Mixer tanks are the backbone of today’s modern liquid fabrication facilities and it is very important to choose the right mixer tank head for the effective blending.
Imagine you are mixing two substances in a glass with a spoon. The shape of the glass determines our hands range of motion and effectiveness of mixing itself. Mixing tanks are just big glasses with different mixing head variations which should be chosen correctly.
As one of the mixing tank head designs, dished head mixer tanks have rounded endings. This blending vessel design offers rigidity and strength. Dished mixing tank head design offers the best overall fluid flow and solids suspension performance, also. The rounded bottom of the mixer vessel helps with the draining of the liquids and provides significantly better solids suspension performance than a flat bottom or cone bottom. In conclusion, dished bottom blending tanks shine out in terms of rigidity, strength, axial flow pattern and drainage of the liquid substances.
The main disadvantage of the dished headed mixer tanks is the increment of the tanks overall size. Since the blending tank height is increased the mixer mill height is also increased correspondingly. This affects the mixer tank fabrication costs in a negative way.
Another type, cone bottom mixer tanks are very common in many industries since they provide successful drainage until every last drop of the product being mixed.
Blending tanks with cone bottom has an ideal geometry for draining high solid content solutions but cone bottom mixer vessels can cause layering, radial flow and heat gradients of the suspension if the solid concentration is more than 5%. This also means that possible liquid-solid separation can happen at the cone bottom of the mixing vessel because of the bottom geometry. Same mill height problem (and increased cost) of the dished head blending tanks is valid for cone bottom designs.
As a third alternative, sloped bottom mixer tanks are designed with a sloped bottom. In this design, accessing the bottom of the tank is easier, ideal for tanks with drainage on the bottom. This type of mixing vessels provide best draining performance without increasing the tank size comparing to the cone bottom. But when the elevation increases it is getting more difficult to the elevated area and also achieve a perfect solids suspension percentage in the mixing tank. Because of that it is very important to choose the right bearing and shaft design for the adaption.
Finally, the last and oldest mixing tank flat bottom design is the flat bottom. These type of mixer tanks are more cost friendly comparing to the other bottom designs. They are broadly used and do not affect the overall mixing performance in a negative way. Since flat bottom mixer tank is designed shorter comparing to the other designs (less height) they require a shorter shaft, also. In addition to the economic advantage of this situation, flat bottom mixing vessel has a neutral shape for solids suspension and liquid movement. As a normal result of being flat, the drainage is not as good as it is in the other mixing tank bottom designs. If the viscosity of the liquid substances is relatively high, the customer can not expect a good drainage of the solution.
As a conclusion, the tank bottom design depends on different factors we explained and it is very circumstantial. It is not possible to say one design surpass the others. As a World-wide mixing tank manufacturer, 3A Makina are eager to recommend the right tank bottom design. We always encourage our potential customers to decide the mixer tank end design altogether. Experience plays a crucial part when deciding the right mixing tank and this is where 3A Makina comes forward.