NZ741916B2 - Method and system for clearing a pipe system - Google Patents
Method and system for clearing a pipe system Download PDFInfo
- Publication number
- NZ741916B2 NZ741916B2 NZ741916A NZ74191616A NZ741916B2 NZ 741916 B2 NZ741916 B2 NZ 741916B2 NZ 741916 A NZ741916 A NZ 741916A NZ 74191616 A NZ74191616 A NZ 74191616A NZ 741916 B2 NZ741916 B2 NZ 741916B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- pipe system
- air
- contents
- volume
- pipe
- Prior art date
Links
- 230000001276 controlling effect Effects 0.000 claims abstract description 22
- 230000003247 decreasing Effects 0.000 claims abstract description 6
- 230000000875 corresponding Effects 0.000 claims description 9
- 229940035295 Ting Drugs 0.000 claims description 4
- 238000007664 blowing Methods 0.000 abstract description 7
- 230000001105 regulatory Effects 0.000 abstract description 6
- 230000001419 dependent Effects 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract description 3
- 239000012530 fluid Substances 0.000 description 18
- 238000004140 cleaning Methods 0.000 description 17
- 239000000047 product Substances 0.000 description 13
- 238000000034 method Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 238000001035 drying Methods 0.000 description 5
- 239000012459 cleaning agent Substances 0.000 description 3
- 239000000645 desinfectant Substances 0.000 description 3
- 230000000249 desinfective Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000003599 detergent Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 210000000078 Claw Anatomy 0.000 description 1
- 241000229754 Iva xanthiifolia Species 0.000 description 1
- 241000700159 Rattus Species 0.000 description 1
- SUKJFIGYRHOWBL-UHFFFAOYSA-N Sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 1
- 239000005708 Sodium hypochlorite Substances 0.000 description 1
- 230000000903 blocking Effects 0.000 description 1
- 238000009530 blood pressure measurement Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006011 modification reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000737 periodic Effects 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Abstract
Method and system clearing a pipe system from its contents, the pipe having a proximal end and a distal end, the method comprising providing an air supply to the pipe system at the proximal end by applying an air pressure decreasing from an initial pressure as the bulk of the pipe contents get discharged gradually at the distal end for obtaining a contents flow in the pipe system. The method further comprises determining a volume of air supplied to the pipe system by the air supply, determining an estimated contents travel speed from the volume of the air supplied to the pipe and regulating the air supply to the proximal end of the pipe for obtaining a predetermined pipe contents travel speed using the estimated contents travel speed. By determining the air volume supplied to the pipe system, and simultaneously controlling the air supply to create a constant contents flow, the pipe system is effectively cleared without air overflowing the contents and without creating air passages in the contents. The contents travel speed can be set dependent on the contents, i.e. the viscous product in the pipe system. By more effectively clearing the pipe system in the push phase, energy is saved in the blow phase, as less blowing activity is required to clear the remaining contents. arged gradually at the distal end for obtaining a contents flow in the pipe system. The method further comprises determining a volume of air supplied to the pipe system by the air supply, determining an estimated contents travel speed from the volume of the air supplied to the pipe and regulating the air supply to the proximal end of the pipe for obtaining a predetermined pipe contents travel speed using the estimated contents travel speed. By determining the air volume supplied to the pipe system, and simultaneously controlling the air supply to create a constant contents flow, the pipe system is effectively cleared without air overflowing the contents and without creating air passages in the contents. The contents travel speed can be set dependent on the contents, i.e. the viscous product in the pipe system. By more effectively clearing the pipe system in the push phase, energy is saved in the blow phase, as less blowing activity is required to clear the remaining contents.
Description
(12) Granted patent specificaon (19) NZ (11) 741916 (13) B2
(47) aon date: 2021.12.24
(54) METHOD AND SYSTEM FOR CLEARING A PIPE SYSTEM
(51) Internaonal Patent Classificaon(s):
B08B 9/032 F17D 3/10
(22) Filing date: (73) Owner(s):
