Dewatering press for dewatering laundry

Abstract

The invention provides a dewatering press with which laundry can be treated in a time- and energy-efficient and space-saving manner. This is achieved by a dewatering press (11) for dewatering laundry (10) comprising a press basket (17) for receiving the laundry (10) and a press ram (13) which is movable up and down by at least one hydraulic cylinder (24) and can be retracted into the press basket (17) from above when moving downwards. Furthermore, the hydraulic cylinder (24) is arranged in a press cylinder (12). The invention also provides that the dewatering press (11) comprises a main cylinder (24) and a pressure intensifier (26), wherein the main cylinder (24) and the pressure intensifier (26) are integrated into the press cylinder (12).

Description

[0001] The invention relates to a dewatering press according to the preamble of claim 1. Furthermore, the invention relates to a dewatering press according to the preamble of claim 12 and a dewatering press according to claim 14.

[0002] Laundry undergoes various treatment steps in industrial laundries. After washing in a washing machine, the remaining liquid, known as the bound liquor, must be removed from the laundry for further processing. For this purpose, the laundry is fed into a dewatering unit, such as a centrifuge or a dewatering press. In the dewatering unit, particularly in the dewatering press, not only is the laundry separated from the bound liquor, but the laundry can also be rinsed in the press before dewatering takes place.

[0003] In a dewatering press for removing water from laundry, the laundry is gathered in a press basket. A lifting cylinder or hydraulic cylinder, mounted on columns above this press basket, contains a press ram that dewaters the laundry within the press basket. The compression of the laundry in the press basket creates a laundry cake, which must be broken up for subsequent processing steps.

[0004] Dewatering presses themselves require a relatively large amount of space. This is due, firstly, to the need to process as large a quantity of laundry as possible per dewatering cycle, and secondly, to the extremely high pressures, which necessitate a high degree of stability in the individual components and thus a very robust construction. Since space is limited, especially in laundries, larger systems prove to be too space-intensive or problematic.

[0005] Hydraulic cylinders with a maximum internal pressure of approximately 350 bar are used for the rapid dewatering of laundry in a dewatering press. Depending on the ratio of the piston area of ​​the hydraulic cylinder to the piston rod, a force is generated that acts on the laundry and dewaters it. The greater the force acting on the laundry, the lower the residual moisture content, which then needs to be evaporated in a dryer. Therefore, reducing the residual moisture in the press leads to overall energy savings in laundry processing. However, further reduction of residual moisture is only possible by increasing the pressure, which would require even larger dewatering presses.

[0006] Another disadvantage of conventional dewatering presses is that they use axial piston pumps with constant rotational speeds to build up pressure. The use of these pumps limits the pressure build-up rate, inevitably resulting in a short dewatering time compared to the total piston movement cycle. Furthermore, high current peaks occur, making the entire dewatering process extremely energy-intensive. Therefore, the use of conventional dewatering presses is very time-consuming and expensive.

[0007] Based on these disadvantages, the present invention aims to create a dewatering press with which laundry can be treated in a time- and energy-efficient and space-saving manner.

[0008] A solution to this problem is described by claim 1. Accordingly, the dewatering press for dewatering laundry comprises a press basket for receiving the laundry and a press ram that is movable up and down by at least one hydraulic cylinder and can be retracted into the press basket from above when moving downwards. Furthermore, the hydraulic cylinder is arranged within a press cylinder. The invention also provides that the dewatering press comprises a main cylinder and a pressure intensifier, the main cylinder and the pressure intensifier being integrated into the press cylinder. While the main cylinder is comparable to a known cylinder for dewatering laundry, the pressure intensifier is a component that increases the pressure exerted on the laundry for dewatering. Since this additional pressure intensifier is integrated into the press cylinder, the size of the press cylinder changes.The dimensions of the dewatering press are only marginally affected. Therefore, it is possible to exert higher pressure on the laundry with an unchanged press ram, without increasing the size of the dewatering press. Similarly, it is conceivable that, for an identical hydraulic pressure compared to known dewatering presses, the size of the press can be reduced by using a pressure intensifier.

