RAVI INTERNATIONAL

Vikhroli, Mumbai, Maharashtra

Rotary Vacuum Paddle Dryers is utilized in varied industries to extract and obtain dry powder either from solutions or wet cake. Operational efficiency is high and the costs incurred are low with this dryer when compared to other dryers in the market. The mechanism, involves a closed system wherein hot water, steam, or hot fluid is used as a heating medium within the jacket, in the hollow paddle as well as in the hallow shaft. This paddle dryer includes vacuum pump, condenser, receiver and dust collection. Wet feed receives good heat transfer with the constant agitation triggering heated rotating paddles and minimum clearance between scrapers and heated walls. This process gives rise to the evaporation of moisture or solvent, which makes the wet material dry to the essential level. Vacuum is used to remove the vapors that are formed already. Further, the dust problems are eradicated with the absence of large air flows, which also results in low energy consumption. These vacuum paddle dryer (RVPD) are highly appreciated in the market.

Brief Introduction :-

RAVI Belt Dryer is a drying equipment for continuous production, which is used for drying flaky, strip and granular materials with good air permeability. It is especially suitable for dehydrated vegetables, catalysts, and other materials with high water content and low/high material temperature.

Belt Dryer is a series of dryers have the advantages of fast drying speed, high evaporation intensity and good product quality. For the paste materials of dehydrated filter cake, they can only be dried after granulating or making into strips. The raw materials can be medicine raw materials, Bulk drug, food items, dairy products, fertilizers, pesticides, paint, powder, granule, packing bottle, pigment, dyestuff, dehydration vegetable, dried fruit and melons, banger, plastic resin, electric elements, drying varnish and so on.

Belt Dryer has the advantages of high drying rate, high evaporation intensity and good product quality. Belt dryer is widely used in industry, mainly for drying small pieces of materials and fibrous materials. In a word, the materials dried by the belt dryer must have a certain shape, and still keep a certain shape after drying.

Working Principle :-

The material is evenly spread on the mesh belt by the feeder, and the mesh belt adopts 12-60 mesh stainless steel mesh. Driven by the transmission device, it moves in the dryer. The dryer is composed of several units. Each unit has an independent hot air circulation. Part of the tail gas is discharged by a special dehumidification fan. The waste gas is controlled by a regulating valve. The hot gas passes through the materials laid on the mesh belt from bottom to top or from top to bottom, and is heated and dried to take away the moisture.

The net belt moves slowly, the running speed can be adjusted freely according to the material temperature, and the dried product falls into the collector continuously. The upper and lower circulation units can be flexibly equipped according to the needs of users, and the number of units can be selected according to the customers needs.

Features :-

Low energy consumption: No heat carried out by the air due to indirect heat. Theres no heat insulation layer with the exterior wall of the dryer. It consumes 1.2kg steam to evaporate 1kg water for drying slurry materials.

Low cost of the blade dryer system: the unit effective volume has a large heat transfer surface, so the processing time is shorted; the size of the equipment becomes small. It greatly reduces the floor area and building space.

Handling wide range of materials: Heat sensitive material and the materials to be processed under high temperature might be processed with different heating media.

Common media are: steam, thermal oil, hot water and cooling water, etc.

Continuous operation or intermittent batch operation, widely used in many fields.

Environmental pollution is less: Without any carrying air, very few powders is carried out. Evaporation of the solvent material is very small, easy to handle. For the materials that might cause pollution or the solvent to be recovered, it might adopt sealed circulation.

Stable operation: the wedge-shaped blades will do special compression, expansion of stirring effect, the material particles will fully contact with the heat transfer surface in the axial section. The difference of the temperature, humidity and mixing effect are very small in the different axial area, so to ensure the stability of process.

Low speed will not break the granular materials or sliced materials.

