A cleaning system, a plate heat exchanger, and a method for cleaning a plate channel in a plate heat exchanger

Abstract

Disclosed is a cleaning system (1) for cleaning plate channels (2) within a plate heat exchanger (3) during normal use of the plate heat exchanger (3), wherein the heat exchanger (3) comprises an inlet channel (4) through which a fluid enters the heat exchanger (3) and an outlet channel (5) through which the fluid leaves the heat exchanger (3). A stack (6) of heat exchanger plates (7) is arranged between the inlet channel (4) and the outlet channel (5), so that the heat exchanger plates (7) form plate channels (2) between the inlet channel (4) and the outlet channel (5) through which the fluid can pass. The cleaning system (1) comprises: a bypass pipe (8) configured to establish a bypass flow of fluid between an inflow channel (4) and an outflow channel (5) to bypass the stack (6) of heat exchanger plates (7); a cleaning head (9) comprising a cleaning hole (10) connected to the bypass pipe (8), wherein the cleaning hole (10) is configured to face the stack (6) of heat exchanger plates (7) during normal use of the cleaning head (9) in the heat exchanger (3); a moving device (11) configured to linearly move the cleaning head (9) in a moving direction within the inflow channel (4) or the outflow channel (5); and a pressure changing device (12) configured to change the pressure in the bypass pipe (8), wherein a projected area (13) of the cleaning head (9) in the moving direction is smaller than a cross-sectional area of ​​the inflow channel (4) or the outflow channel (5) in which the cleaning head (9) is placed in the moving direction, so as to allow fluid to pass through the cleaning head (9) in the inflow channel (4) or the outflow channel (5). Furthermore, a plate heat exchanger (3) and a method for cleaning plate channels (2) in a plate heat exchanger (3) are disclosed.

Description

Technical Field

[0001] The present invention relates to a cleaning system for cleaning plate channels within a plate heat exchanger during normal use of the plate heat exchanger. The plate heat exchanger includes an inlet channel for fluid entering the plate heat exchanger and an outlet channel for fluid leaving the plate heat exchanger. The present invention also relates to a method for cleaning the plate channels within the plate heat exchanger during normal use of the plate heat exchanger, and a plate heat exchanger including the cleaning system. Background Art

[0002] A plate heat exchanger uses metal plates to transfer heat between two fluids. A plate heat exchanger (PHE) is a specialized design with two alternating chambers, which are typically thin in depth and separated by corrugated metal sheets at their maximum surface area. The plates used in a plate heat exchanger are typically obtained by pressing metal sheets into a single piece. Stainless steel is a common metal for these plates due to its ability to withstand high temperatures, strength, and corrosion resistance. The plates are typically sealed with rubber gaskets located in grooves around the plate edges. The plates are pressed into grooves that are perpendicular to the flow direction of the fluids flowing through the channels within the plate heat exchanger. These grooves are interconnected with other plates that form plate channels with inter-plate gaps of, for example, 0.1 to 8 mm. The plates are pressed together within a rigid frame to form a parallel plate channel arrangement with alternating hot and cold fluids. These plates create a large surface area, enabling maximum heat transfer rates. By making each chamber thin, the majority of the liquid volume is in contact with the plates, which also aids heat transfer. However, over time, deposits, also known as fouling, form within the plate channels, reducing the efficiency of plate heat exchangers. Therefore, plate heat exchangers are known to require periodic disassembly, descaling, and reassembly. However, this is a costly operation and requires the plate heat exchanger to be out of service for extended periods of time.

[0003] To this end, International Patent Application WO2013 / 085332A1 discloses a cleaning system comprising a removable cleaning plug located within the inlet channel of a plate heat exchanger. This plug concentrates the flow of fluid to several plate channels simultaneously, thereby increasing the flow rate and enabling cleaning of these channels. However, this system requires the plate heat exchanger to be shut down during the cleaning process.

[0004] To this end, according to International Patent Application WO 2016 / 189184 A1, the plate channels of a plate heat exchanger used in gas cooling applications can be cleaned during use by a movable cleaning device located in the inlet channel. The cleaning device is capable of releasing a transient exhaust gas to form a strong clean air flow through the plate channels covered by the cleaning device. To ensure (almost) normal operation of the plate heat exchanger during the cleaning process, bypass pipes are formed around the inlet channel to ensure normal flow through the plate channels not covered by the cleaning device on both sides. However, this system is expensive and difficult to install.

[0005] Therefore, an object of the present invention is to provide a technology for more efficiently cleaning the inner plate channels of a plate heat exchanger during normal use of the plate heat exchanger. Summary of the Invention

[0006] The present invention provides a cleaning system for cleaning the plate channels within a plate heat exchanger during normal use of the plate heat exchanger. The plate heat exchanger includes an inlet channel through which fluid enters the plate heat exchanger and an outlet channel through which fluid leaves the plate heat exchanger. A stack of plate heat exchanger plates is disposed between the inlet channel and the outlet channel, so that the plate heat exchanger plates form a plate channel between the inlet channel and the outlet channel for fluid to pass through. The cleaning system includes:

[0007] A bypass of the stack of heat exchanger plates is provided to establish a bypass of the fluid between the inlet channel and the outlet channel.

[0008] A bypass pipe for flow;

[0009] a cleaning head comprising a cleaning hole connected to the bypass duct, wherein the cleaning hole is arranged to face the stack of heat exchanger plates during normal use of the cleaning head within the heat exchanger,

[0010] A moving device configured to linearly move the cleaning head in a moving direction within the inflow channel or the outflow channel

[0011] and

[0012] a pressure changing device arranged to change the pressure in the bypass duct,

[0013] The projected area of ​​the cleaning head in the moving direction is smaller than the cross-sectional area of ​​the inflow channel or outflow channel in which the cleaning head is placed in the moving direction, so as to allow the fluid to pass through the cleaning head in the inflow channel or outflow channel.

