Review on design of agitator 1akash j patil, 2sachin b rajude 3mayur s thok, 4ajit r pawar be student. This kitchenaid part comes directly from the manufacture. Years of field experience and laboratory testing, together with advanced calculations, form the basis for development of flygt methods and computer programs used to analyze and dimension the rotating system of a pump or mixer. The differential agitator is an electro mechanic set consists of. Btn agitators installation, operation maintenance manual.
Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices. Shaft deflection, runout, vibration, and axial motion chapter d4 page 4 contact kalsi engineering search this handbook bearing internal and mounting clearances influence shaft runout side loads cause the shaft to articulate within mounting clearances, resulting in lateral shaft deflection at the location of the rotary seal. Shaft and bearing calculations 121 shaft and bearing calculations gert hallgren itt flygt ab abstract. Design stresses in shafts august 15, 2007 23 find the torsion in the shaft. The extension shaft is also designed to minimize deflection for superior seal life. Agitator design and selection standard engineers vineet. Shaft design objectives compute forces acting on shafts from gears, pulleys, and sprockets.
In general, the force exerted by the downsweep side of the agitator is greater than that of the upsweep. The shafts are classified as straight, cranked, flexible or articulated. Even minor shaft deflection causes loss of sealing function and increased wear. Design and analysis of agitator blade of pressure vessel. Complete range of agitator mechanical seals available from top seal manufacturers including chesterton, john crane and flowserve. The main forces are torque, bending loads, and thrust. Unlike static deflection which bends the shaft downward, dynamic deflection forces the axis of the shaft upwards towards the upsweep side of the mixer. If a std is employed, it is possible to change seals with the vessel loaded and under pressure shaft must be stationary. In this video how to remember all the importants formulas of slope and deflection is explained by using a simple algorithm, which will help you to remember it till your lifetimeif you feel. Shaft deflection, runout, vibration, and axial motion kalsi seals. Pdf understanding the mechanisms of shaft deflection in. The dynamic forces of rotation, which act on drive shafts, of course, also increase with rotational speed. Never expose the agitator to undue vibrations or shocks. Agitator shaft is important component of agitation system used in reactor pressure vessel.
Agitator shafts directly supported by gear box bearings or with intermediate bearing housing. This will be the case unless the shaft is overloaded or damaged. One of the major parameter to increase the overall performance of. Large sized agitators with a drive power of up to 3,500 kw, shaft lengths of more than 15 m, as well as 500 mm shaft diameters, have already been supplied. Our core business was and is the technical design and production.
Mixer agitator bending moment and shaft deflection. The other major analysis in the design is the vibration characteristic of the mixer, especially the shaft since system harmonics can lead to amplification of any of the major forces. If the operating conditions are under high pressure or high temperature, the agitator must be equipped with a sealing system to keep tightened the inside of the tank when the shaft is crossing it. Apr 18, 2006 mind mixer mechanical design while most mixers can provide a long service life for instance, some are still operating after more than 30 years mechanical problems can shorten life or even break parts. The speed of the agitator shaft below the red uc ti o ng ab x sh l f than 30 to 40 rpm maximum. Installation, operation and maintenance manual mrd and mrp. The burgmann seccomix is the ideal choice for these applications. Double lip seals on the drive shaft prevents oil loss or the infiltration of contaminants. Mechanical agitator power requirements for liquid batches.
The importance of shaft stiffness in api 610 11th edition. The agitator must be equipped with such a tough sealing system, when the operating conditions are under high pressure or high. The reactor agitators type hwln are the most powerful agitators compared to the others in ekatos product range. The nbi series is a range of vertical agitators with directcoupled speed reduction gearbox. Design and analysis of conical curved agitator for medium. Design and implementation of differential agitators to maximize agitating performance saeed asiri king abdulaziz university, 21589, jeddah, p. Vertical shaft hydrounits description to better understand the alignment process, it is important to understand the basic construction of vertical shaft hydrounits. Installation, operation and maintenance manual mrd and. Maximum radial shaft deflection for agitators is defined in din 28161. Design of shaft length of agitator industrial professionals. Deflection and critical speed are related of course, so shaft stiffness is of primary concern. In order to rotate the agitator at the required speed, it is attached to a shaft. In any case, gear reducers, shafts, impeller blades and other basic components should be chosen to match the maximum motor load. The agitator disperses a powder into water until it dissolves.
