【The beginning design of Bioreactor 】
Micro-giant BioEngineering 2007.05.10
Southern Taiwan University of Science and Technology, Department of Biotechnology speech
Brought the hope of the new century, life sciences, bio-engineering technology assigns may practice a hope. New energy alternatives, functional health food development, specialty chemical raw materials to replace protein drugs, environmental engineering bacteria culture engineering methods, abandonedwas debulking or reuse, medicine cosmetic anti-aging, replacement of antibiotics, biologics quality agriculture, industrial food and feed enzymes ... all these are tried or successful results or improve microbial processes with the technology of modern biotechnologyby leaps and bounds and the increasing complexity of the actual occurrence of exploring chase source, step-by-step experiments and practical operation is becoming increasingly important.bioreactordevice (bioreactor) "essential core technology to achieve that purpose, this core technology covering machinery,chemical, electronics, electrical machinery, automation and microbiology the six specialist in the field, now take this space will come top five specialist surround Microbiology spindle, trying to make the personal the thin cotton humble opinion and practical experience engaged as much as possible to improve the speaking explore.
The broad definition: refers specifically to a chemical process applied to microbial proliferation, metabolic or catalytic reaction can be carried out smoothly device.
The device system instrumentation flowchart said: (See attached)
Three、Device is composed of:
- Power unit
- Transmission unit (including mechanical seal group)
- Mixing system
- Slot monomer
- Stainless steel shell and tube condenser
- Sterilization control valve
- Steam decompression and filtering system
- Temperature control piping manifolds
- Sterile ventilation control pipe valve block 10. The exhaust tank pressure piping manifolds
- The dosing feed material control valve
- Transfer inoculation transmission control valve (including sampling manifolds)
- Electrodes (pH, O2, temperature, AF) and the scene relative instrument the SENSOR (speed, pressure), the pipe rack
- Instrumentation and control electrical automatic control box
- Other accessories
- Power unit:
Roughly posed by motor + reducer, commonly known as motor reducer.
Sometimes due to installation of the positional relationship between the increase in cross steering or the output shaft and the input shaft 90 ° to the reducer, large (100kL) or part of the lower part of the stirred tank using a pulley deceleration mechanism, but this section should be noted Slipand driveshaft rigidity required to enhance motor reducer according to the installation position into horizontal, vertical and upside down (sometimes lower magnetic sealless stirring used) type, horsepower Department of Computing and stirring systems (mainly br />; for stir wing) type and shear force (shear force) on the impact of micro-organisms will be another follow-up special issue.
General need to consider the operating voltage, frequency (associated with the use of the area and power consumption), inside the house or outside the house, Explosion levels (part of the production of hydrogen or contents such as alcohol ... and so on, or switch to air motor), furnishings transmission position (Li, lying down style), speed (number of poles). course for pilot plant or Lab. use noise dB value best 2m <70dB (noise gross that there are other factors to be considered).
Generally in accordance with the way of the drive can be divided into planetary, Planetary, cycloidal gear, helical gear ... Reference factors point contact is better due to the contact surface into the corner to ease, resulting in lower noise and get higherthe transmission efficiency, especially for fluid movements in (turbulent flow turbulent flow, Reynolds number Re> 4,000) for stirring the "transmission coefficient" please use the "load" of change.
- Transmission unit (including mechanical seal group):
Drawings - see photo
By the parts of the motor base, driving seat, driving seat board, drive shafts, couplings, bearings, oil seals and mechanical shaft seal group.
◎ Motor Mount:
Convergence the motor reducer driving seat with the early material the SS400 (Heitie) surface sand blasting or paint coating, the fermentation plants use fermentation but after two or three years, wet wash tank or offshore wind, the occurrence of corrosion caused by rust powder invasion into the bearingeven enter the shaft seal, drive different sound then damaged. amended to read today SUS304 stainless steel, electrolytic polished surface plus excellent corrosion resistance.