[0014] The advantage of designing the projected area of ​​the cleaning head to be smaller than the cross-sectional area of ​​the channel in which it is placed is that it allows fluid to flow through the cleaning head within the channel, thus simply ensuring that the plate heat exchanger remains operational during the cleaning process. Furthermore, by establishing a bypass line connected to the cleaning hole, the plate channel can be cleaned using the fluid already present in the channel, thus reducing costs and the risk of fluid contamination.

[0015] It should be noted that the term "moving device" is to be understood as any type of moving means suitable for linearly moving the cleaning head within the inflow or outflow channel of the plate heat exchanger. In other words, the term includes any type of hydraulic actuator, pneumatic actuator, electric actuator, chain / motor drive, spindle drive, pinion drive, etc., or any combination thereof.

[0016] It should be noted that the term "pressure changing device" should be understood to mean any type of pressure changing device that is suitable for increasing the flow in the bypass conduit by changing or modifying the pressure in the bypass conduit relative to the pressure in the bypass conduit when the pressure changing device is not provided. Therefore, the term includes any type of pump, fluid discharge device, fluid addition device, valve device that controls fluid communication with a region of higher or lower pressure, etc., or any combination thereof. It should also be noted that the pressure changing device can be configured to change the pressure in the bypass conduit so that the pressure at the cleaning head increases, thereby increasing the flow rate of fluid out of the cleaning hole; or, the pressure changing device can be configured to change the pressure in the bypass conduit so that the pressure at the cleaning head decreases, thereby reversing the direction of flow through the cleaning hole, so that the cleaning head draws in fluid. Alternatively, the pressure changing device can be configured to alternately draw in and agitate fluid.

[0017] In one aspect of the present invention, the cleaning system also includes a porous channel configured to guide the linear movement of the cleaning head in the inflow channel or the outflow channel. The channel into which the cleaning head passes may include an edge or protrusion that can capture the cleaning head or at least reduce the ability of the cleaning head to form a dense cleaning flow flowing through the plate channel it covers. Therefore, it is an advantage to allow the fluid to flow freely through the openings in the channel while allowing the cleaning head to move smoothly by lining the porous channel into a given inflow channel or outflow channel. In addition, the porous channel can be used as a screen to prevent foreign matter such as oxide flakes, gasket parts, etc. that may block the plate channel from entering the plate channel. Subsequently, the movement of the cleaning head causes the foreign matter to be pushed or pulled away from the plate stack and ensures that the foreign matter does not affect the operation of the heat exchanger.

[0018] In one aspect of the invention, the porous channel is adapted to mate with the wall of the inflow channel or the outflow channel.

[0019] An advantage of matching the porous channels to the walls of the inflow or outflow channels into which the cleaning head opens is that it ensures that the high velocity fluid stream generated by the cleaning head is focused through the plate channels covered by the cleaning apertures, thereby ensuring more efficient cleaning.

[0020] In one aspect of the invention, the size of the openings in the porous channels is larger at the outer surface of the channels than at the inner surface of the channels.

[0021] An advantage of forming the openings in the outer surface of the channel larger than the inner surface of the channel is that this reduces blockage of flow into and out of the plate channels.

[0022] In one aspect of the invention, the open area on the inner surface of the porous channels is between 10% and 95%, preferably between 40% and 90%, most preferably between 60% and 85%.

[0023] If the opening area is too small, less fluid can flow through the channel walls, reducing the efficiency of the plate heat exchanger. However, if the opening area is too large, the structural integrity of the channel will be compromised and the channel's screening effect will be reduced. Therefore, the above area range can achieve a favorable balance between heat exchanger efficiency and channel durability.

[0024] In one aspect of the invention, the pressure varying means comprises a pump.

[0025] The advantage of using a pump to change the pressure in the bypass line is that a pump is a simple and easy-to-control way to change the pressure.

[0026] In one aspect of the invention, the pump has a capacity between 1 and 90 cubic meters per hour, preferably 5 and 50 cubic meters per hour, most preferably 10 and 35 cubic meters per hour.

[0027] If the pump capacity is too small, the cleaning effect will be reduced and / or the cleaning process will take too long. However, if the pump capacity is too high, the pump will become more power-intensive and costly. Therefore, the above capacity range can achieve a favorable balance between efficiency and cost.

[0028] In one aspect of the present invention, the pressure changing device includes a valve including a mounting member for mounting the valve at an outlet of the plate heat exchanger. In one aspect of the present invention, a bypass conduit is provided to establish a bypass flow between the inlet channel and the outlet channel behind the valve when viewed in the direction of flow during normal use of the plate heat exchanger.

[0029] Placing the valve at the heat exchanger outlet and connecting the bypass conduit to the outflow channel at the rear of the valve in the direction of flow during normal use ensures that the pressure in the bypass conduit can be easily varied by at least partially closing the valve, increasing the pressure in the outflow channel in front of the valve relative to the pressure in the outflow valve behind the valve, thereby increasing the flow rate through the bypass conduit and thus through the cleaning hole. This avoids excessive power consumption by the pump.

[0030] In one aspect of the invention, the moving means comprises a linear actuator.

[0031] Moving the cleaning head within the inflow or outflow channel by means of a linear actuator is a simple and precise way of automating the movement.

[0032] In one aspect of the invention, the cleaning head is connected to the bypass conduit by a telescoping pipe section.

[0033] Connecting the cleaning head to the bypass pipe by means of a telescopic pipe section is a way to efficiently utilize space and ensure that the fixed pipe section of the bypass pipe can be connected to the mobile cleaning head at a low cost.

[0034] In one aspect of the invention, the pressure varying means is arranged to reduce the pressure at the cleaning head so as to cause the cleaning head to draw suction.

