Twin Chamber, Reactor Charging Isolator Systems for Safer Operation

Hosokawa Micron’s new, twin chamber, reactor charging isolator has been installed at one of the largest chemical plants in Europe to satisfy the company’s requirement for shirt sleeve operation designed with full personnel protection.

The isolator is designed in an ergonomic manner to guarantee ambidextrous flexibility, to facilitate manual processes and ensure overall user friendly functionality..

Design of the Isolator

The twin chamber, reactor charging isolator is incorporated with an integral pneumatic drum tipper and utilized for charging catalyst powder into a reactor vessel. The top design priority is the safety of personnel, and hence many features in the isolator are primarily for the purpose of safe operation.

Even though the isolator target Operator Exposure Level (OEL) was less than 10μg/m³, the isolator is designed to the same specification as a system needed to operate at OELs of less than 1μg/m³, with the actual system OEL achieving results of less than 0.01μg/m³ when third party tested using micronized lactose.

Operation of the Isolator

The drum is fitted onto the tipper and the lid is removed after which the safety gate is closed. The pneumatic circuit is interlocked in such a manner that it does not allow the tipper to function unless the gate is in closed mode. Then the drum is raised, tipped and docked with the isolator.

The Hosokawa drum dock system seals the outer liner and the drum rim to the isolator. The system uses compression seal and inflatable seal technology for the sealing process.

The bagged powder from the drum is moved into the transfer chamber, from there into the charging chamber through the transfer door. With the Hosokawa safety knife, the bag is opened and charged into the reactor placed below.

A grid is provided for the discharge hopper so as to stop objects and the bag from falling into the vessel below. Removal of the waste materials is done via the continuous liner bag out port system. Tests to ensure that the isolator adheres to the client’s strict protocols are conducted before dispatch.

Safety Certification

The isolator is cleared for use in an ATEX II 3G (Zone 2) area.

The safety steps include the following:

• Ensuring the safety of live electrical equipment to flammable gases, the system’s central electrical cabinet is air purged.
• Proximity switches and pressure transmitters along with the other electrical field equipment are connected through galvanic barriers to ensure safe functioning.
• The isolator functions with a nitrogen-inerted, negative pressure internal atmosphere and the system controls a multi-speed extract fan and utilizes interlocks to ensure highest safety standards.
• HEPA filtration is carried out for the nitrogen inlet and the isolator extract
• A HEPA Filter is installed between the charging chamber and the transfer chamber to provide a pressure cascade via the isolator so as to minimize the contamination risks related to the transfer chamber.
• The system utilizes only the Hosokawa safe change filter system and the safe change gloves.

Hosokawa Micron's isolators stand out in the market as equipments that decrease operator exposure levels to a great extent and meet strict regulation and compliance, thus justifying the worldwide demand for Hosokawa Micron's expertise by major pharmaceutical and chemical companies. Their range of isolators allows both automatic and manual operation with reduced operator exposure.

This information has been sourced, reviewed and adapted from materials provided by Hosokawa Micron.

For more information on this source, please visit Hosokawa Micron.