GB2156708A - Improvements in or relating to separation - Google Patents

Abstract

A separator 1 includes a main vortex chamber 4 of hollow cylindrical form and a secondary vortex chamber 8 opening out of and circumscribing a part of the main chamber. <IMAGE>

Description

SPECIFICATION Improvements in or relating to separation This invention concerns improvements in or relating to separation, and has reference to the separation of an element from a combination of elements such for example as gas/solid, liquid/solid or liquid/liquid mixtures according to size and/or density.

Separation in the context of the invention includes collection and classification. Thus, for example, in the case of gas/solid combintions, the solid, usually particulate, element may be collected substantially completely from the carrier gas or a specific size fraction or cut of the solid element may be removed from the carrier gas, the solid element thereby being classified.

In our co-pending British Patent Application Nos. 82/30720(2108013) and... (Case No.

4671) we have described novel forms of cyclone separators including the use of a secondary vortex chamber in association with a main vortex chamber, the configuration being such as to allow for the shearing or shaving off into the secondary chamber of the element required to be separated. The main secondary vortex chambers of those separators are generally of circular cross-section overlapping one another in the manner of intersecting circles thus providing intercommunication between chambers. In use the main vortex within the main chamber drives a secondary vortex in the secondary chamber, there being no net carrier fluid flow between the chambers.

An object of the present invention is to provide a separator operating on the same principle but having a different configuration from that of our earlier applications.

Accordingly, the invention provides a separator including a main vortex chamber having an inlet thereto and an outlet therefrom, and a secondary vortex chamber opening out of and circumscribing a part of the main vortex chamber.

The main vortex chamber is preferably of circular section and may conveniently be cylindrical in form. The main vortex chamber may be horizontally or vertically orientated, the chamber being circumferentially relieved at said part to provide communication with the secondary vortex chamber.

The secondary vortex chamber may be of generally circular section and may in one form constitute an annular cylindrical enlargement of the main chamber circumjacent said part.

In an alternative form, the secondary vortex chamber may be of generally circular section, conveniently of cylindrical form with its axis orientated orthogonal to that of the main vortex chamber.

The secondary vortex chamber is preferably closed such that, in use, there is no set flow of a carrier fluid between the main and secondary chambers. The secondary vortex chamber is, however, conveniently provided with means for removing deposits therefrom. Two or more secondary vortex chambers may be provided at different parts of the main vortex chambers.

In operation, a gas/solids, liquid/solids or liquid/liquid combination is introduced tangentially into the main vortex chamber thereby to generate vortical flow therein for the purpose of separting an element from the fluid carrier. The main vortex generates and drives a secondary vortex in the secondary vortex chamber. The element to be separated tends to concentrate in a boundary layer close to the wall of the main chamber. Upon encountering the enlargement constituted by the secondary vortex chamber which circumscribes the main vortex chamber, the element in the boundary layer tends to be thrown outwardly to be entrapped by the secondary vortex from which it is precipitated within the secondary vortex chamber, there being no net flow of the carrier fluid into or out of the secondary vortex chamber.

By way of example only, two embodiments of separator according to the present invention are described below with reference to the accompanying drawings in which: Figure 1 is a diagrammatic end elevation of a first embodiment of separator; Figure 2 is a diagrammatic side view of the separator shown in Fig. 1; Figure 3 is a diagrammatic side view of a second embodiment of separator; and Figure 4 is a diagrammatic plan view of the separator shown in Fig. 3.

Referring first to Figs. 1 and 2, a separator is shown generally at 1 and comprises a horizontally orientated hollow cylindrical body 2 with an inlet and an outlet (not shown), the body 2 constituting a main vortex chamber 4 and being relieved at 6 to provide communication with a substantially annular secondary vortex chamber 8, which leads to a discharge zone 10.

