Bottom Discharge Centrifuge

This type of machine is also known as “Vertical Peeler Centrifuge” in Europe.

In this machine all major parts i.e., the Basket, monitor casing and inertia plate designs are different from the Top Discharge models.

The Bottom Discharge Centrifuge Basket has radial ribs instead of a flat bottom plate. The gaps in the basket bottom facilitate the cake discharge on to the inertia plate and to the Bottom hopper.

The inertia plate too has radial ribs and large openings that allow the discharged cake to fall into a hopper fitted below the inertia plate. The monitor casing is fitted with a Scrapping Arrangement (Also known as Plow) on which a knife is mounted in such a way that the cake inside the basket is peeled off when the knife is engaged.

In this model the cake is filtered in the same manner as the other vertical models but the cake discharge is achieved by means of a scraper knife that plows into the cake. At this point the basket is in rotation at a preset low speed and the cake is peeled off the Basket surface.

The filter bag in a Bottom Discharge Centrifuge is held in place by Tensioned Rings or by screws and the bags may also have backing cloth or mesh to impart structural rigidity to the bag so that the bag does not distort of collapse while the knife is being engaged.

The small gap between the scraper and the Basket Shell results in a thin layer of cake remaining inside the Basket. This layer is known as the Residual Heel. A Blow Off arrangement is provided to remove this Heel. Typically this is achieved by a blast of Air/ Nitrogen from specially arranged Air Delivery nozzles mounted on a pipe. The pipe is aligned with the basket perforations so that when the blast of Air is sent in to the pipe it travels through the Basket perforations and dislodges the Residual Heel.

The Residual Heel Pipe can be swiveled during filtration such that the filtrate does not enter the nozzles and clog them. They swivel into position only during the scrapping cycle.

In cases where Dual Action Scraper is used we can also provide flat Air Nozzles from the inside of the basket in addition to the Heel Pipe outside.

The action of the scraper knife is by means of a Hydraulic Cylinder which is powered by a Hydraulic Power Pack.

Joflo has two Scraper Designs

Full Length Scraper also known as Single Action Scraper and the unique Dual Action Scraper.

For products that are relatively easy to cut we recommend the single Action Scraper.

For cakes are exceptionally hard after filtration we recommend our Dual Action Scraper.

The Scraper knife has mechanical limits so that the knife does not accidentally come in contact with the Basket Shell.

Sizes Available: Starting from 30” Dia. up to 60” Diameter.

Materials of Construction: SS 316, SS 304, SS904L, Hastelloy & Titanium

Coating: Halar (ECTFE), Teflon (PFA), Rubber Lining, FRP Lining

Bottom Discharge Centrifuges are available in the following Designs

1. Half Lid Opening : In this model the lid of the centrifuge only one half of the top cover of the centrifuge is opened to inspect the cake. For complete cleaning of the basket and inner parts of the centrifuge the monitor casing of the centrifuge has to be opened.

2. Full Body Opening : In this model the entire top cover of the centrifuge is accessible for cleaning and visual inspection. This is an ideal model for applications involving product changeovers and special cleaning needs. The basket bottom and the Mother Liquor Drain platform can be manually cleaned and visually inspected in this model. This model is often called cGMP or sanitary model. In this model a Half lid opening or Full Lid Opening design also may be provided on request.

3. Full Lid Open: In this variant the top lid of the centrifuge has a large diameter that equals the diameter of the monitor casing. This gives better access to basket inside and outer periphery (except bottom) and full access to the top cover.

Optional Extras: Proximity switches for Knife In/Out limits, Nitrogen Blanketing, Vibration Limiter, RPM Sensor with Indicator, Zero Speed Interlock, Cleaning in Place (CIP), Cake thickness sensor, Pneumatic Lid Opening System, Hydraulic Lid or Body opening systems, PLC Controlled Automatic operation and Skimming Arrangement and Inclined Filling Cone.

Technical Data Sheet:

Technical Data Of Four Point Suspension Bottom Discharge Centrifuge

VBC-BD	36" x 20"	48" x 24"	48" x 26"	60" x 20"	60" x 24"	60" x 26"	60" x 30"	Unit
Basket diameter	915	1210	1210	1500	1500	1500	1500	[mm]
Basket height	500	610	660	510	610	660	760	[mm]
Filter surface Area	1.43	2.3	2.53	2.4	2.87	3.11	3.6	[m2]
Useful volume	172	350	400	500	600	650	746	[dm3]
Max.load @ Bulk Density 1.0	172	350	400	500	600	650	746	[kg]
Max.speed of Basket	1100	900	900	800	800	800	800	rpm
Max.Gforce	620	550	550	540	540	540	540
Centrifuge weight (with load)	3000	4200	4500	6500	7000	7500	8000	[kg]
Motor power for main drive	10	20	20	30	30	30	40	[HP]
Dimensions
L	2050	2250	2400	2800	2800	2800	3000	[mm]
W	1600	2000	2000	2300	2300	2300	2400	[mm]
H (Lid Open Condition)	2400	2500	2700	2500	2650	2700	2850	[mm]
H1 (Total Height)	2700	3000	3150	3100	3250	3300	3350	[mm]

Technical Data Of Four Point Suspension Full Body Open Bottom Discharge Centrifuge

BD_FBO

VBC-BD	36" x 20"	48" x 24"	48" x 26"	60" x 20"	60" x 24"	60" x 26"	60" x 30"	Unit
Basket diameter	915	1210	1210	1500	1500	1500	1500	[mm]
Basket height	500	610	660	510	610	660	760	[mm]
Filter surface Area	1.43	2.3	2.53	2.4	2.87	3.11	3.6	[m2]
Useful volume	172	350	385	500	600	650	746	[dm3]
Max. load @ Bul Density 1.0	172	350	385	500	600	650	746	[kg]
Max. speed of Basket	1100	900	900	800	800	800	800	rpm
Max. G force	620	550	550	540	540	540	540
Centrifuge weight (with load)	3000	4200	4500	7500	8000	8500	9000	[kg]
Motor power for main drive	10	20	20	30	30	30	40	[HP]
Dimensions
L	2200	2500	2500	3000	3000	3000	3100	[mm]
W	1500	1950	1950	2350	2350	2350	2350	[mm]
H (Body Open Condition)	2250	2750	2800	2900	3050	3100	3200	[mm]
H1 (Total Height)	2700	3300	3350	3450	3600	3650	3800	[mm]

General Features

4 Point Suspension: Centrifuge is mounted on four viscous Dampers.
Variable Frequency Drive: The operating speeds of the centrifuge are controlled by a Variable Frequency Drive. The Standard Braking System for this model is Dynamic Braking.
Taper Lock Pulleys: These pulleys are easier to mount and dismount.
Cake Washing Nozzles: Special Spray nozzles with defined conical pattern spray are provided so that the entire surface of the cake is covered uniformly with minimal quantity while maintaining repeatable washing performance.
Shaft Protection Sleeve: A stainless Steel sleeve is mounted on the exposed part of the shaft to protect it from corrosion.
Proximity Sensor: To prevent the machine from being started while the lid is open a proximity sensor is installed as a standard feature.
Gas Tight Design: The machine is constructed to retain a positive pressure of 400mm WC as per DIN 24400.
Easy Maintenance: The machine design affords minimal maintenance. Greasing points enable easy lubrication to the Bearings.