How Much Water Is Required To Clean A Tank Agitator

Aseptic Design and Maintenance of Equipment

Frank Moerman , Jacques Kastelein , in Food Safety Management, 2014

Hygienic Design of Agitators

Agitators and agitator shaft assemblies passing through the seals shall exist designed and constructed to be smooth, with all surfaces meeting all the hygienic design criteria applicable to a product contact expanse. Anarchist shaft assemblies shall exist readily accessible to allow all surfaces to be effectively cleaned via spray, directed flow, immersion or cleaning-in-place. Anarchist ends shall have surfaces of minimum area immediately side by side to the recipient ends and no longer than necessary to ensure proper incorporation of ingredients into a mix.

The design of agitator production contact parts should minimize the occurrence of crevices, void spaces and dead spaces in grooves. All voids should exist closed past either fabrication (welding) or approved sealing techniques (O-rings, seals, etc.) to give surfaces basis flush and gratis of crevices at points of metallic-to-metal contact. Metal-to-metal joints (e.g. keyways, hub-to-shaft joint, hub-to-stop cap joint, etc.) may allow ingress and accumulation of product and/or microorganisms (Figures 26.22a and b and 26.23).

Food quality gaskets nether controlled compression may seal the propeller hub to the shaft and to the impeller nut (end cap) that secures the finish of the anarchist shaft (Effigy 26.22c). Alternatively, the hub should be welded to the shaft and the cease cap (Figure 26.22d). Because debris may collect on exposed screw threads, the hub shall not be fastened to the shaft past means of a screw. To avoid whatsoever screwed joints (even bolts with dome head basics and washers of suitable food grade material), the blades of appendages (stirrers, homogenizers, mixers, etc.) should be welded to the hub. As an alternative to hub-to-shaft and subsequent impeller bract-to-hub attachment, blades tin be fastened to shafts by welding. All welds used in the assembly of agitator parts should be grounded and polished.

Permanently joined metallic surfaces with a total included internal angle less than 135° on agitators (eastward.g. at hubs and nuts) shall have a radius of not less than iii mm tangential to both side by side surfaces. Corners (eastward.thou. at hubs, nuts, spanner flats, etc.) must be radiused to facilitate cleaning, and horizontal areas must be sloped to prevent debris from becoming lodged on the surfaces and to allow for maximum drainabilty. Machined transitions such as shaft steps, coupling surfaces, spanner flats, etc. should accept 15 to 45° sloped surfaces. Impellers with flat, horizontal surfaces (due east.g. flat-blade disc turbines, concave-blade disc turbines) may require additional design and/or cleaning practice to ensure drainage and cleanability, eastward.g. drain holes, spray ball and/or wand additions, increased CIP flow, adjusted spray coverage, and faster impeller rotation.

Agitators permanently mounted are not required to be removable if they are readily accessible and practise not interfere with drainage from the tank. Where permanently installed agitators are equipped with an outer frame to which safe, plastic or other similar scraping edges are attached, these scrapers shall be readily removable from the agitator. In kettles, however, it is recommended that the unabridged unit shall exist synthetic and so that information technology tin can be tilted or lifted out of the kettle.

Welded in-tank shaft connections are preferred, although in-tank threaded shaft connections (Figure 26.24f) and in-tank shaft couplings (Figure 26.24a–eastward) are allowed if they are of adequate hygienic design. Threaded shaft connections are preferred over in-tank shaft couplings, although shaft rotation of the first is express to a single direction to avoid the shaft sections separating. The designer must ensure that the use of a threaded shaft connection is appropriate for the selected shaft diameter and pattern loads. To avoided exposure of the threads to the product, O-rings or apartment gaskets (preference for the outset mentioned) should be used to seal mating surfaces (Effigy 26.24f). Hygienic bolted coupling construction may be used where appropriate for the particular application. The preferred location for fastening hardware is on the underside of couplings, and the fasteners typically used should be hex-head cap screws, acorn-head cap screws and threaded studs with acorn basics (Effigy 26.24d). These fastener heads shall be free of raised or engraved markings that might inhibit cleanability. Over again O-rings or flat gaskets (preference for the first mentioned) should be used to seal coupling mating surfaces. Elastomer seal washers (Figure 26.24b–d) must avoid metal-to-metallic contact.

