Bottom Discharge is an extremely versatile centrifugal solution. This model has the:
- largest cake volume
- most filter area available, up to 7m2 in one machine
- most economical option
- simplest design
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Production Cycle and Design Advantages
Overview
The next few slides will walk through the entire Production Cycle, showing the feeding, cake washing, centrifugation, discharge, and heel cake removal. This slide shows all 5 at one time before we zoon in to each. After that, there will also be slides detailing design advantages and the main components.
Feeding
The slurry (solid/liquid) suspension is fed through the feed pipe (or optionally via a rotating feed cone) into the centrifuge. The slurry flows towards the filter cloth under the action of centrifugal force, and onto 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, through the filter cloth, and through the holes of the basket. The growth of the cake thickness is controlled by a mechanical paddle detector, which can automatically stop the feeding phase when the desired cake thickness is reached.
Cake Washing
Cake washing removes any impurities present in the cake. The washing liquid is distributed onto the product in the basket, through nozzles located along the washing pipe (or optionally via a rotating feed cone). The liquid passes through the product, then passes from the filter cloth and the holes of the basket, removing impurities present in the cake.
Centrifugation
Once the washing phase is complete, the centrifuge accelerates to the maximum speed allowable for the product being processed, and maintains that speed for a given amount of time to achieve the desired level of residual humidity in the product. At the end of the centrifugation, the centrifuge decelerates to the discharge speed.
Discharge
After reaching the discharge speed, the knife increment command is activated. The scraping knife starts cutting the cake, moving the product into the discharge chute and into the product collection systems (drums, bin, dryers and mixers).
Heel Cake Removal
At the end of the product discharge phase, a heel product cake remains on the filtering cloth. This heel cake can be removed, to improve the filterability of the product, through the high-pressure nitrogen blow from the rear part of the basket or/and via nozzles placed on the knife.
Design Advantages
- Scraper knife – Movement up/down, radially by steps or total peel off. Nitrogen nozzles to remove heel cake internally.
- Feed distributor cone – Homogeneous product distribution independent from slurry flow rate or concentration
- External heel cake removal – Nitrogen blow from the back of the basket to efficiently remove the residual cake
- Inertia base and damping system – The centrifuge is mounted on the inertia base and viscous dampers to keep the dynamic forces transmitted to the ground at a minimum
Design Advantages
- Cake detector – A settable feed and wash mechanical cake controller continuously controls the cake thickness.
- Sight glass with cleaning nozzle – Process control through visual inspection
- Light glass with cleaning nozzle – Light glass to light the centrifuge internally
- CIP spray balls – Distributed CIP spray balls for a high-efficiency centrifuge cleaning system
Main Components
- Cake detector
- Feed and wash distributor cone (optional)
- Knife
- Cover Handle
- Junction box
- CIP (liquid and solid discharge area)
Main Components
- Sight and light glass
- Cover hydraulic cylinder
- Hydraulic unit
- Inertia base
- Product discharge area
- Viscous dampers
- Pharmaceutical and fine chemical products
- Active Product Ingredients (APIs)
- Antibiotics
- Pharmaceutical Intermediate Products
- Bulk and generic pharmaceuticals
- High Potent Active Product Ingredients (HPAPI)
- Fine chemical products
- Agrochemicals
- Food product
- Vertical basket with top load and with bottom discharge
- Automatic discharge with scraper knife
- Fixed frame or GMP design available
- Full inspection of process area is possible with the GMP design, and meets pharmaceutical industry requirements
- Production of bulk pharmaceutical products from synthesis processes
- Suitable for products requiring a wide filtering surface
- No contact between the operator and the product during operation makes it suitable for toxic and flammable products
- The centrifuge may be kept under a constant inert atmosphere
- Rotating distributor for feeding and washing allows for uniform cake distribution and avoids vibrations
- Sizes range from 800mm-1850 mm in basket diameter – See chart below
- Automatic Discharge by scraper knife movement up and down, radially by steps, or total peel off (vertical peeler)
- Nitrogen nozzles to remove heel cake internally
- Complete PLC controls with touch screen interface
- Switch between automatic, semiautomatic, and manual operation
- Variable frequency drive (VFD) speed control for the basket
- Knife and cover opening are hydraulically operated
- ATEX (Europe) electrical enclosures or NEC (North America)
- Optional instrumentation integrated into the control system including oxygen monitoring, temperature, pressure, liquid feed flow, N2 purge flow, effluent particle detection and fluid clarity
- Its highly effective C.I.P. system (Clean-in- Place) uses a Washing Machine Effect and spray balls.
- Multipurpose application: The C.I.P. system avoids cross-contamination between products from one campaign production to another, which makes the machine suitable for multi-purpose applications
- C.I.P.
- The centrifuge should be cleaned at every change of product to avoid cross-contamination between campaign productions. The fully automated centrifuge cleaning system is composed of 2 main stages: Washing Machine Effect and cleaning with spray balls, which can be alternated to achieve maximum cleaning and to optimize the consumption of the cleaning liquid.
- Washing Machine Effect (optional)
- The centrifuge is filled with the washing liquid up to a predetermined height and is put in rotation. During the automatic washing sequence, the basket rotates both clockwise and counterclockwise. The knife goes in and out so that the washing liquid reaches all points of the process area, including the discharge chute.
- Easily replaceable filter cloth is mounted in the basket by rings
- High level surface finishes for the process areas; mirror-like or electrochemical polishing are available
- Relatively small footprint – limited horizontal space required
- Inertia base installation with visco dampers
- 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, SAF 2205.
- Surface coating option: Halar (ECTFE)
- Elastomers: antistatic and FDA certified, Teflon ETFE, and hard rubber
- Field service and technical support available
- Mechanical and electrical parts
- Process control and maintenance manuals
- FDA qualification documentation and book to complete the plant
- Certifications and construction documentation
- Mechanical and electrical upgrades
Chemical Applications
Pharma Applications
Standard Sizes and Technical Data
| Centrifuge model: TM (Unit) | Basket Diameter (mm) | Basket Length (mm) | Filtering Surface (m2) | Cake Volume (liters) | Max Load (kg) | Max Speed (RPM) | G Factor (xg) | Centrifuge Weight (kg) |
|---|---|---|---|---|---|---|---|---|
| 800/250 | 800 | 250 | 0.63 | 63 | 79 | 1650 | 1216 | 1500 |
| 800/400 | 800 | 400 | 1.01 | 100 | 125 | 1500 | 1006 | 2000 |
| 1000/500 | 1000 | 500 | 1.57 | 200 | 250 | 1200 | 805 | 3800 |
| 1000/630 | 1000 | 630 | 1.98 | 250 | 312 | 1200 | 805 | 4250 |
| 1250/700 | 1250 | 700 | 2.75 | 400 | 500 | 1000 | 700 | 6400 |
| 1250/800 | 1250 | 800 | 3.14 | 500 | 625 | 1000 | 700 | 6700 |
| 1600/800 | 1600 | 800 | 4.02 | 820 | 1025 | 900 | 724 | 12000 |
| 1600/1000 | 1600 | 1000 | 5.03 | 1025 | 1280 | 900 | 724 | 13000 |
| 1700/1190 | 1700 | 1190 | 6.3 | 1377 | 1721 | 850 | 686 | 14500 |
| 1850/1250 | 1850 | 1250 | 7.26 | 1710 | 2140 | 800 | 643 | 16500 |