2016.10.14 FLUIDOR EQUIPMENT B.V.
(23) Complete specificaon filing date: (74) Contact:
2016.10.14 PHILLIPS ORMONDE FITZPATRICK
(30) Internaonal Priority Data: (72) Inventor(s):
NL 2015613 2015.10.14 WOUTERS, t Christianus Antonius
(86) Internaonal Applicaon No.:
2016/074791
(87) aonal Publicaon number:
WO/2017/064293
(57) Abstract:
Method and system clearing a pipe system from its contents, the pipe having a proximal end and a
distal end, the method comprising ing an air supply to the pipe system at the proximal end
by applying an air re decreasing from an inial pressure as the bulk of the pipe ts get
discharged gradually at the distal end for obtaining a contents flow in the pipe system. The method
further comprises determining a volume of air ed to the pipe system by the air supply,
determining an esmated contents travel speed from the volume of the air supplied to the pipe
and regulang the air supply to the proximal end of the pipe for obtaining a predetermined pipe
contents travel speed using the esmated contents travel speed. By determining the air volume
supplied to the pipe system, and simultaneously controlling the air supply to create a constant
contents flow, the pipe system is ely cleared without air overflowing the contents and
without creang air passages in the contents. The contents travel speed can be set dependent
on the contents, i.e. the viscous product in the pipe system. By more effecvely clearing the pipe
B2 system in the push phase, energy is saved in the blow phase, as less blowing acvity is required to
741916 clear the remaining contents.
METHOD AND SYSTEM FOR CLEARING A PIPE SYSTEM
FIELD OF THE INVENTION
The invention relates to a method and system for clearing a pipe system.
BACKGROUND
Pipe systems are used in industrial environments, for example food industry or
oil industry, for transporting contents like raw materials, half products or end products
to various stages in corresponding processes. Such pipe systems need periodic
cleaning and therefore the pipe system contents, i.e. the product need to be cleared
from the pipe system. After ng the pipe system, cleaning can be performed. Such
cleaning is in the art also referred to as ‘Cleaning In Place’ (CIP).
While clearing the pipe system, the cleared contents are preferably preserved
for later use or recycling in the process in which the pipe system is used. For this
reason is it advantageous to clear the pipe before cleaning by pushing out the pipe
system contents using a air. Usually compressed air is used, but ent on the
contents, other gasses may be applicable.
In the art it is known that clearing a pipe system can be performed by blowing
out the pipe system contents in a push phase, wherein high pressure air is applied at a
pipe system proximal end such that the pipe contents are set in . When most of
the contents are cleared from the pipe system, a constant air flow in a blow phase will
remove the remaining contents which adhered to the pipe system wa||s, after which the
pipe system can be rinsed and dried in respective rinse and dry phases.
Clearing the pipe system in the push phase requires adequate pressure and
speed. When the pressure is too low, the air used for expelling the contents tends to
flow over the pipe system contents and find its way to an distal end. Thereby contents
are left inside the pipe system.
When the re is too high, the air can push h the pipe contents,
creating so called ‘rat holes’ i.e. passages h the contents.
Adequate l pressure and pressure profile in time of the compressed air in
the push phase can determined from contents viscosity, pipe diameter and
architecture, and can also be determined from experience. The air pressure profile in
time and uential flow, once the air is released in the push phase, also
determines adequate expelling of the pipe system contents.
In the art, a ermined air pressure profile is released upon the pipe system
contents, starting at an initial pressure, decreasing to an end pressure. The push phase
is ended when the end re is d, i.e. the pressure drops below a threshold
value, or when the push phase is timed out. In these cases the pressures and pressure
profiles are chosen such that at the end of the push phase a sufficient normalized
amount of the contents has been cleared. In other cases the push phase is ended
when a sudden cted pressure drop is detected. In the latter case, the pipe
system contents were completely expelled prematurely.
When an insufficient normalized amount of contents have been cleared, or
when the push phase end prematurely relatively large normalized s of contents
remain in the pipe system. Consequently an extensive blow phase is required to
ally clear the pipe system of its contents.
When too much contents are cleared from the pipe system in the push phase,
ssed air may undesirably enter a container used for capturing contents
removed from the pipe system, i.e. product, thereby causing overpressure in such a
ner and consequently obstructing filling of the container.
As a pipe system may comprise many product feed line or pipes, each of which
have to be cleared during production, and wherein pipes are made from opaque
materials such as stainless steel, it is not possible to follow the pipe content while it is
being cleared from the pipe. Thus completion of the ng of the pipe system is
ain.
SUMMARY
It is an object of the invention to provide clearing of a pipe system from contents
without the disadvantages described above.
The object is ed in a method of clearing a pipe system from its contents,
the pipe having a al end and a distal end, the method comprising providing an
air supply to the pipe system at the proximal end by applying an air pressure
decreasing from an l pressure as the bulk of the pipe contents get discharged
gradually at the distal end for obtaining a contents flow in the pipe system. The method
further comprises determining a volume of air supplied to the pipe system by the air
supply, determining an estimated contents travel speed from the volume of the air
ed to the pipe and controlling the air supply to the proximal end of the pipe for
obtaining a ermined pipe contents travel speed using the estimated contents
travel speed.
By determining the air volume supplied to the pipe system, and simultaneously
controlling the air supply to create a constant contents flow, the pipe system is
effectively cleared without air overflowing the contents and without creating air
passages in the contents. The contents travel speed can be set ent on the
contents, i.e. the viscous product in the pipe system.
