Descripción general del equipamiento
Traditional Chinese medicine (TCM) extracts are obtained from the roots, stems and leaves of plants. Those produced by alcohol extraction in particular have a high sugar content and tend to soften and melt at high temperatures, so ordinary centrifugal spray drying can no longer meet the drying requirements. In response to this situation, our company assembled a team of capable technical personnel, summarized the successful experience gained over the years in designing and manufacturing spray dryers at our plant, gathered the advantages of similar products from peers at home and abroad, and, through precise and repeated process calculations and countless experiments, developed a spray dryer unit dedicated to traditional Chinese medicine, which has since been promoted and put into use in pharmaceutical plants.
The Traditional Chinese Medicine Extract Spray Dryer mainly uses a high-speed centrifugal atomizer to atomize extracts, aqueous solutions, organic solvents, suspensions, extracts and similar materials containing TCM ingredients into fine droplets. These droplets come into full contact with hot air and complete evaporation and drying in an instant, forming a powdery finished product. During this process the active ingredients of the TCM are retained, without requiring excessive heat energy or solvents. The equipment is widely used in the TCM pharmaceutical industry for producing TCM granules, TCM decoction pieces, TCM powder and other products. It can also be applied to the drying of similar materials in the food, chemical and other industries.
Principio de funcionamiento
The high-speed centrifugal spray device for TCM extracts is an application of centrifugal spray drying technology to the drying of a specific material. It is a drying device that uses a high-speed centrifugal atomizer to disperse the material into a mist, which comes into full contact with hot air, completes drying in an instant and forms a powdery finished product. The machine adopts a fully enclosed design, all components are made of stainless steel, and it is equipped with a three-stage purification device, so that the filtered air meets the Class 100,000 requirement. The cylinder and the top are fitted with cold-wall devices, keeping the wall temperature below 80°C, and the drying tower is equipped with an air-brush tower-sweeping device. The TCM extract powder dried by this machine shows no scorching or deterioration, greatly increasing the powder recovery rate (above 95%), and produces neither cross-contamination between drugs nor wall sticking.
Main Structure
(1) Hot air system: supplies hot air and serves as the heat source of the drying process. Parameters such as hot air temperature, flow rate and air velocity have an important influence on the drying effect.
(2) Atomization system: usually composed of an atomizer, a peristaltic pump, a feed pipe and other components. The atomizer converts the liquid TCM extract into fine droplets so that it can fully contact the hot air and dry faster.
(3) Drying tower: the main site where the material is dried. Inside the tower the droplets exchange heat with the hot air, moisture evaporates rapidly, and the material gradually dries into powder.
(4) Sistema de tratamiento de gases de escape: treats the exhaust gas generated during drying to reduce environmental pollution. Treatment methods usually include filtration, adsorption and washing.
(5) Sistema de control: controls the operation of the entire unit, including monitoring and adjustment of parameters such as temperature, pressure and flow rate, ensuring stable operation and consistent drying results.
(6) Material collection system: collects the dried TCM powder for subsequent processing or packaging.
Características del equipo
(1) Alta velocidad de secado: thanks to spray drying technology, the material contacts the hot air in an instant and evaporates and dries rapidly, greatly shortening the drying time.
(2) Suitable for heat-sensitive materials: during drying the droplet temperature remains relatively low, so heat-sensitive components in the TCM are not destroyed, safeguarding product quality.
(3) Buena calidad del producto: the TCM extract is dried uniformly into powder, with a uniform particle size distribution and good flowability, making it easy to store and transport.
(4) Compliant with GMP requirements: the parts in contact with the material are normally made of stainless steel and feature good sealing and cleanability, meeting the GMP requirements of pharmaceutical production.
Mejoras técnicas
The Traditional Chinese Medicine Extract Spray Dryer is a spray dryer specially designed and manufactured by Longxin Drying for plant extracts and TCM extracts, addressing the high sugar content of extraction liquids. Combining similar spray drying technology from abroad with the practical experience our technical personnel have accumulated over the long term, we have achieved the following in the design of TCM extract spray dryers:
(1) Specially designed volute and hot air distributor: to avoid the "vortex pumping" airflow phenomenon caused by the high-speed rotating atomizing disc, which leads to droplets returning to the top or powder being drawn to the top, the specially designed main spray drying tower (rapid-inlet structure), hot air volute and hot air distributor ensure that the atomized droplets do not return to the top; combined with primary air cooling technology, this prevents the material from returning to the top and being heat-melted, scorched or deteriorated.
