HEAT EXCHANGER

FIELD OF THE INVENTION

[0001] The present invention relates generally to a closure unit for a plate heat exchanger. More particularly, the present invention relates to a power transmission unit for use on a plate heat exchanger.

BACKGROUND OF THE INVENTION

[0002] It is generally known that plate heat exchangers offer efficient transfer of heat from one fluid to another in a relatively small volume. In certain industries, heat exchangers are required to be opened frequently to inspect the heat transfer plates. This process can require the removal of one or more plates for closer inspection or cleaning.

[0003] Traditionally, one of the end plates, commonly referred to as the head, is fixed and the other end plate, commonly referred to as the follower, is moveable towards the head to close the heat exchanger and is movable away from the head to open the heat exchanger.

[0004] Heat exchangers of this type are well known and often include two spindles that can be rotated through a threaded nut to urge the follower towards the head. Manual rotation of the spindles is tedious and difficult work that requires significant effort and can result in injury. Independent manual rotation of the spindles results in uneven closure forces being applied to the package of heat transfer plates by the follower. This can lead to improper sealing between the heat transfer plates giving rise to leaks.

[0005] Accordingly, it is desirable to provide a closure unit and system that is able to overcome the foregoing disadvantages at least to some extent. SUMMARY OF THE INVENTION

[0006] The foregoing needs are met by the present invention, where in some embodiments a closure unit for a plate heat exchanger that is able to overcome the foregoing disadvantages at least to some extent is provided.

[0007] An embodiment of the present invention pertains to a plate heat exchanger. The plate heat exchanger includes a frame, a set of plates, and a modular closure unit. The set of plates is disposed in the frame between a head and a follower. The modular closure unit includes a drive mechanism and a power unit. The drive mechanism is operable to be added onto the frame while the plate heat exchanger is idle and while the plate heat exchanger is working. The drive mechanism is operable to be sanitarily housed and the drive mechanism is configured to urge the follower to move towards the head to compress the set of plates and configured to urge the follower to move away from the head to release the set of plates. The power unit is configured to be selectably connected to and disconnected from the drive mechanism and to provide power to the drive mechanism. The power unit is configured to control the drive mechanism to compress the set of plates between the follower and the head in response to a controller receiving a close command and wherein the power unit is configured to control the drive mechanism to move the follower away from the head in response to a controller receiving an open command.

[0008] Another embodiment of the present invention relates to a plate heat exchanger system. The plate heat exchanger system includes a plurality of plate heat exchangers and a modular closure unit. Each of the plate heat exchangers includes a frame and a set of plates disposed in the frame between a head and a follower. The modular closure unit includes a plurality of drive mechanisms and a disconnectable power unit. Each of the drive mechanisms is operable to be added onto the respective frame of the plurality of plate heat exchangers. Each drive mechanism is operable to be sanitarily housed and the drive mechanism is configured to urge the follower to move towards the head to compress the set of plates and configured to urge the follower to move away from the head to release the set of plates. Each drive mechanism is operable to be coupled to a respective plate heat exchanger while the plate heat exchanger is idle and each drive mechanism is operable to be coupled to the respective plate heat exchanger while the plate heat exchanger is operational. The disconnectable power unit is configured to provide power to the plurality of drive mechanisms. The disconnectable power unit is configured to be disconnected from one of the plurality of drive mechanisms and connected to another to control the respective drive mechanism to compress the set of plates between the follower and the head in response to a controller receiving a close command and the disconnectable power unit is configured to control the drive mechanism to move the follower away from the head in response to a controller receiving an open command.

[0009] Yet another embodiment of the present invention pertains to an aftermarket modular closure unit for an existing plate heat exchanger having a frame and a set of plates disposed in the frame between a head and a follower. The aftermarket modular closure unit includes a drive mechanism and a power unit. The drive mechanism is operable to be added onto the frame without disruption of the operation of the existing plate heat exchanger. The drive mechanism is operable to be sanitarily housed and the drive mechanism is configured to urge the follower to move towards the head to compress the set of plates and is configured to urge the follower to move away from the head to release the set of plates. The power unit is configured to be connected to and disconnected from the drive mechanism without disruption of the operation of the existing plate heat exchanger. The power unit is configured to provide power to the drive mechanism. The power unit is configured to control the drive mechanism to compress the set of plates between the follower and the head in response to a controller receiving a close command and the power unit is configured to control the drive mechanism to move the follower away from the head in response to a controller receiving an open command. [0010] There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.

[0011] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.

[0012] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a side view of a plate heat exchanger and a closure unit in a disconnected conformation according to an embodiment of the invention.

