What is a Mixing Tank?

What is a Mixing Tank?

What is a Mixing Tank?

Mixing tank means mixing, blending, homogenizing and so on. The design structure and configuration can be standardized and humanized according to the requirements of production process. The mixing tank can realize feeding control, discharging control, stirring control and other manual automatic control.
The agitating tank can also be called water phase tank, widely used in coatings, medicine, building materials, chemical, pigment, resin, food, scientific research and other industries. The equipment can be made of carbon steel, stainless steel and other materials according to the process requirements of user’s products, as well as setting up heating and cooling devices to meet different process and production needs. Heating jacketed electric heating, heating coil, the equipment structure of reasonable design, advanced technology, durable, and possesses the characteristics of simple operation, easy to use and is ideal for less investment, fast production, high yield of chemical equipment.

Component composition

Product structure
Mixing tank structure: the drum by mixing tank, mixing tank cover, mixer, bearing, gear, shaft sealing device and so on, can also be configured according to the technical requirement heating or cooling device.
Mixing tank, mixing tank cover, agitator, shaft seal and other materials can be made according to different process requirements of carbon steel or stainless steel. The mixing tank and mixing tank cover can be connected by flange or welded joint. The mixing tank and mixing tank cover can be made according to the process requirements, such as feeding, discharging, observation, temperature measurement, pressure measuring, steam fractionation, safe discharge and other technological pipe holes. The top of the mixing tank cover is equipped with a drive (motor or reducer), which is driven by the drive shaft. Shaft sealing device can be used in various forms such as machine seal or packing, labyrinth seal, etc. Due to different production process requirements, the agitator can be equipped with various forms such as slurry, anchor, frame type and screw type. If there are any other requirements, please contact with our factory and design and manufacture separately. 

Stirring shaft
The motor output in the stirring equipment is transmitted to the agitator by the mixing shaft, so the stirring shaft must be strong enough. At the same time, the stirring shaft are connected to the mixer, and through the shaft sealing device and the spare parts such as bearings, couplings, so stirring shaft shall also have the reasonable structure, high machining accuracy and tolerance.
According to the supporting condition, the stirring shaft can be divided into cantilever type and single span type. Cantilever stirring shaft at the end of the interior of the mixing equipment is not set intermediate bearing or bearing, and convenient maintenance, especially for high cleanliness requirements of biology, food or medicine mixing equipment, reduce the equipment within the artifacts, reason should be preferable.

In the component
Including baffle, coil, guide tube, gas distributor, etc.
In order to eliminate the swirl of liquid in the mixing vessel, the stirred liquid can be stirred up and down to achieve a uniform mixing, which usually needs to be added to the baffle in the mixing tank. Usually the width of the baffle is about 1/12 ~ 1/10 the diameter of the container, including accessories such as thermometer, heat transfer in coil or various support body can also play a role in baffle, but often can not meet the “baffle conditions”. Generally, the width of the baffle is increased, and the power consumption will increase. However, after increasing to a certain value, the power consumption will not increase again, and the working condition is called “full baffle condition”.
In mixing container, fluid along the direction of flow to the agitator, fluid stroke length is differ, the need to control the speed and direction of reflux, used to determine a first-class condition can use the guide tube. Diversion tube is opening up and down cylinder, installed in a container, plays a guide role in mixing, can increase the degree of fluid mixing container, strengthen the blender to direct shearing action of fluid, and cause certain cyclic flow, make the container strong mixing zones within the fluid can be through a tube, improve the efficiency of hybrid. After installing the guide tube, the circulation path is limited and the short circuit of the fluid is reduced. The guide tube is mainly used for propulsion, screw type and turbine agitator. 

Shaft seal
Shaft seal is an important part of stirring equipment. Belongs to dynamic seal shaft seal, its role is to ensure that the mixing equipment in certain positive pressure or vacuum, prevent escape and impurities by mixing material of infiltration, so not all of the shaft seal can be used for mixing equipment. In the stirring equipment, the most commonly used shaft seals are liquid seal, packing seal and mechanical seal.