[0035] The advantage of causing the cleaning head to draw in suction by reducing the pressure at the cleaning aperture is that this allows the cleaning head to also draw in the material being cleaned and, for example, any foreign matter, which can then be removed in a bypass duct or elsewhere. Furthermore, if the cleaning head is located in an inflow channel, the suction portion of the cleaning head can also reverse the direction of flow through the plate channel being cleaned, thereby further improving the cleaning effect.

[0036] In one aspect of the invention, the moving means is arranged to move the cleaning head within the inflow channel.

[0037] The advantage of moving the cleaning head within the inflow channel is that the movement of the cleaning head can also be used to remove any foreign matter from the plate stack. Furthermore, if the pressure changing device is arranged so that the cleaning head draws suction within the inflow channel, any removed matter, dirt etc. will bypass the plate channels, thereby reducing the risk of this matter clogging the plate channels.

[0038] In one aspect of the invention, the moving device is arranged to move the cleaning head over the entire stack of heat exchanger plates in the heat exchanger, which has the advantage that the entire stack of heat exchanger plates can then be cleaned by the cleaning system.

[0039] In one aspect of the invention the length of the cleaning head in the direction of movement is between 50% and 99%, preferably between 60% and 97%, most preferably between 70% and 95% smaller than the width of the stack of heat exchanger plates viewed in the direction of movement.

[0040] If the length of the cleaning head in the direction of movement is too long, the cleaning head will stop operating in too many plate channels during the cleaning process, resulting in a higher required pump capacity. However, if the cleaning head is too short, the cleaning process will take too long, increasing power consumption and making it difficult to stably and evenly position the cleaning head in the inflow or outflow channels. Therefore, the above length range achieves a favorable balance between efficiency and stability.

[0041] In one aspect of the invention, the projected area of ​​the cleaning head is between 10% and 95%, preferably between 30% and 90%, most preferably between 50% and 85% of the cross-sectional area of ​​the inflow channel or outflow channel in which the cleaning head is placed.

[0042] If the projected area of ​​the cleaning head is too small relative to the cross-sectional area of ​​the channel it enters, the flow rate through the cleaning hole and the structural integrity of the cleaning head will be reduced. However, if the projected area is too large relative to the channel, too little fluid can pass through the cleaning head during use, reducing the efficiency of the plate heat exchanger. Therefore, the above length range can achieve a favorable relationship between cleaning system efficiency and heat exchanger efficiency.

[0043] In one aspect of the present invention, the outer shape of the cleaning head as viewed in the moving direction is substantially the same as the inner shape of the inflow channel or the outflow channel in which the cleaning head is placed.

[0044] The advantage of forming the outer contour of the cleaning head to be substantially the same as the inner contour of the channel into which the cleaning head passes is that the cleaning head can be stably held in the channel.

[0045] In one aspect of the present invention, the cleaning head is provided with one or more through holes in the moving direction.

[0046] An advantage of reducing the projected area of ​​the cleaning head by forming a through hole in the cleaning head is that it allows the fluid to flow freely through the cleaning head during use while stably maintaining the cleaning head within the channel.

[0047] In one aspect of the present invention, a cleaning system includes a first cleaning head configured to be positioned in an inflow channel and a second cleaning head configured to be positioned in an outflow channel.

[0048] An advantage of a cleaning system having a first cleaning head arranged in the inflow channel and a second cleaning head arranged in the outflow channel is that the cleaning process can be made more efficient.

[0049] In one aspect of the present invention, the position of the first cleaning head is aligned with the position of the second cleaning head in the moving direction.

[0050] An advantage of aligning the first cleaning head with the second cleaning head is that a more or less closed cleaning circuit can be formed by means of the bypass duct and the plate channel between the cleaning heads.

[0051] In one aspect of the present invention, the moving device is configured to keep the position of the first cleaning head aligned with the position of the second cleaning head in the moving direction during movement of the first and second cleaning heads.

[0052] An advantage of arranging the movement means so that the first cleaning head is aligned with the second cleaning head is that a more or less closed cleaning circuit can be formed throughout the movement of the cleaning heads via the bypass duct and the plate channel between the cleaning heads.

[0053] In one aspect of the present invention, the cleaning system further comprises a detergent unit configured to add a detergent to the fluid flow in the bypass conduit.

[0054] An advantage of having the cleaning system comprise a detergent unit arranged to add detergent to the fluid flow in the bypass conduit is that this may increase the efficiency of the cleaning system.

[0055] It should be noted that in this context the term "cleaning agent" includes any kind of substance that can improve the efficiency of the cleaning process, for example, any kind of soap, solvent, acid, base, etc., or any combination thereof.

[0056] In one aspect of the present invention, the cleaning system further comprises a heating unit configured to heat the fluid flow in the bypass conduit.

[0057] An advantage of heating the fluid flow in the bypass line, for example even to a vapor state, is that this increases the efficiency of the cleaning process.

[0058] In one aspect of the invention the length of the cleaning hole in the moving direction is between 60% and 99.9%, preferably between 75% and 99.8%, most preferably between 90% and 99.7% of the width of the stack of heat exchanger plates viewed in the moving direction.

[0059] If the cleaning hole is too long in the direction of travel, the cleaning head's capacity must be significantly increased to ensure sufficient cleaning flow. However, if the cleaning hole is too short, the cleaning process will take too long, increasing power consumption. Therefore, the above length range can achieve a favorable relationship in terms of efficiency.

[0060] In one aspect of the invention, the pressure varying means is arranged to vary the pressure such that the flow rate in the bypass conduit is increased between 1.1 and 10 times, preferably between 1.2 and 8 times, most preferably between 1.3 and 5 times.

[0061] If the pressure-varying device is set to alter the flow rate too much relative to the normal flow rate in the bypass duct (i.e., the flow rate in the bypass duct without the pressure-varying device), the equipment will be over-pressurized and the risk of failure or leakage will increase. However, if the flow rate is altered too little, the cleaning effect will be too weak. Therefore, the above pressures can achieve a favorable balance between durability and efficiency.