[0014] FIG. 2 is a side view of the plate heat exchanger and the closure unit in a connected conformation according to an embodiment of the invention.

[0015] FIG. 3 is an oblique view of a drive mechanism according to an embodiment of the invention.

[0016] FIG. 4 is an isometric view of a portion of the drive mechanism in accordance with the embodiment of FIGS. 1 to 3. [0017] FIG. 5 is a block diagram of the system according to FIGS. 1 and 2.

[0018] FIG. 6 is a system architecture for a controller suitable for use in the system according to FIGS. 1 and 2.

[0019] FIG. 7 is an isometric view of a hand operated directional control valve according to another embodiment of the invention.

[0020] FIG. 8 is an isometric view of a retractable spool suitable for use with the embodiment of FIG. 7.

DETAILED DESCRIPTION

[0021] The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides an improved powered closure system for plate heat exchanges and the like. Examples of powered closure system include hydraulic, pneumatic, electric, and the like. This improved closure system is capable of providing a modular, aftermarket add-on device for existing plate heat exchangers. Embodiments of the closure system are configured to be added to existing plate heat exchangers without stopping or disturbing the operation of the plate heat exchanger. In addition, the closure system is capable of automatic opening and/or closing and an auto-stop of the follower in the plate heat exchanger. Furthermore, the closure system may be sanitarily housed to permit the exterior to be cleaned in place along with the plate heat exchanger. In short, embodiments of the inventive closure system greatly improve the function of suitable existing plate heat exchangers as well as suitable newly manufactured plate heat exchangers.

[0022] An embodiment of the invention provides a closure unit suitable for use with an existing plate heat exchanger. Referring now to FIG. 1, a side view of a plate heat exchanger system, generally designated 10, is illustrated. As shown in FIG. 1, the plate heat exchanger system 10 includes a plate heat exchanger 12 and a closure unit 14. The plurality of gaskets 16 disposed between various plates of the plate heat exchanger 12. In the example shown, the plate heat exchanger 12 includes a follower 18 and a head 20 and a heat exchange plate 22. When assembled, a first fluid may be introduced to the plate heat exchanger 12 via a first inlet 24. As a result of the arrangement of the heat exchange plates 22 and gaskets 16, the first fluid is configured to flow through gaps between alternating sets of heat exchange plates 22 and exits the plate heat exchanger 12 via a first outlet 26. In addition, a second fluid may be introduced to the plate heat exchanger 12 via a second inlet 28. As a result of the arrangement of the heat exchange plate 22 and gaskets 16, the second fluid is configured to flow through gaps between alternating sets of heat exchange plates 22 and exits the plate heat exchanger 12 via a second outlet 32.

[0023] As shown in FIG. 1 , the plate heat exchanger 12 may include tens or hundreds of heat exchange plates 22 and gaskets 16. In order to retain the heat exchange plates 22 and gaskets 16 in alignment, the plate heat exchanger 12 may include upper and lower support beams 40 and 42.

[0024] To compress the gaskets 16 between the heat exchange plates 22, the plate heat exchanger 12 may include threaded spindles 44A and 44B configured to pass through an end support 46 having respective threaded nuts 48A and 48B. The threaded spindles 44A and 44B are configured to transmit the compressive force to the follower 18 via respective sockets 50A and 50B. When attached to the plate heat exchanger 12 as shown in FIG. 2, the closure unit 14 is configured to rotate the threaded spindles 44A and 44B and, via the translation of the threaded spindles 44A and 44B through the threaded nuts 48A and 48B, the follower 18 is urged towards the head 20. The threaded spindles 44A and 44B are captured with respect to the sockets 50A and 50B which are affixed to the follower 18. As such, opposite rotation of the threaded spindles 44A and 44B is used to open the plate heat exchanger 12. Not shown in FIGS. 1 and 2, it is well known that additional bolts may be engaged between the head and follower to reduce the deflection of these end plates and reduce the stress on the spindles under fluid operating pressures.

[0025] The closure unit 14 includes a power unit 52 and a drive mechanism 54. The drive mechanism 54 is disposed within a sanitary housing 56. The drive mechanism 54 includes a hydraulic motor 58 and linkage 60 (shown in FIGS. 3 and 4). The power unit 52 includes a motor 62, hydraulic pump 64, hydraulic reservoir 66, and a user interface 68. The motor 62 may include any suitable actuator or device for generating power or torque to power the hydraulic pump 64. In general, the motor 62 may include any suitable electrically, pneumatically, or combustion driven motor. In a particular example, the motor 62 is an electrical motor and the power unit 52 includes a power source such as batteries or a power cord 70. In order to convey the hydraulic power from the power unit 52 to the drive mechanism 54, the plate heat exchanger system 10 may include one or more hydraulic lines. In a particular example, the closure unit 14 includes a pair of hydraulic lines 72 and 74. A quick release-type fitting 76 may be included at one or both ends of each of the hydraulic lines 72 and 74.

