Pilot Scale 10kg/H Closed Cycle Spray Dry Machine

BYP Series Closed cycle spray dryer

General description

This plant works in a closed environment, which needs to be dried in an inert gas atmosphere, generally filled with nitrogen. The closed circulation spray drying system is mainly used for products containing alcohol and flammable and explosive solvents in the slurry, or products which are easily oxidized and cannot be exposed in the air. By filling inert gas such as nitrogen, it can prevent the product from contact with air. The product produced by this plant has good consistency and good fluidity, and can produce spherical materials. Thus the plant is more suitable for high-precision ceramics (such as tungsten carbide, silicon nitride, and nano-ceramics), cemented carbide such as tungsten carbide powder, and pharmaceutical intermediates and etc..

Product details

Technical parameters

Notes:

⒈The equipment of the above specifications is suitable for the research and development and spray granulation for a small amount of products, small batch production or large-scale production and etc.;

⒉The evaporation of ethanol is based on the hot air inlet temperature of 140 ℃ and outlet temperature of 70 ℃.

Model BYP-20 Pilot closed-cycle centrifugal spray dryer

Commercial size Model BYP-30 closed-cycle centrifugal spray dryer

Application

For the sealed-circulation centrifugal spray drying machine , it is suitable for drying the solution, emulsion, suspending liquid and pasty liquid containing organic solvents, volatile poisonous and harmful gas, material which is easily oxidized and afraid of light and needs to be solvent recovery . It not only inherits all the advantages of centrifugal spray drier , but also there is no powder flying outside when drying operation . It can achieve 100% material collecting rate. Through the solvent recovery system ,the collected solvent through secondary processing , it can be recycled, which greatly reduces the production cost. Favored by the majority of users, which is widely used in the pharmaceutical, chemical, food and other industries drying operation.

Definition of closed-cycle spray drying

Closed cycle spray dryer in the drying chamber will be sealed into the mist droplets dispersed solid to liquid and hot medium (nitrogen N2) was dried droplet method of powder products. Atomized by rotary atomizer or a nozzle atomizer to achieve, droplet drying can be adjusted by the temperature or the flow of heat medium to be controlled, evaporation of the solvent to be recovered through the condensation unit, after "removal" and full " dewetting "of the media were highly efficient filters and returned to heat exchanger, and finally recycled into the drying system.

The success of closed cycle spray drying washing and cooling operation requirements will be part of an accurate temperature control. For high boiling point of alcohol generally cooling water or salt water, low boiling point solvents such as dichloromethane, hexane, acetone and the like, you must use compression refrigeration system heat exchange.

Spray drying has developed into the most successful technology for powder drying in the pharmaceutical, food, chemical, and metallurgical industries since the development of drying technology for skimmed milk in Europe in the early 20th century. Especially in recent years, spray drying is a drying form that directly forms liquid slurry into powdery materials and is most widely used in other industries. Spray drying is a drying process in which the raw material liquid is dispersed into droplets with an atomizer, and hot air (or other gas) is directly contacted with the droplets for heat transfer and mass transfer heat exchange to obtain a powdery granular product. The raw material liquid can be a solution, an emulsion or a suspension, or a molten liquid or a paste. The dried product can be made into powder, granule, hollow sphere or pellet form as required. From the perspective of the classification of spray dryers: according to the direction of air flow, there are parallel flow (cocurrent), counter flow and mixed flow; according to the form of atomizer, there are centrifugal, pressure, and air flow; According to the production process, there are mainly two types of open and closed cycles (In subdivision, there are also two types of self-idling cycle and semi-closed cycle).

Physical photo of Model BYP-12 Lab Size closed-cycle centrifugal spray dryer

1. Outline of explosion-proof closed-cycle centrifugal spray dryer

1.1 The composition of the explosion-proof closed cycle centrifugal spray dryer system

Xiandao’s explosion-proof closed-cycle centrifugal spray dryer system (Figure 1) consists of a centrifugal spray dryer host, a heater with an air filter, a blower, a water-gas separator, a cooling tower, a spray tower, an exhaust fan, It consists of two-stage cyclone separator, two-stage cyclone separator, pump, oxygen meter, pipeline and control valve.