(2) The tower diameter and tower height have been adjusted accordingly, ensuring both that the material does not touch the tower wall before drying and that the material has sufficient residence time in the hot air. The tower wall is fitted with a jacketed cooling air device to ensure that material adsorbed on the wall does not soften, melt or even scorch due to excessive local temperature. The cone angle is enlarged and an air knocker is installed on the cone body, using compressed air to pulse-strike the cylinder so that powder adhering to it falls off smoothly.
(3) All material-contact points inside the main machine adopt flat or arc transitions, and all contact surfaces are ground and polished (fine-polished to above grade 10) to avoid sand holes and dead corners and to eliminate material accumulation and blockage. All parts of the unit in contact with the material are made of stainless steel to ensure the material is not contaminated. All transmission parts in contact with the material are well sealed and are waterproof and oil-proof. The discharge point is operated with a sealed butterfly valve to prevent air leakage. All sections of the induced-draft discharge pipe use flexible connections and can be dismantled, reassembled, cleaned, disinfected and sterilized at any time.
(4) Rotary sweeping device on the TCM extract spray drying tower wall: designed specifically for the characteristics of TCM extract materials, namely high sugar content and easy softening and wall sticking at high temperatures. It effectively solves the wall-sticking problem of TCM extract materials and avoids material deterioration caused by material remaining on the tower wall for a long time; in severe cases of wall sticking, production may even become impossible.
(5) The air pretreatment system adopts three-stage filtration — primary, medium and high efficiency — purifying the air to Class 100,000.
(6) Refrigerated dehumidification, air-conveying and cooling collection device: it enables the material to leave the high-temperature zone quickly and cool down, avoiding the softening and caking that occurs when material stays for a long time in the high-temperature zone at the cyclone separator, and also preventing hygroscopic materials from absorbing moisture and caking.
(7) The elbow from the main drying tower to the cyclone separator is made from one-piece formed 304 stainless steel smooth pipe to prevent material build-up, and is connected with quick-opening clamps for convenient wastewater discharge during cleaning.
(8) This unit adopts a PLC program control system loop. The touch screen displays the process flow with animation and is operable; variable operating parameters are adjusted by automatic fuzzy-technology tracking; a frequency converter is used to adjust the atomizer stably and safely; inlet and outlet air temperatures and the pressure inside the tower are digitally displayed and can be set precisely.
Technical Parameters
Ordering Information
(1) Nominal water evaporation capacity: calculated on the basis of an inlet air temperature of 180–220°C and an exhaust air temperature of 70–90°C.
(2) Standard specifications: the specifications listed here are standard specifications named after the nominal water evaporation capacity.
(3) Process specifications: for a specific machine, our company can also name a specific process specification according to the evaporation capacity of the actual process. For most products with temperature resistance of 110°C or above, the process specification is roughly equivalent to the standard specification.
(4) Product yield: according to customer requirements and product characteristics, we can supply various product recovery devices to ensure that the customer's relevant requirements are met.
(5) Testing: our company keeps excellent prototype machines among domestic peers and can carry out various tests for customers, ensuring that the equipment meets the customer requirements specified in the contract.
(6) Configuration: see the flow chart and related descriptions.
(7) Design advancement: in designing the relevant parameters of our equipment, we have taken into account both production requirements and energy-saving requirements. For the same specification and output, we can provide more energy-efficient designs and products. For medium and large equipment, thermal efficiency can generally reach 37–50%, meaning that evaporating one kilogram of water requires approximately 2–2.7 kilograms of steam.
Process Flow Charts
Process Flow Chart 1 — Conventional
Process Flow Chart 2 — Cooling Conveying + Centralized Material Collection
Process Flow Chart 3 — Tower Wall Air Cooling + Rotary Air Sweeping + Cooling Conveying + Centralized Material Collection