[0026] The user interface 68 is configured to receive input from a user and/or display information to the user. Examples of types of input the user interface 68 is configured to receive and/or display include an open command, close command, linear position of the follower 18, set linear position for the follower 18, load on the follower 18, set load on the follower 18, and/or visual feedback of system operation such as a light, and the like. To determine the linear position of and/or the load on the follower 18, the plate heat exchanger system 10 may include one or more sensors 78A and 78B. In various embodiments, the sensors 78A and 78B are each separately configured to sense a linear location of the follower 18, and/or a load exerted upon the follower 18. The one or more sensors 78A and 78B may include mechanical sensory, micro- switches, optical, proximity, laser or ultrasonic distance sensors, and the like. In various examples, the sensors 78A and/or 78B may be configured to communicate with the power unit 52 via a wire or wirelessly such as WiFi or Bluetooth. In a particular example, the plate heat exchanger system 10 includes a data line 80 configured to convey signals between the sensors 78A and 78B, the drive mechanism 54, and the power unit 52.

[0027] According to various embodiments, the power unit 52 may be detachably connected to the drive mechanism 54, non-detachably connected to the drive mechanism 54, mounted on the drive mechanism 54, or disposed within the housing 56. In an embodiment in which the power unit 52 is detachably connected to the drive mechanism 54, a number of benefits may be realized such as, for example: a single power unit 52 may be used to power more than one drive mechanism 54 - saving money, floor space may be increased and the work area may be de-cluttered by storing the power unit 52 in an out of the way location during use of the plate heat exchanger 12, servicing of the power unit 52 may be performed away from the production floor, and the like.

[0028] It is an advantage of the plate heat exchanger system 10 that the drive mechanism 54 is suitable for sanitary clean in place operations. In addition, the drive mechanism 54 may be coupled or decoupled to/from the plate heat exchanger 12 while the plate heater exchanger 12 is operating. That is, even while the plate heat exchanger 12 is actively exchanging heat between fluids, the drive mechanism 54 may be coupled to the plate heater exchanger 12. It is therefore an advantage of some embodiments that the plate heater exchanger 12 can be upgraded with no downtime.

[0029] In addition, as described herein, the linkage of the drive mechanism 54 provides an even tightening of the spindles 44A and 44B. That is, the closure unit 14 provides simultaneous and synchronous tightening of the spindles 44A and 44B. Synchronization is important to prevent uneven tightening and possible binding. [0030] As described in greater detail herein, the plate heat exchanger 12 is maintained and/or inspected by periodically opening the plate heat exchanger 12 by moving the follower 18 away from the head 20 to inspect the heat exchange plates 22 and gaskets 16. Thereafter, the plate heat exchanger 12 is closed for use by moving the follower 18 towards the head 20 to re-compress the gaskets 16 between the heat exchange plates 22. In order for the plate heat exchanger 12 to work properly, the gaskets 16 must be compressed sufficiently but not overly compressed. It is an advantage of aspects described herein that opening and/or closure operations may be performed automatically. That is, upon receiving user instructions to open and/or close, the closure unit 14 may be configured to automatically move the follower 18 accordingly and stop the movement of the follower 18 at the appropriate point of travel.

[0031] With respect to this auto-stop feature, the closure unit 14 is designed to provide automatic power disengagement at the correct closed plate pack pitch, avoiding the need for manual measurement and possible over or under tightening. In addition, the closure unit 14 is designed to provide automatic power disengagement at the desired open dimension permitting plate inspection and/or removal. The automation of this power disengagement function permits the operator to perform other useful work during opening and closing rather than attend to the plate heat exchanger 12.

[0032] It is yet a further advantage that the closure unit 14 can be retrofitted to an existing plate heat exchanger even while the plate heat exchanger is performing its duty. Thus no disruption to production is necessary. It is also simple enough for customer's maintenance personnel to fit, avoiding the need for specialist and expensive assembly personnel. The closure unit 14 is light enough to be installed onto a plate heat exchanger with two or three people. This avoids the need for overhead or moveable rigging for which there is often little or no room. [0033] FIGS. 3 and 4 are views of the drive mechanism 54 according to an embodiment of the invention. As shown in FIG. 3, the drive mechanism 54 includes the hydraulic motor 58 fluidly coupled to the pair of hydraulic lines 72 and 74. Also shown in FIG. 3, the drive mechanism includes a bearing 90 mounted in the housing 56. As shown in FIG. 4, the drive mechanism 54 includes a pair of drive sockets 92 and 94 configured to couple with respective ends of the threaded spindles 44A and 44B. Alternatively single, coaxial hydraulic coupling may be employed.