1.2 Plant Work Principles

Sealed circulation spray dryer works in a seal circumstance. The drying gas is usually inert gas, such N2 . It's applicable for drying material with organic solvent, toxic gas and the material easy to be oxidized. adopt inert gas as circulation gas, so to protect the material to be dried. The inert gas circulates after dehumidification process. N2 is heated and then enters into drying tower. Liquid material is conveyed to centrifugal nozzle by screw pump, and then it's atomized into the liquid mist by the atomizer, the heat transferring process is finished in the drying tower. The dry product is discharged at the bottom of tower, the evaporated organic solvent is sucked by the vacuum generated by the fan. Powder or solid material will be separated in the cyclone and sprinkling tower. The saturated organic gas is drained out after it's condensed in the condenser. The gas not condensed recycles in the system after it's heated continuously. Ordinary normal centrifugal spray drying process is realized by air conveying and exhausting process. This is the obvious difference between explosion proof type sealed circulation centrifugal spray dryer and ordinary centrifugal spray dryer. The drying media in drying system is N2 , the interior is under positive pressure. To keep positive pressure stable, the pressure transmitter controls the inlet amount of N2 automatically.

1.3 Explosion-proof closed cycle centrifugal spray dryer system work instructions

Firstly, the heated nitrogen is filled into the drying tower. The dried liquid material is transported to the centrifugal nozzle by the infusion pump. The liquid material is atomized into fine droplets by the high-speed rotating centrifugal atomizer. The droplets are heated in the drying tower. Nitrogen conducts sufficient heat exchange, the liquid part of the material is instantly evaporated, the powdery material formed by the solid part sinks to the bottom of the tower, and finally the dry powdery material is discharged from the bottom of the tower. Among them, the evaporated organic solvent gas is subjected to a cyclone separator, spray tower and other devices to remove the dust attached to the gas under the action of a fan, and then the saturated organic solvent gas after the dust removal is condensed into a liquid through a condenser. Condenser. In the meantime, the non-condensable inert gas as the drying medium is continuously heated and then recycled as a drying carrier in the system. Conventional ordinary centrifugal spray drying achieves the purpose of dehumidification through continuous air supply and exhaust. This is also an obvious difference between explosion-proof closed centrifugal spray drying equipment and ordinary centrifugal spray drying equipment.

The explosion-proof closed cycle centrifugal spray drying system works in a closed environment. The drying medium is an inert gas such as nitrogen. The drying tower is operated under positive pressure. If the internal pressure drops, the pressure transmitter can automatically control the nitrogen entering To ensure the system pressure balance. Because nitrogen is used as the circulating carrier, it has a protective effect on the dried materials. The circulating carrier such as nitrogen plays the role of moisture-carrying, dehumidifying and circulating transmission, and the carrier medium can be reused. However, conventional ordinary centrifugal spray drying achieves the purpose of dehumidification through continuous air supply and exhaust, and the control in the tower is negative pressure operation. This is also the explosion-proof closed centrifugal spray drying system and the ordinary centrifugal spray drying system. Obvious difference. Therefore, the explosion-proof closed cycle centrifugal spray drying system is especially suitable for drying organic solvent materials, toxic materials, and materials that are prone to oxidation during the drying process.

1.4 Plant main configuration instructions

Features :

1.4.1.The system technology of the equipment is designed for explosion proof in the main body and key parts of the equipment as to ensure the safety of equipment operation.

1.4.2 In the system it has condensing system and solvent recovery system to the solvent of the liquid material .the recovery system can make second processing the solvent in the drying solution and let the solvent recycle, thus greatly reducing the production cost.