[0009] Preferably, the pressure intensifier also includes at least one hydraulic cylinder. This additional hydraulic cylinder can be easily integrated into the existing hydraulic system of the dewatering press. Due to the axial design of the press cylinder, the additional hydraulic cylinder can be readily incorporated into the existing design without requiring major modifications.

[0010] In particular, the pressure intensifier is designed to comprise at least two, three, or more hydraulic cylinders. These ideally two or three hydraulic cylinders are interconnected and controllable. Their dimensions are preferably identical to, and smaller than, the main cylinder.

[0011] A particularly preferred embodiment of the invention provides that the piston area of ​​the at least one hydraulic cylinder of the pressure intensifier is smaller than the piston area of ​​the main cylinder. In particular, the piston area of ​​the hydraulic cylinder of the pressure intensifier is between 1 / 10 and 1 / 2, preferably 1 / 5 and 2 / 5, and more specifically 1 / 3, of the piston area of ​​the main cylinder. This reduction in piston area, while maintaining the same force acting on the cylinder, increases the internal pressure from, for example, the original 350 bar to 500 bar (with an exemplary area ratio of 1:1). The at least one hydraulic cylinder is activated when the system pressure reaches, for example, the original maximum value of 350 bar.This subsequent use of additional, smaller hydraulic cylinders proves particularly advantageous, as at the end of the pressing process, under the increased pressure of the cylinder, a very short cylinder stroke is sufficient to significantly reduce the residual moisture.

[0012] Furthermore, it is preferably provided that the sum of the piston areas of the multiple, preferably two, three or more, hydraulic cylinders of the pressure intensifier is between 1 < 10 and 1 / 2, preferably 1 < 5 and 2 < 5, and in particular 1 / 3, of the piston area of ​​the main cylinder. The use of multiple hydraulic cylinders allows them to be integrated into the existing press cylinder in a particularly space-saving manner. In particular, the dimensions of the individual cylinders can be selected to adapt well to the existing conditions. Likewise, by selecting the number and areas of the cylinders, a pressure intensification can be created that is particularly suitable for the efficient reduction of residual moisture.

[0013] Furthermore, it is preferable that the multiple, preferably two, three or more, hydraulic cylinders of the pressure intensifier are arranged symmetrically and / or concentrically around a longitudinal axis of the press cylinder. Likewise, the individual cylinders can be particularly advantageously coupled to the existing hydraulic system, especially the inlets and outlets. Integrating the cylinders into the press cylinder means that virtually no additional installation space is required for the dewatering press, while simultaneously increasing the pressure applied to the laundry for dewatering.

[0014] Preferably, the press cylinder has at least two pressure chambers and at least two return chambers: one pressure chamber and one return chamber for the main cylinder, and one pressure chamber and one return chamber each for the hydraulic cylinder(s) of the pressure intensifier. In particular, the pressure chamber of the main cylinder is connected to the at least one return chamber for the hydraulic cylinder(s) of the pressure intensifier. As soon as the pressure intensifier is activated, i.e., when pressure builds up in the return chamber of the hydraulic cylinder, the pressure in the pressure chamber of the main cylinder also increases. Consequently, the pressure exerted on the laundry also increases, further reducing residual moisture.

[0015] The invention provides, in particular, that the pressure chamber and the return chamber of the main cylinder each have a valve, and that the pressure chamber of the at least one hydraulic cylinder of the pressure intensifier also has a valve through which the inflow and outflow of hydraulic fluid can be controlled. According to this embodiment, it is provided that the pressure in the pressure chamber of the main cylinder is first increased to a maximum value via the corresponding valve. During this time, the valve for the supply line to the pressure chamber of the hydraulic cylinder is closed. As soon as the maximum pressure in the pressure chamber of the main cylinder is reached, the corresponding valve of the main cylinder is closed, and the pressure is applied to the pressure chamber of the hydraulic cylinder. This pressure is then increased by the hydraulic cylinder in the pressure chamber of the main cylinder, and thus also the pressure on the laundry.After the drainage process is complete, the valves are opened and both the main cylinder and the hydraulic cylinder are returned to their starting position.

