Spray drying plant A1-OR2CH is designed for drying the concentrated skim and whole milk, natural cream and cream with the content of natural vegetable fat, substitutes of whole milk, milk and milk-containing formula - with a fat content up to 50%, and the concentrated cheese, curd and casein whey, for drying melange, blood and yeast.

The plant can be used at enterprises of milk, butter-making, cheese-making and other sectors, is manufactured in accordance with the principles of HACCP.

The plant A1-OR2CH is concurrent spray dryer with centrifugal rotary spraying, upper feeding of the heat carrier, vertical cylindrical chamber and the bottom of the fluidized bed of the product with the following cooling in the vibrating cooler. Air heating is carried out by the heat generator (air heater). Separation of the powder product is in cyclones and/or cleaning system with fabric filters.

Depending on the preferences of the customer, the type and quantity of the processed product the drying plant can be made one, two or three-stage, with different capacity, equipped with one or a row of cyclones, the system of fabric filtration, the system of automated CIP cleaning (drying chamber, air feed pipes, cyclones, pneumatic transport and other units), heat generator or air heater, different level of automation.

Drying plant А1-ОR2Ch. Main characteristics.
Name Parameters
Capacity by evaporated moisture,
at Т of heat carrier 180-200 °C, not less than,
kg/h, that corresponds by the finished product:
 - skim milk powder (with solids 40-48%)
 - whole milk powder (with solids 40-48%)
 - crystallized cheese whey (with solids 58%)
300


300-350
300-350
450
600


600-650
600-650
750
1100


1050-1150
1050-1150
1200
Installed power, kW 75 125 210
Power consumption during operation, kW, not more than 45 90 170
Gas consumption, m3/h:
 - nominal
 - maximum (m3/h from 0 °C to 200 °C)

45
60

90
112

180
204
Steam, kg/h not applicable
Compressed air, nm3/min 6 6 6
Ice water, m3/h, (at Т of ice water = 2 °C) not more than 4 6 8
Volume of fed air at Т = 20 °C, not more than, m3/h 7500 15000 35000
Volume of exhaust air at Т = 90 °C, not more than, m3/h 12000 26000 52000
Temperature of heat carrier heating, °C 180-200 180-200 180-200
Dust emissions into atmosphere, not more than, mg/m3
(at installing fabric filter)

10

10

10
Raw product: skim, whole milk:
 - acidity, not more than, °Т
 - fat presence (skim milk), not more than, %
 - fat presence (whole milk), not more than, %
In dry matter:
 - solids content, %
 - temperature, °C

21
0,05
25

40-48
40-55

21
0,05
25

40-48
40-55

21
0,05
25

40-48
40-55
Raw product: cheese whey:
 - pH, not less than
 - fat presence, not more than, %
 - solids content, %
 - % crystallization, not less than
 - temperature, °C

5,9-6,0
0,06
55 ± 3
60
12-40

5,9-6,0
0,06
55 ± 3
60
12-40

5,9-6,0
0,06
55 ± 3
60
12-40
All parts that contact with product are made from steel AISI 304(12X18H10T) surface class ВА

 

The plant consists of the following main units:

  • Drying chamber.
  • Product feeding system.
  • Heat generator.
  • Cyclones.
  • System of pneumatic transport.
  • System of drying chamber blowing.
  • Maintenance platforms.
  • Extended ladder.
  • Vibrating cooler.
  • Exhaust fan.
  • System of vibrating cooler blowing.
  • System of the top blowing.
  • System of fluidized bed blowing.
  • System of product transport and packaging.
  • Electrical pulley-block.
  • Magnetic and impulse plant with arch destroying.
  • Electrical equipment and automation system.

 

The spray drying plant A1 OR2CH is a set of systems designed to produce pre-packaged and packed milk powder products.

The plant consists of six connected components: the heat generator and its control board, the drying chamber itself, the vibrating cooler, the unit with cyclones and the suction fan, maintenance areas, control and monitoring panel.

