outlet tubes, one tube (2) being axially fixed at the end. top of the cyclonic chamber (1) and another tube (3) axially fixed to the bottom of the chamber (1), both tubes axially extending into the chamber (1).

In this configuration, unlike the prior art, the lower tube (3) has an internal diameter in the range of 1% to 5% of the upper tube (2) internal diameter.

The Gas-Solid Separation Method using the above-described separator comprises the steps of admitting the gas-solid suspension into the chamber (1) through inlet (11a), providing the gas-solid suspension with a tangential force component to separate asuspension; suction the separated gas through the pipe (2) and the pipe (3) simultaneously; remove through the annular space (13) the separated solid particles.

In the present method, a gas fraction of greater than 95% is aspirated by the upper pipe (2), the complementary fraction being aspirated by the lower pipe (3) in order to maintain the inner reversal apex of the pipe (3) and stabilize vorticial flow.The apex of the reversal of the descending to descending vorticial flow occurs within the tube (3), which is far from the walls, which provides for the reduction of the drag of the already separated solid particles gas and prevents erosion in the separator walls. cyclonic.

The present gas-solid separation method is effective for separating suspensions with solid concentrations greater than 1g / m3 preferably, and may be used individually or applied on the first or second stage of equipment separation using multiple series-connected cyclonic separators.

Said separation method may optionally simultaneously concede the gas-solid suspension within the cyclonic chamber via inlet (11a) and at least one additional inlet (11b) symmetrically positioned to inlet (11a).

This method has the following advantages over the technical state:

i. Substantial reduction of erosion in the lower separator region, caused by the instability of the vorticial flow in the apicurant during the reversal of the downward to upward flow

ii. Maintaining separation efficiency throughout the truck run by the gas-solid suspension; and

iii. Reduced gas drag of already separated solid material.

The description thus far of the present separation method should only be considered as a possible embodiment, and any particular characteristics should be understood as having been described for ease of understanding. Accordingly, they cannot be construed as limiting the invention, which is limited only to the scope of the following claims.

Claims (4)

1.- GAS-SOLID REVERSE CYCLONIC SUSPENSION SEPARATOR, comprising a cyclonic chamber (1), with at least one inlet (11a), an annular space (13), for the collection of separate particulates, and two outlet tubes, one of which tube (2) fixed axially to the upper part of the cyclonic chamber (1) and another tube (3) fixed axially to the lower chamber (1), both tubes with an axial extension into the chamber (1), characterized by the tube (3) ) lower has an internal diameter in the range between 1% and 5% of the pipe internal diameter (2). 2. The solid-gas separation method using the separator described in claim 1 and comprising the steps of admitting gas-solid suspension into the chamber (1) through the inlet (11a), aspirating the separated gas through the pipe (2) and the pipe (3) at the same time and remove in the annular space (13) the separated solid particles, characterized in that a fraction of gas in excess of 95% is drawn up through the upper pipe (2) and the complementary fraction after the pipe (3) ), in order to maintain the reversal apex inside the tube (3) and stabilize the vorticial flow. 3.- GAS SOLID SEPARATION METHOD according to claim 2, characterized in that it separates gas-solid suspensions with solid concentrations greater than 1 g / m3 preferably. 4.- GAS SOLID SEPARATION METHOD according to claim 2, characterized in that it simultaneously admits the gas-solid suspension within the cyclonic chamber through the inlet (11a) and at least one additional inlet (11b) symmetrically positioned at the inlet ( 11a).