[0016] A special embodiment of the invention may provide that the inlets and outlets are connected to at least one hydraulic pump.

[0017] Another solution to the aforementioned problem is achieved by the features of claim 12. Accordingly, a dewatering press for dewatering laundry is provided with a drive for moving the at least one hydraulic cylinder up and down, wherein this drive is designed as a hydrodynamic servo pump. The use of the servo pump allows the operation of the hydraulic cylinder or main cylinder to be very energy-efficient. Generally, little energy is required to start the press ram, which is why this process can be carried out quite quickly by the servo drive or servo pump. Once the press ram compresses the laundry and pressure is exerted on it, less energy is required. Ultimately, the press ram only needs to be held in this position. That is to say,The pressure generated by the servo pump, and thus the electrical load, can be controlled depending on the mechanical resistance exerted on the press ram by the laundry. While in known dewatering presses the hydraulic cylinder is constantly subjected to a high force, according to the present invention, the pressure is applied depending on the actual pressure exerted on the press ram. This saves both energy and time. In particular, the faster movement of the press ram into the dewatering position results in time savings compared to previous technology.

[0018] It is also preferably provided that the dewatering press has two, three or four hydraulic cylinders, each hydraulic cylinder having a hydrodynamic servo pump or being connected to a hydrodynamic servo pump.

[0019] Another solution to the aforementioned problem is described by the features of claim 14. Accordingly, it is provided that a dewatering press has both the features according to at least one of claims 1 to 11 and the features according to at least one of claims 12 and 13.

[0020] A preferred embodiment of the present invention is explained in more detail below with reference to the drawing. This shows: Fig. 1 is a schematic representation of a dewatering press, and Fig. 2 is a side view of the dewatering press according to Fig. 1 .

[0021] In industrial laundries, 10 dewatering presses 11 are used to remove a bound liquor from washed laundry. The in Fig. 1The dewatering press 11, shown schematically, has a press cylinder 12, inside which a piston of a main cylinder 24 with a press ram 13 is arranged. The press ram 13 can be moved up and down along the longitudinal axis of the press cylinder 12.

[0022] At the in Fig. 1 In the illustrated dewatering press 11 according to the invention, the press cylinder 12 is directly connected to columns 15 via a cylinder flange 14. In the embodiment shown here, the cylinder flange 14 is attached to a column at each corner. However, it is also conceivable that the cylinder flange 14 is attached to fewer or more columns. The columns 15 are attached to a plate 16 at an end opposite the cylinder flange 14. This plate 16 serves as the base element of the dewatering press 11.

[0023] A press basket 17 is arranged in the interior of the dewatering press 11, which is defined by the columns 15. This press basket 17 can, for example, be designed as a hollow cylinder and serves to hold the laundry 10 to be dewatered. In the exemplary embodiment shown here, an outer dimension, or the diameter, of the press basket 17 is larger than the distance between the columns 15. Therefore, the wall of the press basket 17 projects into the area of ​​the columns 15. The press basket 17 shown here has a funnel-shaped loading aid 18 for easy and quick filling with laundry 10.

[0024] The press basket 17 is positioned in the dewatering press 11 such that the press ram 13 can be lowered precisely into the press basket 17. By lowering the press ram 13 into the press basket 17 and by pressurizing the laundry 10 through a membrane 19 arranged on the press ram 13, the bound liquor is forced out of the laundry 10, so that a cylindrical laundry cake 20 forms in the press basket 17.