1.4.3 For the heating system for the machine , it is very flexible. we can configure it based on the customer site conditions such as steam , electricity , gas furnace and so on , all of them we can design it to match our spray dryer.

1.4.4 The feeding pump , atomizer ,blast fan and the suction fan are with the inverter.

1.4.5 The main parameters such as the inlet temperature , main tower temperature and outlet temperature are adjusted by the temperature meter . The machine has the main tower pressure testing point , air inlet pressure testing point , air outlet pressure testing point, the oxygen testing point and so on . Once machine run , you can see everything clearly .and very convenient for the user to operate it . The main electrical components are international brand and which can ensure the electrics run reliable and safely.the Electrical control are adopted sequential interlock interlock, super temperature, fault alarm and other measures to ensure the safe operation.

1.4.6 The inlet temperature are controlled,displayed and alarmed by the intelligent digital thermometer to ensure constant inlet temperature.

1.4.7 The outlet temperature value are specified through the inverter adjusting the feeding rate .

1.4.8 The main control points as bellow:

1.4.8.1. To adjust the diaphragm pump by inverter or manual to control the The liquid flow rate；

1.4.8.2. The speed of the atomizer are controlled by the inverter( control the line speed and particle size), with oil pressure control and alarm system;

               1.4.8.3. Air inlet has the temperature control system and pressure display device ;

               1.4.8.4. The blast fan use inverter to control the are rate and air pressure ；

1.4.8.5. The suction fan use the inverter to control the air rate and air pressure , and control system pressure ;

               1.4.8.6. The system has the Nitrogen implementing and empty device ;

1.4.8.7. The system has the device for testing the Nitrogen as to ensure the equipment run smoothly and safely;

              1.4.8.8. The cloth bag filter has pulse blowing-back system;

1.4.8.9. The outlet air has the temperature control system and pressure display device;

              1.4.8.10. The condenser has liquid level control system;

              1.4.8.11. Air-liquid separator has the liquid level control system;

The new technical concept formed by the innovation of the explosion-proof closed-cycle centrifugal spray dryer system

2.1 The closed loop system is applied to the explosion-proof centrifugal spray dryer, and it is the first domestic application in the pharmaceutical industry

Xiandao's explosion-proof closed-cycle centrifugal spray dryer system uses a closed-cycle spray dryer with inert gas such as nitrogen. The atomization form of the spray is centrifugal, using heated and filtered nitrogen in the positive pressure closed-circuit drying system Circulation, with liquid materials to see heat and mass transfer, complete the drying of materials and the removal of solvents, and use condensation separation technology for organic solvent recovery, and spray treatment and gas-liquid separation technology to recover the solvent The trace solvent in the gas is recovered twice to make the nitrogen enter a new cycle. Therefore, the system has high explosion-proof safety, high material recovery rate, and extremely low product residual solvent content, which is very suitable for application in the production of bulk drugs. However, the pilot company’s explosion-proof closed-cycle centrifugal spray drying system has been successfully used in the production of the pharmaceutical industry. It has escaped the limitation that the original closed-cycle spray drying can only be applied in fine chemicals, and the atomization uses both classic and innovative The frequency conversion centrifugal spray technology, from this perspective, is a pioneer in the application of centrifugal spray drying technology and is a domestic initiative.

2.1.1 The centrifugal spray and frequency conversion technology are applied in the closed cycle spray drying system to achieve the purpose of energy saving, quality preservation and practicality.

In spray drying, there are three types of material atomization: pressure spray, air flow spray and centrifugal spray. For pressure or airflow spray, the material atomizer is a spray gun or nozzle, with 1 to 4 spray guns or nozzles. Among them, the pressure required for pressure atomization is 10MPa～12MPa, and the pressure will be provided by a high-pressure pump, which consumes a lot of power; the airflow type spray atomization is produced by compressed air, and the compressed air consumption is 4m3/min～8m3/ min, consume a lot of compressed air and generate energy. It can be seen that these two forms of atomization have a large energy consumption side.

