Heat recovery apparatus and continuous washing machine having the same

Abstract

To provide a heat recovery device capable of controlling new water after heat exchange to a desired temperature, and a continuous washing machine including the same.SOLUTION: A tank in which warm wastewater flows, a plurality of rotors provided on a hollow rotary shaft rotatably installed in the tank, a motor that rotates the hollow rotary shaft, and a controller that controls the motor, wherein the rotor is formed to be hollow inside, a space in the hollow rotary shaft and a space of the rotor communicate with each other, the communicating spaces are configured as a flow path through which new water flows, and heat is recovered from the warm wastewater by heat exchange between the warm wastewater flowing through the tank and cold new water flowing through the flow path, the controller controls the motor to adjust the rotational speed of the hollow rotary shaft, thereby changing the amount of heat recovered from the warm drainage water.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a heat recovery device and a tunnel washing machine equipped with the same. [Background technology]

[0002] BACKGROUND ART Conventionally, a heat exchanger is known that heats fresh water by utilizing the heat of high-temperature wastewater discharged from an apparatus that requires drainage, such as a tunnel washing machine.

[0003] One known example of such a heat exchanger is one in which multiple rotors are arranged on a single rotating shaft in a tank through which hot water flows, and the rotors and rotating shaft are hollow, so that cold water flows through the rotors and rotating shaft to exchange heat with the hot water flowing in the tank (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 59-25946 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the heat exchanger described in Patent Document 1, the amount of heat recovered from the hot water in the heat exchanger is constant and not variable, so the temperature of the new water being heated is also constant, and there was a problem that the new water after heat exchange could not be controlled to the desired temperature.

[0006] The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a heat recovery device that can control the temperature of new water after heat exchange to a desired temperature, and a tunnel washing machine equipped with the same. [Means for solving the problem]

[0007] The heat recovery device according to the present invention includes a tank through which a warm fluid flows, a plurality of rotors provided on a hollow rotary shaft rotatably installed in the tank, a drive source for rotating the hollow rotary shaft, and a controller for controlling the drive source, wherein the rotor: The interior is hollow, the space inside the hollow rotating shaft is connected to the space in the rotor, and these connected spaces are configured as a flow path through which a cold fluid flows, and heat is recovered from the warm fluid by heat exchange between the warm fluid flowing in the tank and the cold fluid flowing in the flow path, and the controller is capable of changing the amount of heat recovered from the warm fluid by controlling the drive source to adjust the rotational speed of the hollow rotating shaft. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a heat recovery device capable of controlling the temperature of new water after heat exchange to a desired temperature, and a tunnel washing machine equipped with the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a tunnel washing machine equipped with a heat recovery device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing a main part of a heat recovery device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view of a heat recovery device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a front view of a rotor of a heat recovery system according to one embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view of the rotor taken along line AA in FIG. [Figure 6] FIG. 6 is a graph showing the relationship between the rotor frequency and the rising temperature of new water when heat exchange is performed between wastewater and new water in a heat recovery system according to one embodiment of the present invention. [Figure 7]FIG. 7 is a graph showing an example of transition of the fresh water outlet temperature when the rotor frequency of the heat recovery device according to one embodiment of the present invention is switched. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tunnel washing machine equipped with a heat recovery device according to one embodiment of the present invention will now be described with reference to the drawings.

[0011] As shown in FIG. 1, a tunnel washing machine 1 according to this embodiment comprises a tunnel washing machine main body 2, a heat recovery device 3, and various flow paths.

[0012] [Tunnel washing machine body] The continuous washing machine main body 2 is composed of a pre-wash zone 21 consisting of a plurality of pre-wash tubs 21A, 21B that pre-wash the items to be washed that have been inserted through the input port 20, a main wash zone 22 consisting of a plurality of washing tubs 22A, 22B, 22C, 22D, 22E, 22F that wash the items to be washed while continuously feeding them, a main wash / rinsing tub 23 that washes and rinses the items, a rinsing zone 24 consisting of a plurality of rinsing tubs 24A, 24B, 24C, 24D that rinse the items to be washed, and a processing tub 25 that processes (e.g., finishes) the items to be washed after rinsing.