In operation, for example a gas/solids combination is introduced tangentially into the main chamber 4 to create vortical flow therein, the solids content tending to be concentrated in a boundary layer adjacent to the cylindrical wall. The main vortex also generates and drives a secondary vortex within the chamber 8. As the carrier gas flows vortically through the main chamber, from left to right as seen in Fig. 2, it encounters the enlargement provided by the annular secondary vortex chamber. The particles concentrated in the boundary layer are thrown to the outer wall of the annular secondary vortex chamber 8 and are entrapped in the secondary vortex whence they precipitate, the main vortical flow continuing from the enlarged area into the remainder of the main chamber.The main vortical flow may pass to exit or may upon reaching the end of the main chamber reverse upon itself to pass through the outlet at the other end thereof. The outlet may be constituted by a vortex finder tube (not shown) which may itself be provided with a secondary vortex chamber of the same type as described in relation to the main chamber.

It is to be understood that the main chamber may be provided with more than one secondary vortex chamber, each of which being located at a different part of the main chamber.

Referring now to Figs. 3 and 4, the separator 101 of this second embodiment comprises a horizontally orientated hollow cylindrical body 102 with a tangential inlet and an outlet (not shown), the body 102 constituting a main vortex chamber 104 and being relieved at 106 to provide communication with a closed cylindrical secondary vortex chamber 108 the longitudinal axis of which is arranged vertically, that is orthogonal to the axis of the main chamber. The main and secondary chambers thus intersect each other in a cruciform manner.

In use, and by way of example only a gas/solids combination is introduced through the tangential inlet into the main chamber 104 to create vortical flow therein, the solids content tending to be concentrated in a boundary layer adjacent to the cylindrical wall of body 1 02. The main vortex also generates and drives a secondary vortex within the chamber 108 along the axis thereof, that is orthogonal to that of the main vortex. As the carrier gas flows vortically through the main chamber 104, from left to right as seen in Fig. 4, it encounters the enlargement provided by the cylindrical secondary chamber 1 08.

The particles concentrated in the boundary layer are thrown to the wall of the chamber 108 and are entrapped in the seconday vortex whence they precipitate, the main vortical flow continuing through the remainder of the chamber 104 either directly to exhaust or reversing back upon itself for exhaust. More than one secondary vortex chamber may be provided, each being located at a different part along the lengths of the main vortex chamber. The outlet from the main vortex chamber may be in the form of a tube provided with a secondary vortex chamber of the same kind.

It is to be understood that whilst the specific embodiments have been described operationally in relation to gas/solids combination, other combinations may be passed through the separators, for example liquid/solids or liquid/liquid combinations. The separator of the present invention may be used in a collection or classification mode, that is to collect substantially the whole of an element separated from the fluid carrier or to classify the combination whereby a certain size or density fraction is removed from the fluid carrier.

Claims (11)

1. A separator including a main vortex chamber having an inlet thereto and an outlet therefrom, and a secondary vortex chamber opening out of and circumscribing a part of the main vortex chamber.

2. A separator according to claim 1 in which the main vortex chamber is of circular section.

3. A separator according to claim 1 or 2 in which the main vortex chamber is cylindrical.

4. A separator according to any one of the preceding claims in which the main vortex chamber is circumferentially relieved at said part to provide communication with the secondary vortex chamber.

5. A separator according to any one of the preceding claims in which the secondary vortex chamber is of generally circular crosssection.

6. A separator according to claim 5 in which the secondary vortex chamber is an annular enlargement of the main vortex chamber circumjacent to the said part.

7. A separator according to claim 5 in which the secondary vortex chamber is of cylindrical form with its axis orthogonal to the axis of the main vortex chamber.

8. A separator according to claim 7 in which the main and secondary vortex chambers intersect each other in a cruciform manner.

9. A separator according to any one of the preceding claims in which the secondary vortex chamber is closed.

10. A separator according to any one of the preceding claims in which two or more secondary vortex chambers are provided at different parts of the main vortex chamber.

11. A separator substantially as hereinbefore described with reference to Figs. 1 and 2 or Figs. 3 and 4 of the accompanying drawings.