Most suitable for drying of materials which cannot resist high temperature, material which are easily oxidised, volatile materials which should be retrieved, materials strong irritant and poisonous in nature. The rotocone dryer with improved technology integrates during operation under vacuum. The Dryer rotates at a very low speed (5 - 12 rpm) and thus has very low wear and tear and requires very little maintenance. This machine is ideal for crystalline products, granules used in chemical, pharmaceutical and food industries. Revovery of Loss of material is effectively collected by a specially designed pilot filter fitted on the vacuum side, Solvent recovery is through condenser & receiver. The capacity of the machine ranges from 15 liters to 5000 liters.

The rotocone dryer is working under vacuum, facilitates enhanced drying efficiency, low temperature operation and economy of process by total solvent recovery. Due to vacuum, the drying is enhanced resulting in fast drying, cutting the process time, which saves heat energy and electric energy.

SALIENT FEATURES :

Totally sealed and protected from contamination Provision of sampling nozzle without breaking vacuum. Cyclone separator provided for recovery of any solid particle escape. Suitable size condenser & receiver provided for solvent. Mechanical seals for vacuum & hot water connection. Variable speed drive is provided for fine adjustment of the speed.

ADVATAGES :

Reduces drying time Uniform material shuffling over the heated contact surface of the cone. Handling and exposure of final product is avoided. Eliminates need for re-drying of lumps. System can process crystalline or amorphous powders which are prone for lumps Optimum and continuous vacuum during process.

SALIENT FEATURES - GMP Model :

Inner shell/Cone and contact parts in SS 316. Steam/HW water Jacket in SS 304. Insulation with jacket in SS 304. Cyclone separator in SS316. Condenser (shell & tube type) and Receiver ( cylindrical & cone type) in SS304 Digital Temperature Indicators (FLP) at Hot Water inlet and outlet. Digital Temperature Indicator (FLP) and Dial Vacuum Gauge in vapor line. Digital Temperature Controller (FLP) with Pneumatic Valve at Hot water inlet. Butterfly valve (SS316) at discharge port with dummy and hand wheel. Stand and Structure in SS 304 / MS with SS304 cladding. Drive unit enclosed with SS304 Covers Dry Mechanical Seal for vacuum side. Dry Mechanical Seal for Waterside. FLP Motor & FLP Control panel enclosed in SS304 panel Provision for Nitrogen purging/Vacuum release with interlocking to isolation valve. Temperature and Vacuum Gauges (Dial Type) on Cone. Safety Guard/railing telescopic type with limit switch (FLP) with interlocking. Drain plug and safety valve on Hot Water / Steam Jacket. Pulse jet type dust filter is provided inside the cone. Positioning wheel /inching button for cone DRIVE SYSTEM : Gear Box & Motor Direct Coupled and Gear Box to Cone Drive shaft Bull Gear-Pinion Gear Drive. Extended shaft (drive side) so that drive unit can be kept in service zone (if required) Vacuum loading system of wet material into the Cone. PHARMA FINISH : Internal 320 Grit Mirror Polish and Outer 180 Grit Mat Finish.

OPTIONALS :

Cantilever (One side base) construction for small models only. VFD for Drive Motor with RPM indicator. Condenser and Receiver in SS316 instead of SS304. Lump breakers with FLP motor, Mechanical seals and electrical slip-ring joint. Auto Bin loading mechanism with accessories. Vacuum pump with FLP motor. Hot water system (steam heated) with tank and circulation pump.

SALIENT FEATURES:

Totally sealed and protected from contamination Provision of sampling nozzle without breaking vacuum. Cyclone separator provided for recovery of any solid particle escape. Suitable size condenser & receiver provided for solvent. Mechanical seals for vacuum & hot water connection. Variable speed drive is provided for fine adjustment of the speed. ADVATAGES : Reduces drying time Uniform material shuffling over the heated contact surface of the cone. Handling and exposure of final product is avoided. Eliminates need for redrying of lumps. System can process crystalline or amorphous powders which are prone for lumps Optimum and continuous vacuum during process. Most suitable for drying of materials which can not resist high temperature, material which are easily oxidised, volatile materials which should be retrieved, materials strong irritant and poisonous in nature. The rotocone dryer with improved technology integrates during operation under vacuum. The rotocone dryer facilitates enhanced drying efficiency, low temperature operation and economy of process by total solvent recovery.

