Ultrafine powder and ultrafine grinding technology in the pharmaceutical industry (2)

According to the person in charge of the company’s technology, the new model will develop the crushing area from an approximately planar shape to a three-dimensional one, greatly expanding the crushing area of ​​the fluidized bed jet mill, allowing the material to be crushed to gain more in the crushing room. The chance of collision, squeezing, and mutual friction. In addition, since the upward nozzle is disposed under the conical bottom of the crushing chamber, the material falling into the cone of the crushing chamber can also be promptly crushed by the high-speed airflow emitted by the nozzle, eliminating the blind area in the cone below the previous crushing chamber. Therefore, the smashing chamber, the feed chamber, and the classifying chamber from bottom to top form a complete fluidized state under the action of the jet gas flow. The material, under the combined action of several nozzles, converges into a conical shape and is crushed in an instant.

In addition to completely changing the nozzle settings, this model also uses a new sealing device, which is different from the traditional model of dynamic and static ring sealing device or labyrinth sealing device. It adopts a closed air seal and has no moving parts. Therefore, no wear occurs and the equipment operates more smoothly and safely.

The company's technical director pointed out that the new model meets the relevant requirements of GMP, and the running performance is more secure and reliable. Not only the material selection is strictly in accordance with the GMP requirements for the equipment, but also the structural design fully satisfies the need for convenient disassembly and automatic cleaning (CIP/SIP). The main unit is connected by flanges, hinge bolts and quick clamps; the bearings use multiple sealing devices and special greases to enable the equipment to operate stably for a long period of time under high-speed operation. The grease does not leak and the product is safe from the source; All polished and leveled, internal and external surface roughness is only 0.4 ~ 0.8 microns; the control system uses PLC (Programmable Logic Controller) mode, through the panel button control, to replace the cumbersome operation of traditional open and close valves, not only reduce the labor intensity, Also reflects the humanized design.

Strictly follow production control

The company has accumulated a great deal of practical experience in the development and use of fluidized-bed air ultrafine crushers. The technicians emphasized that when selecting a new type of crusher, its control must meet the following requirements:

1. Strictly control the amount of feed. The low material concentration, the low probability of contact between materials, and the high concentration of materials will affect the gas flow velocity. Therefore, during operation, the material feed rate should be strictly controlled depending on the pressure, the nature of the material, and the characteristics of the organism itself; Determined by its own characteristics, spiral feeders, oscillating feeders or star feeders can be used to ensure that the energy sources in the crushing chamber are continuously supplied with materials to meet the material concentration in the crushing chamber.

2. Optimize the hierarchical structure. Grading is a critical step in the ultrafine crushing system. One of the most outstanding features of the fluidized bed ultrafine crusher is that it can achieve continuous feeding and discharging, prevent the material from being finely crushed, and cause unnecessary energy consumption. Operation should be based on the principle of turbo-classification, appropriately increase the diameter of the grading wheel, increase the speed, reduce the air flow, to ensure that the sizing machine's separation particle size is small.

3. The raw material into the ultrafine crusher should be as small as possible. To achieve this goal, the pre-pulverization process should be carried out using an ordinary mechanical pulverizer before ultrafine pulverization. This is the most direct and effective way to save energy and increase unit production.

4. Ensure that the airtightness requirements of the entire closed system of the equipment, including the jackets of pipes, valves, and equipment, shall not leak. In this way, valuable aerodynamic energy is concentrated on the nozzles to ensure reasonable gas flow rates and pressures and to increase the particle's impact probability.

5 product collection and dust collector to ensure smooth ventilation, should not be too much resistance. This part of the system must not only ensure the collection of qualified products, but also ensure the requirements of the environment, but the equipment is too complex, and it will bring too much burden on the overall work.