BRMU8603056U2 - vacuum container mechanical circulator assembly - Google Patents

Abstract

ASSEMBLY OF MECHANICAL VACUUM CONTAINER CIRCULATOR. The present model relates to a new mechanical circulator assembly (2) which is compact in construction and energy efficient. In the present model, the length of the pump shaft (13) has been considerably reduced to only 0.50 to 0.56 m compared to the conventional shaft length of 5.0 to 8.0 m (in the case of mounted mechanical pumps). top) and 1.7 to 2.5 m (for base-mounted mechanical circulators). This was achieved by two factors - positioning of the sealing and bearing assembly in a special sealing and bearing housing (4) disposed entirely within the vacuum container; and by using the compact, lightweight inline planetary gearbox (15) having hollow key output and hollow keyed inlet for direct inline flange mounting of the drive (16).

Description

Utility Model Patent Descriptive Report for "VACUUM CONTAINER MECHANICAL CIRCULATOR ASSEMBLY".

MODEL FIELD

The present model refers to the field of mechanical engineering. More specifically, it relates to processing machinery for the concentration of sugar syrups and the like. In particular, the model belongs to mechanical circulators in vacuum containers. This application is a divisional application of application NQ 879 / DEL / 2006 entitled "Improved Vertical Continuous Vacuum Pan".

BACKGROUND AND PREVIOUS MODEL TECHNIQUE Definition of Important Terms:

1. Sugar mass: It is a mixture of crystals and mother liquor discharged from a vacuum container.

2. Calandry: Equipment consisting of closely spaced metal tubes for heat exchange.

In sugar factories, evaporation and crystallization of sugar syrup is performed on specially designed machinery called a vacuum container.

Vacuum containers are of two types - Batch Vacuum Containers and Continuous Vacuum Containers.

Batch Vacuum Containers (Batch Evaporation Crystallizer): Consists of a vertical cylindrical hull and a calender at the bottom. The shell is passed over a dome with a liquid droplet separator (juice droplet receiver) to prevent organic contamination of the condenser water. The design of batch vacuum containers has involved virtually uniform basic geometry and consists of:

- a central manhole

- straight sidewalls

- fixed calender

- calendering pipes with diameter 100 mm and length 800 to 1300 mm

- base angle from 18 to 25 degrees and

- device for improving circulation.

In the case of calendered containers, the W-shaped base is preferred over the conical base, provided that the W-base is efficient in distributing the sugar mass. (Circulation in Vacuum Pans - Rein, P.W., Echeverri, L.F. and Acharya, Sumanta - American Journal of Sugar Cane Technologists, Vol. 24, 2004).

Continuous Vacuum Container: These are two types, vertical and horizontal. The vertical continuous vacuum vessel consists of several calendered mixed chambers or chambers (similar to the batch evaporating crystallizer) which are mounted on top of one another. The main design of each compartment resembles a batch evaporating crystallizer. Importance of circulation in syrup processing using vacuum containers

The importance of circulating the mass of sugar in vacuum containers is well established. It has an impact on energy, sugar mass depletion and sugar quality. As a result, considerable efforts have been made around the world to design new, improved or better devices to improve circulation in vacuum containers. Mechanical circulators are one of the most commonly used devices and these have been well described in the prior art. (US387388, US1133821, US1476331, US1785530, US458882, US2355397, GB1061708, US3622387, US3636753, DE2922265, EP0065775, FR2695837).

Mechanical circulation is associated with several industry-level advantages, namely:

i. Product Quality Improvement: Better quality of sugar crystals. That is, consequence of better circulation leading to more homogeneous crystallization conditions within the container. Crystals grow more uniform and there are fewer mother liquor inclusions (vander poel 1980, Rieger et al. 1989: Zukerindustrie, 105, 237-240). There is less color in sugar and reduced risk of sugar loss from overheating.

ii. Reduction in water consumption: In addition, agitation also reduces the consumption of centrifugal washing water by 50% (van der poel 1980: Zukerindustrie, 105, 237-240).