Rotary Vacuum Paddle Dryers is utilized in varied industries to extract and obtain dry powder either from solutions or wet cake. Operational efficiency is high and the costs incurred are low with this dryer when compared to other dryers in the market. The mechanism, involves a closed system wherein hot water, steam, or hot fluid is used as a heating medium within the jacket, in the hollow paddle as well as in the hallow shaft. This paddle dryer includes vacuum pump, condenser, receiver and dust collection.

Wet feed receives good heat transfer with the constant agitation triggering heated rotating paddles and minimum clearance between scrapers and heated walls. This process gives rise to the evaporation of moisture or solvent, which makes the wet material dry to the essential level. Vacuum is used to remove the vapors that are formed already. Further, the dust problems are eradicated with the absence of large air flows, which also results in low energy consumption. These vacuum paddle dryer (RVPD) are highly appreciated in the market.

FEATURES :

Drying optimization is a process that is carried out by means of external and internal heating. The large heat transfer area available on the wide paddles and hollow shaft enable and equip maximum heat transfer efficiency to the product. External heating is generated through jacket or limpet coils, while internal heating through a hollow shaft, along with a set of hollow paddles. These hallow paddles are equipped with scrapers that have very low gap from wall in order to maximize heat transfer. Scrapers move material to all parts of the dryer and additionally help in discharging the material. There is a hollow rotating agitator shaft that imparts heat to the product and scrapes the shell wall tumbles. This facilitates for maximum heat transfer and discharge product whenever required. Mechanical seals at Shell ends/Stuffing Box. The vessel is well designed to take temperature stresses in the process of vacuum drying. Thereby, there is low power consumption with the use of helical bevel gear box. Special floating bearing design to combat temperature stresses. So as to remove the condensate formed by steam heating in the hallow shaft, special rotary joints are also designed to introduce heating media in the hollow shaft. Product Filter is very efficiently used to arrest valuable product carried away with the vapors in a filter bag. The arrested product particles are thrown back into the dryer by reverse flow of pulsating air. Generally, the product filters are heated to avoid condensations of vapors in the filter bag. User friendly discharge valve design provides vacuum tight closing when the material is processed. The quick opening facility lever facilities filling of bags when material discharge and packed. Breaker bars are incorporated in the RVPD to break the lumps when the product forms lumps at some stage in drying process. Insulation with Cladding will provide on heating jacket/Limpet coil

Rotary Vacuum Paddle Dryers (RVPD) is a cylindrical jacketed vessel with a central agitator having specially designed blades. The blades of this Rotary Vacuum Paddle Dryer (RVPD) are so designed that they sweep the entire internal surface and at the same time turn the material so that all the particles are come in contact with the heated surface. GMP construction - Cylindrical, horizontal vessel with flat welded rear cover and a hinged flat front door opening up over the entire vessel diameter. With the door open the internals of the machine are fully accessible for cleaning and inspection purposes All surfaces in contact with the product such as the vessel, rear cover, front door, agitator and vapor filter are heated, providing very efficient heat exchange. To provide for good heat exchange and discharge characteristics the cylindrical vessel, the rear cover, the front door and the agitator are machined to assure the smallest possible tolerances between agitator and vessel walls. The agitator is installed at the rear of the dryer, supported on one side of the vessel only. The agitator is designed to meet the requirements of this particular dryer type to assure good and even mixing action throughout the dryer volume, also in reverse operation. The agitator provides very good emptying characteristics, and at the same time reduces friction onto the product to a minimum to prevent local overheating as well as to prevent directional thrust or local product compression. A double mechanical seal is installed on the rear cover, well accessible for cleaning and maintenance purposes. A spacer in between the seal and the agitator drive permits removal of the seal without disassembling the drive. Dry or wet running mechanical seals may be installed. The central agitator shaft is supported on the one end bearings housed in bearing housing in such a way that the alignment remains always intact. This central agitator is driven by means of a Motor & Gear box through the bull Gear. The horizontal shell is jacketed to heat the shell with steam / hot water or any other thermal fluid. Limpet coil is provided instead of jacket if the heating media is fluid. A Dust Catcher consisting of bag filter is provided on the top to prevent the losses of material particles after the drying process. A Condenser of adequate heating surface area is provided wherein the evaporated vapors are condensed and these condensed vapors are then collected in the receiver of suitable capacity, placed beneath the condenser. A Vacuum Pump of adequate capacity is provided & fitted to the receiver of these rotary vacuum dryers to create the vacuum in the dryer shell through the Receiver, Condenser and Dust Catcher.

