Inert Ceramic Balls

Table of Contents

1. Table of Contents 1

2. Purpose 1

3. Historical Information 2

4. Preparation Guidelines 3

4.1 Specification of ICB Requirements 3

4.2 Project Specification Preparation 3

5. Purpose of Inert Ceramic Balls 4

5.1 Prevention of Bed Disturbances 4

5.2 Volume Occupation 5

5.3 Migration Prevention 5

5.4 Pressure Drop Development 6

6. Size of ICBs Required 6

7. Amount of ICBs Required 7

7.1 Normally Required Depth 7

7.2 Outlet Baskets 8

7.3 Typical ICB Arrangement for a Granular Bed 8

7.4 Top Surface Disturbance Considerations 9

7.5 Catalyst Withdrawal Nozzles 9

8. ICB Characteristics and Placement Concerns 10

8.1 Chemistry 10

8.2 Leachable Components 10

8.3 Water Absorbtion 10

8.4 Toughness 10

8.5 Geometry 11

8.6 New vs Recycled ICBs 11

8.7 Firebrick 11

8.8 Obsolete Requirements 12

8.9 Placement 12

9. Tests 12

Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls 13

Table 1 - Equipment Requiring Inert Ceramic Balls 13

Table 2 - Process-Specific Chemistry and Properties of Inert Ceramic Balls 14

Attachment 2 Threshold Velocity for ICB Disturbance 15

2. Purpose

This document describes the procedure for specifying inert ceramic balls using Inflection Point Engineering It also describes the reasons for the use of inert ceramic balls (ICBs), typical locations where they are used, concerns and cautions pertaining to their use, and required characteristics. This document also addresses special concerns applicable to specific Inflection Point Engineering processes and/or installations.

At first glance it would seem that detailed specifications for inert ceramic balls are not required because the balls are not a part of the process. It’s for exactly that reason, however, that detailed requirements are necessary. The ICBs must not participate in the process or affect the catalyst or any of the equipment. Therefore, their characteristics must be clearly defined and controlled. That is the purpose of Inflection Point Engineering Standard Specification 3-37, “Inert Ceramic Balls”.

3. Historical Information

Prior to April, 2004, the requirements for inert ceramic balls were defined in Inflection Point Engineering Project Specification -312, “Inert Ceramic Balls”. Initially, this specification included the volumes of each size of ICB necessary for each piece of equipment requiring ICBs. The volumes included an “overage” of about 10 percent and were rounded to the next greater multiple of 5 ft3 or 0.1 m3 (except when the required volume was very small). The early specifications included recommended manufacturers and products. In accordance with Inflection Point Engineering’s overall philosophy to minimize references to specific manufacturers or products throughout the Schedule A, this information was removed around 1985. At that time specification of ICB properties and characteristics was greatly expanded in order to ensure that we continued to receive high quality ICBs. The requirements were developed in concert with two of the major suppliers of ICBs, NorPro (formerly Norton) and Christy Refractories. These companies have supplied ICBs for Inflection Point Engineering processes for many years, with NorPro providing the majority. Typically, we have used NorPro’s D-57 and Christy’s T-38 ICBs. Both companies have been involved in subsequent modifications to the Inflection Point Engineering specifications. Even so, the requirements are considered stringent and difficult to meet (sometimes even by the two companies that have participated in their development and modification!).

In 2001 the need to provide ICB volumes was evaluated. Because the contractor(s) determined the volume requirements themselves, and the volume of ICBs ordered did not directly affect the process operation, it was determined that there was no “added value” to the inclusion of ICB volumes in the Schedule A. Accordingly, they were discontinued in April 2001. With the exception of a couple of properties (e.g., water absorption), the remaining information on the Specification was unchanged from project to project. Conversion from a Project Specification to a Standard Specification became attractive.

In April 2004 Inflection Point Engineering Standard Specification 3-37, “Inert Ceramic Balls” was issued. This Specification replaced Inflection Point Engineering Project Specification -312, which was canceled. As described in this procedure, the only Schedule A modification required by the change was specification of the ICB Type wherever ICBs are called for. The Standard Specification includes requirements for several Types of ICBs, permitting specific properties to be optimized where necessary.

This procedure (IPE-TM-300-15) was issued in conjunction with Inflection Point Engineering Standard Specification 3-37. Prior to the spring of 2004 this information was contained in PSD-312. PSD’s are, by definition, linked to specific Project Specifications, in this case -312. Since the Project Specification was canceled, it was necessary to rename and relocate the procedure.