[0013] The pre-washing tub 21A, washing tubs 22A, 22B, 22D, main wash / rinsing tub 23, rinsing tubs 24A, 24D, and finishing tub 25 are configured as double drums. In contrast, the pre-washing tub 21B, washing tubs 22C, 22E, 22F, and rinsing tubs 24B, 24C are configured as single drums.

[0014] In the tunnel washing machine main body 2, the sections from the pre-washing tub 21A to the main wash / rinsing tub 23 are of the batch flow type, in which the items to be washed and the water in the tubs are transferred (moved) together, while the sections from the rinsing tub 24A to the rinsing tub 24D, i.e., the rinsing zone 24, are of the counter flow type, in which the flow of the items to be washed and the flow of the water are reversed. In the counter flow type, the items to be washed are sent from the previous tub to the subsequent tub, while the water flows from the subsequent tub to the previous tub. In addition, the processing tub 25 is of the batch flow type.

[0015] Incidentally, at least high-temperature live steam, or both live steam and flash steam, are introduced into any of the plurality of tanks of the tunnel washing machine main body 2.

[0016] [Heat recovery device] As shown in FIGS. 2 and 3, the heat recovery device 3 includes a rectangular box-shaped tank 30, a plurality of rotors 31, a motor 32 as a drive source, and a controller 33.

[0017] Tub 30 is provided with a drain inlet 30a and a drain outlet 30b. Relatively high-temperature drainage water (hereinafter also referred to as "warm drainage water") from tunnel washing machine body 2 flows into tub 30 as a warm fluid through drain inlet 30a, flows through tub 30, and is discharged from drain outlet 30b.

[0018] A plurality of rotors 31 are provided at predetermined intervals in the axial direction on a hollow rotary shaft 35 that is rotatably installed in the tank 30. The intervals between the rotors 31 are not limited to a predetermined interval, and may be different from each other, for example.

[0019] The hollow rotating shaft 35 has a new water inlet 35a at one axial end through which new water flows in as a cold fluid, and a new water outlet 35b at the other axial end through which new water that has passed through the hollow rotating shaft 35 and the rotor 31 is discharged.

[0020] 4 and 5, the rotor 31 is hollow and is formed by a pair of disks 31A and 31B facing each other in the axial direction. The disks 31A and 31B are joined to each other by, for example, spot welding or a fastening member. The rotor 31 is not limited to being formed by a pair of disks, and may be formed by any configuration as long as it is hollow.

[0021] A space 31a is formed between the disks 31A and 31B of the rotor 31. This space 31a is in communication with a space 35c inside the hollow rotating shaft 35. As a result, the space 31a of the rotor 31 and the space 35c inside the hollow rotating shaft 35 form a flow path through which fresh water flows.

[0022] Fresh water flows in from the fresh water inlet 35a while the rotor 31 is rotating, flows to the radially outer periphery of each rotor 31 as shown by the broken lines in FIGS. 4 and 5, and is then discharged from the fresh water outlet 35b.

[0023] At this time, the fresh water is heated by heat exchange between the outer surface of the rotor 31 and the warm wastewater in contact with the outer surface. Note that a plurality of circular depressions 31b are formed on the outer surface of the rotor 31. By providing the circular depressions 31b, the rotor 31 increases the area of ​​the outer surface that comes into contact with the warm wastewater, thereby increasing the amount of heat exchanged. Note that the shape of the depressions 31b is not limited to a circle. Also, the depressions 31b do not have to be formed.

[0024] In this way, the heat recovery device 3 is configured to recover heat from the warm wastewater by heat exchange between the warm wastewater flowing in the tub 30 and the cold new water flowing through a flow path formed by the spaces 31a of the rotors 31 and the space 35c in the hollow rotary shaft 35. Here, in this embodiment, the flow rate of the warm wastewater flowing in the tub 30 during heat exchange in the heat recovery device 3 and the flow rate of the new water flowing through the above flow path are, for example, approximately the same. Note that the flow rates of the warm wastewater and the new water in the heat recovery device 3 are not limited to being approximately the same and are adjusted as appropriate depending on the specifications of the tunnel washing machine 1, the type of laundry to be washed, the installation environment, etc.