Liquid seal
When work pressure in the mixing equipment for normal pressure, the role of the shaft seal is only in order to prevent dust and impurities in the internal working medium, or isolated working medium and mixing equipment surrounding environment medium contact with each other, can choose liquid seal. The liquid seal structure is simple, without direct contact with the transmission shaft causing friction parts. However, in order to ensure that the gap between the cylindrical shell or the stationary element and the rotating element meets the design requirements, the machining and installation requirements of the sealing parts are higher.
At the same time, the use range of liquid seal is narrow due to the structural characteristics. Generally applicable to the working medium for the mild amount of flammable or toxic hazards, equipment within the work pressure is equal to atmospheric pressure, and the temperature range in the occasion of 20-80 ℃.
It is worth noting that liquid working medium cannot be filled with stirring equipment; In addition, the sealing liquid should be used in the mixing equipment as far as possible, or neutral liquids that do not have physical and chemical effects with the working medium, and must be very rare and not polluting the atmosphere.
 
Packing seal
It is a kind of rotary shaft seal structure which is adopted early in the mixing equipment, which has the advantages of simple structure, low manufacturing requirement and convenient maintenance. But its packing is easy to wear, the sealing reliability is poor, generally only applicable to the normal pressure or low pressure and low speed, non-corrosive and weak corrosive medium, and allow regular maintenance of the stirring equipment.

Mechanical seal
Mechanical seal is the sealing surface from axial to radial shaft, the movable ring and the static ring two ends are mutually jointed, and the relative movement to achieve sealing device, also known as seal. The mechanical seal leakage rate, reliable sealing performance, low power consumption, long service life, without frequent maintenance, and can meet the production process automation and high temperature, low temperature, high pressure, high vacuum, high speed and all kinds of flammable, explosive and corrosive and abrasive medium containing solid particles and medium sealing requirements.
Compared with the packing seal, the mechanical seal has the following advantages:
1. The seal is reliable. In the long run, the sealing state is stable, the leakage is very small, and the leakage is only about 1% of the packing seal.
2. Long service life and generally 1-2 years or longer in oil and water medium, generally working in chemical medium for more than half a year.
3, the friction power consumption is low, and the friction power is only 10-50% of packing seal.
4, the shaft or shaft sleeve is basically not worn;
5, the maintenance period is long, the end face can be automatically compensated after the wear and tear. In general, it does not need regular maintenance.
6, it has good vibration resistance, and is not sensitive to the vibration of the rotating shaft, the deflection of the shaft and the deflection of the shaft to the sealing cavity.
7. It has a wide range of applications and can be used for high temperature, low temperature, high pressure, vacuum, different rotation frequency, and the sealing of various corrosive medium and abrasive media.
Because of the advantages of mechanical seal, it has been widely used in the mixing equipment.
Mechanical seal has two kinds of mechanical seal and double face mechanical seal. The price of single face mechanical seal is low. When the mechanical seal of single face can’t meet the requirement, it needs two face mechanical seals.
When the stirring medium is highly toxic, flammable, explosive, or more expensive, high purity material, or need to operate in a high vacuum state, and the sealing requirements are very high, and the packing seal and mechanical seal can not be satisfied, the fully enclosed magnetic transmission device can be selected.

Transmission
The transmission equipment of the mixing equipment includes motor, transmission, coupling, bearing and frame, etc. The stirring drive mechanism usually adopts the combination of the motor and the transmission or the motor with the frequency converter, so that the stirring can reach the required speed.
The function of the transmission is to make the stirring shaft rotate at the desired speed, and to ensure the required torque for the mixing shaft. In most mixing equipment, the stirring shaft has only one root, and the agitator rotates in one direction at a constant speed. However, there are some special mixing equipment. In order to get better mixing effect, two agitating shaft can be used in a mixing plant, and the complex motion of the agitator is carried out, such as reciprocating, reciprocating, planetary type and so on.