iii. Sugar Height: The height of the sugar mass above the calendar can be increased considerably, above what is reasonable with natural circulation. As a result, a gain in capacity and a decrease in granulation volume.

iv. Capacity Enhancement: Mechanical circulation a-perfects heat transfer and thus shortens the boiling duration of the batch, thus enhancing capacity.

v. Best heat savings: Small temperature differences (<12 K) between heating steam and sugar mass are only possible with stirrers. Reliable operation without agitators (mechanical circulation) is not possible and can lead to crystallization of the crystals (Austmeyer, K.E; Schliephake, D.; Ekelhof, B.; Sittel, G. (1989): Zukerindustrie 114, 875-878). The use of low pressure vapors becomes possible (for example, from the 2- or 32-evaporator effect), allowing the reduction in factory steam requirements.

saw. Less deposition in the calender tubes: There are fewer deposits in the tubes due to the abrasion effect by the friction of the circulating crystals.

These, claiming rational circulation without the use of agitators (mechanical circulators), do this at the cost of simplicity of design and heat savings (Indian Patents IN145885, IN169913 and International Patents US4120745, EP0201629, DE3839182, FR2695837 and IN Patent Application. / PCT / 2002/02149 / CHE).

Therefore, it is evident that the installation of mechanical circulators provides all the advantages associated with good circulation.

Mechanical circulator assembly generally consists of the following elements:

- a circulator containing blades or other propulsion devices

- a vertical axis and

- a drive system connected to the shaft.

The drive system usually consists of the shaft, coupling, bearings, gears, pulleys and belts. Power is supplied by an electric motor.

Container mounted circulators can be top mounted or base mounted. In the case of overhead mounted mechanical circulators, the axle

of the circulator extends across the height of the container (between 5 and 8 meters) and projects its upper end through the top cover of the container (US387388, US1133821, US247542, US1785530, GB458882, GB1061708, EP0065775). In other cases, the circulator shaft projects into the container through its under wall (U.S. Patent Nos. 1476331, US2355397, FR2695837).

Bottom mounted containers offer a distinct advantage over top mounted mechanical circulators, shaft length is reduced to 1.7 to 2.5 meters compared to 5 to 8 meters.

However, regardless of the advantages of base-mounted circulators, top-mounted circulators are still popular in the industry due to the following practical advantages:

i. No need for elaborate support structure: Top mounted circulators can be easily fitted onto the

from above the vacuum container. In contrast, base-mounted mechanical circulators require an elaborate support structure including the foundation to support the large and heavy gear drive and / or gearbox, and to mount the bearings because the container is at a considerable height from from the factory floor.

ii. Free space availability: On top mounted containers, the pump mounting space is not a limitation. However, in the case of base-mounted circulators, this can present practical problems. In the case of conventional containers which are installed at considerable height with other processing equipment installed below them, for example the cooling crystallizer, space becomes a constraint.

Regardless of whether existing mechanical circulators are base-mounted or top-mounted, they still have certain disadvantages, namely:

The. High capital investment; 10 b. High maintenance costs;

ç. Leaks - air and / or syrup leaks;

d. Increased energy load, ie high energy consumption. The main reasons for contributing to these disadvantages are:

1. Long pump shaft length: Increased shaft length is associated with several disadvantages, namely:

The. Load: Increased axial as well as radial loads requiring additional devices to react to these loads.

B. Vibrations: More curvature vibrations, which in turn have adverse effects on seals, are particularly

inopportune, and require additional and supplementary sealing devices (US5078506).

ç. Bearings: Bearing life is reduced;

d. Accessories: An auxiliary bearing used at the free end of the longer shaft to reduce vibration (US1133821,

GB247542, US1785530) has been viewed as creating alignment, lubrication, corrosion, and maintenance issues.

and. Brackets: Additional bracket is required to keep the long shaft aligned, such as a flange coupling or other device (GB458882, US1133821).

f. Shaft Diameter: Also with increasing shaft length, in order to transfer the required torque to the pump, the shaft diameter has to be increased. This requires the use of higher energy and larger accompanying / support components such as gears, bearings, seals, hoops, etc. and also a casing / foundation designed for the same.