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Hygienic Design of Airtight Equipment for the Processing of Liquid Food

F. Moerman , in Food Protection and Security, 2017

7.6.2.2 Acme Mounted Installation of Agitators

Agitators permanently mounted are not required to be removable if they are readily accessible to be effectively cleaned via spray, directed menses, immersion or cleaning-in-place (CIP) and if they do non interfere with drainage from the tank. Top entering agitators with shaft seals are typically mounted to a vessel using a flanged or hygienic clamp connexion, with hygienic O-rings or gaskets to seal betwixt the mating surfaces. The selected mounting arrangement must support the agitator mounting blueprint loads while achieving an appropriate seal. The upstand for the top mounting of the agitator should take limited length Fifty because of the difficulty of cleaning of the annular space in-place. The annular infinite between the anarchist shaft and anarchist nozzle shall, for cleaning purposes, have the target maximum 50/A ratio of 2:1. At least a 25 mm gap is required to facilitate CIP spray coverage (Fig. 7.23) (CFCRA, 1997; BISSC, 2003; ASME BPE committee, 2014).

Agitator motors should be equipped with permanently lubricated bearings. Where lubrication is required, the design and structure shall be such that lubrication cannot leak, drip, or be forced into the product zone. Self-lubricating agitator shaft (packing) seals shall be provided with user-friendly means for aligning to prevent leakage and to allow for complete drainage to the exterior (Fig. 7.23). In that mode, accumulations of foreign material in the event that leakage does occur can be avoided. Farther, baste protection is commonly provided to foreclose lubrication from inbound the production zone. All surfaces of shaft seal ring assemblies passing through a bowl or cover shall be accessible, removable or retractable to allow cleaning of all product zone surfaces.

Rotary shafts running at a high number of revolutions are held in-place in an adaptor sleeve with a radial roller begetting. Unmarried dynamic seals (Fig. seven.24A) will not prevent the passage of microorganisms. If properly designed, they may be like shooting fish in a barrel to clean but not bacteria tight considering rotating shafts always exhibit some axial mobility. This makes single dynamic seals unsuitable for aseptic equipment. A narrow annular space at the product side in the proximity of the seal, such as that shown in Fig. 7.24A, must be avoided because information technology is difficult to clean. The space effectually the seal should be as wide as possible. Rotary shafts with double seal arrangement allow the employ of a barrier medium, and have been shown to be well-suited from a microbiological standpoint. In Fig. vii.24B, one seal is seated rigidly in the housing (longitudinal shading), while the other moves with the shaft. The sealing surface betwixt the ii seals must be lubricated. If the shaft opening has production flowing through it, which could be the instance with agitators having a shaft entry from the bottom of vessels, the product itself can exist directly used as lubricant. The product flowing through can be carried away by the barrier medium, which could be steam, hot water, condensate or a disinfectant solution (e.thou., alcohol). The sterile fluid may scavenge the microorganisms that enter the space between the seals, maintaining sterile conditions. Which flushing fluid should be used will depend on the product and the process but both the barrier medium and lubricant chosen must be production-compatible. To avert transfer of microorganisms from the exterior of the equipment to the inside the distance between the two seals must always be sufficiently big (Lelieveld et al., 2003; Hauser et al., 2007).

Bearings in the product surface area should be avoided but an application may mandate the use of foot bearings. In the example given, if the shaft of a top entry agitator is very long, a pes bearing may be required at the lesser of the vessel to steady information technology. It shall exist of a packless bearing type. The foot bearing must be mounted well clear of the base and so as not to impede complimentary draining of production and to permit like shooting fish in a barrel cleaning of their supports. Blueprint features and/or procedures required to ensure cleanability are: bleed holes, spray ball, and/or wand additions, increased CIP flow, operating the steady bearing immersed in CIP fluid. The arrangement of wear surfaces (bushing, shaft, or shaft sleeve) shall facilitate drainage. A longitudinal or helical groove may exist cut in either the bush or the shaft. It should be deep plenty to allow access into the bearing of either the product as a lubricant or the detergent for cleaning (Fig. 7.25). Sealed bearings should not exist used in the production area because they can cause hygiene risks at their seals. If, however, their employ is unavoidable, their lubricants should be specified as beingness allowed in contact with food.