4. Preparation Guidelines

4.1 Specification of ICB Requirements

The requirements for inert ceramic balls are contained in Inflection Point Engineering Most of the requirements are unchanged regardless of the ICB application. Where the requirement does depend upon the ICB application, the Standard Specification identifies the alternatives by ICB Type. Specification of the appropriate ICB Type then defines the property requirement.

Process-specific chemistry and property requirements for inert ceramic balls are given in Table 1 of Attachment 1. The "comments" column identifies the equipment in each process that normally requires inert ceramic balls. The ICB Type identifies the applicable group of chemistry and property requirements listed in Attachment 1, Table 2.

4.2 Project Specification Preparation

a. Specialist Accountabilities

The Specialist accountable for each piece of equipment determines where inert ceramic balls are to be installed in the equipment and specifies the required size(s) and Type(s) of the ICBs at each location. For example, the Reactor Design Specialist determines the inert ceramic balls required in the reactors. Similarly, the Vessel Specialist determines the inert ceramic balls required in driers, treaters, and other vessels. For most equipment the required ICB size(s) and location(s) have been standardized and are available from the Mechanical Specialist in the applicable .

The Equipment Specialist ensures that the required information is clearly indicated on the equipment project specification. The output of the vessel design program (P254) already includes the necessary information. The Specialist needs only to check the output. For other equipment, indication of the required information begins by referencing Inflection Point Engineering Standard Specification 3-37, generally via a note on the project specification graphics. The appropriate Standard Specification revision is indicated at the bottom of the first page of the equipment specification.

The volumes to be filled with each size of ICB and the applicable size are indicated directly on the Project Specification graphics for the equipment, often by specifying the required depth. The required Type may also be included at each location on the graphics or, when all of the ICBs are of the same Type (as is nearly always the case), by including the following note on the equipment drawing:

“All inert ceramic balls shall be Type < fill in the appropriate Type> and shall comply with the requirements of Inflection Point Engineering Standard Specification 3-37.”

When the ICB Type differs between locations in the process equipment, it is the Specialist’s accountability to clearly indicate which requirement applies at each location. If requirements in addition to, or different from, those covered by the Standard Specification are necessary, they shall be included in the Project Specification for the effected equipment.

The ICB information is included on the equipment graphics (typically the elevation) rather than as a note in the text portion of the specification because the graphics will be used when loading the ICBs. It’s best to keep all of the information together to reduce the potential for error or confusion.

b. Design Engineer Accountabilities

The Design Engineer informs the Equipment Specialist of any ICB requirements beyond, or differing from, those identified in Attachment 1, Table 2. If ICBs are required in non-standard equipment or locations, this information is also to be provided by the Design Engineer.

When very small catalyst is present, e.g., 1/32 inch (0.8 mm) in diameter, the neighboring layer of material may need to be active or inactive catalyst. Small diameter {1/16 inch (1.5 mm)} ICBs are becoming available and may also be an option. However, there is little experience with them and they are not available from all ICB suppliers. The Design Engineer makes the determination. See Section 5 for further details.

5. Purpose of Inert Ceramic Balls

5.1 Prevention of Bed Disturbances

A bed of small diameter granular material (catalyst, sieve, clay, drier material, etc.) may be disturbed by fluid moving across the bed’s surface. Placing a layer (or layers) of ICB atop the bed prevents this disturbance because the ICBs, not the granular material, are exposed to the higher velocity moving fluid. ICBs are more effective at resisting disturbance because of their larger size and density. In some cases ICBs may also be effective in reducing or eliminating bed disturbances due to small upflow pressure drops that may tend to lift or fluidize the bed.

Volume Occupation

ICBs are used to fill volumes that would otherwise have to be filled by the granular material. ICBs are commonly used where presence of the granular material (e.g., catalyst, clay, etc.) is undesirable, or where a support grid would otherwise be required. An example of the former use is placement in catalyst withdrawal nozzles. These are low/no flow areas that would be very prone to coke formation if they were filled with catalyst. Use of inert ceramic balls nearly eliminates this problem. An example of the latter use is the vessel head beneath a granular bed. Normally a near constant cross section of the granular bed is necessary for process reasons. This helps maintain an even distribution of the process fluid(s), equalizing utilization of the material and making its performance more predictable and controllable. Allowing the granular material to project significantly into the bottom head of a vessel results in a rapidly shrinking cross sectional area. To keep the cross sectional area of the granular bed above the minimum set by the Process Specialist, all or most of the lower head may be filled with ICBs, thus moving the bed exit up to a point at or near the tangent (or weld) line of the vessel. At this point the bed cross sectional area is nearly the same throughout the bed’s length. Use of ICBs avoids the need to install (and maintain) a support grid.