[0025] To remove the laundry cake 20, the press ram 13 is first lifted from the laundry cake 20 and the press basket 17 is moved upwards. The laundry cake 20, thus released, is then conveyed from the dewatering press 11 by a conveyor 21 in a conveying direction 22. The laundry cake 20 can be fed from the conveyor 21 to a further processing unit for further treatment. The conveyor 21 could, for example, be a belt conveyor or the like.

[0026] Since the laundry cake 20 formed by the dewatering press 11 described here has a larger diameter than the clear distance between the columns 15, the laundry cake 20 cannot be easily conveyed by the conveyor 21. To enable the laundry cake 20 to pass the columns 15, it is broken up in the dewatering press 11 by radial compression. This radial compression is achieved by compression elements 23. These compression elements 23 are designed as compression plates and are arranged between two columns 15 parallel to the conveying direction 22. Fig. 2 ). The compression means 23 are located on two opposite sides of the laundry cake 20 and are aligned parallel to each other in the embodiment shown here.

[0027] To radially break up the laundry cake 20, the compression elements 23 can be moved towards each other by linear drives transverse to the pressing and conveying direction 22. The laundry cake 20 located between the compression elements 23 is thus broken up and its diameter reduced so that it can be conveyed away through the columns 15.

[0028] To prevent the broken-up laundry cake 20 from getting caught on the columns 15 or falling off the conveyors 21 when being conveyed from the dewatering press 11, guide plates 25 are provided. These guide plates 25 are also plate-like and can serve as an extension of the compression elements 23. Preferably, such guide plates 25 are only provided to the columns 15 in the conveying direction 22.

[0029] To further reduce the residual moisture in the laundry 10, the pressure exerted on the laundry 10 must be increased. The invention provides for this purpose by supplementing the dewatering press 11 with a pressure intensifier 26. This pressure intensifier 26 makes it possible to increase the achievable pressure to such an extent that the residual moisture can be significantly reduced, without modifying the press ram 13. The pressure intensifier 26 is integrated into the press cylinder 12, so that only minor structural modifications to the existing system are required, and no additional installation space is needed for the dewatering press 11.

[0030] In the Fig. 2The drainage press 11 with the pressure intensifier 26 is shown in a highly schematic form. The pressure intensifier 26 and its associated components are partially depicted in a sectional view. It should be emphasized that these figures serve only for illustrative purposes and do not represent a construction plan that meets the requirements of a technical drawing.

[0031] The press cylinder 12 conventionally includes the main cylinder 24. To apply the necessary pressure to the laundry 10, hydraulic fluid is conveyed into a pressure chamber 28 via a valve 27. The hydraulic fluid is pressurized by a unit 29 (shown here only schematically) and conveyed through the valve 27 towards 30. Corresponding hydraulic hoses are located between the unit 29 and the press cylinder 12, but these are not shown here for clarity.

[0032] By applying the appropriate pressure to the pressure chamber 28, the main cylinder 24 is moved towards the washing unit 10, causing the press ram 13 to lower onto the washing unit 10 and drain it. Once the draining process is complete, hydraulic fluid is conveyed through a valve 31 into a return chamber 32 of the main cylinder 24. This also occurs via the hydraulic hoses (not shown) through the unit 29.

[0033] According to the invention, this conventional drainage process is now supplemented by the action of the pressure intensifier 26, namely, in the case of the Fig. 2In the illustrated embodiment of the dewatering press 11, three further identical hydraulic cylinders 33 are located above the pressure chamber 28. It is equally conceivable that there is only one hydraulic cylinder 33 above the pressure chamber 28, or two, or more than three. It is also conceivable that these hydraulic cylinders 33 are not identical in design, but rather have different dimensions.