SALIENT FEATURES OF ROTARY VACUUM DRYERS (RVD) :

Very suitable for drying materials which are heat sensitive, as low temperature for drying can be maintained by high vacuum Lowest energy consumption compared to any other batch type dryer due to higher differential temperatures. Higher Thermal Efficiency. Almost 100% recovery of solvents. Heating Temp.: From 30C to 300C. Evaporation Rate : 4.12 Kg/ HrlSq. Meter of Heating surface area of water at heating temperature of 100C. Limpet coil could be provided instead of jacket if the heating media is fluid. Breaker bars of approximately same length as dryer shell can be provided if lump formation is expected during drying

SALIENT FEATURES:

All stainless steel 304 / 316 / 316L CGMP construction for pharmaceutical applications or external mild steel with stainless steel interiors with rounded corners or full mild steel construction Blower fans are axial flow type with variable pitch blades to adjust air flow to suit product being dried Electric / steam / thermic fluid / diesel oil / LPG heating Tunnel type dryers wherein trolleys are placed one behind the other and double door loading Flame - proof construction with explosion flaps, non-sparking metal combinations, earthing chain etc. Positive exhausts wherever required Continuously wound and crimped fins for the heat exchangers in case of steam / thermic fluid heated models. Steam / thermic fluid heat exchangers tested at 20Kg / cm hydraulically Electric heater terminals situated outside the hot zone in case of electrically heated dryers. Heaters are accessible and replaceable from outside the dryer

This is a combination of filter and dryer unit in single equipment to achieve economy in process, space and energy thereby improving profitability. This equipment can be used in manufacturing process of various Pharmaceuticals, Intermediate Compounds, Chemicals, Fine Chemicals, Agro Chemicals, Insecticides, Pesticides, Dyes and Food Products.

The Agitated Nutsche Filter Dryer is a closed vessel designed to separate solid and liquid by filtration under pressure or vacuum. The advanced technology of agitation and hydraulics used in the equipment makes it versatile and user friendly. The resulting wet cake can be reslurried and washed thoroughly with water or solvents unlike in untsch filters or centrifuges. Wash liquid quantity can be controlled and recycled, reducing effluent load. The discharge of wet cake is automatic. If the process demands filtration in chilled or hot condition, it is also possible. Drying of wet cake is also possible when drying features are incorporated. The unit consists of a totally enclosed and sealed cylindrical shell fitted with a agitator assembly which moves horizontally as well as vertically. The cylinder operates under pressure or vacuum or both. The closed operation ensures odorless, contamination free and nonpolluting working conditions maintaining product purity and hygiene. The equipment is functionally safe and easy to operate.

The equipment is functionally safe and easy to operate. It can carry out various phase of process operations, viz: Crystallization, filtration, extraction, Discoloration, Washing and drying. The number of conventional machines employed for filtration process are also reduced. It has multi- functional utility, saves on power, labor, floor space, material wastage and time.

Additionally, the equipment is fitted with a stirrer mechanism which efficiently agitates the slurry during cake washing, smoothes and squeezes the cake during filtration and assists in the automatic discharge of the cake. A side discharge arrangement is provided, closing and opening through hydraulic / mechanical means. A filter plate with filter cloth is fitted at the bottom of the shell for separating liquids from solids. The cake is retained on top of the plate. The upward and downward movement of the agitator assembly is utilized for cake washing, compressing, drying and discharge of the cake. A vacuum pump connected to receiver is installed for discharging of liquids and vapor collection. The cylindrical shell can also be provided with a jacket. A filter plate is located at the base of the vessel in level with the discharge port. The filter medium, usually a filter cloth, is fitted on the filter plate which is replaceable type.