The centrifugal spray material atomization is caused by the centrifugal force in the high-speed turntable that is thrown out from the edge of the disc. When the liquid is injected into the disc surface, the liquid is subjected to two forces. One is that the centrifugal force and gravity are accelerated to split the mist. The second is that where the liquid and the surrounding air contact the surface at the same time, there is friction to promote the formation of droplets. The former is centrifugal atomization, and the latter is velocity atomization. In fact, the two exist at the same time, which is the centrifugal atomization. The above characteristics of the device can effectively ensure the uniformity of the droplets and achieve the uniformity of the spray. This feature can meet the requirements of good uniformity, fluidity and solubility of the API product. At the same time, its atomization turntable only relies on electricity as its power, and its power consumption is relatively low compared with the above two atomization forms. However, when the traditional centrifugal atomizer is started and stopped, the pressure will fluctuate (that is, the pressure increases from small when starting, and the pressure decreases from large when shutting down). The instability of pressure will affect the atomization of materials In effect, insufficient pressure will cause the atomized liquid material to be in the shape of a water column, thereby causing waste of materials or unqualified products. Pioneer Company’s explosion-proof closed-cycle centrifugal spray dryer faces this problem and adopts a centrifugal turntable with variable frequency speed regulation to effectively overcome the above-mentioned pressure fluctuations and ensure the quality of the product. Its centrifugal rotation speed is between 10000rpm and 25000rpm. The frequency conversion is adjustable, and the speed of the atomizer can also be adjusted according to the required particle size of the material (120 mesh-400 mesh).

2.1.2 Closed loop technology solves the application of centrifugal spray dryer in the production of organic solvents, toxic gases and easily oxidized materials

Because inert gases such as nitrogen have the properties of explosion-proof, flame-retardant and anti-oxidation, nitrogen is used as the carrier of mass transfer and transfer, and the entire centrifugal spray drying system is in a closed loop. This technical concept can solve the problems in the production of pharmaceutical raw materials in the past. Several problems often encountered:

2.1.2.1 It can solve the problem of difficult drying of materials containing organic solvents in the production of APIs. Generally, organic solvents are flammable and explosive. The application of this technology can enable materials to circulate in a closed drying system and avoid organic solvents. The contact between the gas and the outside oxygen and air ensures safe production;

2.1.2.2 It can solve the problem of difficult drying of easily oxidized materials in the production of raw materials. This technology uses the oxidation resistance of nitrogen. Improve the quality of dry production of easily oxidized materials;

2.1.2.3 It can solve the problem of toxic gas pollution in the production of some raw materials, and some materials or solvents will produce toxic gases when gasified. This technology will make these toxic gases generated in the system sealed and collected in the subsequent process to reduce environmental pollution , Which is conducive to environmental protection.

2.1.3 Application of spray and solvent recovery technology to achieve improved yield, energy saving and environmental protection effects

Compared with the traditional open spray drying system, the explosion-proof closed cycle centrifugal spray drying system not only applies the closed cycle technology, but also organically applies the spraying and solvent recovery technology in it. The response is the most concerned by people The concept of improving yield, energy saving and environmental protection is also the practical aspect of its technology applied to the production of pharmaceutical industry. These two technologies are spray washing of the wet heat carrier after solid-gas separation, and further collect the fine materials attached to the wet heat carrier to improve the material yield. At the same time, it also plays a washing role for the next condensed solvent recovery process to improve the purity of the recovered solvent (effective solvent content is 99.9%), so as to facilitate the reuse of the recovered solvent and save energy. In addition, these two technologies can also recycle volatile solvents, achieving the goal of environmental protection.

2.2 The application of pressure difference automatic transmission and online oxygen detection technology makes the system safer and product quality more assured.

