Horizontal Twin-shaft Paddle Mixer(2)

Keywords:

mixer,twin-shaft,mixer

Source: internal company

Horizontal Twin-shaft Paddle Mixer(2)

Fig1: Horizontal Twin-shaft Paddle Mixer Fig2:Mixing state of Twin-shaft paddle mixer

1. Test equipment and testing instruments
1.1 Test Equipment
Production type horizontal double-shaft paddle mixer, the equipment has two shafts, each shaft has 4 stirring paddles and 8 blades. When starting, the mixer uses the two shaft bodies to rotate in opposite directions to drive the blades on the stirring shaft to stir and mix the materials. During stirring, the powder is in a boiling state, and diffusion mixing, shear mixing and convection mixing are carried out at the same time. The mixing efficiency is high and the stirring paddle can be pulled out for cleaning, thus greatly shortening the cleaning time. After cleaning, the stirring paddle can still be pushed back to maintain a sealed state. A horizontal double-shaft paddle mixer of the same type. After cleaning is completed, push the two axes back into the cabin, rotate the two axes inward during mixing, and the blades stir up the materials to make the materials boil, so that the materials can be quickly mixed evenly. At the end of the mixing, the lower discharge hatch cover is opened and the materials fall into the collecting hopper and the collecting bag.
The experimental equipment has a nominal volume of 400L, a minimum charge of 100L, a maximum charge of 500L, a maximum charge weight of 360kg, a stirring shaft speed of 53.1 r/min, and a speed of 1.78 m/s along the paddle edge.

1.2 Testing Instruments
Powder flow tester: PFT3230.
Ultraviolet-visible spectrophotometer: UV-2550.
PH conductivity meter: S40 type.

2. Test on mixing uniformity of particles and powder
2.1 Test Materials
Citric acid granule: isomaltoketol 3.0%, anhydrous citric acid 1.0%, maltose essence 5.5%, povidone K30 0.5%, 60% ethanol appropriate amount, granulate in a wet granulator, dry in an oven, sieve that granules, and prepare granules with more than 40 mesh for later use.

2.2 Evaluation Method and Testing Method of Mixing Uniformity
Mixing uniformity is an index used to evaluate the mixing quality of materials. Now 'coefficient of variation' is widely used as the evaluation index of mixing uniformity in the world. The smaller the coefficient of variation, the better the mixing uniformity, and the coefficient tends to zero in the ideal mixing state, so in a sense, the coefficient of variation indicates the degree of nonuniformity.
Detection method of tracer carmine: 5g sample is accurately weighed in conical flask, heated and dissolved by electric heating plate after adding water, then fixed in 50ml volumetric flask, and finally its absorbance is measured at 508nm, of which the mixture without carmine is taken as blank sample. Ph detection method: take the solution with constant volume and measure it on Ph tester.