Mixing Apparatus And Method

Abstract

The mixable media are passed in uniflow relation through one or more packing elements composed of corrugated lamellas so that a thorough mixing takes place within the packing elements. The corrugations of adjacent lamellas are oriented in different directions while adjacent packing elements are angularly offset from each other.

Description

This invention relates to a mixing apparatus and method.

It is an object of the invention to obtain an efficient rapid mixing of one or more media in a relatively short distance.

It is another object of the invention to obtain efficient mixing of different mixable media.

It is another object of the invention to mix various media together in vessels of large cross-section while achieving a high degree of uniformity.

Briefly, the invention provides a mixing apparatus and method for media which are directed to flow in a uniflow relation. The apparatus utilizes packing elements in the path of flow which serves to mix the various media together both by longitudinal and transverse mixing. Each packing element includes a plurality of lamellas in contact with each other, each of which has corrugations thereon with the corrugations of sequentially arranged lamellas being oriented in different directions. In addition, the corrugations of at least one of two sequentially arranged lamellas relative to the direction of media flow are disposed at an angle to the axis of the apparatus. Also, the adjacent packing elements abut and are angularly offset to each other about the axis of the apparatus to enhance mixing.

The method effects the directing of two mixable media in a single flow direction through the above packing elements so as to achieve a longitudinally and transverse mixing of the part-flows of the media within the elements. This allows the media or mass to be uniformly mixed together or homogenized in a relatively short length.

The basis of the invention is the surprising recognition that the information of packing elements that are of themselves known for counterflow substance-interchange columns, for example, rectification columns, into a mixing apparatus makes it possible to obtain excellent mixing together of fluid media passing through in uniflow. These media include two or more liquids or gases, or a number of gas mixtures, or a liquid with a gas. Also, very viscous media and particles of solid substances that are capable of flowing can be mixed.

The invention is particularly advantageous for mixing apparatus of relatively large diameter, e.g. more than 50 millimeters (mm) such as tubes or vessels, because, even in such contrivances, any lack of uniformity can be quickly corrected by the good transverse mixing achieved by the packing elements.

In one embodiment, perforations are provided at spaced apart positions in the lamellas in order to further improve the mixing effect since part-quantities of the fluid mediums are able to flow through a lamella from one side to the other.

Under certain conditions, it may also be advantageous to dispose an uncorrugated lamella between two corrugated lamella in a filler.

The mixing apparatus according to the invention can be used to carry out various processes such as:

A. For the mixing of two liquids: The neutralization of an acid, for example, a waste acid from pickling baths, by the aid of a lye. The lamella could, for example, consist of synthetic material.

B. For mixing a gas with a liquid: A hydrogenation process; or the chlorination of water.

c. For mixing two gases together: Oxygen and ammonia for producing nitric acid.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

FIG. 1 schematically illustrates a mixing apparatus with two superposed packing elements offset 90.degree. relative to one another;

FIGS. 1a and 1b schematically illustrate views taken along lines 1a-1a and 1b-1b of FIG. 1 to show the orientation of the lamellas in vertically adjacent packing elements;

FIG. 2 illustrates a perspective view of the individual lamellas of a packing element;

FIG. 3a illustrates a lengthwise cross-sectional view of a packing element including a number of equally sized packing elements in contact with each other;

FIG. 3b illustrates a cross-sectional view of the packing element of FIG. 3a; and

FIG. 3c illustrates a perspective view of the packing element of FIGS. 3a and 3b.

Referring to FIG. 1, the mixing apparatus has a cylindrical circular tube 1 for defining a passageway along a longitudinal axis. Alternatively, the tube 1 can be of any suitable cross-section, for example, square. Also, the tube 1 may be set either vertically or horizontally.

The tube 1 has a lower flange 2 for connecting to a pipe supplying a fluid medium a and an upper flange 3 for connecting to an outflow pipe for the mixture, or for the chemical compound c, whereby c is formed of the components a and a fluid medium b introduced into the mixing apparatus through a tube 4. In addition, two packing elements 5a, 5b are superposed in the tube 1 and are offset 90.degree. relative to one another (see FIGS. 1a and 1b).