[0034] The drive socket 94 is affixed to a drive shaft of the hydraulic motor 58 and, in response to rotation of the hydraulic motor 58, the drive socket 94 is driven or otherwise urged to rotate. The linkage 60 is configured to transfer torque from the hydraulic motor 58 to the drive socket 92. In this regard, the linkage 60 includes a series of sprockets or pulleys linked via a chain or belt respectively. In the particular example shown, the linkage 60 includes a sprocket 96 affixed to the drive shaft of the hydraulic motor 58, a sprocket 98 rotationally affixed to the drive socket 92, a tensioning sprocket 100 and a chain 102 to lock the sprocket 98 in rotational alignment with the sprocket 96. Alternatively, the hydraulic motor 58 may be disposed between the pair of drive sockets 92 and 94 and linkage 60 used to transmit torque to both the drive sockets 92 and 94.

[0035] The drive mechanism 54 optionally includes a data chip 82 operable to intercommunicate with the power unit 52. If included, the data chip 82 may include any suitable data pertaining to the plate heat exchanger 12. For example, the data chip 82 may include the current position of the follower 18, the last position reached by the follower 18, the compressed pitch design for the plate heat exchanger 12, the fully opened position, arrangement of the heat exchange plates 22, number of the heat exchange plates 22, thickness and number of grids, and the like. The data chip 82 may be powered via the data line 80. It is an advantage of embodiments that include the data chip 82 that data specific to the plate heat exchanger 12 is retained on the plate heat exchanger 12. As such, the power unit 52 may be moved from one plate heat exchanger to another without the need to input this data. In this manner, data input error may be reduced and ease of use increased.

[0036] FIG. 5 is a system architecture for the plate heat exchanger system 10 according to an embodiment of the invention. As shown in FIG. 5, the plate heat exchanger system 10 includes a controller 110. The controller 110 is configured to receive input from the user interface 68 and send signals to the user interface 68 for display. In addition, the controller 1 10 is configured to receive signals from one or both of the sensors 78A and 78B. The controller 1 10 is further configured to modulate the motor 62. For example, in response to signals from the user interface requesting the plate heat exchanger 12 be opened, the controller 110 may send signals to the motor 62 to rotate in a first direction. This rotation of the motor 62 generates hydraulic power in the hydraulic pump that is conveyed to the hydraulic motor 58 which is urged to rotate and draw the follower 18 away from the head 20.

[0037] The controller 1 10 is configured to intercommunicate with a memory 1 12. The memory 112 is configured to store data received from the controller 1 10. For example, the memory 112 may store plate heat exchanger IDs, sensor readings, dates, set tension levels, set linear location values, and the like. With regard to the plate heat exchanger IDs, in an embodiment of the invention, each plate heat exchanger 12 may include a unique ID so that, when the power unit 52 is connected to the drive mechanism, the plate heat exchanger ID is provided to the power unit 52. In this manner, set loads and/or linear positions of the follower 18 may be stored and recalled. In a particular example, these values may be stored to a file 1 14 and/or used to control the closure unit 14 to open and/or close the plate heat exchanger 12.

[0038] According to an embodiment of the invention, the controller 110 is configured to execute a code 1 16. In this regard, the controller 1 10 is configured to access the memory 1 12 and execute a set of computer readable instructions contained in the code 1 16. According to the code 116, the controller 1 10 is configured to modulate the motor 62 in response to instructions from the user interface 68. For example, in response to the user instructing the controller 1 10 to open or close the plate heat exchanger 12, the controller 1 10 is configured to modulate the motor 62 and automatically stop the motor 62 in response to the follower 18 being moved to a predetermined position and/or a predetermined amount of pressure being applied to the follower 18. In addition, the controller 110 may be configured to generate and store data to the file 114.

[0039] Based on the set of instructions in the code 1 16 and signals from one or more of the sensors 78A and 78B, the controller 1 10 is configured to: determine the position and/or load on the follower 18; determine the set position and/or load on the follower 18; determine a max load not to be exceeded; stop the movement of the follower 18 by stopping the motor 62 in response to the position or load on the follower reaching the max values or the set values; bypass the hydraulic fluid; and/or the like. In this manner, based on instructions from the user via the user interface 68, the controller 110 may be configured to automatically stop at the open and/or closed preset positions and/or loads.