[0062] The present invention also provides a plate heat exchanger comprising a cleaning system according to any one of the aforementioned cleaning systems.

[0063] The advantage of using the cleaning system of the present invention in a plate heat exchanger is that such a plate heat exchanger has a higher efficiency in heat exchange, a lower cost and a higher efficiency in space utilization.

[0064] The present invention also provides a method for cleaning plate channels within a plate heat exchanger during normal use. The heat exchanger includes an inlet channel through which fluid enters the heat exchanger and an outlet channel through which fluid exits the heat exchanger. A stack of heat exchanger plates is disposed between the inlet channel and the outlet channel, such that the heat exchanger plates form a plate channel between the inlet channel and the outlet channel through which fluid can pass. The method comprises the following steps:

[0065] Place the cleaning head in the inflow channel or outflow channel with the cleaning hole of the cleaning head facing the stack of heat exchanger plates.

[0066] The direction of the body;

[0067] A bypass duct is formed between the inlet channel and the outlet channel, bypassing the stack of heat exchanger plates;

[0068] Connect the cleaning hole to the bypass pipe;

[0069] By changing the pressure in the bypass duct, a cleaning flow is formed through the cleaning holes of the cleaning head; and

[0070] • Moving the cleaning head along the stack of heat exchanger plates while allowing fluid to pass through the cleaning head into or out of the channels.

[0071] The advantage of a cleaning head that forms a bypass duct and allows fluid to pass through the channel into which the cleaning head is introduced is that the plate channels can be cleaned by the existing fluid and that the cleaning head does not substantially affect the normal heat exchange operation of the plate.

[0072] In one aspect of the invention, the method is implemented on a plate heat exchanger according to any one of the aforementioned plate heat exchangers.

[0073] In this way, an advantageous embodiment of the present invention is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Hereinafter, the present invention will be described with reference to the accompanying drawings, in which:

[0075] Figure 1 is a partial side sectional view of a plate heat exchanger including a cleaning system;

[0076] Figure 2 This is a bottom view of the cleaning head;

[0077] Figure 3 This is a front view of the cleaning head;

[0078] Figure 4 is a perspective view of a porous channel;

[0079] Figure 5 is a side view of a porous channel cutout;

[0080] Figure 6 a side view of a cleaning system including a valve for a pressure changing device;

[0081] Figure 7 is a side view of a cleaning system including a detergent unit and a heating unit. DETAILED DESCRIPTION

[0082] Figure 1 1 is a partial side sectional view of a plate heat exchanger 3 including a cleaning system 1 .

[0083] In this embodiment, the plate heat exchanger 3 is a conventional large-scale commercial plate heat exchanger 3, comprising a plurality of corrugated stainless steel heat exchanger plates 7, separated by rubber sealing gaskets (not shown) to form a stack 6 of heat exchanger plates 7 compressed between a first end plate 33 and a second end plate 34. The end plates 33 and 34 are held together by transverse fastening bolts (not shown) disposed at the corners of the end plates and / or along their sides. However, in other embodiments, the stack 6 of heat exchanger plates 7 may also be brazed, welded, and / or semi-welded. The heat exchanger plates 7 typically form two plate channels 2 through which two separate fluids flow for heat exchange. Typically, one of the plate channels 2 is part of a closed fluid circuit, which is used to cool or heat another fluid that forms part of an open circuit flowing through the other plate channel 2. Fluid within a closed fluid loop does not become dirty or contaminated by exposure to the surrounding environment. Furthermore, because it flows within a closed loop, additives can be added to prevent fluid decomposition or deterioration, as well as the accumulation of deposits within the plate channels. On the other hand, fluid flowing within an open loop continuously introduces dirt, foreign matter, and / or other substances into the plate channels 2. Furthermore, because the loop is open, it is generally not possible to treat the fluid to prevent the formation of deposits within the plate channels 2. Therefore, while the cleaning system 1 of the present invention can be used to clean plate channels 2 within open fluid loops, it can also be used to clean plate channels 2 within closed fluid loops in certain circumstances.

[0084] A typical plate heat exchanger 3 has an inlet channel 4 and an outlet channel 5 for each of the above-mentioned fluids. Figure 1 、 Figure 6 and Figure 7 4 and outflow channels 5 of an open fluid circuit. Accordingly, in this embodiment, the heat exchanger 3 comprises only one cleaning system 1 arranged in one of the inflow channels 4, but in other embodiments, the cleaning system 1 or at least parts of the cleaning system 1 may be arranged in another inflow channel ( Figure 1 、 Figure 6 and Figure 7 It may also be arranged in one of the outflow channels 5, or in both the inflow channels 4 of the heat exchanger 3, or in both the outflow channels 5 of the heat exchanger 3, or in all the inflow channels 4 and outflow channels 5 of the heat exchanger 3.

[0085] In the present embodiment, the cleaning system 1 includes a single cleaning head 9, which includes a single cleaning hole 10 facing downwardly toward the plate stack 6. However, in other embodiments, the system 1 may include multiple cleaning heads 9 located in the same inflow and / or outflow channel 4, 5, and / or each cleaning head 9 may include more than one cleaning hole 10. In the present embodiment, the projected area 13 of the cleaning head 9 in its moving direction (i.e., the longitudinal projection from one end of the inflow channel 4) is smaller than the cross-sectional area of ​​the inflow channel 4 along the moving direction, so that the fluid can pass through the cleaning head 9 in the inflow channel 4. Therefore, when the cleaning system 1 is in use and moves along the plate stack 6, the fluid can flow normally through the plate channel 2 in front of the cleaning head 9, and the fluid can flow normally through the cleaning head 9 and the plate channel 2 on the other side of the cleaning head 9. Therefore, in the present embodiment, since only the several plate channels 2 covered by the cleaning head 9 stop running during the cleaning process, the plate heat exchanger 3 can almost maintain its normal capacity during the cleaning process. Obviously, this principle also applies to the case where the cleaning head 9 is located in the outflow channel 5. Below, in combination Figure 2 and Figure 3 , the design of the cleaning head 9 is described in further detail.