In addition a special multilayered filter plate can also be provided instead of filter cloth. In dryer construction heating is provided on shell by limpet in bottom by jacket and through hollow agitator and blades. Vacuum is applied for fast drying.

It has multi- functional utility, saves on power, labor, floor space, material wastage and time. We use sophisticated technology that combines hydraulics and agitation, which makes the Agitated filter dryer easy to use and very versatile.

SALIENT FEATURES :

Designed and Manufactured to suit critical hygienic conditions of pharma and food industries. (cGMP MODEL). Operated by hydraulic cylinders and held tightly with zero leakage. Offered in various materials of constructions, like stainless steel, Hastelloy, Titanium, carbon steel, rubber lined carbon steel and lead lined carbon steel. Offered in a wide range of filtration area capacities from 25 Lits upto 10000 Lits. Method of operation is totally enclosed, neat and hygienic. These conditions are excellent for solvent recovery, Hollow Shaft and Hollow Blades for thorough drying. Suitable for handling of sterile compounds or toxic and hazardous materials without human intervention. Enables easy non-manual and automatic cake / solid discharge. Scraper blade is provided to scrap the material which may stay on shell. Hollow Shaft and Hollow Blades for thorough drying. Specially designed tank cleaning nozzle is provided for thorough cleaning of inside of filter body. (CIP) Home>>Product Range>>Dryers Section>>Agitated Nutsch Filter Dryer This is a combination of filter and dryer unit in single equipment to achieve economy in process, space and energy thereby improving profitability. This equipment can be used in manufacturing process of various Pharmaceuticals, Intermediate Compounds, Chemicals, Fine Chemicals, Agro Chemicals, Insecticides, Pesticides, Dyes and Food Products. The Agitated Nutsche Filter Dryer is a closed vessel designed to separate solid and liquid by filtration under pressure or vacuum. The advanced technology of agitation and hydraulics used in the equipment makes it versatile and user friendly. The resulting wet cake can be reslurried and washed thoroughly with water or solvents unlike in untsch filters or centrifuges. Wash liquid quantity can be controlled and recycled, reducing effluent load. The discharge of wet cake is automatic. If the process demands filtration in chilled or hot condition, it is also possible. Drying of wet cake is also possible when drying features are incorporated. The unit consists of a totally enclosed and sealed cylindrical shell fitted with a agitator assembly which moves horizontally as well as vertically. The cylinder operates under pressure or vacuum or both. The closed operation ensures odorless, contamination free and nonpolluting working conditions maintaining product purity and hygiene. The equipment is functionally safe and easy to operate. The equipment is functionally safe and easy to operate. It can carry out various phase of process operations, viz: Crystallization, filtration, extraction, Discoloration, Washing and drying. The number of conventional machines employed for filtration process are also reduced. It has multi- functional utility, saves on power, labor, floor space, material wastage and time. AGITATED NUTSCH FILTER DRYER-GMP AGITATED NUTSCH FILTER DRYER (ANFD-Blade) CONSTRUCTION : Additionally, the equipment is fitted with a stirrer mechanism which efficiently agitates the slurry during cake washing, smoothes and squeezes the cake during filtration and assists in the automatic discharge of the cake. A side discharge arrangement is provided, closing and opening through hydraulic / mechanical means. A filter plate with filter cloth is fitted at the bottom of the shell for separating liquids from solids. The cake is retained on top of the plate. The upward and downward movement of the agitator assembly is utilized for cake washing, compressing, drying and discharge of the cake. A vacuum pump connected to receiver is installed for discharging of liquids and vapor collection. The cylindrical shell can also be provided with a jacket. A filter plate is located at the base of the vessel in level with the discharge port. The filter medium, usually a filter cloth, is fitted on the filter plate which is replaceable type. In addition a special multilayered filter plate can also be provided instead of filter cloth. In dryer construction heating is provided on shell by limpet in bottom by jacket and through hollow agitator and blades. Vacuum is applied for fast drying. It has multi- functional utility, saves on power, labor, floor space, material wastage and time. We use sophisticated technology