[0040] Furthermore, in various embodiments of the invention, the plate heat exchanger system 10 may include a network 1 18 configured to intercommunicate with the controller 1 10. The network 118 may include, for example, a database, server, and a multitude of other networked devices. In this regard, the network 1 18 may include a local area network (LAN), wide area network (WAN), wireless network, the Internet, and the like.

[0041] FIG. 6 is a system architecture for the controller 1 10 suitable for use in the plate heat exchanger system 10 according to FIG. 1. As shown in FIG. 6, the controller 110 includes a processor 120. This processor 120 is operably connected to a power supply 122, memory 124, clock 126, analog to digital converter (A/D) 128, and an input/output (I/O) port 130. The I/O port 130 is configured to receive signals from any suitably attached electronic device and forward these signals to the A/D 128 and/or the processor 120. For example, the I/O port 130 may receive signals associated with a position and/or load sensed by the sensors 78A and/or 78B and forward the signals to the processor 120. If the signals are in analog format, the signals may proceed via the A/D 128. In this regard, the A/D 128 is configured to receive analog format signals and convert these signals into corresponding digital format signals. Conversely, the A/D 128 is configured to receive digital format signals from the processor 120, convert these signals to analog format, and forward the analog signals to the I/O port 130. In this manner, electronic devices configured to receive analog signals may intercommunicate with the processor 120.

[0042] The processor 120 is configured to receive and transmit signals to and from the A/D 128 and/or the I/O port 130. The processor 120 is further configured to receive time signals from the clock 126. In addition, the processor 120 is configured to store and retrieve electronic data to and from the memory 124. Furthermore, the processor 120 is configured to determine signals operable to modulate the motor 62 and control a flow direction of the hydraulic fluid. In this manner, the hydraulic motor 58 is controlled to rotate in a particular direction and or exert a particular force which, in turn, is eventually translated to the follower 18.

[0043] According to an embodiment of the invention, the processor 120 is configured to determine the position and/or load on the follower 18; determine the set position and/or load on the follower 18; determine a max load not to be exceeded; stop the movement of the follower 18 by stopping the motor 62 or bypassing the hydraulic fluid in response to the position or load on the follower reaching the max values or the set values; and/or the like. In addition or alternatively, the processor 120 may be configured to determine a load on the follower 18 based on an amount of resistance provided by the motor 62 or hydraulic motor 58. [0044] However, it is to be understood that the functions of processor 120 and the controller 1 10 may be subsumed within the processor 120. For example, it is within the scope of various embodiments of the invention that one or both of the sensors 78A and 78B may be configured to intercommunicate with the processor 120. Furthermore, in these various embodiments of the invention, the processor 120 may be configured to modulate the hydraulic pump 64 to vary the load upon the follower 18 in a manner similar to that ascribed to the controller 1 10 and described herein.

[0045] FIG. 7 is an isometric view of a hand operated directional control valve 140 according to another embodiment of the invention. As shown in FIG. 7, the hand operated directional control valve 140 is suitable for use with the power unit 52. As is generally known, the hand operated directional control valve 140 includes a three position, user operated, handle suitable for controlling the flow of hydraulic fluid in the power unit 52. In a particular example, the hand operated directional control valve 140 is biased in a neutral position 142 and includes a close position 144 and an open position 146. The close position 144 is configured to control the flow of hydraulic fluid such that the hydraulic motor 58 urges the follower 18 towards the head 20. The open position 146 is configured to control the flow of hydraulic fluid such that the hydraulic motor 58 urges the follower 18 away from the head 20.

[0046] Optionally, a rod (not shown) may be affixed to the plate heat exchanger system 10 and configured to 'bump' the hand operated directional control valve 140 from the close position 144 to the neutral position 142. In this manner, the hand operated directional control valve 140 may be used to automatically close the plate heat exchanger 12.

[0047] FIG. 8 is an isometric view of a retractable spool 150 suitable for use with the embodiment of FIG. 7. The retractable spool 150 is eccentrically located onto a pivoted rotating plate (not shown) such that, at full cable extension, the retractable spool 150 will force the pivot plate to rotate. The pivot plate is installed inside the power unit 52 so that slight rotation will 'bump' the handle of the hand operated directional control valve 140 from the open position 146 to the neutral position 142 thereby stopping the follower 18 movement. The free end of retractable spool 150 is attached to the outside of the end support such that at full cable extension, the follower 18 will be at the desired open position.

[0048] The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.