[0086] In this embodiment, the cleaning head 9 is moved back and forth within the inflow channel 4 by a moving device 11 in the form of a hydraulic linear actuator 23. However, in other embodiments, the moving device 11 can also be implemented in a variety of other ways. In this embodiment, after the cleaning process is started, the moving device 11 will move the cleaning head 9 through the entire plate stack 6 at a fixed speed and then return. In this embodiment, the cleaning process is manually started, but in other embodiments, the cleaning system 1 can be configured to operate continuously during the operation of the plate heat exchanger 3. It can also include a control unit (not shown) configured to start the cleaning process at fixed intervals. It can also be configured to start at a specific time, such as when the heat exchanger is not operating at maximum capacity. It can also be configured in other ways, or it can be configured in any combination of the above methods.

[0087] In other embodiments, the moving device 11 may be configured to move the cleaning head 9 stepwise, that is, the moving device 11 may move the cleaning head 9 a distance corresponding to the width of the cleaning hole 10, then pause, and then move the cleaning head 9 again by this distance.

[0088] In this embodiment, the bypass conduit 8 forms a fluid connection between the outflow channel 5 and the inflow channel 4, wherein the bypass conduit 8 is connected to the cleaning head 9 via a telescopic pipe section 24. The telescopic pipe section allows the bypass conduit 8 to remain connected to the cleaning head 9 even when the cleaning head 9 moves back and forth. However, in other embodiments, the connection between the bypass conduit 8 and the cleaning head 9 can also be formed by a flexible pipe section, a spiral hose, a flexible bypass conduit, etc.

[0089] In order to change the flow conditions in the bypass conduit 8, in this embodiment, the bypass conduit 8 is provided with a pressure changing device 12 in the form of a pump 19. However, in other embodiments, the pressure changing device 12 may also be provided by a combination of Figure 4 This can be achieved in a variety of other ways, including the aforementioned one. In this embodiment, the pressure changing device 12 is used to generate a flow from the cleaning head 9 to the outflow channel 5 within the inflow channel 4, so that the cleaning head 9 draws fluid from the plate channel 2 covered by the cleaning hole 10, thereby causing the cleaning flow within the plate channel 2 to be opposite to the normal flow direction during normal use of the plate heat exchanger 3. However, in other embodiments, the pressure changing device 12 can be used to generate a flow from the outflow channel 5 to the cleaning head 9 within the inflow channel 4, so that the cleaning head 9 flushes toward the outflow channel 5. Alternatively, the pressure changing device 12 can also be configured to alternately change the flow direction.

[0090] In this embodiment, the pressure changing device 12 is configured to increase the flow rate within the bypass duct 8 by approximately three times by changing the pressure within the bypass duct 8. In this embodiment, the cleaning hole 10 is approximately the same size as the cross-sectional area of ​​the bypass duct 8, so that the plate channel 2 covered by the cleaning hole 10 is subjected to a cleaning flow rate approximately three times the normal flow rate during normal use. However, in other embodiments, the pressure changing device 12 can be configured to produce a higher or lower flow rate, for example, depending on the type of plate heat exchanger, the fluid flowing in the plate channel 2, the cleaning frequency, etc.

[0091] In order to generate a three times higher flow rate, in this embodiment, the pump 19 has a capacity of approximately 25 cubic meters per hour, but in other embodiments, the capacity of the pump 19 may be larger or smaller, for example depending on the specific target flow rate, the type of plate heat exchanger, the size of the cleaning hole and the bypass pipe 8, etc.

[0092] In this embodiment, the inflow channel 4 is further provided with a porous channel 14 that extends the entire stroke length of the cleaning head 9 in the inflow channel 4. Some plate heat exchangers 3 are formed with pointed plate joints or the like that can capture the cleaning head 9 during its stroke. The porous channel 14 is formed to match the cross-sectional profile of the inflow channel 4, and thus guides the cleaning head 9 in the inflow channel 4 and acts as a screen to ensure that the plate channel 2 is not blocked by larger foreign matter. Obviously, if a cleaning head 9 is also provided in the outflow channel 5, or the cleaning head 9 is relocated in the outflow channel 5, a porous channel 14 can also be provided in the outflow channel 5. Below, in combination Figure 4 and Figure 5 , the porous channel 14 is described in more detail.

[0093] In this embodiment, the cleaning system 1 cleans the plate channels 2 within the plate heat exchanger 3 during normal operation. The cleaning head 9 is placed within the inflow channel 4, with the cleaning hole 10 oriented toward the stack 6 of heat exchanger plates 7. A bypass conduit 8 is established between the cleaning hole 10 of the cleaning head 9 within the inflow channel 4 and the outflow channel 5, thereby bypassing the stack 6 of heat exchanger plates 7. Subsequently, a pressure changing device 12 within the bypass conduit generates a cleaning flow through the cleaning hole 10 by changing the pressure within the bypass conduit 8, thereby generating a cleaning flow through the cleaning hole 10 and outflowing into the outflow channel 5. Simultaneously, a moving device 11 moves the cleaning head 9 along the stack 6 of heat exchanger plates 7, allowing fluid to flow through the cleaning head 9 into the inflow channel 4. This method is also applicable to situations where the cleaning head 9 is also located within the outflow channel 5, or the cleaning head 9 is relocated within the outflow channel 5.

[0094] Figure 2 is a bottom view of the cleaning head 9, Figure 3 It is a front view of the cleaning head 9.

