Washing facility for business and washing machine for business

Abstract

To achieve further reduction in thermal energy consumed in a washing factory, by providing technical means for reducing the amount of primary steam of a boiler 51 installed in a washing factory.SOLUTION: The heat of primary drain discharged from a post-processing machine 53 for performing post processing such as drying, wrinkle removal and the like of an object to be washed using primary steam as a heat source is directly supplied to a drain heat exchanger 6 or a drain heater 6a for heating washing water, and heats the washing water in a tub transiting to a main washing step from a preliminary washing step of a washing machine 1, for example, a preliminary wash final tub a2, a main wash first tub b1, or a tub provided between the preliminary wash tub (a) and a main washing tub (b). By installing a flash steam generator 52, the washing water is heated by two stages by the generated flash steam and discharged secondary drain.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the use of steam energy in laundry facilities equipped with commercial washing machines, and to a technology for reducing energy consumption in laundry factories. [Background technology]

[0002] In laundry factories, the main types of commercial washing machines used are tunnel washing machines and batch washer-extractors. Tunnel washing machines are used primarily to wash items commonly known as linen, such as sheets and towels used in lodging facilities and hospitals. They are equipped with multiple washing tubs arranged in a row, and wash items are transferred sequentially to each tub for the pre-wash, main wash, rinsing, and finishing processes at time intervals (cycle time) set in the controller. On the other hand, washer-extractors usually perform the pre-wash, main wash, rinsing, finishing, and spin-drying processes for one batch (a group of items washed at once) of items in a single tub.

[0003] While the cycle time of a tunnel washing machine is fixed, the time required for each washing step varies, so the number of tubs for each step is not fixed, and multiple tubs are provided for the main wash and rinsing steps. Also, since the items cannot be dehydrated between steps, the boundaries between each step, especially the pre-wash tub and the main wash tub, are not always clear, but pre-washing is usually done at a relatively low temperature (usually below 40°C) and the main wash at a high temperature (usually 60-80°C).

[0004] Commercial washing machines consume heat energy to heat the wash water, especially the laundry and water when transitioning from pre-wash to main wash. In addition, post-processing machines such as dryers that dry washed laundry and finishing machines that smooth out wrinkles use high-pressure, high-temperature primary steam generated in a boiler as a high-temperature heat source.

[0005] In laundry factories that use steam as a heat source, it is common to return the drain of the primary steam (primary drain) used in the drying and finishing process that follows the washing process to a drain tank for boiler feed water. However, because the primary drain contains a large amount of heat, the temperature of the boiler feed water drain tank may reach its boiling point, and the heat of evaporation may be discarded from the tank into the atmosphere.

[0006] To address this issue, the primary drain is passed through a flash steam generator before being returned to the boiler feedwater drain tank, and the heat contained in the primary drain is extracted as flash steam, and at the same time, it is separated into high-temperature water, the flash steam is fed into the washing machine, and the remaining high-temperature water is returned to the boiler feedwater drain tank. Alternatively, the primary drain is passed through a heat exchanger to recover heat by converting it into hot water for washing, and the drain after heat recovery is returned to the boiler drain tank.

[0007] In such laundry factories, there is a large time difference between the return of primary drains between the drying process and the finishing process when the factory starts up in the morning. The drains from the drying process, which is the process after the washing process, return quickly, but the drains from the finishing process, which is even further back, take time to warm up the finishing machine itself, and the time it takes for the laundry to flow through can be significantly delayed.

[0008] Therefore, when the cold drain from the finishing process system, which returns late, mixes with the drain from the drying process system, which has already started, the temperature of the mixed drain drops, delaying the generation of flash steam, and as a result, the amount of primary steam consumed in the washing process increases. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-97049 [Patent Document 2] Japanese Patent Publication No. 2020-51707 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-190249 Summary of the Invention [Problem to be solved by the invention]

[0010] In this way, flash steam is used to heat the wash water and items being washed during the washing process, but it is difficult to raise the temperature to the 80°C required for the main wash using flash steam alone, so it must be used in conjunction with primary steam.