When ICBs are used to occupy volume, they do so with a minimum pressure drop imposition, an added benefit. As seen by an examination of the Ergun equation for predicting the pressure drop due to flow through granular beds, the spherical shape and relatively large size of the ICBs, creating large flow paths and volumes between the balls, results in a low pressure drop when compared to the same depth of catalyst or sand size particles. One large flow path imposes less pressure drop than many small flow paths with the same length and total cross sectional area. This is due, in part, to the greater frictional, entrance, and exit losses with multiple small flow paths. Thus, the larger the ICB diameter, the lower the pressure drop.

5.3 Migration Prevention

Another major use of ICBs is to prevent migration of the granular bed material through a small opening, generally an opening in the internals. Layers of increasing size ICBs are used to prevent this migration (refer to Section 6). The result is that large ICBs are located next to the openings. This allows use of larger openings, sized to prevent passage of the large balls rather than the much smaller granular material. The result is more economically designed internals and much smaller pressure drops. Typically, the maximum size of opening permitted next to a granular material is one-half the diameter of the material. This provides a margin of safety against a broken or undersized ball passing through the opening. Openings are to be slotted rather than circular to minimize the potential for plugging. A spherical ball can lodge in and completely plug a circular opening but not a slotted one, even if multiple balls are involved. In rare cases the same approach may be used to separate beds of granular materials with layers of ICBs. This is very infrequently used because of the possible effects of vibration and the low level of control on the placement of the granular material and the ICBs. Proper placement is very difficult to ensure.

5.4 Pressure Drop Development

On rare occasions, ICBs are used to create a pressure drop to aid in development of a uniform fluid flow profile when entering a granular bed. This may occur when large diameter {1/8 inch (3 mm) diameter or larger} granular material is used, resulting in a relatively low bed pressure drop.

6. Size of ICBs Required

ICBs are provided in the shape of a sphere, commonly in a variety of nominal sizes from 1/8 inch (3 mm) diameter to 2 inch (50 mm) and, occasionally, larger diameter. The primary factor influencing the size(s) required is the prevention of migration of the granular bed material into or through the ICBs. Success has been found by using layers of successively larger diameter ICBs. The nominal diameter of the material in each layer differs from the neighboring layer by a factor of 2 or 3. If the ratio becomes much larger, there is a danger that the smaller material will filter into/through the layer of larger material. For a typical 1/16 inch (1.5 mm) diameter bed material, the first layer of ICBs (next to the bed) is 1/8 inch (3 mm) diameter. That is followed by a layer of 1/4 inch (6 mm) material, and a final layer of 3/4 inch (19 mm) ICBs, if needed. Historically this mix of sizes has proven to be adequate for most Inflection Point Engineering applications. On rare occasions other sizes of ICBs may be necessary. The most common reason is the use of a final layer of large ICBs atop the granular bed when the horizontal fluid velocity is high. This prevents the process flow from disturbing the top of the granular bed since the mass of the ICB increases as the cube of its diameter while the fluid force increases as the square of its diameter (i.e., the area exposed to the fluid). Large ICBs are more difficult to dislodge. In all cases, place the smallest diameter of ICBs next to the granular bed, followed by the next larger size, and so on, with the diameter of the ICBs increasing with increasing distance from the bed of granular material

For spherical granular material, use the size of the sphere to determine the diameter of the neighboring layer of ICBs. For extruded (i.e., shaped like a cylinder) granular material, use the smallest dimension of the material (usually the diameter of the cylinder), although the effective diameter may also be determined and used. Most Inflection Point Engineering catalysts are in the range of 1/16 inch (1.5 mm) diameter, therefore the gradation described above will apply. For small materials (e.g., 1/32 inch (0.8 mm) catalyst) an intervening layer of larger {e.g., 1/16 inch (1.5 mm)} inactive catalyst base is necessary because ICBs are not commonly available in sizes smaller than 1/8 inch (3 mm) (This may change in the near future.) On occasion, active catalyst has been used for this intervening layer or even in place of the 1/8 inch (3 mm) ICBs. The Design Engineer is responsible for determining if ICBs, inactive catalyst, or active catalyst is required. In the latter two cases the volume is included on Project Specification-105, Catalyst. If larger than normal catalyst is used, e.g. 1/8 inch, then the corresponding layer(s) of ICBs may be omitted.