[0095] In the present embodiment, the projected area 13 of the cleaning head 9 is less than the cross-sectional area of ​​the inflow channel 4. In the present embodiment, the cleaning head 9 includes four through holes 27, and fluid can flow through the cleaning head 9 in the above-mentioned moving direction through these through holes. However, in other embodiments, the cleaning head 9 may include other numbers of through holes 27, such as one, two, six, eight or more through holes 27, or the cleaning head 9 may further or instead adopt forms such as partial cylinders, crescents. However, it is advantageous that the majority of the cleaning head 9 periphery corresponds to the inner profile of the channel 4,5 in which it is located, to ensure a close fit, so that the cleaning hole 10 always remains against the plate stack 6. In the present embodiment, the cleaning head 9 has a circular outer shape to match the circular channel 4,5 and / or porous channel 14. However, if the channel 4,5 and / or porous channel 14 have other shapes such as square, oval, rectangular, the cleaning head 9 is also formed into this shape to match the channel 4,5 and / or porous channel 14.

[0096] In this embodiment, the projected area 13 of the cleaning head 9 is approximately 75% smaller than the cross-sectional area of ​​the inflow channel 4, to ensure that the fluid can flow freely enough through the cleaning head 9 when the cleaning head 9 moves along the stack 6 of heat exchanger plates 7. Therefore, in this embodiment, the cleaning head 9 reduces the accessible area of ​​the channels 4, 5 by only 25%.

[0097] In this embodiment, the length 25 of the cleaning head 9 in its moving direction is about 85% smaller than the width 26 of the stack 6 of heat exchanger plates 7 (see for example Figure 1 ) to ensure that the cleaning head 9 is wide enough to prevent it from getting stuck or stuck during movement.

[0098] In this embodiment, the length 32 of the cleaning hole 10 in the moving direction is about 96% smaller than the width 26 of the stack 6 of heat exchanger plates 7 to ensure a sufficiently high flow rate through the plate channels 2 covered by the cleaning hole 10 .

[0099] In the present embodiment, the cleaning head includes an internal cleaning duct 35 that leads the fluid from the cleaning head surface to which the bypass duct 8 is connected to the cleaning hole 10. In the present embodiment, the cross-sectional area of ​​the cleaning duct 35 is approximately equal to the cross-sectional area of ​​the bypass duct 8. In the present embodiment, the cleaning hole 10 is wider than the cleaning duct 35 in a direction perpendicular to the above-mentioned direction of movement to ensure that the cleaning flow is diffused to the side of the plate stack 6. However, in other embodiments, the cleaning hole 10 may have a smaller size, for example, when the cleaning system 1 includes a swing device (not shown), the swing device is used to make the cleaning head 9, for example, do a 30-degree swing, so that the denser jet ejected from the cleaning hole 10 moves over the entire width of (several) plate channels 2. Alternatively, in other embodiments, the cleaning hole 10 can further increase the width in a direction perpendicular to the above-mentioned direction of movement to ensure that all corners of the plate channels 2 are touched.

[0100] In this embodiment, the cleaning head 9 is provided with a connecting member 36 in the form of a single central hole, through which the mobile device 11 can be connected to the cleaning head 9. In this embodiment, the connecting member 36 is provided in the center of the cleaning head 9 to reduce the risk of the cleaning head 9 getting stuck or becoming stuck when being moved by the mobile device 11. However, in other embodiments, such as when the cleaning head 9 includes more than one connecting member 36, the connecting member 36 may be provided offset from the center.

[0101] In this embodiment, the cleaning head 9 is provided with a cover 37 formed of a plastic material, so that when the cleaning head 9 moves back and forth in the channels 4, 5, the cleaning head 9 moves more smoothly and produces less noise, while at the same time ensuring a tight fit in the channels 4, 5 or the porous channel 14. However, in other embodiments, the cover 37 may not be provided, and the cover 37 may be made of other materials, such as ceramic, composite materials, bronze, other metals, or any combination thereof.

[0102] Figure 4 is a perspective view of the porous channel 14, Figure 5 It is a cut-away side view of the porous channel 14 .

[0103] In this embodiment, the porous channel 14 is cylindrical to match the cylindrical channels 4, 5. However, when the channels 4, 5 have other shapes such as square, oval, rectangular, etc., the porous channel 14 can also be formed in this shape to match the channels 4, 5.

[0104] In this embodiment, the size of the openings 18 within the porous channels 14 is larger at the outer surface 16 of the channels 14 than at the inner surface 17 to reduce the risk of clogging, and all of the openings 18 are substantially the same. However, in other embodiments, the openings 18 may have a constant size within the channel material, and / or at least some of the openings 18 may have different sizes.

[0105] In this embodiment, the open area of ​​the inner surface 17 of the porous channel 14 is about 50%. However, in other embodiments, the open area can be larger to ensure better or more fluid flow through the porous channel 14, or the open area can be smaller to further improve the rigidity of the porous channel 14.

[0106] Figure 6 Side view of the cleaning system 1 including a valve 20 for the pressure changing device 12 .

[0107] In this embodiment, the pressure changing device 12 comprises a valve 20 connected to the outflow outlet 22 of the plate heat exchanger 3 by a mounting 21. In this embodiment, the valve 20 is in the form of a butterfly valve. In this embodiment, the bypass line 8 is connected to the outflow channel 5 behind the valve 20 in the direction of flow during normal use of the plate heat exchanger 3. Thus, during normal operation of the plate heat exchanger 3, the valve 20 is fully open. Once engaged with the cleaning system 1, the valve 20 is opened as shown in FIG. Figure 6 The valve 20 is partially closed in the manner shown to restrict flow through the valve 20. This increases the pressure within the inflow channel 4, the plate channels 2, and the outflow channel 5 below the plate stack 6 relative to the pressure in the bypass duct 8 at the point where it flows into the outflow channel 5 on the other side of the valve 20, causing the pressure in the bypass duct 8 to drop, the degree of which depends on the closure of the valve 20. This causes the cleaning head 9 to begin drawing fluid at a relatively high flow rate, thereby cleaning the plate channels 2 covered by the cleaning hole 10. Therefore, in this embodiment, the pressure changing device 12 can be formed without using a pump.