[0011] The object of this invention is to further reduce the thermal energy consumed in laundry factories by more effectively utilizing the heat of primary drains discharged from equipment that uses high-temperature, high-pressure primary steam generated in boilers as a heat source in multiple stages, thereby reducing the amount of primary steam used in the entire laundry factory. [Means for solving the problem]

[0012] This invention makes it possible to reduce the thermal energy consumed in a laundry factory by using the heat of primary drain discharged from post-treatment machine 53 (53a, 53b), which uses the heat of primary steam from boiler 51 as a heat source to perform post-treatment such as drying and smoothing out clothes washed in commercial washing machine 1 (1a, 1b, hereinafter simply referred to as "washing machine").The invention makes it possible to reduce the thermal energy consumed in a laundry factory by heating the wash water during steady operation.

[0013] In this invention, the heat of the primary drain can be directly supplied to drain heat exchanger 6 or drain heater 6a, which heats the wash water, to heat the wash water. Alternatively, a flash steam generator 52 can be installed near washing machine 1, and the generated flash steam and the discharged secondary drain can be used to heat the wash water in two stages. In this case, the heat required by washing machine 1 can be used more quickly and stably by selectively using either one of dryer 53a and finisher 53b in the post-treatment unit depending on the drain temperature and the difference in discharge time of the primary drain.

[0014] The laundry facility of the present invention includes washing machine 1 and post-treatment machines such as dryer 53a and finisher 53b that use primary steam from boiler 51 to treat the washed items with steam heat.

[0015] The washing equipment of this invention is equipped with a drain heat exchanger 6 or a drain heater 6a that heats wash water using heat from the primary drain discharged from the post-treatment machine 53 as a heat source. The drain heat exchanger 6 can be installed externally, but is preferably built into the washing machine 1. The drain heat exchanger 6 or the drain heater 6a heats the wash water in a tank that transitions from the pre-wash step to the main wash step of the washing machine 1, such as the final pre-wash tank a2, the first main wash tank b1, or a tank located between the pre-wash tank a and the main wash tank b.

[0016] The drain heat exchanger 6 or the drain heater 6a provided on the outer shell 9 of the washing tub is directly supplied with primary drain, or is provided with a flash steam generator 52 that re-evaporates the primary drain, and is supplied with secondary drain discharged from the flash steam generator.

[0017] By providing a hot water tank 54 and switching the primary drain to the hot water tank 54 when the washing machine 1 does not need to heat the wash water, the heat of the hot water stored in the hot water tank 54 can be used to heat the wash water when the primary drain is not rising from the post-treatment machine 53 or to heat the washing tub when the washing machine is started in a cold state. [Effects of the Invention]

[0018] According to this invention, the primary drain discharged from post-treatment machine 53 can heat the wash water in washing machine 1 to the high temperature required for the main wash, thereby reducing the consumption of primary steam used to heat the wash water, and therefore the fuel consumption of boiler 51.

[0019] In addition, when the washing equipment is started in cold mode, the washing water and washing tub are heated using the hot water stored in the hot water tank at the end of the previous operation, and by using the primary drain of the drying process system first, the washing machine 1 can be started up more quickly when started in cold mode, thereby improving the operating efficiency of the washing equipment. [Brief explanation of the drawings]

[0020] [Figure 1] A diagram showing a tunnel washing machine according to a first embodiment of the present invention. [Figure 2] A diagram showing the steam utilization pattern of the laundry facility of the first embodiment. [Figure 3] A diagram showing a tunnel washing machine according to a second embodiment of the present invention. [Figure 4] A diagram showing the steam utilization pattern of the laundry facility of the second embodiment. [Figure 5] A diagram showing the steam utilization pattern of the laundry facility of the third embodiment. [Figure 6] A diagram similar to Figure 5, but with backwashing means for the drain heat exchanger added. [Figure 7] An explanatory diagram showing the flow path during washing (a) and backwashing (b) [Figure 8] 10 is a schematic diagram of a part of a continuous washing machine showing another example of a temperature raising means. [Figure 9] Schematic cross-sectional view of part A of the outer body of Figure 8 [Figure 10] A longitudinal cross-sectional view showing an example of a drain heat exchanger DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be further described below with reference to the drawings. In Fig. 1, which shows an embodiment of a tunnel washing machine, 1a denotes a tunnel washing machine, 2 denotes a dehydrator that dehydrates the items discharged from the tunnel washing machine 1a, 3 denotes a recovered cold water tank, 4 denotes a recovered hot water tank, 5 denotes a buffer tank that mainly stores wastewater from the main washing tank b, 6 denotes a drain heat exchanger that uses the primary drain as a heat source, 6a denotes a heater (radiator) for the drain heat exchanger 6, and 7 denotes a new water heat exchanger that heats the new water supplied to the third rinsing tank c3 by opening control valve 45 and driving pump 34, using the hot water in buffer tank 5 as a heat source. Heating the new water supplied to the rinsing tank c also increases the temperature of the hot water in the recovered hot water tank 4.