By more effectively clearing the pipe system in the push phase, energy is saved
in the blow phase, as less blowing activity is required to clear the remaining contents.
In an embodiment, the controlling the air flow at the proximal end of the pipe
comprises controlling a tion valve between the air supply and the proximal end of
the pipe.
In an embodiment, the controlling the air supply to the proximal end of the pipe
system comprises using a difference between the estimated contents travel speed and
a preset contents travel speed value. This effectively allows the contents to be
travelling in the pipe system at a predetermined preset speed.
In an embodiment, the controlling the air flow at the proximal end of the pipe
system comprises controlling a regulation valve between the air supply and the
proximal end of the pipe . The controllable valve allows continuous real time
control of the air supply into the pipe system, thus the contents travelling speed can be
maintained constant at the preset speed.
In an embodiment, the air supply comprises a compressed air container having
a container volume. This is advantageous since the compressed air required for the
clearing of the pipes can be loaded into the compressed air container which is then
available for fast release in the push phase, alleviating compressed air sources from
providing large quantities of compressed air at once.
In an ment, the determining a volume of air supplied to the pipe system
comprises ing a pressure in the compressed air container, and measuring a
pressure at the proximal end of the pipe system, and calculating the air volume
supplied to the pipe system from a pressure difference in the air container n an
initial pressure and a pressure in the air container after supplying air from the air
ner to the pipe system, the air container , and a pressure at the proximal
end of the pipe system after the ing of the air into the pipe system.
Using this scheme, the volume passed into the pipe system is simply
ined using pressure s. Thus expensive air flow meters are obviated, and
no sensors are required to detect the air front pushing the contents through the pipe
system.
In an embodiment, the determining a volume of air supplied to the pipe system
further comprises compensating the volume of air supplied to the pipe system for a
supply line volume, and an expansion of the air volume stored in the supply line prior to
the ing of the air to the pipe system.
Accuracy in determining the air volume in the pipe system volume is thereby
improved also for pipe clearing systems having an air supply line of substantial
dimensions between the air supply and pipe system. Consequently position and speed
of the air front pushing the pipe system contents are improved.
In an embodiment, the determining an estimated contents travel speed from the
volume of the air supplied to the pipe system ses ining a position of an
air-contents front in the pipe system from the volume of air supplied to the pipe system
by compensating volume of air supplied to the pipe system with a pipe system
diameter.
This allows the position of the air-contents front to be controlled. The air supply
can for e be cut off when the air-contents front approaches the pipe system
distal end. This prevents blow out of the pipe system, i.e. air pushed into a container
capturing contents pushed out of the pipe system to be prevented. This further allows
the speed of the air front pushing the pipe contents to be determined and to be
controlled in a further step.
In an embodiment, the determining an estimated ts travel speed from the
volume of the air supplied to the pipe system further comprises calculating at least two
ons of the air-contents front at at least two corresponding points in time and
calculating the estimated contents travel speed from the difference in the at least two
ons and the time difference between the at least two respective points in time.
Thereby the contents travel speed in the pipe system is determined without
inspection, i.e. sensors, in the pipe system itself.
The object is also achieved in a system for clearing contents from a pipe
system, the pipe system having a , a proximal end and an distal end the
system comprising an air supply connected to the pipe system proximal end for
supplying air to the pipe system at the proximal end, wherein an air pressure
decreases from an initial pressure as the bulk of the pipe system contents get
rged lly at the distal end for obtaining a ts flow in the pipe system,
volume determining means for determining an air volume ed by the air supply,
and calculating means for determining an estimated contents travel speed from the
volume of the air supplied to the pipe system, and control means being arranged for
regulating the air supply to the proximal end of the pipe system for obtaining a
predetermined pipe contents travel speed using the estimated contents travel speed.
In an embodiment, the control means are arranged for regulating the air supply
to the proximal end of the pipe system comprises using a difference between the
estimated contents travel speed and a preset contents travel speed value.
In an embodiment, the control means comprise a controllable valve for
controlling the air supply to the proximal end of the pipe system and a controller,
controllably connected to the controllable valve. This allows the supply of air into the
pipe system to be controlled.
In an embodiment, the controller comprises a PID-controller. This allows
ive, responsive control of the ts speed without .
In an embodiment, the air supply comprises a compressed air ner having
a container volume. The system can be self-sufficient and needs not be connected to
an external compressed air supply.
In an embodiment, the volume determining means comprise a first pressure
sensor for measuring a re in the ssed air container, and a second
pressure sensor for measuring a pressure at the proximal end of the pipe system,
wherein the volume determining means are arranged further for calculating the air
volume supplied to the pipe system from a pressure ence in the air container
between an initial pressure and a pressure in the air container after supplying air from
the air container to the pipe system, the air container volume, and a pressure at the
proximal end of the pipe system after the supplying of the air into the pipe system.