2. Conventional Sealing Device: Used in container circulation assemblies installed in vacuum containers for sealing purposes, it consists of sealing rings (sealing material) firmly wrapped around the pump shaft and compressed by an adjustable component called a material impeller provided with a threaded nut and a spacer. This is mounted on the container wall.

The disadvantages of the above are as follows:

The. Periodic Adjustments: In order to compensate for friction wear, periodic adjustments are required to be made. If the operator fails to detect such wear, this causes loss of vacuum and leakage.

B. Additional Wear: Also, attempts to adjust the stuffing box to provide satisfactory sealing for extended periods cause additional wear.

ç. Periodic Replacement: Sealing rings (packing) is also required.

d. Contamination: Danger of contamination of the contents of the vacuum container (syrup) by the packing in the case of base-mounted mechanical circulators.

and. Energy Loss: In sealing rings (packing) ranges from 0.5 hp for smaller pump shafts and up to 5.0 hp for larger shafts (Joshi, MV: Process Equipment Design, 2 ~ edition, Reprint, 1987, page 399 ).

Mechanical seals are also used in vacuum containers for the same purpose, ie sealing. However, unlike the present embodiment, where the sealing device is disposed entirely within the vacuum container in a special housing, they are disposed entirely outside the vacuum container. These are exposed to high radial and axial movements due to the long length of the circulator shaft and have presented problems requiring additional and supplementary sealing arrangements such as those described in US5078506.

3 bearings. The bearings used in the container circulator assembly are arranged completely outside the container to provide additional support for a long circulator shaft. Bearings are large in size and capacity due to their larger shaft diameter and increased axial and radial loads.

4. Gearboxes: Used in conventional container circulator assemblies, are of the conical, helical, or worm type (US387388, US1133821, US1476331, US2355397, DE2922265, EP0065775). Power is supplied by an electric motor. The disadvantages of these gearboxes are as follows:

The. High power consumption - High coefficient of friction requires higher drive energy;

B. Heavy weight - requires elaborate support structure;

ç. Large size: Requires more space for installation;

d. High speed reduction ratio achieved at the cost of efficiency and size.

and. Radial loads inside gearbox add up

to these of the circulator axis;

f. Lower comparative torque transmission capacity compared to that used in the present model;

g. Cost and time of assembly and initial installation are much higher;

H. Maintenance requirements are high;

i. Time and work involved in ensuring proper alignment of gearbox and driven members is high;

j. The gearbox is not in line with the shaft, which is also one of the reasons for the requirement for additional support structure.

k. cost and complexity of couplings I. Poor reliability;

m Higher noise levels;

no Lower efficiency - mechanical efficiency ranges from 40 to 90%.

The present model has been able to overcome the disadvantages associated with prior art mechanical circulators installed in vacuum containers in a simple but new manner. The innovation involved in the present model lies in the new aspects of construction and combination and ratio of mass-produced components readily available making the compact base-mounted container pump assembly reduced in size and weight inexpensive, maintenance free and efficient. in relation to energy.

A search of Indian Patent databases reveals that no such patent for the present model has been described in the prior art.

MODEL OBJECTIVES

The primary objective of the model is to provide a base-mounted mechanical circulator assembly for a vacuum container that is compact in construction, reduced in size and weight and is energy efficient.

Another objective is for the model to provide an assembly of

mechanical circulator in which maintenance requirements are negligible if required, time for disassembly and reassembly for repairs is short and the need to realign the drive shaft every time is avoided.

Still another objective of the model is that it can be readily combined with or installed in existing vacuum containers used for concentration of sugar syrups or the like, in the tapering cone upwards of the W-shaped base of existing vacuum containers, either batch or continuous.

Other goals lie in the new combinations and arrangement of parts and the new construction details, all of which will be fully described in the course of the following description.

The design involves certain novel aspects of component construction, combination, relationship and arrangement, of which a typical embodiment is revealed in the accompanying description and drawings making the mechanical circulator assembly compact and small in size.