[0022] The items to be washed placed in the hopper 11 of the continuous washing machine 1a are washed in the pre-wash tanks a1 and a2, the main-wash tanks b1 to b6, the rinsing tanks c1 to c3, and the finishing tank d, and are then discharged from the outlet 12 for the items to be washed and placed in the spin dryer 2. The inner body 8 of the continuous washing machine 1a repeats oscillation and one rotation for a cycle time (usually 2 to 3 minutes) set in a controller (not shown), and the items to be washed placed in the first pre-wash tank a1 are transferred sequentially to the adjacent subsequent tank with each rotation of the inner body 8, and are then placed in the spin dryer 2 from the outlet 12. In FIG. 1, the continuous washing machine 1a and the spin dryer 2 are shown separated from each other, but in reality, the spin dryer 2 is installed adjacent to the outlet 12 for the items to be washed.

[0023] A typical continuous washing machine 1a has multiple main washing tubs b and multiple rinsing tubs c, and the wash water and rinsing water flow between the multiple tubs in either a counterflow or batch flow manner. Counterflow is a method in which the wash water flows between the tubs in the opposite direction to the direction in which the items to be washed are transported, while batch flow is a method in which the wash water is transported between the tubs together with the items to be washed. The continuous washing machine 1a shown in Figure 1 uses a batch flow method for the main washing and a counterflow method for the rinsing.

[0024] Primary steam generated in a boiler 51 (Fig. 2) can be supplied from a primary steam pipe 27 to each tank provided with an outer shell 9 of the tunnel washing machine 1a via a control valve 31 and a control valve 29 for each tank. Also, flash steam generated in a flash steam generator 52 (Fig. 2) can be supplied from a flash steam pipe 28 to the first to third main wash tanks b1 to b3 via a check valve 32 and a control valve 29 for each tank.

[0025] The continuous washing machine 1a in FIG. 1 is provided with a recovered cold water tank 3 and a recovered hot water tank 4 to separate and reuse relatively low-temperature recovered water and relatively high-temperature recovered water. Recovered cold water from the spin dryer flows into the recovered cold water tank 3 via a spin recovery pipe 15, and recovered cold water from the finishing tub d flows into and is stored in the recovered cold water tank 3 via a finishing water recovery pipe 14. Recovered hot water from the rinsing tub c1 flows into the recovered hot water tank 4 via a rinsing water recovery pipe 13. High-temperature wastewater from the main wash tub b, wastewater from the rinsing tub c1, and overflow water from the recovered hot water tank 4 and recovered cold water tank 3 flow into and are stored in the buffer tank 5. The recovered cold water tank 3 and the recovered hot water tank 4 are provided with thermometers 46, 47.

[0026] When items to be washed are added, the recovered cold water in the recovered cold water tank 3 is sent to the items to be washed hopper 11 through the cold water piping 18 and the pre-wash water piping 25 by driving the cold water pump 17. The recovered hot water in the recovered hot water tank 4 is sent to the items to be washed hopper 11 through the hot water piping 23 and the pre-wash water piping 25 by driving the hot water pump 22.

[0027] Therefore, by controlling the rotation speed or operating time of the cold water pump 17 and the hot water pump 22 when the items to be washed are added based on the detection values ​​of the thermometers 46 and 47, the temperature of the water that first comes into contact with the items to be washed can be adjusted to an appropriate value.

