Development of Spray BallTM
for Tank Cleaning
1. Introduction
In recent years, CIP（Cleaning In Place）with little orno involvement of workers has become the mainstream
for assembling and removing of industrial tanks andpipes, etc.
This report focuses on cleaning nozzles for cleaning intanks in various industries and introduces the Spray
BallTM（fixed type）and Rotary Spray BallTM of ourWinter 2020
No.38

products and new Rotary Spray BallTM of our developed
products.
Cleaning validations are being implemented for facility
equipment in critical processes in the pharmaceuticalindustry. Our Spray BallTM has also been adopted as

Figure1

Image of Spray BallTM（fixed type）

tanks in all industries, such as medical, chemical, andan important part of cleaning equipment, contributing

food products. Since the wetted part is PTFE having

to the risk management of our customers.

heat and chemical resistance characteristics, makes it
possible to permanently install the product inside a

2. What is cleaning?

tank. In addition, since the spraying position isdesigned according to the customer's tank nozzle

In this report, we define cleaning as removing the dirt

orientation, efficient cleaning is possible in a short time（solid substance adhering to the surface）to the extent

and the consumption of cleaning liquid can bethat there is no problem for the post-process treatment

suppressed.

and processing.

The holes are efficiently arranged by high-precision

In a broad sense, the cleaning also includes removing

machining, and pressure is applied from a small hole toimpurities in the gas or liquid, but it is excluded here.

inject. If the fluid is flammable, conductive PTFE is

The cleanliness of cleaning varies by purpose and use

recommended as the material. This is because staticfrom a level of 100% removal of deposits to a level ofelectricity accumulates during injection, which might

acceptability when it is apparently reduced, and there

cause firing.

is a wide range of demands from each industry.

3. Spray BallTM（fixed type）
Fixed type Spray BallTM is used for cleaning tanks
such as reaction tanks, stirring tanks, and storage
23

Table1

The number of Spray BallTM per tank volume Tankvolume

The number of Spray BallTM
Type～ 600ℓ

5021

1 ～ 5㎥8021

6 ～ 10㎥

100

2

1

Vertical reaction tank Vertical storage tank

Note: The number of units used in the above table is an example.

Product Introductions

Table1 shows the approximate required number ofSpray BallTM.

4. Rotary Spray BallTM

If there are stirring shafts, baffles, etc. in the tank, it isrecommended to increase the number of Spray BallTM
to clean the backside of the shaft.
The structure consists of ① upper ball ② lower ball
③ two-stage flanges as shown in Figure1 & 2. A twostage flange is used to prevent misalignment so thatthe jet can be precisely sprayed to the intended
cleaning point.

Figure3

Image of Rotary Spray BallTM

Rotary Spray Ball TM is similar in application andmaterial properties to fixed Spray BallTM but has theStandard design of Spray BallTM（fixed type）

following features.
● ‌Rotary Spray BallTM is composed ofTable2 shows the standard dimensions.
Table2

CleaningFlange
water
vlume combination（L/min）

φC

SB-50

15 ～ 40

25A×50A

SB-80

30 ～ 70

SB-100L（maximum）
PTFE

ConductivePTFE

46400

300

25A×80A

72600

370

70 ～ 100 40A×100A

97500

370

When attaching the Spray BallTM②

shown in Figures4. The upper and lower ballsStandard dimensions

Type① body

upper ball ③ lower ball ④ fixed ring ⑤ collar as

to a T-tube, etc.,

rotate reversely. Since the cleaning water itself

Winter 2020

Figure2

controls the rotation, there are no parts for rotation
inside. Because of the simple structure, we caneasily maintain this.
● ‌Even at low pressure, we can clean efficiently
because the spraying pattern makes a straight barflow.

attach a joint or steady rest. This is to prevent the● ‌The spraying pattern（angle）and flow rate（holewarpage due to the concentration of holes at certain

diameter/number of holes） can be changed

locations and the application of spraying pressure.

depending on the customer specifications.

For the flange combination, besides Table2, the size
can be specified. The material of the flange is SUS304
as standard, but other materials such as SS400 canalso be specified.

Figure4Standard design of Rotary Spray BallTM

The mounting method is to insert the collar ⑤ between
the nozzle of the tank and the nozzle on the pipingside. This is because the Rotary Spray BallTM needs
24No.38

Development of Spray BallTM for Tank Cleaning

not to spray at the target point, unlike fixed typeTM

the inside of each nozzle, not limited to the particular

Spray Ball .

industry.

Table3 shows the standard dimensions.

