Inverting Filter Centrifuge (HT/GMP)
Inverting Filter Centrifuge (HT/GMP)
The Inverting Filter Centrifuge is the most versatile industrial centrifuge for Active Pharmaceutical Ingredients (APIs), pharmaceutical, and fine chemical processes.
The Inverting Filter Centrifuge is used for Solid Liquid Separation within the API (Active Pharmaceutical Ingredient), pharmaceutical, and chemical industries. Specifically, it is automatic, reliable, and it isolates and washes APIs (Active Pharmaceutical Ingredients) in a safe enclosed environment.
APIs are typically created in a reactor or crystallizer. The API needs to be isolated or separated from the other parts of the slurry through filtration. Filtering centrifuges are used to efficiently collect the solids and discharge the liquids while also incorporating a washing step to increase purity. Mechanically reducing the liquid content reduces the downstream thermal processing requirements such as drying time, thus protecting the quality of the API.
Reserved for challenging products, the inverting centrifuge provides the highest recovery with the most advanced design. If your product is too sticky, compressible, difficult to discharge, or you still need to reach a lower moisture content after trying other centrifuges, then it is time to move toward a more complicated design that can solve your problem.
Production Cycle and Design Advantages
Overview
Feeding
The solid-liquid suspension (slurry) is fed through the feed pipe into the centrifuge. The slurry moves towards the filter cloth under the action of centrifugal force, and onto on a perforated basket. The solid part of the suspension is retained by the filter cloth, forming a cake, while the liquid filters through the cake. The liquid is discharged through the holes of the basket. The feed pipe is located at the center of the basket. A load cell measures the product weight and stops the feeding when the desired weight is reached.
Cake Washing
The washing liquid is fed through the feed pipe. The shape of the basket and the feed pipe position agitate (increase turbulence) the washing liquid and distribute it uniformly throughout the cake.
Final Deliquoring (Centrifugation)
Once the washing phase is complete, the centrifuge accelerates to the maximum speed and maintains that speed for a given amount of time to achieve the desired level of residual humidity in the product. (Settings are both customizable and programmable.)
Further Deliquoring (with Hyperbaric Centrifugation System – HCS)
If the centrifugal force cannot further deliquor the capillaries inside the cake (especially for those products with poor filtration), a Hyperbaric Centrifugation System (HCS) can reduce residual moisture by blowing nitrogen at a high pressure (up to 6 barg) into the basket. The nitrogen pressure and flow reduces the capillary height and the liquid around the product crystals, decreasing the residual moisture. If the nitrogen is also heated up, an additional evaporation effect is achieved.
Solid Discharge
At the end of the centrifugation, the centrifuge reaches the discharging speed and the product is discharged. The mobile part of the basket is moved to the front part of the machine by the axial movement of the inverting shaft. This movement generates the inversion (inside out) of the filter cloth and the discharge of the product.
CLEAN IN PLACE (C.I.P.) Washing Machine Effect (WME)
The centrifuge is filled with the washing liquid up to a predetermined height and put into rotation. During the sequence, the basket rotates clockwise and counterclockwise. The mobile drum moves in and out so the washing liquid reaches all the points of the process area.
Cleaning with Spray Balls
The cleaning liquid is sprayed through the spray balls on all the process area surfaces to completely remove any residue of product.
Baskets
Baskets
Design Advantages
- Process area has full and easy access – the door can be completely opened giving access even to the rear of the basket and the front shaft seal
- Filtrate outlet behind the wall – which allows inspection and sampling without being in the way in the cleanroom
- Open/close automatic locking ring – using a pneumatic device system to open and close the door automatically and quickly
- Feed and wash pipe – allows for homogenous product and wash liquid distribution along the basket with low vibrations
- Hyperbaric Centrifugation System (Option) – allows for sensible residual moisture reduction with respect to the standard filtration by Hyperbaric Centrifugation System (HCS System)
- CIP (Cleaning in Place) – which is a proven and dedicated centrifuge cleaning system to avoid cross-contamination between different products
Typical Applications
- Pharmaceutical and fine chemical products
- Active Pharmaceutical Ingredients (APIs)
- Pharmaceutical intermediate products
- High Potent Active Products (HPAPI)
- Pharmaceutical synthesis products
Highlights
- Ideal for slow filtering and compressible products
- High separation efficiency for products with fine particles, compressible products (low filterability), and fine chemical/API (Active Pharmaceutical Ingredients)
- No residual heel
- Gentle product discharge
- Hyper centrifugation available for fixed bed drying
- 100% access to solids and filtrate housing
- No contact between the operator and product during operation makes it ideal for the production of pharmaceutical synthesis products
- Sizes range from 300mm (11.8 in.) diameter to 1000mm (39.4 in.) diameter – See charts below
- Inertia pad with dampers allows installation directly on the floor
- Through-the-wall installation for clean rooms
- Even cake distribution due to the horizontal design
Discharge
- Gently handles crystals: the solids discharge is achieved by means of filter cloth inversion (reversible bag), allowing soft crystals to be recovered without breaking
- Electromechanical filter cloth inversion (oil-free execution)
- The short discharge time and complete elimination of the heel cake at every cycle result in high yield. Ultra-thin cakes can be processed efficiently. Even products with low filtering properties (those with fine particles and high compressibility) can be separated, resulting in uniform cake washing.