The equipment is installed on the floor of the shop on metal structures (maintenance areas). On the floor of the shop there are installed the drying chamber, the product feeding system, the vibrating cooler, the mixing chamber for blowing fluidized bed, equipment for filling and packaging the powder product.

On the sites there are cyclones the mixing chamber for blowing walls of the drying chamber, the suction fan, the extended ladder, the system of blowing the vibrating cooler and the filter with blower. The sites are connected via walkways between themselves and the top of the drying chamber. The heat generator TG-0,95-200 is mounted in a separate room.

Control and monitoring panel designed as cabinet and the automatic switchboard are installed in a separate room, panel of the impulse unit - on the site close to the drying chamber, panel of the heat generator – in the heat generating room.

 

The principle of operation of the plant.

The principle of operation of the plant is in dehydration of the dispersed in the drying chamber into finest particles liquid product by heated air.

Concentrated up to the desired solids content (e.g., whey 50 ... 60%) in the vacuum evaporator or in the other way the products are fed into one of the tanks of the system a liquid product supply equipped with the agitator. Then the concentrated product is fed by the metering pump to the centrifugal disc atomizer that is mounted on the upper part of the drying chamber.

The product is sprayed (dispersed) by the atomizer in the volume of the drying chamber into the liquid particle with diameter of 10 ... 50 micron and forms a spray pattern.

Air in the room is cleaned by the air filter and is supplied by the blower to the gas heat generator and then into the air distributor of the drying chamber. The interaction of flows of the heated air and the pulverized product in the drying chamber results in a process of dehydration of the product drops and the formation of dry solid particles.

The dried product together with the exhaust air via the air feed pipe enter the cyclone where they are separated.

The drying plant can operate in two modes - manual (remote) and automatic. The adjustable parameters are the air temperature at the outlet of the chamber and the temperature of the incoming air.

Stability of the temperature at the outlet that determines humidity of the dry product is supported by a regulated feed to the centrifugal atomizer of the primary product.

The required temperature is determined by the type of product and is specified during adjusting of the plant and is set by the automatic control unit.

Automatic control of the drying process is based on supporting the constant temperature at the outlet of the drying chamber by adjusting feed of the primary product by the metering gear pump. The adjustment is provided by a programmable frequency converter.

 

Powder separation system may include the installed in series cyclones with resistance to 1500 Pa and the fabric filter consisting of a casing, system of fabric filters installed on the frames and interconnected in groups.

Using the fabric filter allows making emissions into the environment according to the EU regulations - up to 10 mg \ m3.

The maximum concentration of the dust before the filter is 350 mg \ m3.

To prevent humidification of fabric of the filters there is installed the fan that blows the heated in the electric fan heater air during stand-by.

Purified from the powder air is fed by the suction fan into the atmosphere and the dry powder via the rotary valves  of cyclones goes to the vibrating cooler for cooling and transporting or returning back in the spray zone of the drying chamber for receiving the product of increased solubility. Second, the largest part of the product is deposited on the laced bottom for final drying in the fluidized bed (formed by the flow of hot air through the holes in the grid) and also enters the vibrating cooler where the final drying and cooling of the whole mass of the product are carried out. The exhaust air from the vibrating cooler suction is fed by the suction fan via the cyclones to the atmosphere. The powder product from the vibrating cooler goes to the vibratory separator for separation and after that is sent by the vacuum or pneumatic transport to the packaging unit.

The air before feeding into the vibrating cooler is cooled and partially dehumidified in the air cooler and is prepurified in the pocket filters.

 

The system of impulse and dynamic cleaning is a set of equipment for cleaning the inner surface of the drying tower and cyclones from the adhered product. It includes the power unit, the control panel, the set of actuators, high-voltage cables, control cables and brackets. The actuators are mounted on the drying chamber and at the inlet of the cyclone.