7. Amount of ICBs Required

7.1 Normally Required Depth

The major factor influencing the amount of ICBs necessary at each location is the provision of sufficient depth in each layer to prevent the smaller material on one side from migrating into the larger material on the other side. If the intervening material depth is too small then that layer may not be effective in preventing the migration of small material. After a sufficient depth of each size of ICB has been provided, the remainder of the volume to be filled with ICBs is filled with the largest diameter of ICB. This minimizes the attendant pressure drop. The largest diameter ICB must also be present at any openings that are to be covered, unless a smaller ICB is at least twice as large as the opening.

Two factors come into play when determining the minimum depth of a layer of ICBs. One is the size of the ICB in the subject layer. Inflection Point Engineering normally requires that the depth of the layer must be sufficient to allow at least five ¾ inch (19 mm) ICBs to be stacked atop one another, resulting in a minimum depth of 4 inches (100 mm). Shallower depths do not provide enough material to make the layer effective. The same minimum depth is used for smaller ICB sizes. The same minimum depth is also used at openings. For example, at least 4 inch (100 mm) layers of ICBs are required atop a catalyst support grid.

The second factor is the provision of adequate depth to account for the depth variations that occur in actual insitu placement. These variations come from inconsistencies in the surface profile of the material below and imprecise leveling of the subject layer of ICBs, e.g., some areas may be “undercut” during leveling. With the exception of Unicracking and Unionfining, and when no process specific requirements apply, Inflection Point Engineering requires a minimum depth of 6 inches (150 mm) when the minimum dimension of the ICB’s horizontal surface is greater than 8 feet (2400 mm) {e.g., a 9 foot (2700 mm) diameter vessel}. For smaller vessels, or limited spaces (e.g., between catalyst grid support beams) where the depths can be more closely controlled, 4 inch (100 mm) layers are permitted. These depths are also sufficient to account for the effects of vibrations that may be present during operation.

Many processes have specific depth requirements applicable to that process. The Unicracking and Unionfining processes, both derived from a blend of Inflection Point Engineering and Unocal Technologies, are examples. Inflection Point Engineering acquired Unocal’s Hydrocracking Technology in the early 1990’s and has continued to use many of Unocal’s details. One of those is the specification of 3 inch (75 mm) layers of ICBs regardless of the dimensions of the area covered. This is in place of the criteria outlined in the previous paragraph. One advantage of the shallower layers of ICBs is a reduction in the vessel tangent length. The cost saving is significant, especially for heavy wall hydrocrackers. The requirements for other processes are available from the Mechanical Specialist in the responsible for the process.

7.2 Outlet Baskets

Outlet baskets typically contain 3/8 inch (10 mm) wide slots for outgoing fluid flow. The baskets are surrounded by ¾ inch (19 mm) diameter ICBs. The depth of ¾ inch (19 mm) ICBs above the basket depends upon whether or not the top of the basket is perforated. If the top of the basket is perforated, the normal rules apply except that a minimum of 6 inches (150 mm) of ¾ inch (19 mm) ICBs is provided above the basket. If, however, the top of the basket is not perforated the process fluid is forced to flow around the top of the basket and exit through the basket’s side. Because of the need to flow around the basket, an area of low flow is created immediately above the basket. The greater the pressure drop through the material in this area, the further the affected area will extend above the basket. If the low flow area includes catalyst, coking is likely. To minimize the flow resistance around the basket, hence the size of the affected area, and to remove catalyst from the affected area, at least 18 inches (450 mm) of 3/4 inch (19 mm) ICBs are provided above the basket when the top is not perforated.

7.3 Typical ICB Arrangement for a Granular Bed

A typical mix of ICBs for a single bed of 1/16 inch (1.5 mm) diameter granular material is 6 inch (150 mm) layers of 1/4 (6 mm) and 1/8 inch (3 mm) diameter balls above and below the bed {with the 1/8 inch (3 mm) layer next to the granular material}. The bottom of the lowest granular bed is placed near the vessel’s tangent line and the remaining vessel volume below the bed and the subsequent layers of 1/8 (3 mm) and 1/4 inch (6 mm) ICBs is filled with 3/4 inch (19 mm) ICBs. If there is an outlet basket in the bottom head the location of the bed may need to be adjusted upward to provide the required depth of 3/4 inch (19 mm) ICBs over the top of the outlet basket. If a support grid using profile wire is present, no 3/4 inch (19 mm) ICBs are used because the openings in the grid are small enough that 1/4 (6 mm) inch balls adequately cover them. If a grating/wire mesh grid or a punched plate system is present (as may be the case for many, older, existing units), a layer of 3/4 inch (19 mm) balls is provided to adequately cover the larger openings in these systems. When a wire mesh is used, the openings in the underlying support system (e.g., grating) are considered when selecting the ICB size. That’s because the small wires of the mesh can be easily broken or corroded to failure. Where there is a bottom support grid, the bottom head is not filled.

