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%. Designing for anomalies the first step in assessing a design is to calculate the power and torque absorbed by the proposed agitator. The blades of the same type installed in the mixer on both shafts. Relationship between torque and density in agitator. Calculation for agitation scaleup and power requirement. Standard design agitator lkr5 is fitted with a standard motor and the agitator shaft is directly coupled to the motor shaft. Material selection the agitator shaft was made from a standard aisi type 316 stainless steel that is austenitic grade. Never lift the agitator using the extension shaft as a lift point.
Chempute software nonpressurised tank and mixer design. A crack may start at a stress concentration at a keyway or a sharp radius, or in rare cases, from a material impurity. If an agitator is not correctly designed for these fluids, the mixture in regions near the walls can be completely stagnant. Other attachments include inlet and outlet lines, coils, jackets, and wells for thermometers. Inputs inputs moc of vessel shaft type of impeller motor hp cal. Apr 18, 2006 design of the mixer support must consider all of the mechanical loads on the mixer figure 1. Jan 04, 2019 agitator shaft design calculation filetype pdf posted on january 4, 2019 by admin energy utilization in different types of agitators design calculations the mixer shaft is located off center onefourth to onehalf the tank radius, the resulting. Student 2professor 1,2department of mechanical engineering 1,2msss cet, jalna abstractmixing is very important operation in any process industry. Design and implementation of differential agitators to maximize agitating performance saeed asiri king abdulaziz university, 21589, jeddah, p. In both cases a twostage ekato viscoprop agitator system with an impeller diameter d 2 1100mm serves as basis for the calculations.
Some type of seal around the rotating shaft is required for closedtank operation and the type depends on degree of seal required, operating pressure, and operating temperature. Characteristic of application requiring minimum fluid velocities to produce a flat but moving fluid batch surface. Oct 06, 2018 agitator shaft design calculation filetype pdf download. It is a further advantage that the model is running using the actual dimensions and not the model dimensions. Oct 27, 2018 agitator shaft design calculation filetype pdf download. Jul 17, 2015 agitator power consumption calculation posted in industrial professionals. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Figure 881 shows a typical standard tank figure 81. 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. The rotational speed is 100rpm, the viscosity 20 cp and the sp. Shaft design calculation pdf and generated in shaft and bearing calculations. Lower shaft through vessel nozzle into tank and support with approximately 8 inches of shaft extending above the vessel flange. A stirred tank reactor is the simplest type of reactor. Layout of agitator name td geometrical parameters 1 anchor paddle agitator cvs 69 1014 1,11 h v d 0,8 h d 0,12 h 2 d 0,055 2 helicalscrew agitator with draught tube cvs 69 1028 2 h v d 1,5 s d 1 d d 1,1 h c d 1,15 3 eccentrically placed helicalscrew agitator 2 h 2 d 0,25 c t 0,02.
This research is to design and implement a new kind of agitators called differential agitator. Design of agitator free download as excel spreadsheet. Review on design of agitator to optimize its performance rahul h. Torque shaft power fluid density shaft speed2 impeller diameter5 2 pi. Single shaft mixers are proven to be effective for mixing dry powders, granules, slurries and some pastes. Reference 7, studied the failure fracture of an agitator shaft with a circumferential notch was selected as investigation topic. In addition, the article reflects the theoretical calculation of the lobed mixer. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. First, the torsion and bending loads, previously calculated for shaft design, must be used to design the mounting. Various forces contribute to the load that a shaft must contend with.
This type of mixing leads to a less ordered state inside the mixer, the components. The code is provided for download in the supplement section of this manuscript. However, this study is intended for introducing fracture. The additional power required to circulate the liquid can be neglected for most technical applications. Design of shaft length of agitator industrial professionals. Single shaft mixers the standard configuration for horizontal batch mixers is the single shaft design, consisting of a ushaped body and a single horizontal main shaft agitator assembly.
Calculate the power input and dimensionless power number from the. Because the settling power and thus the agitator pow er are proportional to the hindered settling velocity, choosing the design particle size is very important. Process engineering mind mixer mechanical design chemical. Pdf justification of the use of mixers in the processing of mixtures feed is given.
Calculation of power requirement for newtonian fluid c. This means that the powertospeed ratio is typically a square function. Type selection ow llow f llf a ia x ax i a ow llow f llf ia a d ad i ra r flow axial hydrofoil axial flow turbine helical propeller. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. Our core business was and is the technical design and production. Motor hp shaft diameter critical speed blade thickness coupling selection bearing selection for vessel. Cerebro mix light non pressurised tank and mixer design cerebromix is used for the calculation of agitated nonpressurised process tanks. Shaft and bearing calculations gulf states engineering co. Pdf design of stirrer impeller with variable operational speed for. I wanted to calculate power consumption of agitator having 3 impellers installed on a single shaft and running at same speed. Review on design of agitator to optimize its performance.
The joint between the front plate and mating flange is fitted. Fracture and fatigue analysis of an agitator shaft with a. In most agitators, the actual relationship between torque and density is. Design of shaft length of agitator posted in industrial professionals.
