Drying from Liquid to Powder in ONE STEP
Customers looking for dryers to recover solid materials from liquids and produce powders have a variety of applications, and consequently, a variety of needs. A CD Dryer can handle the jobs of concentrating, drying and powdering, saving factory space and the costs necessary for several types of machinery. With the CD Dryer, all kinds of organic and inorganic materials can be made into powders.
ABOUT POWDERS
There is not a definitive distinction between granules and powders. In general, however, a collection of solids with particles sized less than 1mm is considered a powder, while one with somewhat bigger particles is considered granulated material. Although each particle in a powder is a solid, the collection itself has properties similar to liquids.
The size and shape of the particles in a powder, and the form they will take when collected is determined during production.
HOW POWDERS ARE PRODUCED
The production of powders can be done by 3 main methods: pulverization of solids into smaller particles, deposition from a solution, or by atomization. These 3 main methods can be further broken down into 10 sub-methods.
Production by Pulverization of Solids
The most common way of making a powder is through pulverization. Compression, impact, and friction can all cause a solid to break down into smaller particles.
| Mortar and Pestle | Stamp Mill | Ball Mill | Jet Mill |
|---|---|---|---|
| For making small amounts of powder, the friction from a mortar and pestle causes pulverization | The impact of a hammer striking a solid causes pulverization. | Material is placed inside a rotating container with balls. The impact caused by the balls during rotation breaks down the material. | The spray of high pressure gas on materials causes the material particles to collide with each other and break into smaller pieces. |
Production by Deposition from a Solution
Material dissolved in a liquid is allowed to separate from the liquid to form a powder. Deposition is a good process for producing a powder with uniformly sized and shaped particles
| Drying Method | Ion Reaction Method | Hydrolysis Method |
|---|---|---|
| Liquid containing powder material is quickly dried, leaving the particles behind. This is the principle behind the CD Dryer. | Liquid containing the desired material is mixed with another substance, causing a chemical reaction and forming an insoluble sediment. Finer powder can be made by raising the concentration of the solution. | Metal alkoxides and water are used to obtain powder. Using the conjugate base of an alcohol for hydrolysis, fine powder crystals can be obtained. |
Production by Atomization
Atomization is conversion to fine particles or a fine spray. Solids are not pulverized, but powder is directly formed from molten material. Rapid cooling causes coagulation and round particles are formed.
| Gas Atomization | Disk Atomization | Water Atomization |
|---|---|---|
| High pressure gas jets are directed into a flow of heated solution, dispersing it. Powder is formed during the rapid cooling of the solution. | A spinning disk scatters heated solution, which cools to form a powder. | Water jets are used to disperse the heated solution, which quickly cools to form a powder |
Powder Production on the CD Dryer
Of these 3 main methods, the Nishimura Works CD Dryer produces powder by the Deposition from Solution method. The major benefits of using a CD Dryer are listed below:
Benefits of Using a CD Dryer
・Drying capacity is about twice the capacity of a traditional drum dryer (of our make.)
・Heat loss is low and an 80 to 85% energy efficiency can be achieved.
・The light weight of the disk means a short heat-up time (only 5 minutes.) The CD dryer can begin drying soon after start up.
・A speedy drying time of only 3 to 60 seconds means less chance of heat damage to materials.
・Liquids are dried instantly, shortening the process of powderizing.