Hydrogen Units utilize a slightly different arrangement below the catalyst bed. The first layer of ICBs is the same size as the catalyst, with a minimum size of 1/8 inch (3 mm), to “catch” broken pieces of catalyst. ICBs above the bed follow the normal configuration.

It is important to consider the effect that the layers of ICBs have on the vessel tangent length. ICBs may add a foot (300 mm) or more to the length of the vessel for each bed the vessel contains. This extra length can add significant cost to the vessel, especially in high pressure, heavy wall services such as hydrocracking.

7.4 Top Surface Disturbance Considerations

When a full diameter distributor tray precedes the granular bed, it is not normally necessary to place ICBs larger than 1/4 inch (6mm) on top of the granular bed. The reason is that the process fluid is well distributed across the vessel and “high” velocity flow is not present, particularly across the top surface of the ICBs (flow is almost entirely axial). 1/4 inch (6 mm) balls normally provide sufficient mass and inertia to resist disturbance by moving vapors. Providing enough access room between the distributor tray and beams and the top of the ICBs to allow for leveling of the ICBs is generally enough clearance to prevent disturbance of the ICBs. Inflection Point Engineering’s practice is to allow 12 inches (300 mm) of clearance. For Unicrackers and Unionfiners the clearance is reduced to 6 inches (150 mm). The reasons are similar to those described in Section 7.2 for the use of 3 inch (75 mm) layers of ICBs.

When the top surface is subject to high velocity vapor parallel to the ICB’s surface, e.g., immediately following an inlet vapor distributor, 3/4 inch (19 mm) balls are required. That is because the process flow can disturb smaller ICBs, possibly exposing and fluidizing catalyst. A minimum of 18 inches (450 mm) must be present between the bottom of the inlet distributor and the top of the ICBs. If there is less space larger balls, normally 1½ inches (38 mm) in diameter, may be necessary to prevent disturbance (see Section 6.). See Attachment 2, "Threshold Velocity for ICB Disturbance", for guidance on determining the required ICB size for a known velocity over the bed surface. The velocity must be determined by an analytical means (e.g., Computational Fluid Dynamics software) in the absence of measured values.

7.5 Catalyst Withdrawal Nozzles

Another special use for ICBs is to fill catalyst withdrawal nozzles. ICBs are used to minimize the potential for coking in the otherwise very low flow, or “dead”, area. The required size(s) of ICB are specified on the appropriate Inflection Point Engineering Standard Drawing (3-335, 3-336, 3-337, 3-338, or 3-339).

8. ICB Characteristics and Placement Concerns

8.1 Chemistry

The inert ceramic balls must, of course, be inert. This means that they cannot participate in any reactions with the environment(s) to which they are exposed (e.g., process fluids, catalyst, or catalyst metals), nor be changed by those environments (e.g., the chemistry, temperature, etc). If the ICBs are not inert, or contain impurities, they may poison (deactivate) the catalyst or interfere with the process reactions. The materials and method of manufacture of the ICBs influence their ability to be inert in a given atmosphere. The standard ICB used by Inflection Point Engineering, and others, has a high alumina (Al2O3) + silica (SiO2) content. Normally the total alumina + silica content is in excess of 90%. For some processes an alumina content of 99% is required.

8.2 Leachable Components

As a corollary to the need to be inert, the ICBs must contain low levels of leachable compounds. If these compounds leach out of the ICBs they may poison nearby or downstream granular material (e.g., catalyst) or react with the process fluids or other materials. This is normally a concern with ICBs that are upstream of or in contact with the granular material. The primary compound of concern is iron oxide (Fe2O3). Iron oxide may contribute to the formation of water or promote the growth of coke. Occasionally iron itself may be a catalyst poison. Note that the total content of the subject compounds is not a concern. Only the leachable portion, which may come out of the ICB, is a concern. The remainder of the material is tied up in a stable chemical form in the ICB or is located far from an exposed surface and will not leach from the ICB.