Therefore, knowledge and understanding of the variety of factors that. Figure 2 stepped shaft showing relationship of shaft deflection. Figure 1 shows a typical vertical shaft hydroelectric unit as found in bureau of reclamation powerplants. Design and implementation of differential agitators to. Examples of lateral shaft displacement are dynamic runout, deflection, and vibration. Agitator output speed, shaft diameter and extension, impeller.
During starting, the shaft must be capable of resisting 1. During a starting up, the shaft has to withstand key words. Agitator shaft deflection free download as pdf file. Castiglianos theorem, dummy loads, heaviside step functions and numerical integration. The deflection due to each load p contact pressure acting independently is given. The loads are active and are transmitted from the impeller blades to the agitator shaft. Shaft deflection, runout, vibration, and axial motion. Such shafts are commonly designed as stepped cylindrical bars, that is, they have various diameters along their. Tubular shafts provide a stiff, light weight design which may be more cost effective in longer shaft designs. It is true that flexible couplings are designed to take misalignment, typically up to 400 mils or more radial offset of the shafts. Complete range of materials available, carbon steel, stainless steel, and high corrosion resistant alloys hastelloy, titanium, tantalum, etc. Alwayssupport the shaft adequately, to protect shaft and bearings. Therefore, all measurements follow imperial units, and standard designs are available for inchsized agitator shafts from 1.
I have an agitator that bolts to the center nozzle on the top head of a tank. Redesign and structural analysis of agitator shaft for. It was a 3200 mm long, 50 mm 2 diameter, schedule 40, 316 stainless steel pipe with the 1. Complex designs with auxiliary bearings do exist, which prevent radial deflection at the seal between the lips and the shaft. Model 20 ht and gt agitators reliable performance and value. Bending moment causes the shaft to bend away from the central rotational axis and is critical to determine the shaft material. Shaft design for industrial tank agitators thomasnet. Agitation free download as powerpoint presentation. Agitator should be designed to operate at less than 70% of the critical speed. Figure 2 stepped shaft showing relationship of shaft deflection and wear for.
Review on design of agitator to optimize its performance rahul h. Finite element analysis fea used to calculate critical speed and shaft deflection. Mixer agitator bending moment and shaft deflection tuesday, september 06, 2016 bending moment is the hydraulic force fh acting on a shaft at a length away from the bearings perpendicular to the axis of rotation. To do this, it is necessary to know the local viscosity, which may vary with shear rate. Use plant vessel entry procedure if it is necessary to enter the vessel. Never lift the agitator using the extension shaft as a lift point. Whether a kalsi seal is being used for high or low pressure. Shaft shown drives a gear set that is transmitting 5 hp at 1750 rpm. An agitator is composed of a drive device, a guiding system of the shaft, a shaft and impellers. Shortcut method deflection of beam mechanicalcivil. When an agitator is supplied with a shaft seal for closed stirred tank applications or when stirred tank internals heating coils, draft tube, limit ring, etc. This research is to design and implement a new kind of agitators called differential agitator. Lock out the mixer or agitator motor and valves to and from the vessel and seal.
Vertical shaft deflection mechanical engineering general. The agitator was driven thru a right angle gearbox via a motor operating at 1,780. Drive features internal shafting lowspeed internal shaft short bearing span reduces deflection and harmful gear misalignment lowspeed shafts have extra large. Dynamic shaft deflection occurs when the mixer is operating. Jan 18, 2009 design of shaft length of agitator posted in industrial professionals.
A crack starts at a stress concentration from a keyway or a sharp radius, or, in rare cases, from a material impurity. Figure 1 illustrates the forces acting on the impeller and shaft configuration. The screw conveyor auger shaft was broken in half right at the center. Centrifugal forces are also present while the shaft is rotating and agitator is out of balance. In this video, i show how to set up define an ansys mechanical model and solve for the deflections of a stepped shaft subjected to an intermediate load. The agitator is subjected to vibration due to multiaxial forces resulting from bending and torsional loading imposed by the mixing operation. Tom 05 vibration critical speed or whirling of shaft youtube. Shaft is supported in selfaligning ball bearings and gears are both 10 pitch, 40 tooth, 20 spur gears. Straight shafts are commonest to be used for power transmission. Design specification of the motor is then determined by. Agitator shaft, bending stress, impeller, reactor pressure vessel, torsional stress. Another aspect to consider when you are selecting your seal is radial shaft deflection. In this article, learn about all the mechanical problems that may befall your mixing equipment. Shaft deflection, runout, vibration, and axial motion kalsi.