The principle of operation of the plant: the power unit generates a powerful pulse of current in the inductor coil. The magnetic field of the inductor created by this pulse induces a current pulse in the plate installed near the inductor. The interaction of pulse currents makes the plate have pulse mechanical impact on the cleaned surface that leads to a local elastic deformation in the surface to be cleaned and in the adhered matter – to arising of shear stresses and destroying the integrity of the layer adhered product, destroying the adhesion to the surface and allowing brushing of deposits. The strength of the mechanical effect and the number of pulses are regulated for the selection of the best mode for cleaning.

 

Fire extinguishing system based on automatic steam supply into the drying chamber at exceeding the allowable temperature of the air in the drying tower.

Control over fire safety is carried out automatically by the temperature control by the automation system. The drying chamber has two drying explosive valves. The signal from the system is automatically sent to the solenoid valve which is installed on the steam pipe.

The plant control is centralized and carried out by the monitoring and control panel, the automation switchboard, the panel of magnetic and pulse unit, the panel of the heat generator in which the control devices and automatic adjustment, launch protection equipment and controls (buttons "start - stop") are mounted.

Control and monitoring cabinet is executed as a unified construction. The used electrical devices and control devices are from companies Simens, Legrand, Telemechanik, Wago and others.

For the convenience of the control the plant is completed with a computer that allows monitoring and archiving its operation settings.

SCADA-system of the top level on the basis of the software WinCC from Simens allows displaying all the parameters of the process on a computer screen, monitoring the operation of the plant and archiving the operation parameters for a certain period and setting the parameters of the drying plant remotely from the operator's station.

Automatics provides visualization:

  • load currents of engines of: the suction fan, the blower, the atomizer, the pneumatic transport fan;
  • Temperature of: the air at the inlet of the drying tower and at its outlet, primary product, air in the cooler the final product;
  • engine rpm speed of the metering pump;
  • availability of the product in the system;
  • rarefication and excessive pressure in the tower;
  • the product level in the receiving tank of the drying plant and otheroperationparameters.

 

Design and operation of the components of the plant.

Product Delivery System.

It is designed to create a reserve of liquid product prior to drying, its heating or cooling, mixing and dispensing on the spraying device which consists of two tanks with agitators, the water tank, the metering pump, control panels and the set of pipes.

The metering pump is also designed for CIP cleaning of pipelines after the end of the drying process by the circulation in the system of detergents and cleaning of the spraying device.

The tank for concentrate is equipped with the upper top with mounted thereon level sensors, thermal converter for temperature and the agitator with drive.

The motor speed and correspondingly the pump flow are controlled by the frequency converter via variation of voltage frequency. In automatic mode the frequency converter regulates the flow depending on the product temperature at the outlet of the drying chamber.

The set of product lines is made of corrosion-resistant pipes.

 

Heat generator.

It is designed for heating of the pre-purified from dust air and its supply into a drying chamber.

It consists of the air filter, the blower, the heat generator, the filter for the hot air, the duct system with the flap having the mechanical drive and smoke stack.

The plant operates as follows:

The air from the room by means of the fan passes through the air filter where is cleaned from dust and is fed through the diffuser in the heat generator. The heated air from the heat generator through the filter for hot air is fed into the air diffuser of the drying chamber in the mixing chambers of the systems of blowing fluidized bed and walls of the drying chamber.

Adjusting the amount of the supplied air is made by the air flap with mechanical drive that is installed on the hot air pipeline.

The air filter is a rectangular casing on the basement in which the pocket filters are installed.

 

Drying chamber.

Designed for the dehydration process of the atomized liquid product by the heated air and obtaining the dry powder.

It consists of the cylindrical drying chamber with the door, the roof and the bottom, the centrifugal disk atomizer, fences and struts and actuators of the magnetic and pulse plant and is equipped with nozzles for supply the hot air inside the chamber.

The fed liquid product is sprayed in the drying chamber; the hot air that is supplied into the air distributor of the drying chamber goes to the torch sprayed product by an annular swirling flow. The heat and mass exchange of the hot air and the atomized product results in dehydration of the latter with formation of solid particles. Product particles precipitated in the chamber get in the bottom the additional tangential impulse of the hot air fed from the nozzles. Further part of the powder is taken by flow of the exhaust air in the cyclone and the particles deposited on the fluid bottom of the chamber are finally dried in the fluidized bed.