In the present model, the length of the pump shaft has been considerably reduced to only 0.50 to 0.56 m compared to the conventional shaft length of 5.0 to 8.0 m (in the case of overhead mounted mechanical pump). and 1.7 to 2.5 m (for base-mounted mechanical circulators).

This was achieved by two factors:

O Positioning: The positioning of the sealing devices and the bearing assembly in a special sealing and bearing housing disposed entirely within the vacuum container; and b. Enhanced Gearbox Usage: The use of a gearbox

Compact, lightweight inline planetary gearbox featuring a hollow key outlet and hollow keyed inlet for direct inline flange mounting of the drive unit. DECLARATION OF THE MODEL Accordingly, the present model provides a vacuum container assembly (1) for evaporating - crystallizing a sugar solution equipped with a mechanical circulator assembly;

a circulator shaft with blades or other propulsion elements attached to a hub mounted at its inner end;

a gearbox driven by an electric motor at its other (outer) end;

sealing device; a limp; and

a slotted retaining ring disposed below said bearing;

said mechanical circulator assembly mounted on the tapering cone upwards of the W-shaped base of the vacuum container along its geometrical axis;

wherein said mechanical circulator assembly is of compact construction with considerably reduced circulator shaft length.

BRIEF DESCRIPTION OF DRAWINGS

The structural arrangements of the present model will be better understood by reference to the accompanying drawings.

Figure 1 is an elevational view of a vacuum container in which the mechanical circulator assembly has been installed. Figure 2 is an enlarged view of the mechanical circulator assembly shown in Figure 1.

DETAILED DESCRIPTION OF THE MODEL WITH REFERENCE TO DRAWINGS

A prior art research has revealed that while it is highly desirable to install a base-mounted mechanical circulator in the taper cone above the W-shaped base of the vacuum container used as an evaporator - crystallizer for sugar solutions, a number of series still exist. of factors that work against its use as already discussed above.

Accordingly, the present model provides a vacuum container assembly for evaporating - crystallizing a sugar solution comprising:

a mechanical circulator assembly;

a circulator shaft with blades or other propulsion elements attached to a hub mounted at its inner end;

a gearbox driven by an electric motor at its other (outer) end;

sealing device; a limp; and

a slotted retaining ring disposed below said bearing,

said mechanical circulator assembly mounted on the tapering cone upwards of the substantially W-shaped base of the vacuum container along its geometrical axis;

wherein said mechanical circulator assembly is of compact construction with the length of the circulator shaft.

In one embodiment of the present embodiment, the sealing device and the bearing of the mechanical circulator assembly are disposed within the vacuum container in a special housing.

In another embodiment of the present embodiment, the seal and bearing housing is provided with an inverted cone.

In yet another embodiment of the present embodiment, the sealing device is having a mechanical seal made of Silicon Carbide.

In yet another embodiment of the present embodiment, the bearing is mounted on the stuffing box and the bearing on a shielded deep groove ball bearing.

In a further embodiment of the present embodiment, the gearbox and gear drive are coaxial (inline) and are mounted directly on the base of the vacuum container without any coupling structure and support.

In another embodiment of the present embodiment, the mechanical circulator assembly has an inline gearbox, which is of planetary type having hollow keyway and a hollow inlet with a key arrangement for direct inline flange mounting of the drive.

In the present model, the length of the pump shaft has been considerably reduced to only 0.50 to 0.56 m compared to the conventional shaft length of 5.0 to 8.0 m (in the case of mechanical pump mounted on the above) and 1,7 to 2,5 m (in the case of base-mounted mechanical circulators). This was achieved by two factors:

positioning the sealing and bearing assembly in a special sealing and bearing housing within the vacuum container; and

The use of a lightweight, compact planetary-type gearbox with a hollow keyway and a hollow inlet for direct flange mounting of the drive unit.

Figure 1 shows an elevation view of a vacuum container assembly 1 in which the mechanical circulator assembly 2 of the model has been installed in the upward tapering cone of the W-shaped base 3. The vacuum container is supported by devices not shown in the drawing from the factory floor.