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Industrial Fermentation Processes

T.M. Anderson , in Encyclopedia of Microbiology (Third Edition), 2009

Electricity

Agitators, air compressors, and chillers crave a big corporeality of electricity. Where economies of scale are adequate, cogeneration of steam and electricity is very toll-constructive. Boilers using natural gas, oil, or coal produce very loftier pressure level steam used for electricity generation. The waste steam produced from generation of electricity is at loftier enough pressure for use in fermentation and downstream processing. This steam is captured and used equally the process steam for the plant, reducing the cost of both electricity and steam. Whenever possible, the condensate water from process steam is returned to the cogeneration constitute for reuse.

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PROCESS AND PLANT DESIGN

R.P. Singh , Due south.E. Zorrilla , in Encyclopedia of Dairy Sciences, 2002

AGITATORS IN MILK PROCESSING PLANTS

D.A. MacCarthy , ... One thousand. Cronin , in Encyclopedia of Dairy Sciences, 2002

Turbine Agitators

These agitators have an impeller to tank diameter ratio in the range of 0.2–0.5, and tin be operated at a high speed if required. They are used to agitate low viscosity liquids (ordinarily <1 Pa southward), but they have also been used to agitate liquids with a viscosity as high as 50 Pa south. The bones turbine is a apartment-blade pattern and one of the most common turbines is the six flat-bladed disc-mounted impeller ( Figure ii ), which is oft used in fermentors. Turbine impellers tin can induce stiff radial flow in improver to axial menstruation, which imparts a much greater mixing capability than propeller agitators. Pitch-bladed turbines have their blades prepare at an angle of less than 90° from the horizontal ( Effigy three ) and are used in the dairy industry, for example, in lactose crystallization and yoghurt manufacture. The smaller the bending, the milder the agitation every bit less shear forces are exerted on the liquid and on whatsoever particles or droplets inside the liquid.

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Processing plants and equipment

A.Y. Tamime , R.K. Robinson , in Tamime and Robinson's Yoghurt (Tertiary Edition), 2007

Speed of rotation

The agitator speed is reduced as much as possible to give effective mixing of the coagulum simply minimum shearing. Some commercially bachelor tanks reflect this aim with the speed of rotation ranging between eight and <50 rpm. Maiocchi (2003) reported that, at the beginning of the cooling stage, the speed of rotation was 15–20 rpm for five min and later reduced to ii–3 rpm. In some instances, two-agitator systems rotating in reverse directions may exist installed in a tank or one agitator paddle may exist needed which can rotate clockwise or anti-clockwise alternately. Nevertheless, the in-tank cooling of yoghurt requires a long time and according to Kessler (1981), the formula used to measure out the rut transfer in a tank during the heating of milk tin be used to summate the time required to absurd the yoghurt. He illustrated this point with the following instance:

$\begin{array}{l} = \frac{\begin{array}{l} Volume \\ (m^{three}) \end{array} \times \begin{array}{l} Density of \\ yoghurt ({kg m}^{- 3}) \end{array} \times \begin{array}{l} Specific heat \\ ({J kg}^{- i} K^{- 1}) \end{array}}{\begin{array}{l} Constructive heat/cool \\ substitution area ({thousand}^{3}) \end{array} \times \begin{array}{l} Heat transfer \\ coefficient ({Westward m}^{- 2} 1000^{- i}) \end{array}} & \ln \frac{\begin{array}{l} Temperature of \\ warm yoghurt \end{array} - \begin{array}{l} Temperature of \\ cooling medium \end{array}}{\begin{array}{l} Temperature of \\ cool yoghurt \end{array} - \begin{array}{l} Temperature of \\ cooling medium \end{array}} \\ = \frac{iii \times 1040 \times 3800}{9.55 \times 150} & \ln = \frac{40 - xv}{xx - 15} = 1.61 \\ = \frac{3 \times 1040 \times 3800}{9.55 \times 150} \times 1.61 & \ln = natural logarithm \\ = 13 325 s = 222 min = 3 .7 h \end{array}$

where In is the natural logarithm. High-speed agitation was used during cooling.