[0025] As shown in FIG. 1, in the continuous washing machine 1 of this embodiment, wastewater from each of the pre-washing tub 21A, washing tubs 22A, 22B, 22D, main wash / rinsing tub 23, rinsing tub 24A, 24D and processing tub 25, water overflowing from the pre-washing tub 21A, washing tub 22A, main wash / rinsing tub 23, rinsing tub 24A and processing tub 25, and wastewater from the rinse recovery tank 27 and flash tank 28 are sent to the heat recovery device 3 as warm wastewater and flow through tub 30.

[0026] In addition, in the continuous washing machine 1 of this embodiment, the fresh water that has been heated by heat exchange through the heat recovery device 3 is supplied to the pre-wash tank 21A, the rinsing tank 24D, the processing tank 25, the rinsing recovery tank 27 and the flash tank 28.

[0027] Furthermore, in the continuous washing machine 1 of this embodiment, manual valves and automatic valves are provided in each supply path to which fresh water that has been heated by heat exchange through the heat recovery device 3 is supplied, and by switching these valves on and off, the supply destination of the heated fresh water can be changed as desired.

[0028] Rinse water overflowing from the rinsing tank 24A is collected in the rinsing recovery tank 27 through a rotary screen 27a that captures lint. The rinsing water in the rinsing recovery tank 27 can be supplied to the pre-wash tank 21A, washing tanks 22A, 22B, and 22D, main wash / rinse tank 23, and rinsing tank 24A.

[0029] In the flash tank 28, water that overflows from the processing tank 25 is collected through a rotary screen 28a. The water in the flash tank 28 can be supplied to the pre-wash tank 21A, the main wash / rinse tank 23, and the rinsing tank 24D.

[0030] In addition, in the heat recovery device 3, the wastewater that has flowed through the tub 30 (see FIG. 2) and exchanged heat is discharged from the drain outlet 30b as final wastewater. The wastewater that overflows from the tub 30 is also discharged as final wastewater. Furthermore, when the operation of the tunnel washing machine 1 is completed, the wastewater remaining in the tub 30 is discharged through a drain outlet provided in a position different from the drain outlet 30b (for example, at the bottom or below the tub). This drain outlet used when the operation is completed is kept closed by an automatic valve, and can be drained by controlling the automatic valve to open, for example, at the timing when the operation is completed.

[0031] The motor 32 is mechanically connected to the hollow rotating shaft 35 and drives the hollow rotating shaft 35 to rotate. The motor 32 is electrically connected to the controller 33 and the rotation speed of the motor 32 is controlled in response to commands from the controller 33. In this way, the rotation speed of the hollow rotating shaft 35 is adjusted.

[0032] Water flow meters 41 and 42 and thermometers 51, 52, 53, and 54 are connected to the controller 33. The water flow meter 41 measures the flow rate of warm wastewater introduced into the heat recovery device 3 and outputs the measurement result to the controller 33. The water flow meter 42 measures the flow rate of new water discharged from the heat recovery device 3 and outputs the measurement result to the controller 33.

[0033] Thermometer 51 detects the temperature of the hot wastewater introduced into heat recovery device 3 (hereinafter referred to as "wastewater inlet temperature") and outputs the detection result to controller 33. Thermometer 52 detects the temperature of the hot wastewater discharged from heat recovery device 3 (hereinafter referred to as "wastewater outlet temperature") and outputs the detection result to controller 33.

[0034] Thermometer 53 detects the temperature of new water introduced into heat recovery device 3 (hereinafter referred to as "new water inlet temperature") and outputs the detection result to controller 33. Thermometer 54 detects the temperature of new water discharged from heat recovery device 3 (hereinafter referred to as "new water outlet temperature") and outputs the detection result to controller 33.