This allows air volume supplied to the pipe system be determined without the
need for air flow sensors.
In an embodiment, the volume determining means are further arranged for
sating the air volume supplied to the pipe system for a volume of a supply line
to the pipe system and an expansion of air in the supply line prior to supplying the air
into the pipe system.
In an embodiment, the calculating means for determining an ted contents
travel speed from the volume of the air supplied to the pipe system are further arranged
for determining a position of an air-contents front in the pipe system between the
supplied air and the contents in the pipe system from the volume of the air supplied to
the pipe system and a pipe system cross section area.
In an ment, the calculating means for determining an estimated contents
travel speed are further arranged for calculating at least two positions of the air-
contents front in the pipe system at at least two corresponding time points, calculating
the estimated contents travel speed from a difference between the at least two
positions at the at least two points in time and a time difference between the respective
at least two point in time.
The invention will now be elucidated by the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a schematic m of a system for cleaning a pipe according
to an embodiment of the invention.
Figure 1a shows a partial schematic diagram of a system for cleaning a pipe
ing to an embodiment of the invention.
Figure 2 shows a block diagram of a method of controlling the system of figure
1 according to the invention.
Figure 3 shows a block diagram of a further embodiment of the system of figure
1 according to an embodiment of the invention.
Figure 4a shows a block diagram of a method of clearing a pipe from its
contents ing to an embodiment of the ion.
Figure 4b shows a block diagram of a method of clearing a pipe from its
contents according to a further embodiment of the invention.
DETAILED DESCRIPTION
The invention will be further elucidated by the following ption of
exemplary embodiments.
In figure 1 a system 100 is shown for clearing a pipe system 101 from its
ts. The pipe system 101 can be supplied with liquid viscous product via line 113,
which can be shut off by valve 112. The pipe system 101 has a proximal end 115 near
valve 106 and a distal end 116 near an outlet manifold 111. The outlet manifold
provides various outlets 114, 114’, 114” for example for connecting to a further
process, a container for content cleared from the pipe system 101, or a separator for
separating content from air or rinse quids used for ng the pipe system 101. The
pipe system 101 can comprise at least one pipe which may be a one-segment pipe.
The pipe system 101 may also comprise for example a multi-segmented, bent, ,
bifurcated pipes or a ramification of pipes. The pipes and/or segments may run in
different directions, including horizontal, oblique and vertical directions. Furthermore,
the pipes or pipe ts in the pipe system 101 can have cross sections of arbitrary
dimensions and/or shapes. There may also be segments in the same pipe system
having different cross sections and cross section .
Contents transported in pipe system 101 can relate to viscous, low-viscous or
non-viscous ts which adhere to the pipe system waIIs. These products can be
finished products, half-products or raw materials used in various industrial processes
as can be utilized in petrochemical industry or food industry. The products may be
smooth, but may also contain particles and/or soIid fractions.
The system 100 for clearing the pipe system 101 comprises a compressed air
container 102, a supply line 103, a regulation valve 104 for controlling a compressed
air flow from the ssed air ner 102 to the pipe system 101, a compressor
108, a blower 109 connected to the supply line 103 via controllable valve 107. The air
used is for example compressed air. A pressure sensor 105 is connected to the supply
line 103. The supply line 103 may connect to the pipe system 101 via valve 106. The
various valves 104, 107, 106, 112, 114-114”, compressor 108 and blower 109 are
controlled by control unit 110. Outlet manifold 111 can be formed by for e a
three-way valve or separate valves 114, 114’, 114” connected to the distal end 116 of
the pipe system 101. The valves 114, 114’, 114” can be controlled by control unit 110
such that only a single valve is allowed to be opened while the remaining valves are
closed. The blower 109 can for example be a claw pump, a screw pump or a side
channel blower. The compressor 108 can be any type le air compression pump
for filling compressed air container 102 with sufficient capacity for filling the container
and at a sufficient re for allowing the compressed air container 102 to perform
the moving of the pipe system contents.
As an ative to the compressor 108, the ssed air container 102 may
be connected to a main compressed air supply which is usually available in food,
petrochemical or other industry. rmore, the air container 102 and regulation
valve 104 can be supplemented or replaced by a high pressure low volume
compressor 118 as shown in fig. 1a. The high pressure low volume compressor 118 is
connected to the air supply line 103 via a valve 119. The high pressure low volume
compressor 118 can be controlled by the control unit 110 to provide the required
pressure measured by pressure sensor 105 for performing the push phase.
