RU2008989C1 - Method of cleaning parts with solvent and device for its realization - Google Patents

Abstract

FIELD: mechanical engineering, cleaning of parts. SUBSTANCE: device has reservoir for cleaning, ultrasonic generator, reservoir for keeping solvent, means for delivering the solvent in liquid state from the reservoir for keeping solvent into the reservoir for cleaning, means for removing the solvent in liquid state from the reservoir for cleaning into the reservoir for keeping solvent, condenser, and device for discharging the solvent in vaporous state into the condenser. The reservoir for keeping the solvent communicates in its top section with the condenser through connecting pipeline facilitating removal of the vaporous solvent and returning solvent condensate in the condenser into the reservoir for keeping solvent. The means for discharging the solvent in liquid state into the reservoir for keeping solvent is provided with pump. Part to be subjected to cleaning is placed in the reservoir for cleaning, the reservoir is pressure- sealed, and the solvent is delivered in the liquid state from the reservoir for keeping solvent into the reservoir for cleaning where the solvent cleans the part. After cleaning the solvent in liquid state is removed from the reservoir for cleaning into the reservoir for keeping solvent for lifting the level of the liquid solvent to facilitate forced delivery of the solvent vapors into the condenser where they are to be condensate. The condensate solvent is delivered from the condenser into the reservoir for keeping solvent through the connecting pipeline. EFFECT: extended operating capabilities. 22 cl, 22 twig

Description

 The invention relates to a method for cleaning parts with a solvent and to a device for implementing the method, in particular (but not exclusively), relates to a method for cleaning parts, such as a metal mold, porous sintered metal and an integrated circuit substrate, using an organic solvent such as Freon (trade name), trichlorethylene, etc., and a device for implementing the method.

 A device is known for cleaning parts from dirt adhering to them by means of an organic solvent. This device contains a workpiece, a cleaning tank, an ultrasonic generator mounted in this part of the cleaning tank, a solvent storage tank, means for supplying a solvent in a liquid state from a storage tank to a cleaning tank, a means for removing the solvent in a liquid state from the tank for cleaning into a storage tank, a condenser, means for removing the solvent in the vapor state into the condenser are placed in the tank for cleaning, seal after days. The solvent is supplied in a liquid state from the storage tank to the cleaning tank. After supplying the organic solvent, the part is cleaned. After the parts are cleaned with solvent, the solvent is withdrawn in a liquid state from the cleaning tank to the storage tank in order to force the solvent vapor into the condenser to compensate. After cleaning, the part is removed from the cleaning tank.

 In a conventional cleaning device when feeding and discharging an organic solvent, the escape of organic solvent vapor into the atmosphere is inevitable, which can lead to environmental pollution.

 Therefore, the aim of the present invention is to provide such a cleaning method and device for its implementation, which would during the cleaning ensure the efficient use of the solvent and prevent its leakage into the atmosphere, thereby solving the problem of preventing environmental pollution.

 To achieve this goal in accordance with the present invention, there is proposed, firstly, a method of cleaning parts with a solvent. After placing the parts to be cleaned in the tank for cleaning the latter is closed. From the solvent storage tank, the solvent is supplied to the cleaning tank. The solvent is applied to clean the part. After cleaning, the solvent in a liquid state is drained from the tank for cleaning, and the remaining solvent vapors in it are removed to a condenser to condense them. The condensed solvent is returned from the condenser to the solvent storage tank. After removal of the liquid and vaporous solvent from the cleaning tank, the cleaned part is removed from this tank.

 Secondly, in accordance with the present invention, there is provided a device for cleaning parts with a solvent, comprising a cleaning tank having a body with an open upper end and a closed bottom of a convex down form to which an ultrasonic generator is attached, and the housing of the cleaning tank is configured to receive a part to be cleaned and a cover for tightly closing the upper open end of the housing; a solvent storage tank having an upper space filled during storage of the solvent with vapor; means for supplying a solvent in a liquid state from a storage tank to a cleaning tank, means for draining a solvent in a liquid state from a cleaning tank to a storage tank; a condenser, means for removing the solvent in a vapor state into the condenser, the solvent storage tank being connected in its upper part to the condenser via a connecting pipe to allow the removal of the vapor solvent and the return of the condensed solvent to the storage tank, while the means for removing the solvent in the original The condition of the storage tank is equipped with a pump.