2.2.1 New concept of pressure difference automatic transmission technology

The traditional open spray drying system is a negative pressure operation. Based on the original explosion-proof spray dryer with a safety vent device, the company designed the explosion-proof closed-circulation centrifugal spray drying system as a positive pressure inert gas cycle and used it In addition to the pressure difference automatic transmission technology, this technology is rarely used in this system in China. The explosion-proof closed-cycle centrifugal spray drying system has a working pressure of 0.1MPa and has the characteristics of normal pressure operation. One is that the container and pipeline itself have a higher safety factor; the other is that the positive pressure can better control the system's nitrogen and other inert gases run. The pressure difference automatic transmission technology can ensure: when the nitrogen pressure consumed by the system for drying is lower than the working pressure of 0.1MPa, the nitrogen charging valve will automatically open and inflate; when the pressure reaches the working pressure of 0.1MPa, the nitrogen charging valve will automatically close. Production is safer. At the same time, the drying tower itself is equipped with an explosion venting device such as an explosion-proof membrane. When the system pressure rises to 0.2MPa, the explosion-proof membrane will automatically open and release the pressure to ensure equipment safety. The combination of these two technologies can effectively eliminate the hidden dangers of overpressure or explosion even if there is static electricity generated by powder friction accumulation or gas vaporization expansion during drying production, which causes the pressure in the system to rise. Equipment and production safety.

2.2.2 New concept of online oxygen detection technology

The system applies online oxygen detection technology, which is not available in other spray drying systems in China. Its purpose is twofold: one is to prevent the spray drying system from malfunctioning and causing leaks, which can further ensure safe production; the other is to prevent leakage from leaks. Oxygen affects the purity of nitrogen to ensure that the product is not oxidized to ensure the quality of the product. The explosion-proof closed cycle centrifugal spray drying system is equipped with oxygen online detection. The online oxygen detection device can set the system oxygen residual volume to 10ppm. When the system oxygen volume exceeds the set value, it will sound and light alarm, and automatically Cut off the power to show that there is a leak in the system, and you can take effective measures to adopt the application.

2.3 The application of intelligent automatic control technology has upgraded the traditional centrifugal spray drying equipment

There are few products that can implement PLC intelligent control on many domestic centrifugal spray equipment, so that the domestic products of this kind are still at the middle and low level. Intelligent automatic control technology is the basic means for product upgrades, and it is also an applied new technology. One of the implications of the idea. When the company developed this product, the explosion-proof closed-cycle centrifugal spray drying system adopts PLC programming operation control, which can dynamically display the entire process flow and process parameters, and can select process parameters in a menu or set parameters according to process requirements. Process parameters can also be stored and printed. This product can achieve over-temperature and super-oxygen interlocking alarms while having online temperature testing and automatic adjustment control. These intelligent control technologies appropriately highlight the signs of modern equipment and also reflect the explainability and traceability required by cGMP. Therefore, this is the special feature of this type of equipment used in the production of the pharmaceutical industry, which will help improve the management of modern pharmaceutical production.

2.4 Innovative mechanical seal non-leakage technology effectively solves the leakage problem of such systems.

It is a difficult problem to solve the leakage in the domestic spray drying system, and there are not many manufacturers that can have an effect on this problem. For the explosion-proof closed-cycle centrifugal spray drying system, the key is to achieve no leakage. In order to achieve safe production, it is particularly important that the drying system does not leak. For this reason, the company adopts high-precision mechanical sealing technology at the flange and pipeline connection. The connecting flange adopted adopts the grinding process and the traditional scraping and grinding process to ensure the fit of the flange contact surface. The degree is more than 95%. Among them, the flange welding process is created to make the flange welding not deformed, and the parallelism after welding reaches 100%. Through the assembly of high-precision processing technology, it effectively ensures that the entire drying system is leak-free.

