Author: Site Editor Publish Time: 09-14-2026 Origin: Site
A complete milk powder production line integrates raw material reception, standardization, pasteurization, homogenization, evaporation/concentration, spray drying, powder cooling, and final packaging, while also incorporating cleaning and control systems.
The entire production line can be viewed as comprising four interconnected sections:
1. Standardization system
2. Concentration and drying system
3. Finished product packaging system
4. Cleaning and control system
While equipment configurations may vary depending on the specific product, these four sections form the fundamental structure of a milk powder production line.
A production system is not equivalent to a single piece of equipment.
In a milk powder production line, a system typically comprises more than just one major piece of equipment.
For instance, an evaporation and concentration system requires not only an evaporator but also preheating equipment, vacuum systems, condensing units, transfer pumps, buffer tanks, instrumentation, valves, and control programs.
Therefore, assessing the completeness of a production line requires looking beyond the names and quantities of the equipment; one must also verify that each system is fully equipped for transfer, monitoring, control, and cleaning operations.
The standardization processing system is responsible for receiving raw materials and carrying out filtration, storage, ingredient blending, and heat treatment prior to the evaporation and drying stages.
The ultimate objective of this section is to provide the downstream evaporation system with a continuous supply of liquid material that is consistent in composition, at the appropriate temperature, and compliant with hygiene standards.
Raw Milk Reception and Storage System
If the production line begins with fresh raw milk, a raw material reception and storage system is required.
This system typically includes:
• Raw milk reception unit
• Filtration equipment
• Flow or weight metering devices
• Raw material cooling equipment
• Raw material storage tanks
• Transfer pumps
• Piping and valves
• Temperature and level monitoring devices
Raw material storage tanks serve not only to store the raw material but also to provide a buffer between material delivery and continuous production.
Storage capacity must be determined based on daily raw material volume, transport batches, material inspection times, and production schedules; tank selection should not be based solely on the hourly processing rate.
If the production line receives concentrated milk or other liquid milk-based ingredients directly, this system can be adjusted accordingly, though it must still facilitate material inspection, metering, temporary storage, and stable supply.
Once raw milk enters the production line, visible impurities must be removed, and the levels of fat, protein, and total solids adjusted to meet product specifications.
The system may include:
• Milk clarification equipment
• Milk fat separation equipment
• Standardization equipment
• Buffer tanks
• Heat exchange equipment
• Composition analysis and flow control devices
Fat separation is a necessary step when producing skimmed milk powder. Adjustments based on the fat content of the raw material and the standards for the finished product may also be required when producing whole milk powder.
The composition of raw milk varies depending on the milk source, season, and feeding conditions. The function of the standardization system is to maintain consistent composition despite these variations in the raw material.
Ingredient requirements for standard whole milk powder and skimmed milk powder are relatively simple. However, the production of formulated milk powders, nutritional milk powders, or specialized formula products requires a comprehensive ingredient preparation and mixing system.
Such a system may include:
• Powder feeding units
• Liquid ingredient tanks
• Fat/oil addition units
• Mixing equipment
• Weighing and metering devices
• Filtration equipment
• Raw material conveying systems
An ingredient system must do more than simply introduce raw materials; it must ensure accurate dosing, thorough dispersion of ingredients, and batch traceability, while avoiding residues that are difficult to clean.
Therefore, the ingredient system must be designed based on the specific formulation. Knowing only the product name is insufficient to determine the correct equipment configuration.
The pasteurization system is designed to eliminate microorganisms in milk to achieve commercial sterility and to impart specific properties to the milk powder in accordance with product requirements.
This system typically comprises:
• Pasteurization equipment
• Holding tube
• Temperature control unit
• Buffer tank
Pasteurization conditions affect not only microbiological safety but also protein state, solubility, and other finished product characteristics. Consequently, identical temperature and holding time parameters cannot be applied across different products.
A homogenization system is not a standard component of every milk powder production line. The necessity of homogenization and the optimal placement of the homogenizer within the process flow should be determined based on fat content, formulation composition, and finished product specifications.
Emulsion stability is a key consideration when producing full-fat milk powder or formulated products containing added fats or oils. Conversely, for products that do not require homogenization, the inclusion of such equipment—which would add unnecessary complexity and energy consumption—should be avoided.
The concentration and drying system is responsible for transforming the pasteurized liquid raw material into milk powder; it is the core component of the entire production line for generating the powdered product.
It typically comprises several interconnected subsystems, including evaporation and concentration, high-pressure transfer, atomization, spray drying, fluidization, and powder recovery.
Raw milk contains a significant amount of water. Relying solely on the spray drying system to remove all this moisture would require massive drying equipment and result in a substantial increase in energy consumption.
The evaporation and concentration system removes the majority of the water first, transforming the raw milk into a concentrate with a higher solids content.
The system typically includes:
• Evaporation equipment
• Preheating and heat treatment units
• Vacuum system
• Condensing system
• Concentrate buffer tank
• Product transfer pumps
• Concentration, temperature, and flow monitoring devices
• Steam and condensate systems
The capacity of the evaporation system must be matched to that of the drying system. Insufficient evaporation capacity limits the output of the entire production line. Furthermore, if the outlet concentration is unstable, the load on the drying system and the moisture content of the final product will fluctuate.
Before entering the drying tower, the concentrated milk must be maintained at stable temperature, flow rate, pressure, and viscosity.
The system typically includes:
• Concentrate buffer tank
• High-pressure feed pump
• Filtration unit
• Heating or temperature maintenance unit
• Flow and pressure control units
• Atomization unit
The atomization system disperses the concentrated milk into fine droplets. Droplet size and distribution influence the drying rate, particle size, bulk density, and final product moisture content.