[0028] In the figure, T in a circle indicates a thermometer, Lv in a circle indicates a water level gauge, P in a circle indicates a pump, FM in a square indicates a flow meter, the valve symbol with a T-shaped handle is a manual valve, and the valve symbol with a T-shaped handle but a square part of the horizontal line is a control valve. The control valve that opens and closes the pipe that supplies primary condensate to the flash steam generator 52 (the valve drawn to the left of the flash steam generator 52 in Figure 2) is controlled by the controller of the flash steam generator 52, the controller of the tunnel washing machine, or an external controller. The control valve that opens and closes the pipe of the condensate heat exchanger 6 is preferably controlled by the controller of the tunnel washing machine.

[0029] Although not shown to avoid cluttering the diagram, thermometers and water level gauges are provided in the pre-wash second tank a2, which has the outer body 9, the main wash third tank b3, the rinsing first tank c1, the rinsing third tank and the finishing tank d.

[0030] The commercial washing machine of this invention is equipped with pipe fittings 43, 44 for supplying and discharging steam drain to drain heat exchanger 6, which uses steam drain (primary drain or secondary drain) as a heat source to heat the wash water in the tub as it transitions from the pre-wash process to the main wash process.

[0031] The example in Figure 1 shows a case in which the wash water in the second pre-wash tank a2 is heated by the drain heat exchanger 6 and then heated to the main-wash temperature by supplying flash steam to the first main-wash tank b1. The drain heat exchanger 6 and circulation pump 42 are installed in the circulation piping 41 connecting the bottom and top of the second pre-wash tank a2, and the circulation pump 42 is operated while secondary drain is flowing through the drain heat exchanger 6 to heat the wash water in the second pre-wash tank a2, and then heated to the main-wash temperature by flash steam in the next first main-wash tank b1.

[0032] 8 and 9, a drain heater 6a using primary drain as a heat source can be provided at the bottom of the outer body 9 of the second pre-wash tank a2 instead of the drain heat exchanger 6. That is, the drain heater 6a is provided at the bottom of the outer body 9 of the second pre-wash tank a2, and the wash water in the second pre-wash tank a2 is heated by flowing primary drain through the heater.

[0033] Figure 2 shows a laundry facility equipped with the continuous washing machine of Figure 1, in which primary steam generated in boiler 51 is supplied to dryer 53a and finisher 53b, and primary drain generated by these devices is supplied to flash steam generator 52. When the laundry factory starts up, the primary drain from dryer 53a is supplied first, and when the operation ends, the primary drain from finisher 53b stops later. Therefore, control valves Va1 and Vb1 are provided so that when there is a temperature difference between the primary drain from dryer 53a and the primary drain from the finisher, only high-temperature primary drain is supplied to flash steam generator 52, and primary drain that has not reached the required temperature is drained.

[0034] In Figure 2, Ta: Primary drain temperature from the dryer Tb: Primary drain temperature from the finishing machine Va1: Dryer drain valve Va2: Dryer drain supply valve Vb1: Finishing machine drain discharge valve Vb2: Finishing machine drain supply valve Vc: Flash steam supply valve Vd1: Drain discharge valve of drain heat exchanger Vd2: Drain heat exchanger drain on-off valve Ve: Drain bypass valve for drain heat exchanger is.

[0035] The flash steam generated by the flash steam generator 52 is supplied to the flash steam pipe 28, and can be used to heat the first main-wash tank b1 by opening the control valve 29 in Fig. 1. In addition, by opening the control valve Vd1 and closing Vd2 to drive the circulation pump 42, the secondary drain generated by the flash steam generator can be supplied to the drain heat exchanger 6 while circulating the wash water in the second pre-wash tank a2, thereby heating the wash water in the second pre-wash tank a2.

[0036] When drain heat exchanger 6 is not in use, the secondary drain flows into hot water heat exchanger 55 and heated hot water is stored in hot water tank 54 by opening control valve Vd2, and the hot water stored in this tank is supplied to the washing tub of washer-extractor 1b and to the recovered hot water tank when the tunnel washing machine is started. Of these control valves Vc, Vd1, and Vd2, Vd1 is controlled by the controller of the tunnel washing machine, but Vc and Vd may also be controlled from the flash steam generator side.

[0037] The following is an example of the procedure for heating the main wash water to 80°C using the recovered water and primary drain during steady-state operation of a tunnel washing machine.