- Various levels of containment options are available for solids discharge
Control Options
- Complete PLC controls with touch-screen interface
- Switch between automatic and manual operation
- Variable frequency drive (VRD) speed control
- ATEX (Europe) electrical enclosures or NEC (North America)
- Optional instrumentation integrated into the control system including oxygen monitoring, temperature, pressure, liquid feed flow, and N2 purge
Cleaning
- Its highly effective C.I.P. system (Clean-in- Place) uses a W.M.E. (Washing Machine Effect) and spray balls
- Removal of bound moisture is achieved by dry or heated gas at up to 6 barg differential pressure across the cake (Hyperbaric Centrifugation System – HCS)
- The front casing can be fully opened, allowing the process area to be completely inspected
Machine Characteristics
- Cake volumes from 7 (pilot unit) to 210 liters – See charts below
- High G factors from 1018 to 1663 (pilot unit) – See charts below
- Basket load setting via load cell system
- Filter cloths available in polypropylene, HALAR, or PTFE
- Gas tightness at 400 mm H2O
- High surface finishes
- Complete FDA validation documentation
- Construction materials
- Parts in contact with the product: all stainless steels and special alloys are available, such as AISI 316L, AISI 904L, hastelloy, monel, alloy 59, 254 SMO, nickel, titanium, and SAF 2205
- Surface coating option: Halar (ECTFE)
- Elastomers: antistatic and FDA certified, Teflon ETFE, and hard rubber
Technical Services
- Field service and technical support available
- Mechanical and electrical parts
- Process control and maintenance manuals
- Certifications and construction documentation
- Mechanical and electrical upgrades
Standard Sizes and Technical Data
| Centrifuge model: HT/GMP Unit |
Basket Diameter mm |
Basket Length mm |
Filtering Surface m2 |
Cake Volume liter |
Slurry Density kg/dm2 |
Max Load kg |
Max Speed RPM |
G Factor xg |
Centrifuge Weight kg |
| 300/110 | 300 | 110 | 0.1 | 7 | 1.25 | 9 | 3150 | 1663 | 1400 |
| 470/180 | 470 | 180 | 0.27 | 27 | 1.25 | 34 | 2300 | 1390 | 3000 |
| 600/225 | 600 | 225 | 0.45 | 52 | 1.25 | 65 | 2000 | 1340 | 4000 |
| 700/225 | 700 | 225 | 0.52 | 65 | 1.25 | 81 | 1850 | 1338 | 4600 |
| 800/350 | 800 | 350 | 0.90 | 122 | 1.25 | 152 | 1600 | 1144 | 8500 |
| 900/350 | 900 | 350 | 1 | 145 | 1.25 | 181 | 1500 | 1131 | 8700 |
| 1000/430 | 1000 | 430 | 1.35 | 210 | 1.25 | 262 | 1350 | 1018 | 9400 |
| 300/110* | 300 | 110 | 0.1 | 7 | 1.25 | 9 | 3150 | 1663 | 1400 |
| 470/180* | 470 | 180 | 0.27 | 27 | 1.25 | 34 | 2300 | 1390 | 3000 |
*Pilot Centrifuges
The smaller machines are considered pilot centrifuges and are used for both research and development laboratories, as well as small productions of high-added value products. These machines, while smaller, have the same features as the industrial scale module plus can be skid mounted for easier mobility.