 In FIG. 1 shows a proposed cleaning device, a vertical section; in FIG. 2 is a modified embodiment of the cleaning device shown in FIG. 1, a vertical section; in FIG. 3 is a modified embodiment of the cleaning tank shown in FIG. 1, a vertical section; in FIG. 4 and 5 - modified versions of the combined storage tank and distiller, vertical section; in FIG. 6 is a device for supplying solvent vapor to the storage tank shown in FIG. 2; in FIG. 7 - device for supplying solvent vapor to the tank for cleaning, vertical section; in FIG. 8 and 9 are modified versions of the second distillation condenser in FIG. 2 (respectively), vertical section; in FIG. 10 and 11 are schematic views of modified versions of FIG. 1 distillation apparatus (respectively), in FIG. 12 is a control system lacking pressure in the cleaning tank shown in FIG. 2, become negative; in FIG. 13 - the body of a traditional tank for cleaning, vertical section; in FIG. 14 is a vertical section through the body of a cleaning tank used in the present invention; in FIG. 15 is a view of a modified embodiment of FIG. 2 cleaning devices with important elements, vertical section; in FIG. 16 is a view of an apparatus for preventing condensation of water in a distiller of the present invention, wherein important elements are shown in vertical section; in FIG. 17 is a view of a modified embodiment of the distiller shown in FIG. 16, with important elements, a vertical section; in FIG. 18 is a vertical sectional view of a modified embodiment of the distiller shown in FIG. 1; in FIG. 19 is a view (partially in section) of a device for preventing pulsating boiling of a liquid organic solvent in a steam generator; in FIG. 20 is a view illustrating another modified embodiment of a cleaning device; in FIG. 21 is a partial view of an improvement of the device shown in FIG. twenty; in FIG. 22 is a partial view of yet another improved cleaning device.

 The present invention is described below with reference to the accompanying drawings, in which the same reference numerals denote the corresponding parts in all numerous embodiments of the present invention, and the description of these parts, once given, is no longer repeated.

 The cleaning tank 1 with an open upper end is shown hermetically closed by means of a cover 12. The tank 1 is equipped with ultrasonic generators 11 mounted on its bottom to convey pulsations to the liquid organic solvent contained therein for efficient cleaning of the part 2 immersed in the solvent.

 At a higher level than the cleaning tank 1, there is a solvent storage tank 3 connected to the middle part of the cleaning tank 1 by a feed pipe 4 extending from its conical bottom including a solenoid valve 5. By opening the solenoid valve 5, the supply by gravity of the liquid organic solvent from the storage tank 3 to the cleaning tank 1 through the supply pipe 4. The storage tank 3 is communicated by its upper part with the intermediate part of the distillate ora 14 (or trough 21 of the condenser 16) through the connecting pipe 13, as a result of which the organic solvent in liquid and gaseous state flows from the distiller 14 into the storage tank 3, ensuring the filling of the upper space 10 of the tank 3 with pairs of organic solvent.

 The cleaning tank 1 is communicated with its lower part with the upper part of the storage tank 3 by means of a drain pipe 6, which is equipped with a solenoid valve 7 and a pump 8 for pumping liquid. When the solenoid valve 7 is open, the organic solvent is returned from the cleaning tank 1 to the storage tank 3 by activating the pump 8 for pumping the liquid.

 The distiller 14 has an evaporator 15 located in its lower part, and a condenser 16 located in its upper part. The evaporator 15 is equipped with a tube-shaped body 17 having a closed lower part for storing the organic solvent in a liquid state, and a heater 18 installed in the lower part of the body 17 for evaporating the liquid organic solvent. The condenser 16 has a tube-shaped housing 19, closed at its upper open end by a cover 12. In the housing 19, near the inner wall, a cooler 20 in the form of a coil is placed. The horizontal sectional area of the evaporator body 17 is smaller than the horizontal sectional area of the condenser body 19. The evaporator body 17 extends through the bottom of the condenser body 19, as a result of which its upper end protrudes relative to the bottom. The protruding upper end of the evaporator body 17 and the lower part of the condenser body 19 form an annular condensed solvent trough 21. The cooler 20 is located directly above the annular trough 21, as a result of which the organic solvent condensed by contacting it with the cooler 20 is fed into the trough 21 for the condensed organic solvent.

 The tank 1 for cleaning is communicated with its upper part with the intermediate part of the evaporator 15 by means of a steam discharge pipe 24 equipped with a solenoid valve 22 and a vacuum pump 23. Vapor organic solvent from the upper part of the tank 1 for cleaning is pumped by means of a vacuum pump 23 to the distiller 14, to condense it. In FIG. 1 shows an air suction pipe 25 for introducing air into the upper part of the cleaning tank 1 and a solenoid valve 26 located in the air suction pipe 25.