The process of clearing the pipe system 101 has four phases as is depicted in
figure 4a. The first phase is the push phase 401, wherein a high pressure generated
from compressed air container 102 and controlled by regulation valve 104 is d to
the proximal end 115 of the pipe system 101. The pressure Poemmr is measured by
pressure sensor 117, which value is communicated to the control unit 110. Control unit
110 controls controllable valve 106, such that the re in the supply line 103 is
applied to the proximal end 115 when the pressure has d a pre-set level.
When valve 106 is opened, air from compressed air ner 102 pushes the
contents of pipe system 101 towards to distal end 116 of the pipe system 101 wherein
the outlet manifold 111 is set such that at least one of the outlet 114, 114’, 114” is open
to allow the contents being pushed out of the pipe system 101 to be removed. The
contents may for example be collected for re-use.
The pressure Pcomame, measured by pressure sensor 117 and the pressure Ppipe
measured by pressure sensor 105 is used to control regulation valve 104 to create a
decreasing pressure in time at the proximal end 115 of the pipe system 101. The
controlling by l unit 110 is arranged to cause contents in the pipe system 101 to
ue moving towards the distal end 116 at a constant speed. The push phase 401
ends when the ts are sufficiently removed from the pipe system 101. Preferably
the end of the push phase 401 is alternatively determined by calculating a position of
an air front in the pipe and establish that the air front is near the distal end 116 of the
pipe system 101. This air front is the interface of the air released from the compressed
air container 102 into the pipe system 101 with the contents to be pushed out.
Alternatively, as a ard, the ient removal of the contents can be detected by
a sudden re drop measured by pressure sensor 105, indicating that the
compressed air can escape from the pipe system t blocking by contents within
the pipe system 101.
The control unit 110 is arranged to te the position of the air-contents front
from the measured pressure Ppipe at the proximal end 115 by pressure gage 105. When
the control unit 110 has determined that the air front is near the distal end 116 of the
pipe system 101, corresponding to a position n for example at least 85% of the
contents is pushed out of the pipe system 101, then regulation valve 104 is closed.
Thereby the push phase 401 of fig. 4 ends.
A new phase 402 of blowing the pipe system 101 is entered by starting blower
109 and opening valve 107 whilst valve 106 is kept open. In the blow phase 402, the
blower 109 provides an air flow in pipe system 101 such that any contents left behind
on the pipe system walls during the push phase 401 is blown out. The blow phase 402
is usually performed during a preset time period and timed by control system 110. The
preset time period depends on the size and length of the pipe system, the ity of
the contents, temperature, etc..
When the blow phase 402 is completed, the pipe system 101 can be rinsed in a
rinse phase 403. In the rinse phase 403, the blower 109 blows air into the pipe system
101, while simultaneously rinse fluid is ed in the supply line 103 connecting the
blower 109 to the valve 106 and proximal end 115 of the pipe system 101. The rinse
fluid is for example water.
Following the rinse phase 403 the blower 109 is used for providing constant air
flow through the rinsed pipe system 101 for drying in a drying phase 403.
In figure 4b an extra cleaning phase 405 is shown following drying phase 404.
De cleaning phase 405 is similar to the rinse phase 403, n cleaning agents or
disinfectants can be added to the rinse fluid. The cleaning phase 405 can be followed
by an additional rinse phase 406 and/or drying phase 407.
In Figure 2 a block diagram is shown of a control system 200 which is active in
the push phase for controlling the pipe contents travel speed l/contents . The functions
202, 203, and 204 shown in the block diagram 200 described below are performed in
control unit 110, to which the container pressure sensor 117 and the pipe system
pressure sensor 105 are connected..
The pipe contents travel speed l/ComemS is controlled by regulating an airflow
from the compressed air container 102 into the pipe system 101 using a controlled
valve 104 to obtain the set value l/set. Thus a pipe contents travel speed l/ComemS can be
maintained which is sufficiently high for removing the pipe contents from the pipe
system 101, and sufficiently low to prevent compressed air used for pushing out the
contents from the pipe system 101 to be overrun with air, thereby leaving too much of
the pipe ts in the pipe system.
In function block 204 the estimated pipe contents travel speed s is
determined on the basis of the air volume in the pipe system Vpipe which has been
supplied from the compressed air container 102 to the pipe system 101 in the push
phase.
In block 203 the air volume in the pipe system Vpipe is determined from the of air
volume supplied from the compressed air ner 102 which is calculated from the
pressure drop APcomame, in the compressed air container which occurs when the air is
released from the compressed air container 102 into the pipe system 101, the
compressed air container volume Vcomaine, and the pressure Ppipe in the pipe system.