In the background, small parts such as inside theTable3nozzles that cannot be cleaned with Spray BallTM haveStandard dimensions

TypeCleaning
water
vlume
（L/min）

φA

φB

C

Taper
screw

SB-50R

25

100

4257

1/2”

the tank due to human intervention, causing serious

SB-80R

90

130

64

86

3/4”

damage to the post-process. This is so-called

SB-100R

14015588

118

1”

contamination problem.

been cleaned manually by workers using brushes orcloths. As a result, cloth fibers and dust remained inTherefore, each industry has proposed CIP that

5. Selection of fixed type or rotary type
TMSo far, we have described Spray Ball （fixed type）
TM

eliminating contamination. Another advantage of CIP
is that a certain cleaning effect can be expected soand Rotary Spray Ball , but we have received a lot ofthat the product quality can be stabilized andfeedback about which one should actually be installed,improved. Because of these factors, CIP became theso we compare the features of each one in a Table4.

mainstream, and cleaning nozzles attracted attention.

Table4Comparing fixed type and rotary type Spray BallTM

Type

Cleaning
water
vlume

Cleaningtime

Spraying
target

Maintenance

Cost

Fixed

〇〇〇△〇

Rotary△△△〇〇6-2）SolutionsFirst, the cleaning inside each nozzle was examinedusing a fixed type Spray BallTM. When cleaning withthis product, it is possible to clean by increasing theRegarding the amount of cleaning water, cleaning

length of the pipes as shown in Figure5 and spraying

time, and point cleaning, since the fixed type targets

them into the nozzles from the downward direction.

the point for cleaning, it is possible to perform more

However, because the maximum elevation angle isefficient cleaning than scattering the cleaning liquid55°, as shown in Figure2, the area above the fixed

like a rotary type, to suppress the amount of cleaning

type Spray Ball TM cannot be cleaned. In addition,water and cleaning time.

designing the spraying point for each customer's tankOn the other hand, the rotary type is suitable for thenozzle orientation is a laborious work.

rinse in the tank, and it is easy to disassemble andNext, Rotary Spray BallTM is examined. When cleaning

maintain because of the simple structure. In addition,with this product, it is impossible to wash the inside ofsince the hole diameter is large there is no concern

the nozzle because the maximum elevation angle isabout clogging.

50°as shown in Figure4 and only specific spray axes
pass through.

6. Cleaning challenges

diﬃcult area to clean

6-1）Background
The issue of tank cleaning is cleaning inside eachnozzle.
Conventionally, if head of tank, manholes（hand holes）,

adjust length

Winter 2020
No.38

requires no human intervention with the goal ofand lighting hole（through-lamp openings）in the tankwere able to be cleaned, the cleaning inspection wouldhave passed. But in recent years, it would have been
judged to be unacceptable if it could not be cleaned to25

Figure5

Washing image of each nozzles

Product Introductions

7. ‌New developed productRotary Spray BallTM

７-2）Hole Pattern type

Straight barflow
Liquid film
formation range

As described above, it takes time to design the Spray
BallTM（fixed type）and the inside of the nozzle cannot
be cleaned with the conventional Rotary Spray BallTM.
So we have newly developed a "Slit type" and a "HolePattern type" to meet customer requirements. Next,Figure8

Cleaning image of Hole Pattern typethe features of each developed product are explained.
The structure and material of the Hole Pattern type
Hole Pattern type

are the same as the standard products, upper andlower balls rotate reversely. It can clean directly

Slit typeabove and below the nozzle tending to be unavailable
for cleaning owing to the straight bar flow. And it canalso clean the manhole, lighting hole, and each nozzle
by small holes vertically arranged in two rows. This
hole reaches the cleaning point while keeping waterpressure, so it exhibits high cleaning power like fixed

Figure6

New developed Spray BallTM

7-1）Slit typemade close by our unique design and processing,which makes it possible to enter each nozzle.
In addition, the efficient cleaning is possible, because
the rotation speed is also low compared with the Slit

Straight barflow
Wide area
injection range
Liquid film
formation range

Figure7

Cleaning image of Slit type

Winter 2020

type Spray BallTM. The distance between the holes istype（Figure8）.
7-3）‌Comparison of cleaning rate between standard
Rotary Spray BallTM and newly developed Products
Figure9 shows the comparing the result of cleaning
rate between the newly developed product as "Slittype" and "Hole Pattern type" and conventional Rotary

The structure and material of the Slit type are theSpray BallTM.