 To clean the part 2, open the lid 12 of the tank 1 and place the part 2 in this tank. Then, the cover 12 is closed. After that, the solenoid valve 5 is opened to ensure the supply of organic solvent from the storage tank 3 through the supply pipe 4 to the tank 1, where the part 2 to be cleaned is subjected to ultrasonic cleaning by activating the ultrasonic generators 11. After cleaning, bring action of a pump 8 for pumping liquid (the solenoid valve 7 is opened for this), for returning the liquid organic solvent to the tank 3, for storage through a drain pipe 6. To return the liquid solvent to the tank 3, the level of the liquid solvent in the storage tank 3 is increased, as a result of which the volume of the space 10 for the vaporous solvent in the upper part of the tank 3 is reduced. This leads to the displacement of the solvent vapor filling the space 10 through the connecting pipe 13 into the trough 21, through which the vaporous solvent enters the condenser 16 of the distiller 14. In the condenser 16, the vaporous solvent is cooled and condensed using a cooler 20 located on the inner wall of the condenser body 19 16. The resulting liquid solvent is collected in a trough 21 and then returned to the storage tank 3 through a connecting pipe 13.

 After the return of all the liquid solvent from the cleaning tank 1 to the storage tank 3, the solenoid valve 22 is opened and the vacuum pump 23 is activated, thereby removing the remaining solvent vapor in the cleaning tank 1 to the evaporator 15 of the distiller 14 through the steam discharge pipe 24. Vapor the solvent thus returned to the evaporator 15 flows upward along with the vapors already in the evaporator 15 into the condenser 16, where it is expected by means of a cooler 20 and collected in a condenser trough 21 solvated solvent, from where it is returned to the storage tank 3 through a connecting pipe 13.

 When the pressure sensor detects that the pressure in the cleaning tank 1 reaches a predetermined resolution level, it supplies an electrical signal representing the pressure level to a control device that, in response to this signal, closes the solenoid valve 26 for introducing air into the cleaning tank 1 through the suction pipe 25 to increase the pressure in the tank 1. When the pressure in the tank 1 reaches atmospheric, open the cover 12 to remove the cleaned part 2.

 To regenerate the solvent contaminated as a result of repeated use, the liquid solvent from the storage tank 3 can be sent to the evaporator 15 of the distiller 14 via the regeneration pipe 27 shown in FIG. 1 dashed lines.

 Although in this embodiment, the evaporator 15 and the condenser 16 are integrated into a single distiller 14, they can be made separate from each other. As shown in FIG. 1, the condenser body 19 is sealed, and in this case, the pressure therein must be kept within predetermined limits by regulating the energy supply to the heater 18 and the supply of cooling medium to the cooler 20. The condenser body 19 can be connected to the atmosphere through a communicating pipe (not shown) attached to its upper part, and in this case it is also necessary to regulate the energy supply to the heater 18 and the supply of cooling medium to the cooler 20 to prevent the possibility of the release of solvent vapor from the condenser and 16 into the atmosphere through a reporting pipe.

 With this design, the cleaning device in accordance with this embodiment prevents the release of solvent into the atmosphere and therefore provides an important environmental benefit.

 In FIG. 2 shows a modified version of a cleaning device equipped with a vapor supply unit comprising an evaporator 34 with a heater 33 installed therein for evaporating a liquid organic solvent and a steam supply pipe 36 provided with a solenoid valve 35. The steam supply pipe 36 connects the upper part of the evaporator 34 to the upper part of the tank 1 for cleaning and serves to supply organic solvent vapor from the upper part of the evaporator 34 to the tank 1 for cleaning by opening the solenoid valve 35. To the cover 12, for discontinuity open upper end of the housing 19 of the capacitor 16 is connected a discharge conduit 30 connecting condenser 16 with filter 29 with activated charcoal. The exhaust pipe 30 is provided with a secondary condenser 32 having a cooler 31. In this modification, the steam discharge pipe 24 is divided behind the vacuum pump 23 into a first branch pipe 40 leading to the evaporator 15 and a second branch pipe 41 in communication with the filter 26. The first and second branch pipes 40 and 41 are provided with valves 42 and 43, respectively.

 During operation of the modified device, the part 2 to be cleaned is placed in the cleaning tank 1, as shown in FIG. 2, the vacuum pump 23 is activated (having previously opened the solenoid valve 22), which ensures the evacuation of the tank 1 for cleaning. In this case, the first solenoid valve 42 is closed and the second solenoid valve 43 is opened. Thus, the vapors sucked out from the tank 1 enter the second branch pipe 41 into the activated carbon filter 29, where a small amount of residual solvent is absorbed, which was used in the previous cleaning operation and remained in the sucked vapors. Filtered vapors are released into the atmosphere, and, therefore, thereby prevent the release of solvent into the atmosphere. After evacuation of the cleaning tank 1, the solenoid valve 5 is opened to supply solvent from the storage tank 3 to the cleaning tank 1. The supply of solvent is carried out efficiently and quickly under the influence of rarefaction and under the action of gravity. After supplying a sufficient amount of solvent to the tank 1, the part 2 is cleaned by actuating the ultrasonic generators 11.