Therefore, the choice of atomization unit must be based not only on production capacity but also on the characteristics of the concentrated milk and the target particle specifications.
A spray drying system brings atomized droplets into contact with filtered, heated air to rapidly remove moisture and form powder particles.
The system typically includes:
• Inlet air filtration unit
• Inlet air fan
• Air heating unit
• Hot air distribution unit
• Drying chamber
• Exhaust ductwork
• Exhaust fan
• Temperature and pressure monitoring devices
• Safety protection devices
The drying tower is merely the most prominent component of the system. Inlet air filtration, air heating, atomization, exhaust, and pressure control all play critical roles in ensuring drying stability.
Only when these components are designed to match the same processing capacity can the spray drying system consistently achieve the target output and final product moisture content.
During the spray drying process, some smaller milk powder particles exit the drying chamber along with the exhaust air. The powder recovery system is responsible for separating these fines from the air stream.
The system typically comprises:
• Cyclone separators
• Bag filters
• Rotary discharge valves
• Fines conveying piping
• Fines return mechanism
The recovered fines can be reintroduced into the drying chamber, the fluidization system, or the downstream powder conveying system.
In the case of agglomerated milk powder, the return of fines also plays a role in particle formation. Therefore, the point of fines reintroduction must be determined based on the target particle structure, rather than simply returning the recovered powder to an arbitrary location.
Once milk powder has undergone drying and cooling, it cannot yet be considered a finished product. It must pass through screening, inspection, conveying, and temporary storage stages before it can be reliably fed into the packaging process.
The powder handling system should be designed to minimize particle breakage, dust generation, moisture absorption, and external contamination.
The screening system is used to remove lumps, oversized or undersized particles, and any potential foreign objects.
This system typically includes:
• Vibrating screen
• Foreign object detection device
• Sampling device
• Dust extraction connection
Screen specifications should be determined based on the target particle size. The screening capacity must exceed the normal powder output of the drying system; otherwise, a new bottleneck will be created between the drying and packaging stages.
Powder Conveying and Temporary Storage System
After sieving, the milk powder must be conveyed to the finished product silo or packaging equipment.
This system typically includes:
• Powder conveying equipment
• Rotary discharge device
• Finished product silo
• Weighing system
• Level detection device
• Sampling device
The finished product silo serves to balance the speed difference between the drying system and the packaging system. It acts as a buffer during brief stoppages of the packaging equipment, preventing the immediate shutdown of the drying system.
The packaging system is responsible for filling packaging containers with milk powder to a specified weight, as well as sealing, inspection, and discharging the finished product.
Depending on the sales format, the packaging system may include:
• Large-bag packaging equipment
• Small-bag packaging equipment
• Canning equipment
• Automatic weighing units
• Gas-filling units
• Sealing units
• Check-weighing units
• Foreign object detection units
• Coding and labeling units
• Finished product conveying units
• Case packing and palletizing equipment
Industrial-grade milk powder is typically packaged in large bags, whereas retail milk powder and formula products may be packaged in bags or cans. Different packaging formats entail varying requirements regarding weighing accuracy, the packaging environment, the level of automation, and dust control.
The actual capacity of the packaging system must not be lower than the powder discharge capacity of the drying system. Otherwise, even if the drying system achieves its design output, the entire production line will be unable to operate continuously.
Automatic control systems link various production systems, regulating flow rates, temperatures, pressures, liquid levels, concentrations, and equipment operating sequences.
These systems typically include:
• Central control units
• Field operation units
• Instrumentation
• Valve and motor controls
• Recipe management
• Production data logging
• Alarms and safety interlocks
• Cleaning process controls
• Batch traceability
If disparate systems operate independently without unified control, operators struggle to promptly determine whether upstream and downstream equipment are synchronized, and cannot accurately trace product batches or identify the root causes of anomalies.
A complete production line requires clearly defined control boundaries to ensure seamless coordination among wet processing, evaporation, drying, powder conveying, and packaging systems.
Dust is generated during the drying, sifting, conveying, and packaging of milk powder.
Dust collection and safety systems typically include:
• Enclosed equipment design
• Localized dust extraction units
• Centralized dust removal systems
• Static electricity control
• Pressure monitoring
• Protection against abnormal conditions
• Safety shutdown interlocks
Dust control cannot rely solely on a single dust removal unit in the packaging area; a unified design approach is required, accounting for specific dust generation points, airflow patterns, and equipment connections.
Specific safety configurations must also comply with local fire safety and dust safety regulations.
A "complete" line does not mean including every piece of purchasable equipment.
The need for a specific system depends on the product and raw materials.
Production of skimmed milk powder
Requires milk fat separation and standardization systems, but typically does not require complex fat-addition equipment.
Production of whole milk powder
Requires a focus on controlling fat standardization, the spray drying process, and cooling of the finished product.
Production of formulated milk powder
Requires the addition of systems for ingredient dosing, mixing, precise metering, and raw material traceability.
Production of instant milk powder
Requires equipment for particle agglomeration, fines recycling, and gentle conveying, as well as surface treatment units depending on product specifications.
Production of infant formula
Requires higher-precision dosing, stricter hygiene controls, comprehensive batch traceability, and a packaging environment suited to product requirements.
Determining whether a production line is complete requires looking beyond the mere number of systems; one must assess whether all systems essential for producing the target product are installed.
A complete milk powder production line is neither a single piece of spray-drying equipment nor merely a simple list of machinery.
It comprises standardized processing, evaporation and concentration, spray drying, fluidization, powder recovery, powder conveying, and finished product packaging, alongside cleaning and control systems.
Different milk powder products require different system configurations. A truly complete setup ensures that all necessary stages—from the entry of raw materials into the line to the packaging of the finished, compliant milk powder—are seamlessly integrated and operate reliably.