Installation dimensions according to din 288 part 1 are possible. Review on design of agitator to optimize its performance. Consider adding bracing under the motor base to eliminate deflection at 2x motor speed. I am asking this because on low level alarm 20 % of tank, agitator is not getting immersed in liquid resulting in frequent damage to bearing due to vibration so we have changed alarm value to 50% instead of 20%. Bending moment is the hydraulic force fh acting on a shaft at a length away from the bearings perpendicular to the axis of rotation. Agitator shaft length should be calculated on which basis. Adaptations to interim or metricsized shafts are available on request. Food for thought you wanted to stir things up but, your mixing gave only agitation. The approach of metzner and otto 4 can often be used to predict local shear rate. For side insert agitators, there is really no substitute for shaft diameter, since deflection is critical to packing, and even more to mechanical seal performance.
Failure of agitator shaft leads to breakdown of whole plant. Agitator shaft deflection bearing mechanical gear scribd. Lower shaft through vessel nozzle into tank and support with approximately 8 inches of shaft extending above the vessel flange. Compare combined stresses to suitable allowable stresses. However, these thresholds are often exceeded in practical application.
The 7800 vessel seal family was originally developed for the north american market. Shaft stress can usually be handled by using better materials, and is a lesser problem. Shaft deflection, runout, vibration, and axial motion chapter d4 page 4 contact kalsi engineering search this handbook bearing internal and mounting clearances influence shaft runout side loads cause the shaft to articulate within mounting clearances, resulting in lateral shaft deflection at. Propeller shaft tolerance tables aqualoy 17, 19, 22 and 22hs for new product home up aqualoy 17 propeller shaft aqualoy 19 propeller shaft aqualoy 22 and 22 hs propeller shaft 316 stainless steel propeller shaft 174 stainless steel propeller. Student 2professor 1,2department of mechanical engineering 1,2msss cet, jalna abstractmixing is very important operation in any process industry. Extra capacity reducer shaft due to a large crosssection, the lowspeed shaft inside the drive minimizes gear misalignment and deflection. The agitator shaft assembly is used in all kitchenaid stand mixers.
Detection of failure mode of pressure vessel agitator due to. Shafts are always made to have circular crosssection and could be either solid or hollow. The calculus of the mixing rotating devices shafts based on the energonics method 109 on each mixer i i 1,n0 mounted on the shaft, a bending radial force acts either in the xoy plan being notedfy,i, or in the xoz plan being noted fz,i, depending on the mixer blades orientation as function of the chosen coordinate system. The break was dead in the middle between the two endsupporting roller bearings. Rotating shafts under bending stress accendo reliability. In this study, the failure fracture of an agitator shaft with a circumferential notch was selected. We then calculate deflection, due to this force and impeller with hub acting at the end of shaft via. The flat beater, dough hook, and wire whip couple with this part to allow for mixing. The result is ultimate fatigue failure of the gearbox shaft. Detection of failure mode of pressure vessel agitator due.
Process engineering mind mixer mechanical design chemical. It also has an oversized output shaft, which reduces gear deflection and noise, with a true. Tubular applications with shaft lengths exceeding 60 feet. Feb 27, 2019 in this video, i show how to set up define an ansys mechanical model and solve for the deflections of a stepped shaft subjected to an intermediate load. Agitator design and agitator systems about us we have figured it out stelzer ruhrtechnik is one of the leading companies in agitation technology and a soughtafter solutions partner for projectspecific process technology solutions. Still process overloads can occur and may damage the motor or shorten the life of other components. Mixing solutions web strategy and design by advonet communications and ampedpixel media. The agitator mounting plate fixed to the tank is constructed from stainless steel and a vring shaft sealing system is used. A practical guide to shaft alignment plant services.
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