that combines hydraulics and agitation, which makes the Agitated filter dryer easy to use and very versatile. SALIENT FEATURES : Designed and Manufactured to suit critical hygienic conditions of pharma and food industries. (cGMP MODEL). Operated by hydraulic cylinders and held tightly with zero leakage. Offered in various materials of constructions, like stainless steel, Hastelloy, Titanium, carbon steel, rubber lined carbon steel and lead lined carbon steel. Offered in a wide range of filtration area capacities from 25 Lits upto 10000 Lits. Method of operation is totally enclosed, neat and hygienic. These conditions are excellent for solvent recovery, Hollow Shaft and Hollow Blades for thorough drying. Suitable for handling of sterile compounds or toxic and hazardous materials without human intervention. Enables easy non-manual and automatic cake / solid discharge. Scraper blade is provided to scrap the material which may stay on shell. Hollow Shaft and Hollow Blades for thorough drying. Specially designed tank cleaning nozzle is provided for thorough cleaning of inside of filter body. (CIP) TECHNICAL DESIGN PARAMETERS : Design Pressure Vessel -Full Vaccum , Jacket/Limpet 4bar Design Temp 150deg Finish Internal: 240gr Mirror finish, External 180gr Mat finish OPERATIONAL SEQUENCE : The operation of Nutsche Filters requires a complex manipulation of valves and hydraulics so present day installations are always semi or fully automated. Filtration The filter is charged with slurry and pressure is applied to displace the filtrate leaving the cake retained over the filter medium. For slurries with a wide distribution of coarse fast settling solids and slow settling fines there is a risk of segregation with the finer fraction settling over the coarse fraction. When this happens the fines seal the cake and slow down the cake formation so keeping the slurry in suspension with rotating arms during filtration assists in forming a homogeneous cake. Cake Washing In the washing stage a spray ring or connections on top of the cover introduce the wash liquid over the cake. This displaces the mother solution with the wash liquid but with such in-situ washing the efficiency may be quite low if the cake forms with an uneven thickness. One of the advantages of the Nutsche Filter is the ability to smoothen the cake's surface prior to applying spray wash so that the entire bed is washed evenly. Washing efficiency may be further improved if air or gas are not allowed to enter the cake in a multi-washing system so the wash liquids always displace the solutions in a "piston" like manner. This is achieved by a special detector that monitors the surface of the cake for moisture and once air or gas start entering the bed a signal is transmitted to close the filtrate valve and reopen it once next washing commences. Cake Repulping Many processes require high washing efficiency to remove the contaminating liquid from the product and washing the cake by repulping yields the most efficient product purity. This is done by resuspending the cake with the paddle arms for thorough mixing with the wash solution. During resuspension the rotating arms are moving slowly downwards and are "shaving" the bed gradually layer after layer until the entire cake enters the slurry. Pressure Drying In the drying stage air or gas purges the cake until the captive moisture is reduced to an asymptotic level and in practical terms the cake is considered to be as dry as possible. To obtain minimum moisture the cake is smoothened by reversing the rotation of the paddle or auger arms and exerting controlled pressure on its surface with the hydraulic system. This seals cracks in the cake so that air or gas will not bypass the bed. Vacuum Drying Further reduction in cake moisture may be obtained by slowly rotating and lowering the paddle arms to scrape and de-lump the cake. To take advantage of the drying ability of the Nutsche Filter it is worth considering the option of heating components such as the vessel, filter floor and paddles to enhance drying. Cake Discharge Once all the stages are completed the cake discharge valve opens and the paddle arms on the smaller machines or the auger arms on the larger ones are rotated and lowered to convey the dry cake towards the center. The same procedure also applies to side discharge machines however it should be noted that in this case the cake comes out intermittently and not continuously. This may have a layout impact on the downstream facility such as the conveyor that handles the product to storage. On some filters the cloth or woven mesh screen may be backwashed with water to dislodge and remove any cake residue that adhered to the medium after cake discharge.