Electric machinery
The stirring shaft of the mixing equipment is usually driven by an electric motor. Because the speed of mixing equipment is generally low, so the motor is mostly combined with transmission in most cases. Sometimes it uses frequency converter to speed directly. Therefore, when the motor is selected, the problem of matching with the transmission should be considered.

Agitator
The blender is also called the impeller or the blade, which is the core component of the agitator. According to the flow pattern produced in the stirrer, the agitator can be divided into two kinds of axial flow and radial flow basically. For example, the propeller impeller, the new airfoil impeller, and so on belong to the axial flow agitator, and all kinds of straight and curved blade turbine impeller are radial flow agitators.
The agitator is usually inserted into the kettle vertically from the top center of the agitator, and sometimes it is inserted by the side, and the bottom is in or on the side. Different installation methods should be selected according to different mixing requirements.

Type of agitator
(1) the propeller agitator consists of 2~3 propeller blades (Figure 2). The rotating speed is higher and the circumferential velocity of the outer edge of the blade is generally 5 ~ 15m/s. Propeller type stirrer is mainly caused by the axial flow, producing larger volume, suitable for mixing low viscosity (<2Pa – s), liquid emulsion and solid particle content of less than 10% suspension. The rotating shaft of the agitator can also be inserted horizontally or slanted into the slot, when the circulation loop of the liquid flow is asymmetrical, which can increase the turbulence and prevent the depression of the liquid surface.
The turbine stirrer is composed of 2~4 flat or curved blades on a horizontal disk (Figure 3). The ratio of the outer diameter, width and height of the blade is generally 20:5:4, and the circumference velocity is generally 3 ~ 8m/s. The radial flow of high turbulence is caused by the rotation of the turbine, which is suitable for the dispersing and liquid-liquid reaction of the gas and the insoluble liquid. The viscosity of the stirred liquid is generally not more than 25Pa. S.
There are two kinds of oar type and inclined propeller type. A flat paddle mixer consists of two flat blades. The ratio of blade diameter to height is 4~10, and the circumferential velocity is 1.5 ~ 3m/s, and the radial flow velocity is smaller. Inclined paddle type agitator (Figure 4) of the two opposite leaves turn 45 degrees or 60 degrees, resulting in axial flow. The structure of the paddle agitator is simple, which is often used in the mixture of low viscosity liquids and the dissolution and suspension of solid particles.
(4) the shape of the outer edge of the anchor impeller is consistent with the inner wall of the stirred tank (Fig. 5). There is only a small gap between them, which can remove the viscous reaction products attached to the groove wall or solid matter accumulated on the bottom of the tank, and maintain good heat transfer effect. The circumferential velocity of the outer edge of the blade is 0.5 ~ 1.5m/s, which can be used to stir the Newtonian fluid and the quasi plastic fluid with the viscosity up to 200Pa s (see viscous fluid flow. When the high viscosity liquid is stirred, there is a large stagnation zone in the liquid layer.
5. The outer diameter and the pitch of the screw belt mixer are equal (Figure 6). They are specially used for mixing high viscosity liquid (200 to 500Pa. S) and pseudo plastic fluid. They are usually operated under laminar flow condition.
The magnetic stirrer Corning digital heater with a closed-circuit monitoring and regulating the stirring speed knob. The microprocessor automatically adjusts the power of the motor to adapt to the water quality, the viscous solution and the semisolid solution.
The external temperature controller and magnetic stirrer stirrer with optional digital Corning (Cat. No. 6795PR), they can also monitor and control the temperature of the container.

