[01] principle

When it comes to the wet granulator, the first thing that comes to mind is, chop.

In fact, shredding is only 40 percent of the function of the cutter.

We know that when we look down at a wet pelletizer in working state, the materials are distributed in a ring around the wall of the pot due to centripetal force, so we temporarily call this "material belt". So, the cutter, for the material in the pan of the diversion plays a vital role; If we observe carefully, we will find that the material in the material belt is not parallel to do circular movement, but in the place of the knife rolling! Don't tell me that you haven't noticed a phenomenon. If it's not the design of the equipment, it's your carelessness. This roll, when we analyze it, includes two directions: up and down and inside and outside (relative to the material belt, side view).

Roll up and down to ensure that the upper and lower layers of the material are fully mixed, because granulation mainly occurs in the lower layer (mixing between the main paddle and the wall of the pot and the material). This is mainly dependent on the material along the wall of the pot is carried by the main paddle parallel to do circular movement, after the high-speed turnover of the cutter, and the bending of the pot wall with the realization (see, a wet granulator pot shape, and the cutter is related!). .

Similarly, the inner and outer tumbling ensures that one side of the wall of the concentric circular pot (with high granulation strength) rolls to the inside of the material, ensuring that all the internal materials can realize and participate in the granulation; How does this work? We carefully observe that the knife is mostly similar to the structure of flowers, this structure is conducive to the material from the outside to the inside of the diversion. But I have seen some knives designed like a tower, I do not know what purpose.

This rolling up and down, left and right, is the core value of the knife, because cutting, in fact, can be achieved through the wet whole behind; This tumbling effect, described by a fellow lilac gardener as a "burst stream," is appropriate.

Direction of rotation

For our vast preparation r & d workers, what clockwise and counterclockwise, remember it is a bit complicated, remember that the direction of the cutter must be consistent with the direction of material operation.

[03] shape

To be honest, I have seen ten different designs from ten suppliers of domestic equipment, with more designs than the main paddle. I am not engineering background background, really no way to tell you, which design is good, unless one by one use and test. However, from the user's point of view, the effect of detonation flow is the most direct indicator to judge whether it is excellent or not.

Size (diameter and depth), height from the bottom of the pot

This parameter directly affects the efficiency of material tumbling when different loads are loaded. How to design the cutter of a wet granulator to cover the loading volume range of 30-70% as far as possible is the direction that an excellent equipment supplier needs to strive for. A good cutter design, can make the pelletizer up to 20~80% of the load, in this way, to the use of equipment and process batch tolerance, bring a very large flexibility, sometimes, can top two; Specific brand, everybody oneself go investigating.

When using the same granulator for different loads, it is necessary to consider the position of the high and low loading positions of the wet granulator. This is mainly determined by the height and diameter of the cutter. Of course, this is usually fixed. As for the depth, when we look down at the pelleting process, we know that the materials in the pelleting process are mainly concentrated on the outside of the concentric circle, forming a circular "material belt", the width of the material belt, the cutter is not necessary to reach this width; For the same equipment, these parameters are fixed, but it does not matter, the shape of the pharmaceutical cutter and the shape of the pot design is good enough, we can completely adjust the speed of the cutter to make up for the above shortcomings.

In the process of amplification, the ideal state is to use the same loading, at this time, the amplification of your cutter parameters refers to the same principle of linear speed amplification, it is enough; However, when it is necessary to use a different load, it is necessary to consider the speed of the cutter to make appropriate adjustments, to balance the smooth flow of materials and turnover; Therefore, when a equipment supplier tells you how wide a range his equipment load can cover, it is very simple to directly look at the detonation effect of the equipment load in the operation of the highest and lowest bit, and you can basically judge;

Take a look at the picture below. Do you think it is a good design?