The powder moving in a circle precipitates on the fluid bottom and reaching a certain height layer is poured into the vibrating cooler.

The roof of the chamber consists of three parts executed monolithically with the air diffuser. The air diffuser is an insulated channel. In the central part there are two hatches for illuminating the chamber.

The cylindrical part of the drying chamber is divided into six sections that are assembled end to end via bolted connections and welding of joints of the inner cladding. One section is made with the door and inspection door. The inner cladding of sections is made of corrosion-resistant sheet steel, the outer cladding – of stainless steel. The interior space of sections is filled with insulation.

The pipeline of the supply system in the steam chamber is mounted in the upper part of the chamber.

Powder discharge is made from the bottom of the drying chamber.

The drying chamber is mounted on the ground of the shop on four pillars.

The drying camera is equipped with the air temperature sensor, air pressure sensor in the chamber, door switch and hazard lamp above the door.

 

Exhaust air extraction system.

Is designed for extraction of the exhaust air and the dried product from the drying chamber and the vibrating cooler, their separation in the cyclones and supplying the purified air to the atmosphere; it consists of the system of air pipes, cyclones and the suction fan.

The air from the drying chamber and the vibrating cooler that contain the dry product in suspension are fed via air pipes to the cyclone where they are separated. The dry product from the cyclones goes via the rotary valve into the pneumatic transport; the purified air is fed via the suction fan into the atmosphere. Air line through which the air suction is performed from the vibrating cooler is equipped with the slide damper with the drive for adjusting the degree of vacuum in the latter.

The cyclones are made of corrosion-resistant sheet steel in the bottom of which the actuators of the magnetic and pulse plant are installed.

Pipelines of the system before the cyclone are made of corrosion-resistant sheet steel, their connections are executed as quick-disconnected on tip clamps.

For automatic CIP cleaning the cyclones and pipes can be provided with nozzles.

 

Vibrating cooler.

Is designed for final drying and cooling of the powder during transport it in terms of vibrofluidized bed.

It is a closed chamber on the flexible suspension mounted on the frame. The chamber is made in the form of a box along which the grate is mounted; from the bottom of the grade the air is supplied and from the top the powder is fed. For the convenience of the chamber maintenance it is equipped with hatches and inspection holes.

In the longitudinal respect the chamber is divided into two sections – for the powder and for the air supply. Under the chamber the electric vibrator is mounted creating the perturbative force to vibration. During operation the chamber vibrates; the powder in the suspended state goes through the cold zone with final drying and cooling. Integrated fluid bottom is made of the perforated sheet. The cross section of the holes is calculated for the quantity of air required for boiling of the product.

The system of blowing

The system of blowing the drying chamber and the fluidized bed

It is designed for supply the air of the set temperature into the bottom of the drying chamber and the fluidized bed in order to blow them.

It consists of the fan, the intake filter, the air pipeline with integrated mechanical and manual slide dampers, the mixing chamber and the flexible pipes. The flow of the hot air from the heat generator is regulated by the flap with drive; is controlled by the system that automatically supports the set temperature at the outlet of the fan. The air pressure is adjusted manually by means of the damper.

 

The system of blowing the vibrating cooler.

It is designed for supply of the heated, cooled and conventional air under pressure in the cooling zone of the vibrating cooler.

It consists of the air filter, cooler (heating system), the fans and the system of air pipes. The air filter is designed for air purification and separation of the air flow into two main pipelines. The cooler is designed for cooling and dehumidifying the air supplied to the cooling zone of the vibrating cooler.

The heating system is designed for heating the air supplied to the final drying zone to the first stage of the vibrating cooler.

The filters are removable and mounted in the casing. On the side surface of the cooler there are stub tubes of the air heater for supply and discharge of the ice water.

The droplet separator is designed for collecting water droplets formed at the condensation of air on the plates of the air heater and is a set of vertical zigzag plates arranged in front of the heater.

