Double shaft paddle mixer, also known as pug mill, is an industrial mixer reserved for especially heavy-duty processing application, such as those found in the mining industry where small amounts of liquid additives are mixed into raw materials. Its high-speed choppers and twin shafts result in excellent homogeneity in the inished product. It meets the needs of high output, large scale mixing of raw materials.
It has a continuous mixing process which offers an economical alternative to batch mixing when considerations include high volume production, volume flexibility, lower energy costs, and / or limited space.
- Blending dry ingredients
- blending liquid(s) with dry ingredients
- Liquid coating of dry materials
- Paste / sludge / slurry blending
All powder-type products with all shapes and densities can be mixed in double shaft paddle mixer.
Our double shaft paddle mixers are manufactured of carbon steel, or stainless steel with commercial or sanitary finishes. Abrasion resistant steel and / or welded hard-facing can be incorporated for high wear applications. Each of the mixer is designed and manufactured to the specific blending application. Custom mixers are available.
- Mixing takes place in a very short time. An average mixing cycle for dry mixing can be as follows: filling 20-30 seconds, mixing 40-60 seconds and discharging 10-20 seconds. This gives a total cycle time of 1.5 to 2 minutes. A relatively small twin-shaft paddle mixer will provide a large output – thus giving savings both in investment costs and space requirements.
- Liquids can be added easily to the powder mixture. This is done by means of quick connection nozzles (single component flat spray nozzles are most commonly used) for adding oil, fat, water, flavours, etc.
- Spraying of liquids requires approximately one minute ensuring the best possible distribution of the liquids in the powdered material. In this case, total cycle time, including spraying of liquids, will be as low as 2.5 – 3.5 minutes.
- Liquid should be sprayed at a specific angle and at a specific distance to obtain the best possible distribution. The particles rotate around their own axes in the fluidized zone, exposing the total particle surface to the liquid during rotation. The liquid will hit the particles and be distributed in the mixture.
- High melting point liquids, such as fats, can be sprayed in free flowing liquid state with special nozzle arrangements.
- Homogeneous mixing is achieved in the space of a few seconds thanks to the fluidizing of the material. All particles can be mixed (small, large, light, heavy, round, etc.) without segregation, since the forces of mixing are stronger than the forces of segregation during the mixing action in these mixers. Segregation only takes place when the product is handled after mixing, so it is recommended to minimise the distance between the mixer and the packaging point to avoid segregation.
- The benefits of the mechanical fluidizing zone are gentle mixing, no segregation and very short mixing time. This gives savings in terms of minimal wear and tear and low energy consumption. Maintenance costs are also very low. The mixer’s low energy consumption is an important consideration in reducing production costs.
Special Duty Options
- Abrasion-resistant (A/R) steel can be incorporated in critical wear areas for abrasive applications.
- Welded overlay hard-facing can be applied to paddle faces and tips.
Shaft Seal Options
- Split Block Seals – UHMW body, steel front and back plates, two wraps of packing material
- Flange Gland Seals – Steel body and back plate, one wrap of packing material, adjustable as packing wears
- Packing Gland Seals – UHMW or stainless steel body, multiple wraps of packing material, adjustable as packing wears, with or without air purge.
- Seals by other manufacturers available.
Stainless Steel Sanitary/Food Grade
- USSS – Sanitary stainless steel construction, 120 grit finish
- SS – Sanitary stainless steel construction, 80 grit finish
- SSC-II – Stainless steel construction, unfinished
- SSC-I – Stainless product contact surfaces, unfinished
- Solid bolted covers
- Hinged cover sections
- Inlet ports for dry and/or liquid addition
- Access for inspection and cleaning
- Liquid manifolds and/or spray nozzles
- H&S Liquid Injector
- Heating and cooling jackets
- Support structures and platforms
- Custom designs and options