[0034] Each of the individual hydraulic cylinders 33 also has a return chamber 34, which is connected via an opening 35 to the pressure chamber 28 of the main cylinder 24. During the pressure build-up in the pressure chamber 28 of the main cylinder 24, the valves 36, which are connected to the return chambers 34 of the hydraulic cylinders 33, are closed. The pistons 37 of the hydraulic cylinders 33 are in the position shown in the Fig. 2The initial position shown is such that the volume of the return chambers 32 is at its maximum and the volume of the corresponding pressure chambers 38 of the individual hydraulic cylinders 33 is at its minimum. As soon as the unit 29 has built up maximum pressure in the pressure chamber 28 of the main cylinder 24, the valve 27 is closed, so that the pressure within the pressure chamber 28 is kept constant, at least briefly. Subsequently, the valves 39 of the pressure chambers 38 of the hydraulic cylinders 33 are opened, so that hydraulic fluid is conveyed from the unit 29 into the pressure chambers 38 via hydraulic hoses (not shown). Due to the smaller piston areas of the hydraulic cylinders 33 compared to the main cylinder 24, the pressure that can be built up within the return chamber 34 or the pressure chamber 28 increases for a constant force, and thus also the pressure that can be exerted on the laundry 10 by the press ram 13.This additional pressure on the laundry is sufficient to significantly reduce the residual moisture.

[0035] After the drainage process is complete, the hydraulic fluid is conveyed in the reverse direction through valves 31 and 36 into return chambers 32 and 34, so that the hydraulic fluid from pressure chambers 28 and 38 is returned to the unit 29 in the direction 40. It is conceivable that valve 36 can be omitted. In this case, the hydraulic fluid flows from pressure chamber 28 through openings 35 into return chambers 34 and pushes pistons 37 upwards, so that the hydraulic fluid from pressure chambers 38 is returned through valves 39.

[0036] By varying the number and size or shape of the hydraulic cylinders 33, the pressure transmission to the main cylinder 24 can be varied. Depending on the design of the dewatering press 11 and the dewatering requirements, different dimensions can be selected.

[0037] In a particular embodiment of the invention, the unit 29 may be a hydrodynamic servo pump. This servo pump generates and delivers precisely the hydraulic fluid pressure required at any given time to move the aforementioned components of the main cylinder 24 and the hydraulic cylinders 33. The servo pump thus operates dynamically and adjusts the fluid pressure according to the operating conditions. If a higher pressure is required, for example, when increasing the pressure in the pressure chamber 28 or 38, the pump increases the pressure, allowing the cylinders to move more quickly into the draining position due to the lack of opposing force. Once the maximum pressure has been built up in the aforementioned chambers, the servo pump reduces its output to maintain the existing pressure for a certain period of time.

[0038] By reducing the electrical power consumption of the servo pump, a significant amount of electrical energy can be saved. Possible implementations for this servo pump include a vane pump, a gear pump, a piston pump, or similar designs. These pumps are driven by a suitable motor. Due to the aforementioned operating principle, servo pumps are particularly energy-efficient and offer precise control, allowing the entire dewatering process to be carried out very quickly and energy-efficiently.

[0039] The valves 27, 31, 36, and 39 mentioned here, as well as the unit 29, which is preferably a servo pump, are controlled by a controller (not shown). This controller allows pressures to be set depending on the dewatering process. The controller regulates the pressures within the pressure chambers via the lines and valves; these pressures can change depending on the fill level in the press basket 17 and the type of laundry. By using the aforementioned servo pump, the controller can react very efficiently to various dewatering situations.

[0040] Thus, by using the pressure intensifier 26 and additionally by using the servo pump, the space requirement for the dewatering press 11 can be reduced and the entire process can be made more time- and energy-efficient. Reference symbol list:

[0041] 10 wash 36 valves 11 Drainage press 37 Pistons 12 Press cylinder 38 Printing room 13 Press die 39 valve 14 cylinder flange 40 Direction 15 column 16 plate 17 Press basket 18 Loading aid 19 membrane 20 Laundry cake 21 Supporters 22 Discharge direction 23 Compression agent 24 Master cylinder 25 Guide cheek 26 Print translator 27 valve 28 Printing room 29 Aggregat 30 Direction 31 valve 32 Return chamber 33 hydraulic cylinder 34 Return chamber 35 opening

Claims

1. Dewatering press (11) for dewatering laundry (10) with a press basket (17) for receiving the laundry (10), a press ram (13) which can be moved up and down by at least one hydraulic cylinder (24) and can be inserted into the press basket (17) from above when moving downwards, wherein the hydraulic cylinder (24) is arranged in a press cylinder (12), characterized by a main cylinder (24) and a pressure intensifier (26), wherein the main cylinder (24) and the pressure intensifier (26) are integrated into the press cylinder (12).