Calculates agitator speed and power requirement for a given reactor geometry and mixture properties. In industrial process engineering, mixing is a unit operation that involves manipulation of a. Mechanical agitator power requirements for liquid batches. Redesign and structural analysis of agitator shaft for. The welding flange is designed for welding into the tank. Short term training programme on process engineering. Design of the mixer support must consider all of the mechanical loads on the mixer figure 1. First, the torsion and bending loads, previously calculated for shaft design, must be. Scaleup of mixing systems the calculation of power requirements for agitation is only a part of the mixer design. This will be the case unless the shaft is overloaded or damaged.
Mixer agitator mixtank calculators white mountain process. For the flat, sixblade open turbine, varying d a d t from 0. Agitator power consumption calculation posted in industrial professionals. Power input measurements in stirred bioreactors at laboratory scale. How do you design the shaft diameter, impeller rpm and. Scale of agitation 1 is quite mild, 3 is normal, 6 is vigorous and 10 is violent. 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 sound design of a doubleshaft mixer with a horizontal shaft and. This will be the case unless the shaft is overloaded or. Impeller design for mixing of suspensions tomas jirout, frantisek rieger czech technical university in prague, faculty of mechanical engineering, department of process engineering, technicka 4, 166 07 prague 6, czech republic abstract this paper deals with effect of impeller type on offbottom particle suspension. Anonymous 17 october at hello sir, i am chemical engineering student i agitator shaft design calculation filetype doing my final year calculatioon on extraction of oil from slurry in oil refineries. Ss304, ss304l, ss316, ss316l, c22, cs and custom to add bottom shaft support.
Multiple turbines mounted on the same shaft can reduce power draw. Jan 18, 2009 design of shaft length of agitator posted in industrial professionals. Shaft and bearing calculations 121 shaft and bearing calculations gert hallgren itt flygt ab abstract. By using the formula you gave on a precedent topic may 31, 2011, i estimated the reynolds 1. The differential agitator is an electro mechanic set consists of.
In any mixing problem, there are several defined objectives such as the time required for blending two immiscible liquids, rates of heat transfer from a heated jacket per unit volume of. Agitator shaft length should be calculated on which basis. The first shaft is the bearing axis while the second shaft is the axis of the quartet upper bearing impellers group and the triple lower group which are called as agitating group. As per the design calculation existing agitator gb is designed for max. The viscosity of newtonian media is independent of the agitator shaft speed or shear rate. The combination of the cfd investigations with conventional agitator software ensures maximum safety regarding the process engineering design for the agitator.
Impeller type mixing equipment represents the largest category of general purpose. A large change in stiffness close to the top of the shafting where the small gearbox shaft is coupled to the large tank shaft concentrates the. The differential agitator is an electro mechanic set consists of two shafts. A good industrial mixer design cannot use a gearbox that has an output shaft significantly smaller than the mixer in tank shaft, even if the overall critical speed of the system would be sufficient. The product mixed is so sensitive, that is why that design has been used. To design calculations at different viscosities illustrate the typical effect of viscosity on the required agitator power. Pdf justification of the design of the twoshaft mixer of forages. The shaft for a mixer, especially a large one, involves signi. Calculation of power absorbed at agitator shaft physics. The impeller generated flow can be calculated with the following equation. Design and implementation of differential agitators to. It provides high speed radial flow stirring, while drawing head space gas down a hollow shaft and dispersing the gas through the impeller ports, for effective entrainment of the gas into the liquid.
On internet i found articles for power consumption calculation for agitator with one impeller only. I offer design and drawing program which designs and draws a detailed drawing of agitator mixer, with user friendly dialog boxes, which is an addon for any cad program for designing and developing ga drawing for agitator mixer. Tubular applications with shaft lengths exceeding 60 feet. When two sixblade open turbines are installed on the. Customer questionhow are industrial agitators and blender designs evaluated and agitator shaft design calculation filetype can i be sure that my process goals will. Any type of shock or impact should be avoided as the carbon seal element is easily damaged. Dynamic characteristics analysis of agitator design for. Determine suitability of shaft design andor necessary size of shafting. Tubular shafts provide a stiff, light weight design which may be more cost effective in longer shaft designs. Introduction to nonnewtonian fluid and power requirement for nonnewtonian fluids d. The agitator impeller type that has been designed based on the operating conditions in the soy sauce cooking process is anchor.
In this paper, agitator shaft design modification carried out for selection of another material, motor selection, mounting of agitator, no. It provides for the optimisation of stirrer power consumption as well as the. V elocity profiles for kia impeller homogenizer in yz plane, for six impeller rotat ional speeds. Design specification of the motor is then determined by. Pdf a conceptualized impeller called kia is designed for impact. Use this value then as a default orientation value when executing a design of the real shape of the shaft. Btn agitators installation, operation maintenance manual. Connect the agitator shaft to the measurement shaft of the torque. 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. There is a bracket and a front plate between the motor and the welding flange. In the file dialog window, browse to the desire folder, type a file name into the.
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