It is articulate that chilled water rather than mains water should be used in gild to maximise the temperature differential between the warm yoghurt and the cooling amanuensis and if the surface area can exist increased, the cooling time will likewise exist reduced.

An alternative technique for the in-tank cooling of yoghurt would be the insertion of a heat exchanger (plate or coil) into the coagulum at the terminate of the fermentation stage (Ehrmann, 1972 ). Yet, this type of apparatus restricts the use of agitators in the tank and since these coolers are inserted into the coagulum after the incubation flow, issues of contamination may arise.

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Volume five

Thou. Cronin , D. Band , in Encyclopedia of Dairy Sciences (Third Edition), 2022

Paddle Agitators

The basic paddle anarchist resembles the basic turbine agitator except that information technology has a larger impeller to tank diameter ratio (>0.five to <1) and rotates at low speeds, typically x–150 rpm. Paddle agitators are used in the dairy manufacture for agitating medium viscosity liquids (0.five–10 Pa s). Increasing the viscosity will more quickly dampen the momentum transfer through the liquid and thus greater contact between the impeller and the liquid is required which results in larger diameter impellers with greater contact expanse. In that location are many variants of the basic paddle, as illustrated in Fig. 4, which give greater contact area. Some of these, such as the gate-ballast agitator can be used with loftier viscosity liquids up to effectually 100 Pa south.

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Familiarization With Procedure Equipment

Monoj K. Gupta , in Practical Guide to Vegetable Oil Processing (2d Edition), 2017

14.2.11 Agitators

Mechanical agitators are very common equipment used in the oil processing plant. Examples of most usually used mixers are shown in Table xiv.v. These are used for various purposes, such as:

Table 14.4. Stride by Pace Procedure for Troubleshooting Steam Ejectors

Symptom	Probable cause	Recommended solution
Poor vacuum (or loftier absolute pressure).	• Water vapor load is high because of higher volume of stripping steam. • Motive steam pressure is high. • Condenser water temperature is high. • Low menses of condenser h2o. • At that place may be a blockage in the condenser h2o line.	• Reduce stripping steam flow if it is loftier. If this does non ameliorate the vacuum then reduce oil flow in a continuous deodorizer or reduce the oil volume per tray slightly in a semicontinuous deodorizer and reduce the stripping steam menses accordingly. • Reduce motive steam pressure if information technology is high. • Check and right water distribution in the cooling tower. • Check and correct the flow of water to the condenser. • Bank check for whatsoever blockage and remove it.
The greasy water temperature is okay but the barometric leg is common cold and the vacuum is poor.	• There is a blockage in the condenser or the barometric leg.	• The water menstruation may be high. Check the water period and reduce it if information technology is found to be high. • If this is not the cause and then close off the greasy h2o and allow the steam run through the barometric leg for 15 min. This volition clean any grease build up. Restart the greasy h2o flow. • If this does not work, the blockage must exist serious. Shut down the arrangement and make clean it.
Poor vacuum or high accented pressure continues even after some of the in a higher place measures accept been taken.	• There may be a leak on any of the joints, flanges, man heads, etc. • Leaky steam coil within the deodorizer. • Leaky h2o coil in the cooling tray. • Leak in the ejector system. Any of the in a higher place situations will require the deodorizer to be close downwardly for inspection and repair.	• Shut off h2o into the cooling coil. The vacuum will improve if there is a leak in the cooling curlicue. • Each condenser stage is designed to show some specific force per unit area as indicated by the ejector manufacturer. • Bare off each stage at a fourth dimension and check the pressure. An air leakage volition produce a higher pressure at the ejector stage. • Place the stage that produces higher than the designed pressure level and repair the leak.
Poor vacuum or loftier absolute force per unit area continues even after some of the above measures have been taken.	• The ejector nozzle tin can be eroded, or steam leaking from the joint surrounding the nozzle of the first stage. • There can be blockage in the ejector nozzle.	• Repair any steam leak or supercede the nozzle. • Open up and clean the blockage.
Vacuum is unsteady and fluctuating.	• The atmospheric phase nozzle is eroded. This occurs if the motive steam is moisture or if the nozzle is made of carbon steel and eroded past the wet steam.	• Check if the steam purifier is working properly. • Replace the nozzle with a 304 or 316 stainless steel nozzle.

ane.: mixing two or more miscible liquids,
two.: dissolve a solid into a liquid,
3.: dispersion of a nonmiscible liquid into other using high shear mixers, and
4.: append and create an intimate contact betwixt solids and liquid.