In function block 204 a sequence of air volume values Vpipe Supplied to the pipe
system 101 is determined from corresponding pressure measurements Pcomame, in the
container 102 and the pipe system Ppipe . From there a ce of changes in volume
AVp,pe of the air in the pipe system 101 Le. a flow into the pipe system is determined. By
compensating the air volume changes AVp,pe in the pipe system for pipe diameter d in
block 204, the estimated pipe contents travel speed l/ComemS being the speed of the air
front pushing the contents from the pipe system 101 can be determined.
Alternatively the normalized amount of air released from the compressed air
container can be determined with an air flow meter positioned in the supply line 103. By
adding up flow measurements in time, a normalized amount of air can be determined.
In ctor 201 the estimated pipe contents travel speed \/contents is subtracted
from the set speed value Vset . With the calculated speed difference and a Proportional-
lntegration-Differentiation (PID) control on in block 202 a variable control signal is
ted to control tion valve 104. The regulation valve 104 causes a variable
air flow from the compressed air container 102 into the pipe system 101.
The calculated estimate of the pipe contents travel speed Vcomems can be
corrected for t viscosity with a contents speed correction factor F, which is
determined by experiments using different products as pipe system contents. This
prevents air to ow the product near the end of the push phase, when most of the
pipe contents have been pushed out of the pipe system 101.
While emptying the pipe system 101 from contents by filling it with compressed
air from the compressed air ner 102, the control unit 110 can determine that a
predetermined threshold value of for example 85% of the air volume in the pipe system
is exceeded, ting that the contents are sufficiently expelled from the pipe system
101. The regulation valve 104 and/or the valve 106 can be closed, thereby ending the
push phase.
In ce often the supply line 103 from the regulation valve 104 to the
proximal end 115 of the pipe system has a non-negligible volume, affecting the
calculation of the normalized amount of air released into the pipe system 101,as the
ized amount of air from the compressed air container first has to fill the supply
line 103 as well. In a pre-push phase, the supply line 103 is filled with air up to a preset
pressure value Ps measured by pressure sensor 105 air by opening regulation valve
104. When the preset re value Ps is attained the regulation valve 104 is closed
again. The compressed air is then released into the pipe system in the push phase by
opening valve 106. This connects the pipe system 106 to the supply line 103.
Subsequently the re in the supply line 103 and pipe system 101 is regulated by
the control system 110 and the regulation valve 104.
When the valve 106 is opened, the pressure in the pipe system 101 and the
supply line 103 together is controlled by the control unit 110 by controlling regulation
valve 104 on the basis of the estimated contents speed l/Comems. The total amount of air
supplied to the pipe system is now determined from air supplied from the air container
102 as described, and the air y in the supply line using the supply line volume
Vsupplynne the pressure drop in the supply in
, line, which is equal to the pressure drop
the pipe system APp,pe since supply line 103 and pipe system 101 are now connected,
and the pressure in the supply line and pipe system Ppipe.
In figure 3 fluid supplies 302, 302’ are shown connected to supply line 103 via
respective valves 303, 303’. The supply line 103 can be separated from the blower 109
via valve 107. In the blow phase 402 the blower 109 is ed on and valve 107
activated for providing a sufficient air flow in the pipe system 101 to n the outward
motion of the remaining contents in the pipe system.
Remaining contents in the pipe system 101 may form fluid plugs which move
from the proximal end 115 to the distal end 116 of the pipe system 101. In order to
prevent mechanical vibration of the pipe system 101 caused by these fluid plugs, the
blower 109 can be soft-started such that the pressure generated by blower 109
increases gradually at startup.
The rinse phase fluid supply 302 usually comprises water, but ing in the
pipe contents, the rinse fluid composition may vary. Agents like detergents or
disinfectants may be added to the rinse fluid.
As described, in a cleaning phase 405 instead of rinse fluid such as water, a
cleaning fluid with a cleaning agents such as detergents or disinfectants can be
injected from for example fluid supply 302’ into the supply line 103 via valve 303’. A
commonly used agent is for example sodium hypochlorite. After cleaning the pipe
system 101, the pipe system 101 can be rinsed using rinsing fluid to remove the
cleaning fluid as in the rinse phase and subsequently dried as in the drying phase as is
the case in the process of clearing the pipe system 101. The combined blowing air in
the supply line 103 using blower 109 and injecting a cleaning fluid with cleaning agent
into the supply line 103, and the injected cleaning fluid is blown by the airflow in the
supply line 103 into a spray.
The control unit 110 can comprise a programmable logic controller (PLC) or any
other computing device having input ports for acquiring process data such as
pressures, flows, etc. and output ports for controlling devices in the process such as
valves, compressors, blowers.
The computing device may comprise a microprocessor or microcontroller
connected to a memory having programming instructions which are executable on the
ing device. The programming instructions can be stored in the memory such as
EPROM, Flash memory, computer discs and other computer readable s.