Referring to FIG. 2, each packing element has corrugated lamellas 6 which adjoin one another to form the element. The element can then be pushed into the tube 1 of the mixing apparatus. As shown, different sizes of individual lamellas are used which increase from the two outsides toward the middle so that a cylindrical shape results. The lamellas, of which only four are shown accurately and the remainder schematically, are made of sheet metal, and are perforated at spaced apart positions to produce an improved mixing together of the fluid mediums in the packing element. In addition, the corrugations of each lamella are of substantially equal slope and the corrugations of adjacent lamellas are directed so that they intersect.

The dots of FIG. 1 show schematically the distribution of the medium b in the medium a within the mixing apparatus. In the case where the mixing apparatus is of very large diameter, it may be advantageous to make each packing element of a number of parts.

As shown, the packing elements 5a, 5b are adapted to the inner cross-section of the tube 1 of the mixing apparatus. Because each two adjacent packing elements 5a, 5b are offset relative to one another, preferably at an angle of 90.degree., excellent distribution is produced and thereby excellent mixing together of the two fluid mediums passing in uniflow (i.e. concurrent) through the apparatus. If, in the case of certain mixing processes, there simultaneously occurs a chemical reaction, then because of the lateral mixing, any maldistribution or irregular course of reaction that might occur is compensated for.

Referring to FIGS. 3a, 3b and 3 c, a packing element as described above can include a number of equally sized part packing elements in contact with each other as shown. The construction of each part packing element is similar to that described above.

The invention thus provides an apparatus in which two or more flowable media can be suitably mixed in longitudinal and transverse directions by directing the media part-flows in a plurality of criss-crossing zig-zag paths through the length of the packing elements. The mixing action obtained is such that a homogenous mixture is easily and rapidly obtained over a relatively short tube length.

It is also noted that, in the case of chemical reactions, the apparatus of the invention permits a considerable improvement in the heat transfer from the flowable media during reaction through the outer walls of the apparatus.

Claims

What is claimed is:

1. A mixing apparatus comprising

a first means for defining a passageway along a longitudinal axis thereof for the flow of at least two mixable media therethrough in concurrent flow relation;

at least two packing elements disposed in said passageway for the flow of the media therethrough, each said packing element including a plurality of lamellas in contact with each other and in parallel relation to said longitudinal axis, each lamella having corrugations thereon with the corrugations of sequentially arranged lamellas being oriented in different directions and with the corrugations of at least one of two sequentially arranged lamellas relative to the direction of media flow being disposed at an angle to said longitudinal axis of said means, and each said packing element being angularly offset to an adjacent packing element about said longitudinal axis of said means at an angle not more than 90.degree.; and

means disposed on one side of said packing elements for introducing at least two mixable media into said passageway to flow through said packing elements in the same direction relative to said longitudinal axis for mixing therein.

2. A mixing apparatus as set forth in claim 1 wherein said corrugations of said lamellas are of substantially equal slope and said corrugations of adjacent lamellas are disposed in an intersecting direction.

3. A mixing apparatus as set forth in claim 1 wherein each packing element includes a number of equally-sized part-packing elements in contact with each other.

4. A mixing apparatus as set forth in claim 1 wherein each said lamella is unperforated.

5. A mixing apparatus as set forth in claim 1 wherein each said lamella is made of a metal weave.

6. A mixing apparatus as set forth in claim 1 wherein each lamella has a plurality of spaced perforations therein for the passage of a flowable medium therethrough from one side to the opposite side.

7. A method of mixing at least two mixable media which comprises the steps of

directing two mixable media in a concurrent flow direction through a common passageway, and

passing the media into and through at least two packing elements within said passageway wherein each packing element includes a plurality of lamellas in contact with each other and in parallel relation to said flow direction, each lamella having corrugations thereon with the corrugations of sequentially arranged lamellas being oriented in different directions and with the corrugations of at least one of two sequentially arranged lamellas relative to the direction of media flow being disposed at an angle to the axis of flow, and each said packing element being angularly offset to an adjacent packing element about said axis of flow, the media being mixed within the packing elements.