2. Dewatering press (11) according to claim 1, characterized by the fact that the pressure intensifier (26) comprises at least one hydraulic cylinder (33).

3. Dewatering press (11) according to claim 1 or 2, characterized by the fact that the pressure intensifier (26) comprises at least two, three or more hydraulic cylinders (33).

4. Dewatering press (11) according to any of the preceding claims, characterized by the fact thata piston area of ​​the at least one hydraulic cylinder (33) of the pressure intensifier (26) is smaller than a piston area of ​​the main cylinder (24).

5. Dewatering press (11) according to claim 4, characterized by the fact that the piston area of ​​the hydraulic cylinder (33) of the pressure intensifier (26) between 1 / 10 up to ½, preferably 1 / 5 to 2 / 5, in particular ⅓, of the piston area of ​​the main cylinder (24).

6. Dewatering press (11) according to any one of claims 3 to 5, characterized by the fact that the sum of the piston areas of the several, preferably the two, three or more, hydraulic cylinders (33) of the pressure intensifier (26) between 1 / 10 up to ½, preferably 1 / 5 to 2 / 5, in particular ⅓, of the piston area of ​​the main cylinder (24).

7. Dewatering press (11) according to claim 3, characterized by the fact thatthe several, preferably two, three or more, hydraulic cylinders (33) of the pressure intensifier (26) are arranged symmetrically and / or concentrically around a longitudinal axis of the press cylinder (12).

8. Dewatering press (11) according to any of the preceding claims, characterized by the fact that the press cylinder (12) has at least two pressure chambers (28, 38) and at least two return chambers (32, 34), namely a pressure chamber (28) and a return chamber (32) of the main cylinder (24) and one pressure chamber (38) and one return chamber (34) each for the hydraulic cylinder(s) (33) of the pressure intensifier (26).

9. Dewatering press (11) according to claim 8, characterized by the fact that the pressure chamber (28) of the main cylinder (24) is connected to at least one return chamber (34) for the hydraulic cylinder(s) (33) of the pressure intensifier (26).

10. Dewatering press (11) according to claim 8 or 9, characterized by the fact thatthe pressure chamber (28) and the return chamber (32) of the main cylinder (24) each have a valve (27, 31) and the pressure chamber (38) of the at least one hydraulic cylinder (33) of the pressure intensifier (26) also has a valve (39) through which an inflow and outflow of the hydraulic fluid can be controlled.

11. Dewatering press (11) according to claim 10, characterized by the fact that the hydraulic inlets and outlets of the hydraulic cylinder (33) are connected to at least one hydraulic pump.

12. Dewatering press (11) for dewatering laundry (10) with a press ram (13) which is movable up and down by at least one hydraulic cylinder (24) and with at least one drive (29) about which at least one hydraulic cylinder (24) is movable up and down, in particular according to one of claims 1 to 11, characterized by the fact that the drive (29) is a hydrodynamic servo pump.

13. Dewatering press (11) according to claim 12, characterized bytwo, three or four hydraulic cylinders (33), each hydraulic cylinder (33) having a hydrodynamic servo pump.

14. Dewatering press (11) for dewatering laundry (10) with a press basket (17) for receiving the laundry (10), a press ram (13) which can be moved up and down by at least one hydraulic cylinder (24) and can be inserted into the press basket (17) from above when moving downwards, wherein the hydraulic cylinder (33) is arranged in a press cylinder (12) according to at least one of claims 1 to 11 and according to at least one of claims 12 and 13.

Images