The described embodiments herein are given by way of example only.
Deviations of and modifications to these examples can be made t departing from
the scope of protection as et out in the claims below.
REFERENCE LS
100 system for clearing a pipe
101 pipe system
102 ssed air container
103 supply line
104 ting valve
105 pressure sensor
106 proximal end valve
107 valve
108 compressor system
109 blower
110 control unit
111 outlet manifold
112 proximal end valve
113 preceding process
114 outlet
114’ outlet
114” outlet
115 proximal end
116 distal end
117 pressure sensor
118 high pressure low volume compressor
119 valve
200 control system
201 subtraction
202 control function
203 air pressure to volume sion
204 estimated contents travel speed calculation
301 valve
302 fluid supply
302’ fluid supply
303 valve
303’ valve
400 process stages
401 push
402 blow
403 nnse
404 dry
405 clean
406 dry
Claims (17)
1. Method of clearing a pipe system from its contents, the pipe system having a proximal end and a distal end, the method comprising: - providing an air supply to the pipe system at the al end by applying an air pressure decreasing from an initial pressure as the bulk of the pipe contents get discharged gradually at the distal end for obtaining a contents flow in the pipe system; the method r comprising: - determining a volume of air ed to the pipe system by the air supply; - determining an estimated contents travel speed from the volume of the air supplied to the pipe system; - ting the estimated contents travel speed for content viscosity with a contents speed correction factor F for obtaining a corrected estimated contents travel speed; - controlling the air supply at the proximal end of the pipe system for obtaining a predetermined pipe contents travel speed using the corrected estimated contents travel speed; - ining a position of an air-contents front in the pipe system based on a pressure at the proximal end thereof; and - preventing the air supply to the proximal end of the pipe system upon ining that the position of the air-contents front in the pipe system ponds to a predetermined position in the pipe system relative to the distal end thereof, said predetermined position corresponding to a position at which a sufficient amount of the contents is cleared from the pipe system.
2. Method ing to claim 1, n controlling the air supply at the proximal end of the pipe system comprises controlling a regulation valve between the air supply and the proximal end of the pipe system.
3. Method according to any one of the preceding claims, wherein the controlling the air supply to the proximal end of the pipe system comprises using a difference between the estimated contents travel speed and a preset contents travel speed value..
4. Method according to any one of the preceding claims, wherein the air supply comprises a compressed air container having a container .
5. Method ing to claim 4, wherein the determining a volume of air supplied to the pipe system comprises: - measuring a pressure in the compressed air container; and - measuring a pressure at the proximal end of the pipe system; - calculating the air volume supplied to the pipe system from a pressure difference in the air container between an initial pressure and a pressure in the air container after supplying air from the air container to the pipe system.
6. Method according to claim 5, wherein the determining a volume of air supplied to the pipe system further comprises compensating the volume of air supplied to the pipe system for a supply line volume and an expansion of the air volume stored in the supply line prior to the supplying of the air to the pipe system.
7. Method according to any one of the preceding claims, wherein the determining an estimated ts travel speed from the volume of the air supplied to the pipe system comprises determining a position of the air-contents front in the pipe system from the volume of air supplied to the pipe system by compensating the volume of air supplied to the pipe system with a pipe system diameter.
8. Method according to claim 7, wherein the determining an ted contents travel speed from the volume of the air ed to the pipe system further comprises: - calculating at least two positions of the air-contents front at least at two corresponding points in time; and - calculating the estimated contents travel speed from the difference in the at least two positions and the time difference between the at least two respective points in time.
9. System for clearing ts from a pipe system, wherein pipe system having a volume, a proximal end and an distal end, the system comprising: - an air supply connected to the pipe system proximal end for supplying air to the pipe system at the proximal end, wherein an air re decreases from an initial re as the bulk of the pipe system ts get discharged gradually at the distal end for obtaining a contents flow in the pipe system; the system further comprising: - volume determining means for determining an air volume supplied by the air supply; and - calculating means for determining an estimated contents travel speed from the volume of the air supplied to the pipe system and for correcting the estimated ts travel speed for content viscosity with a contents speed correction factor F for ing a corrected estimated contents travel speed; - control means ed for lling the air supply to the proximal end of the pipe system for obtaining a predetermined pipe contents travel speed using the corrected estimated contents travel speed; - position determining means configured and arranged for determining a position of an air-contents front in the pipe system based on a pressure at the proximal end thereof; - wherein the control means are configured and arranged for ting the air supply to the proximal end of the pipe system upon determining that the position of the air-contents front in the pipe system corresponds to a predetermined position in the pipe system relative to the distal end thereof, said ermined position corresponding to a on at which a ient amount of the contents is cleared from the pipe system.