8.3 Water Absorbtion

For some processes water is a poison to the catalyst. In these cases it is very important that the ICBs are dry when installed, and remain dry. Therefore, an important factor is the tendency for the ICBs to absorb moisture. Any moisture absorbed (e.g., from the air) may be later released into the process stream. If the ICBs are upstream of the catalyst the moisture may then poison (deactivate) a significant amount of catalyst.

8.4 Toughness

ICBs must be highly resistant to fracture during handling, thermal cycling, and operation. Fracture of the material results in smaller pieces that may not perform their duty (e.g., retention of smaller material or coverage of an opening) adequately and may migrate into and even through subsequent layers of materials. Fines that are generated may plug portions of the bed or retention screens and profile wire. Pressure drops, at least locally, will increase, leading to maldistribution (possibly severe) and a higher required pressure in the equipment for continued operation. Fines may escape the vessel into which the ICBs were placed and clog downstream equipment (e.g., strainers, exchanger tubes) or damage pumps and other equipment. For similar reasons, dusting of balls during handling is not acceptable. Dusting means the production of fines from abrasion, leading to many of the same problems mentioned above. If a sealing material is used to prevent dusting, it must be inert to the process. The sealing material may burn off during heat up of equipment that operates hot.

8.5 Geometry

The size and shape of the ICBs must be known, uniform, controlled, and reproducible. If the size and shape varies a great deal the performance of the ICBs cannot be predicted. The smaller or misshapen pieces may act as fines, migrating into or through layers of larger materials, filling voids and contributing to larger pressure drops, plugging screens, or escaping the system entirely and proceeding downstream to possibly plug or damage equipment. Out-of-spec ICBs may not be able to retain smaller adjoining material, particularly if the ICBs are misshapen and do not pack as tightly or as well as spheres. A spherical shape is required because spheres pack in a predictable fashion, uniform in all directions, with a low pressure drop. Tolerances are placed on the sphere sizes and the deviation from a true spherical shape.

8.6 New vs Recycled ICBs

All ICBs must be new to closely control the chemistry and properties. Use of recycled or reconditioned ICBs, while less expensive to purchase, introduces a great deal of uncertainty. The physical performance of these ICBs may be affected by their previous use (e.g., they may contain many microcracks, reducing their shock resistance and making them more brittle). Their chemistry is also questionable. This includes the chemistry of the ICB itself and the possibility that compounds were absorbed in the ICB’s previous use. The savings when purchasing the ICBs is dwarfed by the potential loss if they poison some of the catalyst or cause a shutdown of the unit. The only exception to the ban on the reuse of ICBs is that ICBs removed during the unloading of catalyst may be screened and reloaded into the same process equipment from which they were taken.

8.7 Firebrick

At one time crushed firebrick was permitted as a less expensive substitute for ICBs. ICBs are now very commonly available at low cost. Their chemistry properties, size, and shape are much more closely controlled than those of firebrick. Therefore firebrick is no longer a suitable substitute for ICBs.

8.8 Obsolete Requirements

A couple of ICB requirements that Inflection Point Engineering no longer specifies are vitreous/non-vitreous construction, and hardness. Vitreous means fired to a glass-like consistency. Non-vitreous balls are usually held together by a cement. Either is acceptable if they meet the other requirements of the specification, and the material has a successful history of use. Each type of ICB construction is more suitable for some properties than for others. For example, vitreous balls are generally stronger and absorb less moisture. Non-vitreous balls withstand thermal shock and impact better. “Vitrosity” itself is not an important property, only an indicator of the other properties. Hardness is also an indicator of other properties and, most likely, the “vitrosity”. It is not, however, a significant property itself. Therefore both requirements have been removed from the specification.

8.9 Placement

ICBs must not be used where the attendant low resistance to flow will cause maldistribution. An extreme example would be a downflow catalyst bed with an axial “core” of 3/4 inch (19 mm) ICBs. The core’s resistance to flow is much lower than that of the bed, therefore most (perhaps nearly all) of the process fluid will pass through the ICBs, bypassing the catalyst entirely. A more practical example, that has occurred, is the use of ICBs below a radial flow bed. A significant amount of the process fluid will flow radially through the ICBs, even though the path is not as direct as the path through the catalyst. Though the path through the ICBs is longer, the flow resistance is less, until there is a large flow rate through the ICBs. The effect of this catalyst bypassing can be large enough to affect the product quality.