Figure 2 is an enlarged view of the mechanical circulator assembly 2. According to one aspect of the present embodiment, a new packing and bearing housing 4 is disposed entirely within the vacuum container between the base of the tapered cone above the W3-shaped base and the lower level of calender 5.

Said sealing device comprises a cannon metal bushing 6, sealing gasket 7 and mechanical seal 8 preferably made of Silicon Carbide rather than the conventional method of stuffing box and packings. The mechanical seal's stationary and rotary sealing rings are held in place by flexible O-rings 9. Silicon Carbide is preferred over other materials because of low heat generation, eliminating the need for cooling devices and their self-lubricating property. In Tungsten Carbide materials, due to the high heat generation, the small amount of juice coming into contact with the seal is burnt creating carbon resulting in wear. The advantages of mechanical sealing over conventional sealing devices are well known, namely:

a) Leak blocking efficiency;

b) Self-lubricating - No periodic lubrication is required;

c) Self Adjustment - No periodic adjustments are required to compensate for friction wear;

d) Suitable for high temperature and pressure conditions;

e) Has extended service life - has very low coefficient of friction f) Very low maintenance requirements;

g) There is no risk of contamination of vacuum container contents due to lubricant degradation and / or leakage.

The bearing 10 is housed in a bearing housing plate 11 connected with the bearing and bearing housing 4 and held in place by a bearing retainer plate 12. A shielded deep groove ball bearing 10 is used which is well adapted to contain both the radial load and the axial load of the circulator shaft. This one also has low noise levels. The size of the bearing 10 used is also small due to the small diameter of the pump shaft 13 due to its own reduced length and decreased axial and radial loads. Another advantage of the bearing 10 used is that it does not require periodic lubrication and operates with minimal maintenance.

Decreased axial and radial loads on the pump shaft 13 resulting in very low vibrations in and virtually zero alignment problems contribute to the life of both the sealing device and the bearing 10.

The sealing and bearing housing 4 is provided on the outside by an inverted cone 14. The advantage of said inverted cone 14 is that it avoids stagnant areas adjacent to housing 4 and aids in the circulation of the sugar mass in the vacuum container. An additional advantage of inverted cone 14 is that it provides reinforcement for the stuffing box and bearing 4.

At the lower (outer) end of the circulator shaft 13 is mounted an inline hollow key planetary gearbox 15 eliminating the use of the coupling. Gearbox 15 has a hollow inlet with key device for direct inline flange mounting of drive unit 16 without coupling. The use of such gearbox 15 has several advantages over gearboxes conventionally used in vacuum containers as follows:

a) Inline: The Planetary System is coaxial (inline) and is particularly suitable for low speed high torque applications.

b) Efficiency: It is extremely competitively priced compared to other gear systems and offers high efficiency with minimum dimensions. The planetary drive unit can be up to 98% efficient and critically capable of delivering extremely low speeds without much loss of efficiency. The efficiency losses for most gearboxes (except planetary gearboxes) are anywhere between 5% (Helical and Sprocket) and 30% (Worm) per stage. This is not the case with planetary gearboxes which minimize efficiency losses to just 1% per stage (planetary gearboxes are the energy saving choice - Internet site: http://www.engineeringtalk). com / news / bvr / bvr104.html)

c) Energy efficiency: Planetary gears have a very low coefficient of friction. Less energy is required to rotate them and thus more of the drive force is converted to rotational usable force after the speed has decreased. A major benefit is that the power consumption is much lower than that of the conventional gearbox and thus saves a lot of money.

d) Higher Reduction Rates: Planetary gear assemblies are able to provide high reduction rates in small packages, and to transmit several times the torque of similarly sized conventional gear units.

e) Compactness: The planetary gearbox is smaller and lighter, up to half the size and 60% lighter than the heavier designed conventional gearboxes. These require little space for installation. These aspects of the inline planetary drive system eliminate the increased space requirement and elaborate support structure for mounting it.

f) Technical Advance: Compared to a parallel shaft arrangement, a planetary gearbox in intermittent / high torque operations can often achieve the same ratio with a smaller, cost saving and dimension reduction stage.