Brief analysis of the explosion-proof safety of the explosion-proof closed cycle centrifugal spray dryer system

There are often many organic solvents in the production of the pharmaceutical and chemical industries. Once some high-concentration volatile organic solutions are used for spray drying or spray drying of some easily oxidized materials, the drying process will have very large risks, such as volatilization. Sexual gases or organic solutions are very easy to explode in the air, causing damage to the equipment itself or injury to the operator. In order to ensure the safety of equipment operation and production, the explosion-proof closed-cycle centrifugal spray dryer developed by Pioneer Drying Equipment Co., Ltd. is based on a fully enclosed basis, and is equipped with explosion venting membranes, explosion vents and pressure detection on the body System, this can effectively curb the occurrence of the above phenomenon and protect the personal safety and the safe operation of the equipment.

(1) The system process design of the equipment is fully enclosed to meet the basic requirements of the explosion-proof type, and its safety is guaranteed through the fully enclosed design. The material works in a fully airtight environment, and the system has no leakage under a pressure of 0.5 MPa, and the material does not directly contact the air, ensuring the safety of equipment and personnel.

(2) Explosion venting discs are also arranged on the main body and key parts of the equipment, so as to ensure the safety of equipment operation in the system and structure. It should be noted that there is no explosion venting device for systems with volatile toxic and harmful gases.

(3) Many spray dryers in China do not have the explosion-proof function, and most of them are open systems, which makes their application range very narrow and the utilization value of the equipment is not high. For example, the drying of catalysts in the chemical industry (most of the catalysts contain volatile gases such as alcohol) requires explosion-proof devices and a closed design to a large extent. Solvents can be subjected to secondary treatment, while inert gas is used as a drying carrier to ensure that the materials are in operation Time is not oxidized, classical and practical control methods, process parameters can be freely. Therefore, the explosion-proof closed cycle centrifugal spray dryer can be equipped with complete and complete alarm devices to ensure peace of mind during equipment operation, which not only reduces costs, but also ensures the safety of the system.

Features and applications of explosion-proof closed-cycle centrifugal spray dryer

4.1 The main features of the explosion-proof closed cycle centrifugal spray dryer

(1) The connection of each pipeline of the closed system adopts a unique sealing structure, which has good airtightness, which can ensure that the system has no leakage under a pressure of 0.5MPa and has high thermal efficiency;

(2) Using inert nitrogen gas as the drying medium gas, it is anti-virus, anti-oxidation and anti-explosion. The gas can be reused after being wetted and dehumidified;

(3) The system is equipped with a condensation system and a recovery system for the solvent of the drying material liquid, so that the solvent in the drying material liquid can be recycled through secondary treatment, and the material can be dried in a closed state and a nitrogen environment in a hot state (solvent Remove) and recover the solvent through the condenser, the safety of the whole machine is high. At the same time, the equipment is a fully enclosed design, and the material recovery rate is high. The high yield of this equipment system is not achieved by other types of dryers. Main technical indicators: dry powder material recovery rate ≥95%, product residual solvent ≤2%, thus greatly reducing production costs;

(4)The drying speed is very fast. After the material liquid is sprayed, the surface area increases. In the high-temperature airflow, 95%-98% of the water can be evaporated instantly, and the drying time generally only takes about 5-40sec;

(5) Spray drying is usually used to process solutions with a moisture content of 40%-60%. It can be dried into powder products at one time. Most products do not need to be crushed and screened after drying, thereby reducing the production process and simplifying the production process. At the same time, the product has good dispersibility, fluidity and solubility. Because the drying process is completed in the air, the product instinctively maintains a spherical shape similar to the droplet phase, and has good fluidity.

(6) The equipment has an online system pressure test device, an online oxygen concentration detection and control device, and an on-site cleaning device;

(7) The equipment control system adopts man-machine interface, namely PLC + touch screen control, and the process flow chart is displayed dynamically. The particle size, bulk density, and moisture of the product are within a certain range and can be adjusted by changing the operating conditions, which is more convenient to control.