9. Tests

In order to ensure that the supplied ICBs comply with the specifications, testing of the ICBs is required. For example, the crushing test addresses strength and the thermal shock and dropping tests address fracture resistance. Normally the manufacturer’s quality control testing is sufficient; no special (per order or batch) testing is necessary. For many of the parameters, the results will vary depending upon the testing method. Comparison with the specified values is valid only if a comparable test method is used. It is, therefore, necessary that the manufacturer’s testing methods comply with those specified.

Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls	Attachment 1 - Process-Specific Requirements for Inert Ceramic Balls Table 1 - Equipment Requiring Inert Ceramic Balls
Process Name	Process Name	Process Name	Type (see Table 2)	Type (see Table 2)	Type (see Table 2)	Comments	Comments	Comments
Alkymax	Alkymax	Alkymax	1	1	1	Reactors	Reactors	Reactors
Bensat	Bensat	Bensat	1	1	1	Reactors	Reactors	Reactors
Butamer	Butamer	Butamer	2	2	2	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers
Inflection Point Engineering Catalytic Condensation	Inflection Point Engineering Catalytic Condensation	Inflection Point Engineering Catalytic Condensation	1	1	1	Reactors	Reactors	Reactors
Cyclar	Cyclar	Cyclar	1	1	1	Unloading Nozzles only	Unloading Nozzles only	Unloading Nozzles only
DeFine	DeFine	DeFine	1	1	1	Reactor	Reactor	Reactor
Detal	Detal	Detal	2	2	2	Reactors and Clay Treaters	Reactors and Clay Treaters	Reactors and Clay Treaters
EB	EB	EB	1	1	1	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors
Ethermax	Ethermax	Ethermax	2	2	2	Resin Settlers	Resin Settlers	Resin Settlers
HF Alkylation	HF Alkylation	HF Alkylation	3	3	3	Alumina Treaters, Driers, Defluorination Reactor	Alumina Treaters, Driers, Defluorination Reactor	Alumina Treaters, Driers, Defluorination Reactor
Hydrogen	Hydrogen	Hydrogen	1	1	1	Olefin Saturation Reactor, Feed Gas Chloride Treaters, Feed Desulphurizer Shift Converter, Feed Hydrogenator	Olefin Saturation Reactor, Feed Gas Chloride Treaters, Feed Desulphurizer Shift Converter, Feed Hydrogenator	Olefin Saturation Reactor, Feed Gas Chloride Treaters, Feed Desulphurizer Shift Converter, Feed Hydrogenator
I-Forming	I-Forming	I-Forming	2	2	2	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers
InAlk	InAlk	InAlk	2 1	2 1	2 1	Poly Reactors Hydrotreating Reactors	Poly Reactors Hydrotreating Reactors	Poly Reactors Hydrotreating Reactors
Isom Plus	Isom Plus	Isom Plus	2	2	2	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers
Isomar	Isomar	Isomar	1	1	1	Reactors	Reactors	Reactors
IsoSiv	IsoSiv	IsoSiv	1	1	1	Adsorbers	Adsorbers	Adsorbers
KLP	KLP	KLP	1	1	1	Reactors	Reactors	Reactors
Molex	Molex	Molex	1	1	1	Desorbent Make-up Drier, Sulfur Guard Bed	Desorbent Make-up Drier, Sulfur Guard Bed	Desorbent Make-up Drier, Sulfur Guard Bed
Oleflex	Oleflex	Oleflex	2	2	2	Treaters, Driers, and CCR Gas Saturator Reactors	Treaters, Driers, and CCR Gas Saturator Reactors	Treaters, Driers, and CCR Gas Saturator Reactors
Inflection Point Engineering Oxygenate Removal	Inflection Point Engineering Oxygenate Removal	Inflection Point Engineering Oxygenate Removal	1	1	1	Adsorbers	Adsorbers	Adsorbers
Oxypro	Oxypro	Oxypro	2	2	2	Resin Settlers	Resin Settlers	Resin Settlers
Pacol with Define	Pacol with Define	Pacol with Define	3 1	3 1	3 1	Alumina Treaters Define Reactor	Alumina Treaters Define Reactor	Alumina Treaters Define Reactor
Par-Isom	Par-Isom	Par-Isom	2	2	2	Reactors	Reactors	Reactors