[0038] a: The main wash wastewater recovered in the buffer tank 5 is supplied to the new water heat exchanger 7 to heat the new rinsing water from 15°C to 40°C (at this time, the temperature of the third rinsing tank c3 is approximately 50°C, the temperature of the recovered cold water is 50°C, and the temperature of the recovered hot water is 70°C). Furthermore, if the temperature of the final rinse tank c3 exceeds 50°C, wrinkles are more likely to remain on sheets, wraps, etc., so when processing these items, the temperature of the final rinse tank c3 is monitored, and if it exceeds 50°C, the heating of new rinse water by the new water heat exchanger 7 is stopped. b: Based on the detection values ​​of the thermometers 46, 47 of the recovered cold water tank and the recovered hot water tank, the rotation speed or operating time of the cold water pump 17 and the hot water pump 22 is controlled to set the temperature of the water poured into the first pre-wash tank a1 together with the items to be washed to 60°C. c: Control valve Vd1 is opened and control valve Vd2 is closed, and circulation pump 42 is operated to supply primary drain to drain heat exchanger 6, thereby heating the wash water in second pre-wash tank b2 to 60°C to 70°C. d: Open the control valve Vc to supply flush steam to the first main wash tank b1 and heat the main wash water to 70 to 80°C.

[0039] Next, the procedure from the start-up in the morning to the steady operation of the laundry equipment of the first embodiment will be described. a: Before supplying the primary drains of the dryer system and the finisher system to the flash steam generator 52, a-1: Open the control valves Va1 and Vb1 to discharge the low-temperature drain until the temperature of the primary drain reaches the set temperature (for example, 120°C) or higher. a-2: Primary drain (0.3 to 0.8 MPa) is supplied to the flash steam generator 52 from the system where the primary drain temperature has reached or exceeded the set temperature, b: The flash steam generated from the flash steam generator 52 is supplied to the continuous washing machine 1a by opening and closing the control valve Vc. c: After generating flash steam, the secondary drain (about 133°C) at low pressure (about 0.2 MPa) c-1: Heating (heat exchange) the circulating water (40-60°C) in the pre-washing tub of the continuous washing machine. c-2: The low-pressure drain (around 100°C) after heat exchange is returned to the drain recovery tank 56, d: When there is an excess of low-pressure (about 0.2 MPa) secondary drain (about 133°C) after generating flash steam or secondary drain in the flash steam generator 52, d-1: Open the control valves Ve and Vd2 to supply hot water to the hot water heat exchanger 55 and heat the water used in the tunnel washer and water washer. d-2: The generated hot water is stored in a hot water tank and used for washing. d-3: The tertiary drain (100°C or less) after heat exchange is returned to the drain recovery tank 56.

[0040] When the continuous washing machine 1a is shut down, there is no need to heat the flash steam or the pre-wash water of the continuous washing machine. However, since the primary drain from the subsequent dryer and finisher continues for about 30 minutes after the continuous washing machine stops operating, the following procedure is used to store the high-temperature water (at a temperature of 60 to 95°C) needed to start the continuous washing machine 1a and washer-extractor 1b the next morning. e-1: Close the control valves Vc, Vd1, and Vd2. e-2: Open the control valve Ve to supply the primary drain to the hot water heat exchanger 55, e-3: Automatically change the set value of the hot water temperature generated by the hot water heat exchanger 55 to generate high-temperature water of around 60 to 95°C. e-4: The generated high-temperature water is used to heat the tub and wash water when the continuous washing machine is started up the next morning, thereby reducing the energy consumption of the boiler 51 when the continuous washing machine is started up.

[0041] An example of a preferable drain heat exchanger 6 is shown in Fig. 10. The drain heat exchanger shown in the figure has a structure in which a coiled heat transfer tube 62 is inserted into a body 61, steam drain is passed through the heat transfer tube 62 side, and wash water in the washing tub is sent into the body 61 by a pump 42 to perform heat exchange. An inner tube 63 is provided to promote contact between the wash water and the heat transfer tube, restricting the flow path of the wash water, and a filter 67 is provided to prevent adhesion of dirt to the heat transfer tube 62.