10. System according to claim 9, wherein the control means are arranged for controlling the air supply to the proximal end of the pipe system comprises using a difference between the estimated contents travel speed and a preset contents travel speed value.
11. System according to any one of the claims 9 and claim 10, wherein the control means comprise a llable valve for lling the air supply to the proximal end of the pipe system and a controller, controllably connected to the controllable valve.
12. System according to claim 11, wherein the ller comprises a PID-controller.
13. System according to any one of the claims 9 - 12, wherein the air supply comprises a compressed air ner having a container volume.
14. System according to claim 13, wherein the volume determining means comprise: - a first pressure sensor for measuring a pressure in the compressed air container; - a second pressure sensor for measuring a pressure at the proximal end of the pipe system; - wherein the volume ining means are arranged further for ating the air volume supplied to the pipe system from a pressure difference in the air container between an initial pressure and a pressure in the air container after supplying air from the air container to the pipe system, the air container volume, and a pressure at the proximal end of the pipe system after the supplying of the air into the pipe system.
15. System according to claim 14, wherein the volume determining means are further arranged for compensating the air volume supplied to the pipe system for a volume of a supply line to the pipe system and an expansion of air in the supply line prior to supplying the air into the pipe system.
16. System according to any one of the claims 9 – 15, wherein the calculating means for ining an estimated contents travel speed from the volume of the air supplied to the pipe system are further arranged for determining a position of an air-contents front in the pipe system between the supplied air and the contents in the pipe system from the volume of the air ed to the pipe system and a pipe system cross section area.
17. System according to any one of the claims 9 – 16, wherein the calculating means for determining an estimated contents travel speed are further arranged for: - calculating at least two positions of the air-contents front in the pipe system at least two corresponding time points; - ating the estimated contents travel speed from a difference between the at least two positions at the at least two points in time and a time difference between the respective at least two point in time.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL2015613A NL2015613B1 (en) | 2015-10-14 | 2015-10-14 | Method and system for clearing a pipe system. |
NL2015613 | 2015-10-14 | ||
PCT/EP2016/074791 WO2017064293A2 (en) | 2015-10-14 | 2016-10-14 | Method and system for clearing a pipe system |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ741916A NZ741916A (en) | 2021-08-27 |
NZ741916B2 true NZ741916B2 (en) | 2021-11-30 |
Family
ID=
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CA3001235C (en) | Method and system for clearing a pipe system | |
US9745149B2 (en) | Material delivery system | |
US9630218B2 (en) | Air-flushing method, air-flushing device, and recording medium | |
JP7050806B2 (en) | Water Abrasive Suspension Jet Cutting Device and Water Abrasive Suspension Jet Cutting Method | |
WO2009144014A1 (en) | Method and filling system for filling bags | |
NZ741916B2 (en) | Method and system for clearing a pipe system | |
NL2014285B1 (en) | Pump system. | |
WO2007085247A3 (en) | Process for conducting cleaning operations in a fluid-receiving device of a foodstuff-processing apparatus, and fluid-receiving device and foodstuff-processing apparatus therefor | |
US8104139B2 (en) | Method and apparatus for removing the contents from a pipe | |
US11186012B2 (en) | Method for performing a material change in a feeding device of an extruder | |
JP7001387B2 (en) | Steam trap with cleaning mechanism and how to clean the steam trap | |
EP1860027A2 (en) | Method and facility for filling containers, in particular for filling sacks | |
US11267181B2 (en) | Method for preparing for a change of material in an extrusion device for a film machine | |
CN105102100A (en) | Suction device | |
JP7097384B2 (en) | Water Abrasive Suspension Jet Cutting Device and Water Abrasive Suspension Jet Cutting Method | |
CN206366242U (en) | A kind of filter of automatic cleaning filter core | |
CN108851162B (en) | Control method and system for vacuum moisture regaining of materials and moisture regaining machine | |
KR102565220B1 (en) | A pipe pigging system for controlling pigging speed and cleaning pig | |
NL2026653B1 (en) | Method for operating a fluid bulk material transport system and bulk material transport system | |
KR102579653B1 (en) | System for removing fluid in a bilge well | |
CN107078077B (en) | Polycrystalline silicon chip recovery assembly and method for recovering polycrystalline silicon chips from polycrystalline silicon cleaning device | |
JP6940958B2 (en) | How to flush pipes | |
WO2011042600A3 (en) | Method for and system of pneumatically conveying materials | |
SE538793C2 (en) | Method and arrangement for de-gassing of fluids | |
DD211326A1 (en) | METHOD OF INCREASING THE SUPPORT PROCESS OF PNEUMATIC PRESSURE FILLING MACHINERY |