◎ Driving seat:
Placed shaft seals, bearings and top-cover with material Ibid instructions, in addition to rigid, the height of the driving seat, need to be cautious attention to the transmission span, the so-called "drive span" refers to the upper and lower bearingthe distance span of less than will procure stirring shaft swing partial pieces of angle is too large, and early leak caused by mechanical seal damage, resulting in the airtight adverse or produce dead ends occur Ranjun.
◎ Driving seat board:
Undertake the driving seat (for small groove, flat cover drive base plate), the material the same within the groove of wetted parts generally SUS316 or 316L grade. Welding to Tongcao container to be the center of attention degree andhorizontal correction.
◎ Transmission shaft:
Successfully passed the power unit of the power to the mixing unit with generally small groove (about 50L), designed to be integrated to consider the problem of high-speed, rigid and centrality (ie, drive shaft = stirring shaft), but the disadvantage is less susceptible to maintain (decomposition transmission system), but fortunately, the small groove lighter, it can be ignored due to another drive shaft with bearings, oil seals, shaft seal contact at, had to design hard chrome plated to increase wear resistance, improve mixingshaft life and avoid bites scratches axial plane to destroy the air tightness, especially due to the same drive shaft as with material of wetted parts made of stainless steel, rigidity and toughness than S45C (medium carbon steel) or SF (Forged) steels actual occurrence for bothcorrosion and wear-resistant, surface plating layer of chromium (Cr) about of 0.03 ~~ 0.06tmm then subjected to precision grinding of the program can not be omitted.
◎ Couplings :
As the name suggests link the output shaft and the shaft of the motor reducer of general chain pass-CR series (small shaft diameter 30 can be used spider glue type) to convey the power models interference coupling can absorb 3 to 5 degrees of partialswing angle to reduce the transmission amplitude, but also the effective transmission power. otherwise shall design This design should be noted that their philosophy is to decelerate the machine output shaft rigid coupling flanges bonded (Key)the transmission span "of the upper span point, so please do not be designed to go beyond the two o'clock over the span point reducer best to improve on the 1st Specifications.
Upper span point, can be used the UKF or a UCF Pillow Block Bearing, attention to the need to add tapered sleeve the automatically help group immediately assembled center degrees positive point in the lower part of the second span, it is recommended that automatic alignment ball ora set of roller bearings in pairs plus oil seal provides lubricants add mouth. to select ball gap value of small high-precision grade bearings need to pay attention to more than 1,000 rpm.
◎ (Mechanical) shaft seal :
Early (about 20 years ago), Grand (Ground) type packing (PTFE material) to 3 to 6 laps around the shaft packing washer combination into a sealed timber, but its shortcomings no longer using,changed to replace the mechanical seal (Mechanicals Seal). mechanical shaft seal is divided roughly according to the lubrication method both wet and dry lubricant should be noted that the use of wet sterile water and sterile water generator must be a single set ofset a group of devices (One by one), can not be shared. avoid a single set of sterile water contamination will not affect other sets of bioreactor plant production using dry-(dry Mechanicals Seal), are exempt from the above-mentioned problems. new machineryshaft seal has a cartridge design, can significantly reduce the assembly surface equal pressure force of the technical requirements, but within the casing design, so the shaft diameter to increase the 1st induced increase in manufacturing costs. mechanical seal broadly divide slewing ring and retaining ringtwo parts, retaining ring material can be used tungsten carbide or ceramic, while slewing ring graphite rings or tungsten carbide metal part of the material can be used SUS316, SUS316L or titanium. shaft seal soft sealing material (ex. O ring or gasket) are using Vitonor EPDM material, does not recommend Teflon, easily fold surfaces (ie grinding) excessive precision grinding, sterilization segment mirror sucking effect, nor the positioning pin will generate Slip destruction of the soft seal material. mechanical axisclosure for the biotech industry, in addition to the normal considerations, yet extraordinarily should be noted that in the sterilization segment arising moist heat sterilization method, high temperature and cooling water (Drain) emissions will cause condensation because sterilization 121 ° C is maintained for 20 to 30minwater residue, so the steam progress under a difficult to produce dead ends, resulting in the shaft seal is not completely sterilized. seal design or select, pay attention to have a thermal break design considerations, the fermentation heat generated due to the cultivation cycle will be extendedforward to stirring shaft up the heat convey accumulated to transmission system, prompting shaft seal or bearing seal material damage early.