[0042] The arrows in the figure indicate the flow of wash water. Wash water flows in through wash water inlet 64, passes through filter 67, passes through the gaps in heat transfer tubes 62 arranged in flow path 65 between body 61 and inner cylinder 63 from the top of inner cylinder 63, and flows out from wash water outlet 66 provided at the bottom of body 61.

[0043] The steam drain flows in through a steam drain inlet 68 , passes through the heat transfer tube 62 , and is discharged from a steam drain outlet 69 .

[0044] The water in the washing tub contains dirt such as lint that has adhered to the items being washed, detergent, etc., and if the flow path 65 around the heat transfer tube 62 is narrowed, the dirt will accumulate and block the flow path. Therefore, it is important that the drain heat exchanger shown in the figure has a structure that is easy to clean, and it has the following structural features.

[0045] The inner cylinder 63 is inserted and attached inside a flow path 65 in which the heat transfer tubes 62 are arranged, and when cleaning, the inner cylinder 63 can be easily removed to expose the heat transfer tubes 62.

[0046] In addition, a filter 67 is installed inside the wall of the inner cylinder 63 to remove lint and other debris from the wash water beforehand, preventing the gap between the heat transfer tube 62 and the inner cylinder 63 from becoming clogged with debris. The filter 67 is inserted into the inner cylinder 63 from above, making it easy to attach and detach.

[0047] By arranging the body, inner body and filter vertically, the lid can be opened even when the water inside the body has not completely drained, and the lid 70 can be easily attached and detached with a one-touch clamp.

[0048] In the first embodiment, a flash steam generator is used, but it is also possible to directly supply the primary drain to the drain heat exchanger 6 that heats the wash water in the first main-wash tank b1. Figures 3 and 4 show a second embodiment in this way. Figure 3 differs from Figure 1 only in that the drain heat exchanger 6 is provided to heat the wash water in the first main-wash tank and that no flash steam piping is provided, but otherwise is the same as Figure 1.

[0049] Tunnel washing machine 1a shown in FIG. 3 is provided with pipes 48 that detect the temperature of primary drain discharged from dryer 53a and finisher 53b using thermometers Ta and Tb shown in FIG. 4, compare the temperature with the temperature set in the controller of the tunnel washing machine, and close control valve Va1 or Vb1 and open control valve Va2 or Vb2, thereby directly supplying primary drain discharged from dryer 53a and finisher 53b at a temperature equal to or higher than the set temperature to drain heat exchanger 6.

[0050] During the period from when the items to be washed are placed in the first main wash tank b1 until the end of the cycle time, the control valves Va2 and Vb2 are opened to drive the circulation pump 42, thereby heating the wash water in the first main wash tank during that cycle time. If it is determined from the change in temperature detected by a thermometer (not shown) installed in the first main wash tank that the water cannot be heated to the specified temperature (usually 80°C) during the cycle time, the control valve 29 shown in Figure 3 is opened to introduce primary steam from the primary steam pipe 27 to heat the water to the specified temperature.

[0051] In the second embodiment, as in the first embodiment, the temperature difference in heating in the first main wash tank can be reduced by increasing the temperature of the new water supplied to the third rinsing tank c3 using the new water heat exchanger 7 and thereby increasing the temperature of the input water. By taking such measures, it is possible to heat the water to the 80°C required for the main wash using only the drain heat exchanger 6.

[0052] In the above example, a circulation pipe 41, a circulation pump 42 installed in the pipe, and a drain heat exchanger 6 are provided to heat the wash water in the pre-wash tank a2 and the main wash tank b1. However, instead of these devices, as shown in Figures 8 and 9, a drain heater 6a can be installed at the bottom of the outer body 9 of the tank to be heated, and primary drain can be supplied to the heater to heat the wash water in the tank.

[0053] The above-described embodiment is an example of a tunnel washing machine, but the present invention is not limited to a tunnel washing machine. The third embodiment described below is an example in which the present invention is applied to a laundry facility equipped with a washer-extractor 1b.