Heating and cooling device
Generally, the use unit depends on whether or not the material is heated or dried or cooled. Within the range of customization, the temperature should be below 200 c, and the use pressure is less than 0.1Mpa. The heating method can be determined according to the production conditions of the unit. There are two kinds of heating methods, such as hot oil and other medium circulation and direct electric heating. The circulation of hot oil and other media is heat conducting oil, which is heated to a certain temperature in a heated tank of another configuration, and then circulates through a hot oil pump. The direct heating is to directly install electric heating pipes on the jacket to heat the heat conducting oil to the required temperature (the temperature can be adjusted according to the actual situation). The cooling cycle is the use of water in the inner and outer loops of the jacket so that the material does not produce caking or stickiness at a certain temperature. It can also be heated or cooled according to the request of the user to increase the coil and other forms.
(Note: the general use of heating or cooling medium is to take the low pipe entrance, the principle of the executive’s mouth.)

Standard operating process

Objective
To prevent the occurrence of human operation accidents, to ensure the normal operation of the equipment.
Scope of application
400L, 300L, 600L mixing tank.

Duty
1. the operating personnel are used and hygienic in accordance with the regulations.
2. maintenance personnel are maintained and maintained according to the regulations.
3. the manager of the production management department is responsible for supervising the implementation of the regulations.

Content
1. use
(1) check whether the equipment is “normal”, confirm that the equipment is clean and meet the requirements.
(2) Check the connection between the mixing pulp and the motor is firm and reliable.
(3) choose the mixing tank according to the quantity of the processed material, and the sample volume of the general liquid is not less than 1/3 of the volume of the mixing tank.
(4) Slowly adjust the speed regulation knob (frequency conversion speed regulator) to make the stirring speed increase slowly to the required speed. The speed range is 80–1400 r/min.
Turn the speed knob to the position of zero speed.
Add liquid, turn on the power switch.
The equipment after use, turn off the power.
The cleaning and disinfection by cleaning and disinfection tank mixing “standard operating procedures”.
To fill in the relevant records.
2. matters of attention
One should pay attention to the distance between the rotor and the container, and if it is the glass container, it should be noticed that the stirring speed should not be too fast.
If you need to deal with the sample, you must turn off the power switch and adjust the speed knob to the minimum, then repeat the above operation.
(3) if serious sparks occur, it is necessary to stop the inspection immediately and repair it so as not to cause greater loss.
4. If the motor does not turn in operation, check the power supply, governor, fuse and motor brush. If the speed governing part is damaged or the motor is damaged, the maintenance personnel should be notified.

Related document record
1. equipment management rules
Cleaning and disinfection records

2. agitator
3. mixing tank running record table

Installation and debugging
1, please check whether the device has serious damage and serious deformation in transportation, fasteners and inspection equipment have loose phenomenon!
2. Please use the pre buried anchor bolt to install the equipment horizontally on a solid foundation.
3, under the guidance of professionals, equipment, electrical control devices and accessories installed correctly, and check whether the pipeline flow, installation of the instrument is correct, if there are defects. People or objects start equipment before you check the inside and outside of the equipment and the surrounding whether influence the normal operation of the equipment, in order to avoid danger.
4, after the installation, please first take a few seconds of trial operation to determine that no electrical short circuit or abnormal sound, a short time test can be carried out.
5, if there is a mechanical seal on the mixing tank, the proper amount of 10# or sewing machine oil must be injected into the machine sealing groove before the main engine starts. The cooling water must be cooled into the cooling cavity of the machine seal, so that the machine package can be well lubricated and cooled. The machine seal is not adjusted when it is out of the factory. After the installation is completed, the machine is sealed to the best position according to the installation instructions, so it can run normally (according to the user’s needs).
6, after the normal operation of the equipment, please check the bearing temperature, running smoothness, sealing and so on, as well as whether the instrument is normal, confirm the normal, and then put it into operation.