Vacuum Tray Dryer is used mainly for drying of high grade, temperature and oxygen sensitive products. Vacuum Tray Dryer is highly suitable for drying hygroscopic substances, which are dried to very low residual moisture, content level. Frequently vacuum drying cabinets are the sole possibility for drying lumpy, glutinous products or products of low pomposity.

Its also suitable for drying of thermal sensitive materials easily resolved, polymerized or deteriorated under higher temperature. Sterilization can be conducted prior to the drying process, during which no matter is allowed to enter the product. Static vacuum dryer eliminates the configuration damage of the drying materials, therefore widely used in pharmaceutical, chemicals and foodstuff etc.

SALIENT FEATURES :

Vacuum Tray dryer is the most commonly used batch dryer. They are box-shaped and loaded and unloaded via a door. Inside are several heating plates mounted one above the other on which the product is placed in trays.

The bottoms of both heating plates and trays should be as smooth as possible to permit optimal heat transfer between plates and product.

The medium flowing through the heating plates is water, steam or thermal oil.

The distance between the heating plates is determined primarily by the surface loading and the foaming of the product.

To avoid retrograde condensation the cabinet walls are indirectly preheated by the heating plates. Next, the product is introduced and heated at atmospheric pressure. Only after all individual product trays reach the same temperature the cabinet is evacuated and drying can start.

The preheating phase is very important in order that the drying curve and the foaming of the product is identical throughout the cabinet.

During the main drying phase the vacuum is in the range of 40 to 80 mbar abs and in the final drying phase vacuums of only few mbar abs are reached.

Heating temperatures are normally in the range between 800C and 1100C. Depending on product and surface load, drying takes from a few hours to 1 to 2 days.

For some products the vacuum and temperature profiles are automatically controlled in order to prevent a pass over of the critical product temperature.

The dimensioning of the vacuum system is an important factor in the design of drying cabinet systems. If for example vigorous foaming of the product is desired, evacuation to the operational vacuum level must take place very quickly.

Vapours produced during drying are taken out direct, or via a steam jet compressor to a surface condenser in which the vapours condensate. The non-condensable vapours are extracted by the vacuum system.

On completion of the drying, the product can be cooled by circulating of cooling water through the heating plates.

Often vacuum drying cabinets are supplied to new, small production operations in newly opened markets. Following successful development of the market, it could be worthwhile to replace the cabinets through continuous vacuum belt type dryers.

Ravi Fluid Bed Dryers are available in the following options:

Design confirming to GMP norms.Model available ranging from 5Kgs. To 500kgs. Bucket type bottom chamber above ground level. Intrinsically safe earthing arrangement. Air filteration supplied with 20 micron washable filter followed by 5 micron Microvee filter & finally air is passes through 0.3 micron Hepa Filter . Differential pressure gauges to monitor pressure drop across inletfilters and finger bag. (CIP)Clean in Place systems for washing down during product changes. Pneumatically Operated system for lifting & sealing of Product Container. Product container lifting platform and air cylinder replaced by pneumatically operated gasket. Inflatable gasket system for sealing lifting platform with bottom jack chamber instead of bottom bag. PP Finger bag fitted with the help of inflatable silicon rubber tube. Automatic pneumatically operated shaking system with timer & butterfly valve. Fully sealed air control damper with positional for accurate air monitoring. Solid flow chart monitor for detection of torn finger bag also available, which automatically STOP the machine blower if it detects any particle escaping from torn finger bag towards exhaust. Fully sealed air control damper with positional for accurate air monitoring. Solid flow chart monitor for detection of torn finger bag also available, which automatically STOP the machine blower if it detects any particle escaping from torn finger bag towards exhaust. Rear chamber with heating coils and air inlet filter modules to be mounted in remote areas. Fan motor unit to be mounted in remote areas. Stainless steel interconnecting duct lines with flanges for connecting remote mounted heating and fan motor modules. Noise level below 90 DB with specially designed silencer Microprocessor based control panels with key board, display unit & printer.