[0054] Referring to Fig. 5, which shows an example in which a flash steam generator is not provided, in the figure, 1b is a commercial washer-extractor, 8 is an inner body, 9 is an outer body, and other reference numerals are the same as in Figs. 3 and 4. As in the case of a continuous washing machine, it is provided with a drain heat exchanger 6 that heats the wash water in the tub of the washer-extractor by circulating it with a circulation pump 42. As in the continuous washing machine, the drain heat exchanger 6 can also be provided inside the housing of the washer-extractor 1b.

[0055] When the circulation pump 42 is stopped (heating is stopped), the primary drain is supplied to the hot water heat exchanger 55. When the water temperature in the hot water tank 54 is equal to or higher than the upper limit temperature, the primary drain from the finisher (roll ironer) 53b and the dryer 53a is collected in the drain collection tank 56.

[0056] In a washer / extractor, a batch of laundry is washed in the same tub, and each step of the washing process (pre-wash, main wash, rinsing, and necessary finishing) is carried out in succession over time. The washing operation in each step is explained below.

[0057] Either fresh water or hot water from the hot water tank 54, or both, is supplied up to the set water level. If the hot water temperature is below the pre-wash set temperature, only hot water is supplied. If the hot water temperature is higher than the pre-wash set temperature, fresh water and hot water are supplied simultaneously, and when the set temperature is exceeded, the supply of hot water is stopped and only fresh water is supplied. When the temperature drops to 3 to 5°C below the pre-wash set temperature, the supply of fresh water is stopped and only hot water is supplied. This operation can be repeated until the set water level is reached.

[0058] If the water level in the hot water tank falls below the lower limit, only new water is supplied. If the pre-wash temperature has not been reached after the water supply, the circulation pump 42 passes the water in the tank through the drain heat exchanger 6 and heats it up to the pre-wash temperature setting.

[0059] Add detergent when water supply starts or after water supply has started. After the set time has elapsed, the machine will move on to the next main wash process without draining the water, but if the items being washed are heavily soiled, the water will be drained after a pre-wash.

[0060] If water is drained in the pre-washing step, or if only the main washing step is carried out without the pre-washing step, water is supplied up to the set water level in the same manner as the water supply operation described in the pre-washing step.

[0061] The circulation pump 42 passes the water in the tank through the drain heat exchanger 6, and the control valves Va2 and Vb2 are opened to heat the water to the set temperature for the main wash. When the set temperature is reached, the circulation pump is stopped and the control valves Va2 and Vb2 are closed to stop heating. When the temperature drops below the set temperature, the drain heat exchanger 6 and circulation pump 42 are restarted to heat the water.

[0062] Add bleach or detergent as needed. If the set temperature is not reached within the specified time, open the control valve 33 to supply steam and heat up to the set temperature. After the set time for the main wash has elapsed, open the drain valve 49 and perform a slow spin or drain.

[0063] Only fresh water or fresh water and hot water from the hot water tank 54 is supplied up to a set water level. The rinsing temperature may be set and the water may be heated in the same manner as in the pre-wash and main wash steps.

[0064] If the rinsing process is performed multiple times, the drain valve 49 is opened after a set time has elapsed, and after performing a slow spin or drain, the second or subsequent rinsing process begins. After the final rinsing process is completed, the process moves to the final spin process.

[0065] The washing and spinning is completed by spinning at high speed.

[0066] Before the primary drains of the dryer system and the finisher system are fed to the drain heat exchanger, a: Low temperature drain is discharged until the temperature of the primary drain reaches the set temperature (for example, 120°C), b: Primary drain is supplied to the hot water heat exchanger 55 or drain heat exchanger 6 from the system where the temperature has reached or exceeded the set temperature.

[0067] Fig. 6 is a diagram showing an example in which the secondary drain discharged from the flash steam generator 52 is used as the heat source for the drain heat exchanger 6 of the third embodiment (Fig. 5), and cleaning piping for the heat exchanger is further provided, and Fig. 7 is an explanatory diagram showing the state during backwashing. The examples of Figs. 6 and 7 use a shell-and-tube type heat exchanger as the drain heat exchanger 6, and are examples in which cleaning is performed by backwashing.

[0068] During normal washing operation with drain heat exchanger 6 in operation, switching valve 72 is opened, and circulation pump 42 is operated with switching valves 73 and 74 closed, so that the wash water in the washing tub of washer-extractor 1b passes through the hatched path in Figure 7(a) and returns to the washing tub through pipe 77, thereby heating the wash water.