[0035] The controller 33 adjusts the amount of heat recovered in the heat recovery device 3 based on the new water inlet temperature and the wastewater inlet temperature so as to achieve a target new water outlet temperature. Here, the amount of heat recovered in the heat recovery device 3 refers to the amount of temperature rise in the new water caused by the amount of heat transferred from the warm wastewater to the new water per unit time, in other words, the amount of temperature rise in the new water per unit time. The controller 33 can adjust the new water outlet temperature by adjusting this amount of heat recovery.

[0036] Specifically, the controller 33 is equipped with an inverter (not shown) and is capable of adjusting the rotation speed of the motor 32 by changing the frequency (hereinafter referred to as the "rotor frequency") applied to the motor 32. This makes it possible to adjust the amount of heat recovered in the heat recovery device 3. In other words, by changing the rotor frequency, the controller 33 can adjust the amount of temperature rise from the new water inlet temperature to the new water outlet temperature. In this embodiment, the difference between the new water inlet temperature and the new water outlet temperature at this time, i.e., the amount of temperature rise, is referred to as the "new water temperature rise."

[0037] Here, the relationship between rotor frequency and new water rising temperature is as shown in Figure 6. Figure 6 shows the relationship between rotor frequency and new water rising temperature when the new water flow rate is a predetermined flow rate [t / H] and the wastewater inlet temperature is a predetermined temperature [°C]. In the example shown in Figure 6, the wastewater flow rate is also approximately the same as the new water flow rate.

[0038] 6, the higher the rotor frequency, the higher the rising temperature of the new water. This indicates that the amount of heat recovered by the heat recovery device 3 increases as the rotation speed of the motor 32 increases.

[0039] The controller 33 controls the rotor frequency by, for example, feedback control based on the relationship between the rotor frequency and the new water rising temperature as described above so that the new water outlet temperature becomes the target new water outlet temperature.

[0040] The target new water outlet temperature may be, for example, a temperature input by an operator via an operation input unit (not shown) connected to controller 33 in accordance with the type of laundry to be loaded into the tunnel washer 1, or it may be a temperature set based on the type of laundry obtained by monitoring in advance the type of laundry to be loaded into the tunnel washer 1. The type of laundry is monitored, for example, by inputting the detection results of a detection means (e.g., a sensor or a camera) provided in a transport device that transports the laundry to the tunnel washer into controller 33.

[0041] Next, with reference to FIG. 7, a transition of the new water rising temperature in response to switching of the rotor frequency will be described.

[0042] FIG. 7 shows an example in which the controller 33 intermittently switches the rotor frequency between a predetermined frequency [Hz] and 0 [Hz].

[0043] 7, the controller 33 can also control the new water outlet temperature by switching the rotor frequency from a predetermined frequency [Hz] to 0 [Hz]. In this embodiment, even when the controller 33 switches the rotor frequency from a predetermined frequency [Hz] to 0 [Hz], the responsiveness of the change in the new water outlet temperature is high.

[0044] [Action and effect] As described above, in the heat recovery device of this embodiment, the controller 33 controls the motor 32 to adjust the rotation speed of the hollow rotating shaft 35, thereby changing the amount of heat recovered from the warm wastewater flowing through the tank 30, and therefore the temperature of the new water after heat exchange can be controlled to the desired temperature.

[0045] If the temperature of the new water is too high, the items being washed will shrink and wrinkle during spin-drying, which can damage the items and increase the amount of finishing work required. Also, if the temperature of the new water is too high, the temperature of the pre-wash tank will also rise, which tends to make it difficult to remove protein-based stains.

[0046] In the past, to solve these problems, a separate device was provided to lower the temperature of the new water supplied to the tunnel washer by adding new water to the new water whose temperature had risen by passing through a heat recovery device that did not control rotation.

[0047] In contrast, in the heat recovery device of this embodiment, as described above, the new water after heat exchange can be controlled to the desired temperature, so for example, there is no need to add additional new water or install a separate device to lower the temperature of new water that has been raised too high by the heat recovery device, and the temperature of the new water can be adjusted with a simple configuration.

