In-line mixers were developed to accommodate the requirements of the chemical industries where continuous mixing was required, but there were spatial limitations. In-line mixers were designed to ensure that the continuous mixing was still achieved, as well as taking into account that the mixer more than likely was required to fit into existing pipe work on the site. Using in-line mixers where there are other limitations such as capital investment, and concerns for saving in areas such as operating and maintenance costs, became a most sought after solution, solving many concerns with one application.
There are two types of in-line mixers:
CONVENTIONAL IN-LINE MIXERS
Conventional in-line mixers provide instantaneous mixing, blending or dispersing in a small volume and at a lower horsepower per total process. These types of in-line mixers require an additional power supply in addition to that of the flowing process stream. Using this type of mixer, the retention time is usually in seconds or low minutes, as opposed to in tank mixers, which have higher minutes to hours for retention and blend time to achieve the uniformed concentration throughout.
STATIC IN-LINE MIXERS
AFX specialises in the design and manufacture of static in-line mixers. This particular type of mixer is “motionless”. This description provides an indication of the elements located within the pipe (conduit) part of the mixer, this, the mixing only occurs from the process stream while passing through the mixer. The in-line mixer is flanged and done so the mixer can be bolted into the existing process pipeline. Each mixer is sized to suit the application requirements, and many vary with some having as many as seven inlets for various probes and technical apparatus, other than the injectors which are used for the addition of particular chemicals or streams. In-Line mixers may also be found in the pulp and paper industry in very shear-sensitive applications.
The elements within the mixer are mirror image structures strategically placed for the required mix to take place, as the stream moves through the length of the mixer. These mixers differ from supplier to supplier, but the majority are classified by their operating in flow regimes. Most applications fall into either the laminar or turbulent flow, and all others usually fall in between these two.
Having tried and tested a few many of the previous design means for building the internal elements, AFX has their own design which has proven successful across many broad industries, on very large varying scales; with some having an inner diameter exceeding 600mm, and to as small as 25mm internal diameter. Carefully assessing the process requirements, the in-line mixer is sized to suit and achieve the required results successfully.