 

The system of transportation and packaging of the product.

It is designed for screening and transportation of the dry product by the dry air in the mode of the pneumatic transportation, supply of the product to the intermediate tank before filling and packaging.

It consists of the vibroseparator AMCKO, the waste tanks, the flexible pipes, the vacuum pneumatic transport, the hopper, the maintenance platforms and packaging line DREWMAX.

The product from the vibrating cooler goes to the vibroseparator where the product is separated from clumps and solids from the bulk powder. The separated particles are collected in the waste tank and the standard product is sent to the intake device of the vacuum pneumatic transport.

The product that enters through the vacuum pump accumulates in the intermediate hopper from which it is fed to the packaging line.

To ensure good separation of flows the rotary valve is used during the cyclone cleaning that has the system with free access for maintenance. The rotary valve is made of stainless steel for processing with detergents. For aerosol transportation of the product after purification with the cyclones the air blower with product offsets.

To feed the product into packaging line the vacuum transportation system may be used, the principle of operation of which is to create a vacuum in the conveying line by means of injection of the compressed air. The design of the vacuum pump has filters that purify the air and pressure relief valve. When cutting off the air supply to the pump, the pressure-relief valve opens pouring the material into the intake hopper. Simultaneously the compressed air from the tank that is situated in the filter insert expands purging and cleaning the filter. Then the cycle is repeated.

The plant is completed with an optional spray circulation cleaning. In this case the cleaning is performed without disassembling; the disc is not removed and the atomizer is immersed in the bath mounted on the stand. The inlet nozzle of the atomizer product is connected to the circulation pump which circulates detergents.

 

HACCP principles applied in the design and manufacture of the drying plants.

HACCP (Hazard Analysis and Critical Control Points) is a set of measures to prevent food from entering the chemical, biological, mechanical and other harmful to human health inclusions by monitoring all critical points at all stages of production.

One of the main characteristics of the food products which are provided by HACCP is safety. To ensure the safety and quality of products in the spray drying plants manufactured by PJSC "Kalinovskiy machine building plant" the following elements are provided:

  • The automation system of the plant.
  • Automatic control of the drying process is based on supporting the constant outlet temperature of the drying chamber by adjusting the supply of the primary product by the metering pump.
  • The system for gathering and displaying information with the output of all parameters to the display allows controlling of operation of the plant and saving records of performance indicators of the drying plant, namely the temperature of the incoming and outgoing air, temperature of primary and dry product, product level in the tanks, the motor load, including on the atomizer and other indicators of the plant operation.
  • All the actions required to manage the process with optimum efficiency are carried out by the control system in accordance with the instructions set in the program.
  • Safety is provided by the fact that the control system operates continuously and monitors processes in real time;
  • The process is carried out in a similar way - the final product will have high quality as it excludes any deviations from the specified process.
  • Due to the fine control of the process the losses of products and service media and power consumptions are minimum.
  • The software allows storing and processing the information on the drying plant operation.
  • Filtration of the air that is fed into the drying chamber
  • To eliminate the ingress of mechanical impurities and other possible contaminants, the air intake of the heat generator, the mixing device for supply of the air for blowing the walls of the chamber and fluidized bed is equipped with the high-efficiency particulate air filter (by European standards EN779-96) -F7; the air intake of the cooling system and the system of transportation of the product is equipped with a two-stage filtration system - F9.
  • The system of the plant cleaning
  • The system is equipped with orbital spray heads for cleaning the drying chamber and cyclones and extended spray heads for cleaning of air pipes that provides high-quality cleaning with detergents under high pressure of components of the plant in the shortest time.
  • The system for cleaning the chamber walls and cyclones
  • To prevent the formation and ingress of the finished product with burnt particles the actuators of the pulse and dynamic cleaning system are mounted on the walls of the drying chamber and cyclones preventing sedimentation of the powder on the walls of the plant.

 

© Kalinovskiy machine building plant 1934-2017