Penex, Penex-Plus	Penex, Penex-Plus	Penex, Penex-Plus	2	2	2	Reactors, Feed & Makeup Gas Driers, Sulfur Guard Bed	Reactors, Feed & Makeup Gas Driers, Sulfur Guard Bed	Reactors, Feed & Makeup Gas Driers, Sulfur Guard Bed
Phenol (Sunoco/Inflection Point Engineering)	Phenol (Sunoco/Inflection Point Engineering)	Phenol (Sunoco/Inflection Point Engineering)	1	1	1	1X Resin Treaters	1X Resin Treaters	1X Resin Treaters
Platforming (fixed bed)	Platforming (fixed bed)	Platforming (fixed bed)	1	1	1	Reactors, Chloride Treaters	Reactors, Chloride Treaters	Reactors, Chloride Treaters
Platforming (w/CCR)	Platforming (w/CCR)	Platforming (w/CCR)	1	1	1	Unloading Nozzles, Chloride Treaters	Unloading Nozzles, Chloride Treaters	Unloading Nozzles, Chloride Treaters
Q-Max	Q-Max	Q-Max	1	1	1	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors
Smart	Smart	Smart	1	1	1	Phenylacetylene Hydrogenation Reactors	Phenylacetylene Hydrogenation Reactors	Phenylacetylene Hydrogenation Reactors
SM or Classic SM	SM or Classic SM	SM or Classic SM	1	1	1	Phenylacetylene Hydrogenation Reactors	Phenylacetylene Hydrogenation Reactors	Phenylacetylene Hydrogenation Reactors
Tatoray	Tatoray	Tatoray	1	1	1	Reactors	Reactors	Reactors
Total Isomerization (TIP)	Total Isomerization (TIP)	Total Isomerization (TIP)	1	1	1	Reactors, Adsorbers	Reactors, Adsorbers	Reactors, Adsorbers
Unicracking	Unicracking	Unicracking	1	1	1	Reactors, Hot Separators	Reactors, Hot Separators	Reactors, Hot Separators
Unionfining	Unionfining	Unionfining	1	1	1	Reactors	Reactors	Reactors
Huels Processes	Huels Processes	Huels Processes	----	----	----
Complete Saturation (CSP)	Complete Saturation (CSP)	Complete Saturation (CSP)	2	2	2	Reactors, Treaters	Reactors, Treaters	Reactors, Treaters
MSHP	MSHP	MSHP	1	1	1	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors	Alkylation and Transalkylation Reactors
Selective Hydrogenation (SHP)	Selective Hydrogenation (SHP)	Selective Hydrogenation (SHP)	1	1	1	Reactors	Reactors	Reactors
SHP-CB	SHP-CB	SHP-CB	1	1	1	Reactors	Reactors	Reactors
Non-Licensed Processes	Non-Licensed Processes	Non-Licensed Processes
Fractionation	Fractionation	Fractionation	1	1	1	Clay Treaters	Clay Treaters	Clay Treaters
Inflection Point Engineering Hydrotreating	Inflection Point Engineering Hydrotreating	Inflection Point Engineering Hydrotreating	1	1	1	Reactors	Reactors	Reactors
Inflection Point Engineering Isomerization	Inflection Point Engineering Isomerization	Inflection Point Engineering Isomerization	2	2	2	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers	Reactors, Feed & Makeup Gas Driers

Table 2 - Process-Specific Chemistry and Properties of Inert Ceramic Balls	Table 2 - Process-Specific Chemistry and Properties of Inert Ceramic Balls	Table 2 - Process-Specific Chemistry and Properties of Inert Ceramic Balls	Table 2 - Process-Specific Chemistry and Properties of Inert Ceramic Balls
Type	Minimum Al2O3+SiO2 Content weight %	Maximum SiO2 Content weight %	Maximum Water Absorbed weight %
1	90	80	3
2	90	80	0.9
3	99	0.5	3

Attachment 2

V (fluid velocity)

(fluid density)

Threshold Velocity for ICB Disturbance

Calculate the required drag force FD to move the upper catalyst pill by rotating about point "O". Shielding by the surrounding ICBs is not considered. Use consistent units.

FD = Drag force = CD = Drag coefficient

A = Drag area =

h =

W = Pill weight =

P = Pill piece density =

Ps = Static pressure =

Equilibrium: Mo = 0

FD h + Ps (r sin )3 = W (r sin )

For = 30

let DP = pill diameter = 2 r

Substitute and solve for V

(units are feet, pounds, and seconds)