[0108] Figure 7 FIG. 3 is a side view of the cleaning system 1 including the detergent unit 30 and the heating unit 31 .

[0109] In this embodiment, the cleaning system 1 includes a first cleaning head 28 extending into the inflow channel 4 and a second cleaning head 29 extending into the outflow channel 5. The first cleaning head 28 and the second cleaning head 29 are held in alignment with each other by a moving device 11, so that the cleaning heads 9, 28, 29, the plate channels 2 covered by the cleaning holes 10 of the cleaning heads 9, 28, 29, and the bypass duct 8 form a (nearly) closed circuit. Therefore, in this embodiment, the cleaning system 1 further includes a detergent unit 30 for adding a detergent to the fluid flowing in the bypass duct 8. In this embodiment, the detergent is a soap-based detergent. However, in other embodiments, the detergent unit 30 may add any type of substance that can increase the efficiency of the cleaning process. In this embodiment, the cleaning system 1 is configured to first clean the plate channels 2 covered by the cleaning holes 10 of the cleaning heads 9, 28, 29 by adding a detergent. Then, before the cleaning heads 9, 28, 29 are moved to a new position, the plate channels 2 are flushed with the cleaning fluid to reduce the risk of the detergent mixing with the fluid flowing in the heat exchanger 3. In other embodiments, it may be acceptable to add some type of cleaning agent to the fluid and omit the flush cycle.

[0110] In this embodiment, the cleaning system 1 further comprises a heating unit 31 for heating the fluid flowing in the bypass conduit 8 so that the fluid used in the cleaning process can be hotter than the fluid normally flowing through the plate channel 2. In this embodiment, the heating unit 31 is used to increase the temperature of the fluid by 50 degrees Celsius. However, in other embodiments, the heating unit 31 can also be used to heat the fluid to a lower degree, for example, by increasing the temperature by 40 degrees Celsius, 30 degrees Celsius, 20 degrees Celsius, or less, or the heating unit 31 can also be used to heat the fluid to a higher degree, for example, by increasing the temperature by 60 degrees Celsius, 70 degrees Celsius, 80 degrees Celsius, or more, in order to, for example, dissolve fat without the use of detergents by converting the fluid into steam, or to accelerate chemical reactions and improve the efficiency of the cleaning system 1.

[0111] In this embodiment, the detergent unit 30 and the heating unit 31 are shown in combination with a first cleaning head 28 extending into the inflow channel 4 and a second cleaning head 29 extending into the outflow channel 5. However, in other embodiments, the detergent unit 30 and / or the heating unit 31 can also be used with a cleaning system 1 that includes only a single cleaning head 9 extending into the inflow channel 4 or the outflow channel 5.

[0112] The present invention has been described above with reference to specific embodiments of the cleaning system 1, plate heat exchanger 3, pressure changing device 12, etc. However, it should be understood that the present invention is not limited to the above-described specific embodiments, but can be designed and modified in various ways within the scope of the invention as specified in the claims.

[0113] List

[0114] 1. Clean the system

[0115] 2. Plate channel

[0116] 3. Plate heat exchanger

[0117] 4. Inflow channel

[0118] 5. Outflow channel

[0119] 6. Stack of heat exchanger plates

[0120] 7. Heat exchanger plates

[0121] 8.Bypass pipe

[0122] 9. Cleaning head

[0123] 10. Clean the hole

[0124] 11. Mobile devices

[0125] 12. Pressure changing device

[0126] 13. Cleaning head projection area

[0127] 14.Porous channels

[0128] 15. Channel wall of inflow channel or outflow channel

[0129] 16. Channel outer surface

[0130] 17. Inner surface of channel

[0131] 18. Opening

[0132] 19. Pump

[0133] 20. Valve

[0134] 21.Mounting parts

[0135] 22. Outflow

[0136] 23. Linear actuator

[0137] 24. Telescopic pipe section

[0138] 25. Length of the cleaning head in the direction of movement

[0139] 26. The width of the stack of heat exchanger plates in the moving direction

[0140] 27.Through hole

[0141] 28.First cleaning head

[0142] 29. Second cleaning head

[0143] 30. Cleaner unit

[0144] 31. Heating unit

[0145] 32. Length of the cleaning hole in the moving direction

[0146] 33.First end plate

[0147] 34. Second end plate

[0148] 35. Clean pipes

[0149] 36.Connectors

[0150] 37. Outer cover

Claims

1. A cleaning system (1) for cleaning the inner plate channels (2) of a plate heat exchanger (3) during normal use of the plate heat exchanger (3), wherein: The heat exchanger (3) comprises an inlet channel (4) for a fluid to enter the heat exchanger (3) and an outlet channel (5) for the fluid to leave the heat exchanger (3), wherein a stack (6) of heat exchanger plates (7) is arranged between the inlet channel (4) and the outlet channel (5), so that the heat exchanger plates (7) form a plate channel (2) between the inlet channel (4) and the outlet channel (5) for the fluid to pass through. The cleaning system (1) comprises: a bypass conduit (8) arranged to establish a bypass flow of the fluid between the inflow channel (4) and the outflow channel (5) bypassing the stack (6) of heat exchanger plates (7); a cleaning head (9) comprising a cleaning hole (10) connected to the bypass duct (8), wherein the cleaning hole (10) is arranged to face the stack (6) of heat exchanger plates (7) during normal use of the cleaning head (9) in the heat exchanger (3), a moving device (11) configured to linearly move the cleaning head (9) in a moving direction within the inflow channel (4) or the outflow channel (5); and a pressure changing device (12) configured to change the pressure in the bypass duct (8), The projection area (13) of the cleaning head (9) in the moving direction is smaller than the cross-sectional area of ​​the inflow channel (4) or the outflow channel (5) in which the cleaning head (9) is placed in the moving direction, so as to allow the fluid to pass through the cleaning head (9) in the inflow channel (4) or the outflow channel (5).