Use maintenance
1, this equipment is the normal pressure equipment, if the heat exchanger is also regarded as a normal pressure, if the pressure is super high, please check whether there is a blockage in the import and export.
2, reducer should be equipped with 40#–50# oil or 70#–90# extreme pressure industrial gear oil. After running for 20 days for the first time (8 hours per day), replace the oil and clean the oil contamination in the tank, then replace it once every 3 to 5 months and clean the tank. (except for no reducer)
3, if the condenser is configured, it can be judged whether the heat transfer pipeline should be cleaned according to the effect of heat exchange.
4, the loading capacity of the mixing tank should be strictly in accordance with the effective volume of the mixing tank, and no overload shall be strictly prohibited, so as to avoid damaging the motor or damaging the reducer and other components.
5, if the equipment is not used for a long time, all of them should be cleaned and cleaned. The lubricating oil is injected into each place and the power supply should be cut off.

Stainless Steel Mixing Tank be designed, manufactured and inspected in accordance with the pressure vessel standard(GB150-2011) and the steel welded atmospheric pressure vessel standard(NB/T 47003.1-2009) , strictly meet to GMP certificate requirements. 
The Mixing Tank adopts Vertical circular tanks, both of top and bottom are standard oval and torispherical head. Transition section in tank using circular arc transition, without dead corner, easy to clean. Single layer, double layer(insulation for tank and bottom head) or Jacket(tank and bottom head have jacket and insulation), equipped with mechanical stirring according to customers’ requirement.

Tank Optional Configuration 
The body of Mixing Tank can configure aseptic air filter, thermometer(Digital display or Dial type), PH meter, pressure gauge, steam sterilization hole, sight glasses, sanitary manhole, liquid in-outlet, CIP cleaning ball, liquidometer and Liquid level control system(Bearing module, non-contact ultrasonic, static pressure transmitting device) and so on, also can configure as customers’ requirement.

Application 
• Can be used as Storage Tank, mixing tank, temporary Storage Tank, mixing tank, etc., Used in liquid materials’ mixing and storage such as medicine, food, fruit juice beverage, dairy products, seasoning, brewing, beer, pharmaceutical, chemical and biological engineering.

Feature
• Volume:100L~5000L and multiple specification, also can design and manufacture according to customers’ requirement.
• Jacket can pass steam (or hot water), can also pass the cooling water. Jacket has full jacketed、half-pipe coil jacketed, dimple jacketed and plate coils. Jacketed outside covered with insulation, thermal insulation material for rock wool (warm) or PU (cold).
• The connection adopt Tri-clamp, the tanks’ inner layer use 304 or 316L. The inner surface mirror polishing Ra≤0.28μm～0.6μm, outer surface can polishing, wire drawing and sand blasting according to customers’ requirement.
• According to the requirements of production and processing, can design with low heating, cooling, high-speed mixing system, sealing pressure system, vacuum system, measuring system and so on.
• According to different mixing materials and requirements to the mixing effect of the structure of impeller can adjust the turbine type design, paddle, anchor type, frame type, screw conveyor and so on..

Design Parameter

Design pressure	-0.1MPa～0.6MPa
Design  temperature	According to customers’ requirement（0℃～160℃）

Material

Liner	304、316L
Jacket	304
Insulation	Rock wool or PU
Feet	304

Connection

In-outlet

Tri-clamp, Flange

Surface Finish

Finish Type	Mechanical polishing, electrolytic polishing, sand blasting, pickling
Polishing precision	Inner surface Ra≤0.3μm，  Outer surface Ra≤0.6μm

Normal Model And Main Technical Parameters

Parameters		Model	SECRPG—100	SECRPG—300	SECRPG—600	SECRPG—1000	SECRPG—2000
Effective volume：L			100	300	600	600	2000
Barrel	Diameter：mm		Φ500	Φ800	Φ900	Φ1100	Φ1300
	Height：mm		500	700	900	1000	1500
Agitator	Power：kW		0.37	0.75	1.1	1.5	2.2
	RPM：r/min		36～53（倾叶开启涡轮式）（The design can be adjusted according to customer use condition）
The above-mentioned data is the standard, for reference only. It can customize according to customer’s requirements.

Source: China Mixing Tank Manufacturer – www.secmachinery.com