[0069] As washing operations are repeated, dirt such as lint accumulates inside drain heat exchanger 6, making it necessary to periodically perform backwashing to clean the inside of drain heat exchanger 6. During this backwashing, switching valve 72 is closed, switching valves 73 and 74 are opened, and circulation pump 42 is operated, causing wash water injected into the washing tub of washer-extractor 1b to flow through bypass pipes 75 and 76, hatched in Figure 7(b), and then flow in the reverse direction through drain heat exchanger 6, cleaning the inside and returning to the washing tub. This removes dirt from the inside of drain heat exchanger 6.

[0070] Such a drain heat exchanger cleaning means can be employed as a drain heat exchanger cleaning means in the continuous washing equipment described in Figures 1 to 4. In the examples of Figures 6 and 7, no switching valve is provided in piping 77 to avoid the risk of the wash water in drain heat exchanger 6 boiling due to an incorrect operation, causing the pressure to rise to the withstand pressure level of the equipment. [Explanation of symbols]

[0071] 1(1a, 1b) Commercial washing machine 6 Drain heat exchanger 6a Drain heater 9 Outer body 41 Circulation piping 43 Pipe fittings 44 Pipe fittings 51 Boiler 52 Flash Steam Generator 53 Post-processing machine 53a Dryer 53b Finishing machine 54 Hot Water Tank 55 Hot water heat exchanger 72, 73, 74 Switching valve 75, 76 Bypass piping a Prewash tank b Main washing tank a2 Prewash final tank b1 Main washing tank 1 Vc, Vd1, Vd2, Ve control valves

Claims

1. In a commercial laundry facility equipped with a washing machine and a dryer, finishing machine or other post-processing machine that processes washed items using primary steam heat generated by a boiler, a drain heat exchanger or drain heater that uses heat from primary drain discharged from the after-treatment machine as a heat source, The heat exchanger or drain heater heats the washing water in the tub of the washing machine as it transitions from the pre-wash process to the main wash process.

2. 2. The commercial laundry facility of claim 1, wherein the primary drain is supplied directly to the drain heat exchanger or drain heater.

3. 2. The commercial laundry facility according to claim 1, further comprising a flash steam generator between the post-treatment machine and the drain heat exchanger or the drain heater for re-evaporating the primary drain, and the secondary drain discharged from the flash steam generator is supplied to the drain heat exchanger or the drain heater.

4. The washing machine further comprises a hot water tank, a hot water heat exchanger that heats water stored in the hot water tank, and a control valve that switches the supply of the primary drain to the drain heat exchanger or drain heater and the hot water heat exchanger in association with the operation of the washing machine, 4. The commercial laundry facility of claim 1, wherein the control valve supplies the primary drain to the hot water heat exchanger when the water is not heated.

5. 2. The commercial laundry facility of claim 1, wherein the washing machine is a tunnel washing machine.

6. A commercial washing machine comprising: a circulation pipe having an inlet and an outlet connected to a tub that transitions from a pre-washing process to a main washing process; a circulation pump and a heat exchanger installed in the circulation pipe; a pipe fitting connected to the heat exchanger; and a controller that controls the operation and stopping of the circulation pump and the opening and closing of a control valve installed in a pipe line connected to the heat exchanger.

7. A commercial washing machine is provided with a drain heater disposed on the outer body of a tub that performs a process of transitioning from a pre-washing process to a main washing process, a pipe joint connected to the drain heater, and a controller that controls the opening and closing of a control valve installed in a pipe line connected to the drain heater.

8. In a commercial laundry facility equipped with a washing machine and a dryer, finishing machine or other post-processing machine that processes washed items using primary steam heat generated by a boiler, a drain heat exchanger that uses heat from primary drain discharged from the post-treatment machine as a heat source, and a circulation pump that circulates wash water from the washing machine through the heat exchanger, The commercial laundry equipment is equipped with two bypass pipes for flowing the discharge water of the circulation pump to the drain heat exchanger in a direction opposite to the normal direction, and a switching valve for simultaneously opening and closing the two bypass pipes.

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