same as the standard products. The upper and lower

As observed from this result, the developed products

balls rotate in the reverse direction and efficient

as Slit type and Hole Pattern type are superior to thecleaning is possible. Clean directly above and below

standard product in cleaning in the tank and in thethe area where cleaning is impossible, using a straightnozzle. The Slit type can clean a wider area in a short

bar flow, and clean manholes, lighting ports andtime and the Hole Pattern type reaches the cleaning

nozzles with a wide area jet（slit）.（Figure7）

point while keeping strong pressure, so it is especially

The spraying pressure is slightly weaker than thesuperior for cleaning in the nozzle.

hole shape due to the widened slit opening, but theThis cleaning evaluation test is the result described inspray is wider, so it is better at cleaning a wider area

the following section 8 "cleaning evaluation test"

than the hole.

devised by our company. The value in the graph islower because the material having high adhesion anddirty is used to carried out the evaluation test under26

No.38

Development of Spray BallTM for Tank Cleaning

The cleaning evaluation test method and inspection

severe conditions.

timing are specified in the operation manual of eachcompany, and no particular standards are set in eachindustry.
Our customer may performt the cleaning evaluation
test when delivering our Spray BallTM products. The
purpose is to attach Spray BallTM to the customer'stank and check if cleaning at the level requested byStandard

Hole pattern type

Slit type

Cleaning rate of the tank inside

the customer is possible. In this case, visual inspectionis the mainstream. The method is to spray riboflavinor food coloring（viscosity is about 100cp）, whichlooks like dirt was sprayed thoroughly into the tankand then operate the Spray BallTM for about 1 to 2minutes（depending on the customer）. After that,visually check that the dirt has been removed. In thecase of riboflavin, it is easy to find dirt because it isStandard

Hole pattern type

Slit type

Cleaning rate of the nozzle inside

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No.38

Figure9

Cleaning rate of the tank and nozzle insidereflected by illuminating the black light, but careshould be taken in handling because it has theproperty of being vulnerable to light. Food coloring isoften used because they are available and handy. In

8. Cleaning evaluation test

the case of visual inspection, as shown in Table5, there
is an advantage that it can be easily implemented and

Typical cleaning evaluation methods include visualan analyzer is not required, but there is a disadvantage

inspection, solvent extraction using water, andthat the determination level is affected by thesampling from the surface. When determining theknowledge and experience of the assessor. Therefore,cleaning evaluation method, it is necessary to firstin order to eliminate such differences, a new method

consider the general dirt related to the target

was devised for simply quantifying the cleaning

equipment and select an appropriate cleaningevaluation test results. The advantage of thisevaluation method.

evaluation method is that a cleaning evaluation test

Table5 summarizes typical cleaning evaluation

can be easily performed at a low cost because special

methods and their advantages and disadvantages.

materials and analytical equipment are not required,

Table5Comparison of cleaning evaluation methods

Evaluation
methodAdvantage

Disadvantage

Visualinspection

・Easily implementable・‌Surface dirt can bedetected
・No need for analyzer・‌Subjective・‌Cannot detect the entireequipment・‌Low concentration
substances cannot bedetected

・Easily implementable・‌Can detect detergents
residue
Rinsing water and other water-soluble ・‌Adhesive
cannot be detected
sampling
substances・‌High
precision
analysis
inspection ・‌Can be used for daily
monitoring of thecleaning cycle
Swabinspection

27・‌Depending on inspector
may vary・‌Can be detect attached ・‌results
It is necessary to enter
substancesor disassemble theequipment

and the result can be obtained immediately. Also,
Since it is possible to quantify the value different fromvisual inspection, there is no concern that thejudgment level is influenced by the judgment person.
The challenge is that it is difficult to test the entire
equipment and it is necessary to enter into theequipment.
Now, we are trying to improve this new method forpractical application.

Product Introductions

9. Conclusion

In addition, developing from conventional technology,
we have successfully quantified the cleaningThis report introduces the cleaning nozzle in theevaluation test. Starting with this research, we would

cleaning tank and a new cleaning evaluation test. So

like to try to further improve the cleaning rate andfar, we had only two types of cleaning nozzle, fixed

devise new cleaning methods and strive to develop

and rotary type, so it was difficult to respond to aservices adapted to the times and the environment.

wide range of customer needs.

We will continue to pursue true customer needs andThe development of new cleaning nozzle "Slit type"make efforts to provide new products and services.

and "Hole Pattern type" has made it possible toprovide various spraying patterns. We hope that ourcustomers will be able to select a cleaning nozzle
suitable for each application in the future.

10. References
1）Valqua Valflon Lining Catalog

Mayumi Motoyoshi
Winter 2020

High Performance plastics
Group
Product Division
Technical Support Section

No.38

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