The Difference Between Dry And Wet Granulation

Are you searching for difference between dry and wet granulation machines? Here’s everything you need to know about the difference in these processes and when it’s appropriate to choose one over another.

In the wet granulation process, the dry primary powder is mixed with a liquid solution. This liquid solution is a volatile solvent. The solvent needs to be volatile as it needs to be removed later by drying. Also, it needs to be non-toxic. Some of the common solvents used in this process include ethanol and water, among others. These liquids can be used alone or in various combinations.

Pan grnaulator and rotary drum fertilizer pelletizer adopt wet granulation.

Manure Pellet Machine in Organic Fertilizer Plant
Manure Pellet Machine in Organic Fertilizer Plant

As far as the liquid solution is concerned, it can be solvent based or aqueous based. In some cases, water is not enough and in such situations, a liquid solution containing a binder is used. Once powder has become denser, the process of granulation is started. As far as this process is concerned, its complexity depends on the powder characteristics as well as the equipment used in the process. In the typical method, a sieve is used where the wet mass is forced through this sieve for production of organic fertilizer granules or compound fertilizer manufacturing.

Rotary drum granulator for making compound fertilizer pellets
Rotary drum granulator for making compound fertilizer pellets

These wet granules are then dried in order to produce the final product. In the subsequent stages, the granules are broken apart. Wet granulation is often preferred as many active substances cannot be processed through direct compressing which is nothing but dry granulation. Thanks to the use of modern technology, there is absolutely no problem with wet granulation method is even when used with sensitive active substances.

As far as the dry granulation method is concerned, it should be clear from its name that no liquid solution is used in this process. This is typically due to the reason that the product that needs to be granulated is too sensitive to heat or moisture or does not compress effectively. Making granules without use of moisture is a challenging process. It typically involves compaction and reduction of the size of the mix in order to produce a free flowing granular blend. In this process, the powder particles are put under high pressure using various machines. This processing can be done in various ways that involves use of various machines such as a roller fertilizer granulator. All these methods have their own advantages and are used for different kinds of materials. In short, a variety of machines and processes are used for dry granulation method of processing.

Double Roller Fertilizer Granulator Machine
Double Roller Fertilizer Granulator Machine

When it comes to choosing between these 2 processes, it should be clear by now that dry granulation is much more challenging and complex process as compared to wet granulation. This is why, wet granulation is the preferred method of processing though in some cases, dry granulation becomes necessary due to the active substances being too sensitive to the moisture or due to other problems. Various types of machines are used for both these processes. The machines need to be chosen carefully and after thorough research as even a slight mistake can lead to huge problems in the granulation process.