Ps.Note (mechanical) shaft seal design, the first from the culture vessel wetted recent Department, during the non-plus other seal material ex. Seal or bearing.
Another shaft seal design, such as magnetic stirring, but to convey the power leakage larger, and escape the worries is the lower part, due to occupy the lowest lows, it is out of the discharge port design there will be a salvage doubts, nowlittle used.
- Mixing system:
Department of stirring shaft, breaking foam wing, stirring wing, baffle, shaft support blocks and other parts.
◎ Stirring shaft:
The same material should be wetted portion (generally SUS316 or SUS316L) flange coupling shaft end design in order to converge the drive shaft in the culture tank with stirring wing junction, small pilot production (200L), oftenSet Screw design stirring wing wheels, but there should be two mutually 90 °. prevent the decline or shift, but also convenient to change the position of the paddle and you have to have a keyway (key way) as for the medium and large designboth have to change paddle bit, you have to design long bond, for stirring wing wheels slide to the desired location with Set Screw locking If you are worried the stirring wing loose decline in long button belowdo take the lead in key design. culture tank shall be designed shaft supports seat in order to narrow the agitation center offset axis end in large (500L).
◎ Breaking foam wing:
Also known as foam hit the wing or defoaming wing design for easy Impeller (flat paddle-type), often as a kind of physical defoaming strategy, not burden stirring momentum effect, and it can not hit other parts Rotary Trail,try to lengthen. practice bubble generates overflow (Foaming), mostly along the tank wall attachment in accordance with the the bridging phenomenon stack up. therefore undermining Tongbi bridge early in the foam generated is the new design of the physical defoaming strategyin addition there are designs both physical and chemical defoaming strategy that is defoamer through broken bulbs wing lower edge of the rotary action do spill out evenly, so that the fermentation broth (Broth) surface in the same doseThe surface area of contact with the liquid level increase, increase defoamer effect.
◎ Stirring wings :
General aerobic training biological cultivation wheel models (Turbine, also known as Rushton type) can be divided into 6 wing, four-wing, swash plate, curved plate a variety of changes. Cikuan commonly used type Department because the ventilation device (Air sparger) too oftennearly stirring wing the polymerization or flooding of the bubble, too far nor easily stir the wing to break dispersed, so measured both high ventilation and dispersed bubble wheel models fins is better than the the ship propeller type (propeller type) but ifconsider biological culture for anaerobic gas or anaerobic training, emphasis should be placed in the form and amount of sexual material viscosity or solid ingredients, and pay attention to the precipitation in the form of paddle.
Ps.Note that the wheel models flap design, the optimum tangential velocity of the outer edge of the wing diameter of 2 ~ 5 M / sec operation.
Placed in the container Tongbi upright, can be divided into three groups (50L) or four groups and its purpose is to increase the turbulence degree of agitation to achieve uniform average temperature, gas and liquid delivery, the drug solution (pH defoam) and nutritionsource (nitrogen, carbon, trace elements) adds a degree of dispersion and destruction stirred center swirl phenomenon (i.e. rid vortex) in the large-scale culture device (50kL above), due to the laminated heat transfer area, and therefore special straight row bundles substitutedoriginal damper position, so not only increase the heat transfer area and can be reached spoiler state but the relative increase in cleaning difficult.
◎ Shaft support seat :
In the culture device in a large (500L), hanging shaft lengthened shaft support base of support mixing shaft, at the end of the stirring shaft design, it can absorb yaw, increase driving stability. Lined design to absorb the amplitude correspondingforce, is not responsible for the axial stress. material Teflon (Teflon) dissecting fiberglass increase hardness, to consider the strong pH and hardness, PEEK is a good choice.
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