2. The cleaning system (1) according to claim 1, wherein The cleaning system (1) further comprises a porous channel (14) arranged to guide the linear movement of the cleaning head (9) within the inflow channel (4) or the outflow channel (5).

3. The cleaning system (1) according to claim 2, wherein The porous channel (14) is adapted to cooperate with a wall (15) of the inflow channel (4) or the outflow channel (5).

4. Cleaning system (1) according to claim 2 or 3, wherein The size of the openings (18) in the porous channel (14) is larger at the outer surface (16) of the channel (14) than at the inner surface (17) of the channel (14).

5. The cleaning system (1) according to claim 2, wherein The open area on the inner surface (17) of the porous channel (14) is between 10% and 95%.

6. The cleaning system (1) according to claim 1, wherein The pressure changing device (12) comprises a pump (19).

7. The cleaning system (1) according to claim 1, wherein The pressure changing device (12) comprises a valve (20), and the valve (20) comprises a mounting member (21) for mounting the valve (20) at an outflow outlet (22) of the plate heat exchanger (3).

8. The cleaning system (1) according to claim 7, wherein The bypass conduit (8) is arranged to establish a bypass flow between the inflow channel (4) and the outflow channel (5) behind the valve (20) when viewed in the flow direction during normal use of the plate heat exchanger (3).

9. The cleaning system (1) according to claim 1, wherein The moving device (11) comprises a linear actuator (23).

10. The cleaning system (1) according to claim 1, wherein The cleaning head (9) is connected to the bypass pipe (8) via a telescopic pipe section (24).

11. The cleaning system (1) according to claim 1, wherein The pressure changing device (12) is arranged to reduce the pressure at the cleaning head (9) so that the cleaning head (9) draws suction.

12. The cleaning system (1) according to claim 1, wherein The moving device (11) is configured to move the cleaning head (9) within the inflow channel (4).

13. The cleaning system (1) according to claim 1, wherein The moving device (11) is arranged to move the cleaning head (9) across the entire stack (6) of heat exchanger plates (7) within the heat exchanger (3).

14. The cleaning system (1) according to claim 1, wherein The length (25) of the cleaning head (9) in the direction of movement has a value between 50% and 99% less than the width (26) of the stack (6) of heat exchanger plates (7) when viewed in the direction of movement.

15. The cleaning system (1) according to claim 1, wherein The projected area (13) of the cleaning head (9) has a value between 10% and 95% smaller than the cross-sectional area of ​​the inflow channel (4) or the outflow channel (5) in which the cleaning head (9) is placed.

16. The cleaning system (1) according to claim 1, wherein The external shape of the cleaning head (9) when viewed in the moving direction is the same as the internal shape of the inflow channel (4) or the outflow channel (5) in which the cleaning head (9) is placed.

17. The cleaning system (1) according to claim 1, wherein The cleaning head (9) is provided with one or more through holes (27) in the moving direction.

18. The cleaning system (1) according to claim 1, wherein The cleaning system (1) comprises a first cleaning head (28) arranged to be placed in the inflow channel (4) and a second cleaning head (29) arranged to be placed in the outflow channel (5).

19. The cleaning system (1) according to claim 18, wherein The position of the first cleaning head (28) is aligned with the position of the second cleaning head (29) in the moving direction.

20. The cleaning system (1) according to claim 18, wherein The moving device (11) is configured to keep the position of the first cleaning head (28) aligned with the position of the second cleaning head (29) in the moving direction during the movement of the first and second cleaning heads.

21. The cleaning system (1) according to claim 18, wherein The cleaning system (1) further comprises a detergent unit (30) configured to add a detergent to the fluid in the bypass conduit (8).

22. The cleaning system (1) according to claim 18, wherein The cleaning system (1) further comprises a heating unit (31) configured to heat the fluid in the bypass pipe (8).

23. The cleaning system (1) according to claim 1, wherein The length (32) of the cleaning hole (10) in the direction of movement is between 60% and 99.9% smaller than the width (26) of the stack (6) of heat exchanger plates (7) when viewed in the direction of movement.

24. The cleaning system (1) according to claim 1, wherein The pressure changing device (12) is arranged to change the pressure so that the flow rate in the bypass conduit (8) is increased between 1.1 and 10 times.

25. The cleaning system (1) according to claim 6, wherein The pump (19) has a capacity of between 1 and 90 cubic meters per hour.

26. A plate heat exchanger (3) comprising a cleaning system (1) according to any one of the preceding claims.

27. A method for cleaning the inner plate channels (2) of a plate heat exchanger (3) during normal use of the heat exchanger (3), wherein: The heat exchanger (3) comprises an inlet channel (4) for a fluid to enter the heat exchanger (3) and an outlet channel (5) for the fluid to leave the heat exchanger (3), wherein a stack (6) of heat exchanger plates (7) is arranged between the inlet channel (4) and the outlet channel (5), so that the heat exchanger plates (7) form a plate channel (2) between the inlet channel (4) and the outlet channel (5) for the fluid to pass through. The method comprises the following steps: placing a cleaning head (9) in the inflow channel (4) or the outflow channel (5), with the cleaning hole (10) of the cleaning head (9) facing the stack (6) of the heat exchanger plates (7); A bypass pipe (8) is formed between the inflow channel (4) and the outflow channel (5) to bypass the stack (6) of heat exchanger plates (7); Connecting the cleaning hole (10) to the bypass pipe (8); By changing the pressure in the bypass pipe (8), a cleaning flow is formed to flow through the cleaning hole (10) of the cleaning head (9); and The cleaning head (9) is moved along the stack (6) of heat exchanger plates (7) while allowing the fluid to pass through the cleaning head (9) in the inflow channel (4) or the outflow channel (5).

28. The method according to claim 27, wherein The method is carried out on a plate heat exchanger (3) according to claim 26.

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