[0048] Furthermore, in the past, to increase the amount of heat recovered in a heat recovery system, it was necessary to increase the capacity of the system itself by, for example, increasing the rotor diameter or the size of the tub, but in the heat recovery system of this embodiment, the amount of heat recovered can be increased by increasing the rotation speed of the rotor 31, so there is no need to increase the rotor diameter or the size of the tub, and a compact heat recovery system can be made. This means that it can be installed below the tunnel washer, which was previously impossible, and it is possible to save space in the linen factory.

[0049] In the tunnel washing machine according to this embodiment, warm wastewater discharged from at least one of pre-wash tub 21A, washing tubs 22A, 22B, and 22D, and rinsing tubs 24A and 24D flows into tub 30 of heat recovery device 3, and fresh water heated by heat exchange in the flow path of heat recovery device 3 is supplied to at least one of pre-wash tub 21A and rinsing tub 24D. This allows efficient use of the thermal energy of the high-temperature wastewater while supplying heated fresh water to locations where relatively high-temperature fresh water is required. This allows, for example, the amount of live steam supplied to tunnel washing machine 1 to be reduced, thereby saving energy.

[0050] [Variations] In this embodiment, an example in which the heat recovery device 3 is applied to a continuous washing machine 1 has been described, but the heat recovery device 3 according to this embodiment is not limited to this and can also be applied to various devices such as a washer / extractor that require heat exchange between a fluid such as high-temperature wastewater and a low-temperature fluid.

[0051] Furthermore, the tunnel washing machine 1 of the present embodiment is an example of a tunnel washing machine to which the heat recovery device 3 is applied, and is not limited thereto. Therefore, the heat recovery device 3 of the present embodiment is not limited to the tunnel washing machine 1, and can also be applied to tunnel washing machines of other configurations.

[0052] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0053] 1 tunnel washing machine 2 Tunnel washing machine body 3. Heat recovery equipment 20 Inlet 21 Pre-wash Zone 21A, 21B Prewash tank 22 Main washing zone 22A, 22B, 22C, 22D, 22E, 22F washing machine tub 23 Main washing / rinsing tub 24 Rinse Zone 24A, 24B, 24C, 24D Rinsing tank 25 Processing tank 27 Rinse recovery tank 28 Flash Tank 30 tanks 30a Drain inlet 30b Drain outlet 31 Rotor 31a Space 31b depression 31A, 31B disc 32 Motor (drive source) 33 Controller 35 Hollow rotating shaft 35a New water entrance 35b Shinsui exit 35c space 41, 42 Water flow meter 51, 52, 53, 54 thermometer

Claims

1. A tank in which a warm fluid flows; a plurality of rotors provided on a hollow rotary shaft rotatably installed in the tank; a drive source that rotates the hollow rotary shaft; a controller for controlling the drive source, The rotor is formed to have a hollow interior, a space within the hollow rotating shaft and a space within the rotor are communicated with each other, and these communicated spaces are configured as a flow path through which a cold fluid flows; heat is recovered from the warm fluid by heat exchange between the warm fluid flowing through the reservoir and the cold fluid flowing through the flow path; The heat recovery device, wherein the controller is capable of changing the amount of heat recovered from the warm fluid by controlling the drive source to adjust the rotation speed of the hollow rotating shaft.

2. The heat recovery device according to claim 1 , wherein the controller increases the amount of recovered heat as the rotation speed of the hollow rotary shaft increases.

3. the controller is configured to be able to control the temperature of the cold fluid after heat exchange to a target temperature by controlling the rotation speed of the hollow rotating shaft; 3. The heat recovery system according to claim 2, wherein controlling the rotation speed of the hollow rotating shaft includes controlling the rotation speed of the hollow rotating shaft to zero.

4. The heat recovery device according to any one of claims 1 to 3; A pre-washing tank for pre-washing the items to be washed; A washing tub for washing the items to be washed; A rinsing tank for rinsing the items to be washed, In the heat recovery device, The tub is configured so that warm wastewater discharged from at least one of the pre-wash tub, the washing tub, and the rinsing tub flows as the warm fluid, The flow path is configured to allow fresh water to flow as the cold fluid, The tunnel washing machine is configured to supply fresh water heated by heat exchange in the flow path to at least one of the pre-wash tub and the rinsing tub.

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