14.2.11.one Examples

14.2.xi.1.1 Category #1

This is most usually used in blending two or more than oils to codify shortening or margarine production.

14.2.xi.1.2 Category #2

Dissolving solid caustic pellets into water.

14.2.xi.1.3 Category #iii

The mutual examples are:

•: Dispersion of NaOH solution into the crude oil in refining.
•: Dispersing citric acid solution into the deodorized oil.
•: Dispersion of oil soluble and h2o soluble components in making margarine emulsion.
•: Dispersion of dimethylsiloxane in frying oil.
•: Dispersion of antioxidants into the oil.

14.2.11.1.4 Category #4

The mutual examples are:

•: Dispersion of bleaching clay into the oil in bleaching.
•: Dispersion of nickel catalyst in the hydrogenation reactor.

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Finished Product Storage and Handling

Monoj Yard. Gupta , in Practical Guide to Vegetable Oil Processing (2nd Edition), 2017

9.iii.4 Agitator

A side-mounted agitator is needed for hydrogenated or higher melting stocks to keep the production well mixed. A heating coil using low-pressure steam is used in the tank (not shown in Fig. 9.1). The agitator also prevents any scorching of the stock on the heating coil surface. A low level switch disables the agitator motor at a predetermined oil level (above the anarchist blades) in order to protect the anarchist shaft and the seal.

Likewise non shown in Fig. 9.1 are the three or four baffles in the tank. The baffles are placed at every 120 degree or at every quadrant and run vertically along the wall of the tank. The width of each bamboozle is 1 twelfth of the diameter of the tank. The baffles prevent churning of the oil within the tank and break any vortex.

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Aseptic Design of Open up Food Processing Equipment

F. Moerman , K. Lorenzen , in Food Protection and Security, 2017

6.vi.2 Installation of Agitators in Open Vessels (due east.g., Kettles)

Installation of agitators in open vessels should occur every bit follow ( Moerman & Kastelein, 2014):

•: Stirrers, homogenizers, or mixers installed via the bottom side or a side wall require sealing of the shaft at the product side. The problem is that seals may wearable with time resulting in leakage of production to the outside and production contagion. Parts of the seal may get lost in the production as a foreign torso contaminant (Fig. half-dozen.17). Moreover, when the seal gets damaged, product buildup around the shaft will occur, providing nutrients for microorganisms to abound. These microorganisms may later on catamenia back into the product.

Effigy half-dozen.17. Stirrers, homogenizers, or mixers installed via a side wall require sealing of the shaft at the production side. When the seal is worn, however, leakage of product to the outside and product contamination may occur. Particles of the broken seal act as foreign body contaminants, and the nutrient may be spoiled with microorganisms migrating out of the gap in which they could grow due to the presence of nutrients.
world wide web.ourfood.com, courtesy of Karl Heinz Wilm, © 2016.
•: Where mounting of the equipment outside the product zone is possible, the mixer used to mix open product should be fixed beside the equipment, not only to prevent the contamination of the product with dripping oil, merely also to avoid the introduction of soil, and concomitantly spoiling microorganisms and pathogens into the product along with overhanging electrical cabling (Fig. 6.xviii).

Effigy 6.18. (A) A motor and cabling mounted over whatsoever exposed product (one) tin can contaminate it by soil, condensate, or lubricants (2). (B) The motor drive (3) and electric line should be placed beside the recipient. Just without drip protection, soil, condensate, and lubricants still can contaminate the product. (C) A self-draining protection sheet with "upstand" (4) in combination with a cowl (5) on the shaft must exclude any food safe risk. The bottom side of the thrower band (cowl) should be made inspectable (Lelieveld et al., 2003; Hauser et al., 2004b; Moerman, 2011).

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