g) Reduced Maintenance: In addition to the oil change routine, no maintenance is required during the projected service life, not even bearing replacement.

h) Coupling Elimination: Elimination of the cost and complexity of couplings.

i) Easy Alignment: Eliminating the time and labor involved in ensuring the correct alignment of the gearbox and the equipment it is driving makes it especially suitable for mounting the pump shaft.

j) Reduced radial loads: Direct drive through shaft mounting also avoids radial loads imposed by belt drive units. The planetary gearbox also has tolerance for handling radial loads from the equipment it is driving.

k) Reliability: Finally, high levels of reliability are an aspect of planetary design due to the stress distribution across various load bearing components.

Gearbox 15 and drive unit 16 are mounted directly underneath the vacuum container housing providing for mechanical pump assembly 2 compactness along with all the advantages of the short length of the pump shaft.

With such short shaft length 13 from only 0.50 to 0.56

m, there is a dramatic reduction in both radial load and axial load. This reduces the need to contain these loads and correspondingly a smaller number, and less capacity components or parts can be used and, for example, there is no need for additional support / bearing devices, nor are there any the requirement for additional / supplementary support devices or bearings with higher load tolerance capability.

The benefits of reduced loads and vibration include extended bearing and seal life respectively, a critical component to machinery reliability.

Shaft 13 is also smaller in diameter allowing the use of smaller components or accompanying / supporting parts such as bearings, bearings, gears, rings, etc.

After aligning the shaft during initial installation, there is virtually no need to realign the shaft after each disassembly and reassembly for repair or maintenance of the gearbox and motor. The reduction in pump shaft length by using the new devices as described not only made the mechanical pump assembly 2 compact and energy efficient, but also reduced capital and maintenance costs compared to existing mechanical pumps.

Although the model has been described with reference to specific embodiments, this description is not intended to be construed in a sense of limitation. Various modifications of the disclosed embodiments, as well as alternative embodiments of the model, will become apparent to those skilled in the art upon reference to the description of the model. Therefore, it is contemplated that such modifications may be made without departing from the spirit and scope of the present model as described.

For ease of reference, a comparative table presenting the new aspects of the present model in relation to the existing prior art is given in Table 1 below:

TABLE 1

<table> table see original document page 17 </column> </row> <table> <table> table see original document page 18 </column> </row> <table>

Claims (8)

1. Vacuum container assembly (1) for evaporating - crystallizing a sugar solution comprising: a mechanical circulator assembly (2); a circulator shaft 13 with blades or other propulsion elements attached to a hub mounted at its inner end; a gearbox (15) driven by an electric motor (16) mounted at its other (outer) end; sealing device; a bearing (10); and a slotted retaining ring disposed below said bearing (10), said mechanical circulator assembly (2) mounted on the tapering cone upwardly of the substantially W-shaped base (3) of the vacuum vessel along its axis. wherein said mechanical circulator assembly (2) is of compact construction with a considerably reduced length of the circulator shaft (13). Assembly (1) according to claim 1, wherein the sealing device and the bearing (10) of the mechanical circulator assembly (2) are disposed entirely within the vacuum container in a special sealing and bearing housing. (4). Assembly (1) according to claims 1 and 2, wherein the seal and bearing housing (4) is provided with an inverted cone (14). Assembly (1) according to Claims 1 to 3, wherein the sealing device has a mechanical seal (8) made of Silicon Carbide. Assembly (1) according to claims 1 to 4, wherein the bearing (10) which is mounted on the stuffing box and bearing (4) is a shielded deep groove ball bearing. Mounting (1) according to claims 1 to 5, wherein the gearbox (15) and gear drive unit (16) are coaxial and the gearbox (15) is mounted directly on the base (3) of the vacuum container (3), without any coupling and support structure. Assembly (1) according to any one of claims 1 to 6, wherein the gearbox (15) is a planetary gearbox directly mounted in-line (15) with hollow key outlet and hollow inlet arrangement. inline flange mounting switch for drive unit. 8. Assembly (1) substantially as described herein with reference to the accompanying drawings.