 To increase the cleaning efficiency of the part 2, the liquid supply pipe 4 can be connected as shown in FIG. 3, with a shower nozzle 45 attached to the inner surface of the lid 12 and used to spray the organic solvent onto part 2. In addition, an agitator or a circulation pump (both of which are not shown) can be installed in the tank 1 to circulate the organic solvent. However, if the part 2 to be cleaned is easily damaged physically, then it can simply be immersed in an organic solvent in the tank 1, without being subjected to any additional effects, including exposure to ultrasonic vibrations.

 After cleaning with a liquid solvent, a pump 8 for pumping liquid is turned on at a low speed to gradually return the liquid solvent to the storage tank 3. At the same time, the heater 38 of the evaporator 34 is activated (with the solenoid valve 35 open), which ensures the supply of solvent vapor at a relatively high temperature from the evaporator 24 to the tank 1 for cleaning.

 Since part of the cleaned part 2 is below the solvent level and is open to solvent vapor, this leads to condensation of the solvent vapor due to their contact with the open part of part 2. Thus, the part 2 to be cleaned is subjected to so-called steam cleaning, in which the surfaces of the part are finally cleaned with a clean condensed solvent. During steam cleaning, part of part 2 is exposed to a vaporous solvent, and the rest is immersed in a liquid solvent, which provides a temperature difference between part 2 and vaporous solvent sufficient to condense the vapor, so that enough condensed solvent gets onto the exposed surfaces of the part 2 to be cleaned .

 Conversely, when steam cleaning is performed if the entire part 2 is above the level of a liquid solvent, then upon condensation of the solvent vapor, the temperature of the part rises and the temperature difference between them decreases, which leads to a significant decrease in the efficiency of vapor condensation. This reduces the effectiveness of steam cleaning. When, during steam cleaning, part of part 2 is immersed in a solvent, as in this modified version, a liquid solvent cools the part of part 2 immersed in it, which ensures a temperature difference between part 2 and solvent vapors sufficient to efficiently condense the vapors when they come in contact with open surfaces the details.

 During steam cleaning, the liquid solvent in the tank 1 can be forced back into the storage tank 3 by increasing the pressure of the vaporous solvent. In this case, the pump 8 for pumping liquid can be excluded. With increasing pressure in the tank 1 for cleaning during steam cleaning, the amount of condensate increases, resulting in an additional increase in the efficiency of steam cleaning.

 The transportation of solvent between the tank 1 for cleaning and the tank 3 for storage can be carried out only by means of pumps. How to transport the solvent depends on the physical nature of the cleaned part 2, the scale of the equipment and other factors.

 After the entire amount of the organic solvent has been returned during steam cleaning to the storage tank 3, the organic solvent vapors remaining in the cleaning tank 1 are returned to the distiller 14 via the exhaust pipe 24 and then through the first branch pipe 40 for condensation. To do this, the vacuum pump 23 is activated by first opening the solenoid valves 22 and 42 and closing the solenoid valve 43. When the pressure in the cleaning tank 1 drops to a predetermined vacuum level, the control device closes the solenoid valve 22 and turns off the vacuum pump 23. At the same time, the control device opens the solenoid valve 26 to ensure that air is sucked into the tank 1 through the suction pipe 25. As a result, the pressure in the tank 1 rises to atmospheric pressure, at which the lid 12 is opened removing the cleaned part 2.

 In this modified cleaning device, the level of solvent vapor in the condenser 16, that is, the level of the interface between the solvent vapor and air in the condenser 1, varies depending on the presence and termination of the supply of solvent vapor through the first branch pipe 40. The greater the change in the vapor level solvent in the condenser 16, the easier it is to discharge a gaseous mixture, including solvent vapor, into the exhaust pipe 30. This change in level can be reduced by appropriately controlling the supply of ergii to the heater 18 and supplying the cooling medium to a cooler 20, whereby the release of solvent vapors through the exhaust pipe 30 can be made as small as possible.

 In the cleaning device shown in FIG. 2, a secondary condenser 32 containing a cooler 31 substantially reduces the amount of solvent vapor discharged through the exhaust pipe 30, and an activated carbon filter absorbs a small amount of solvent vapor, which, without being condensed in the secondary condenser 32, inevitably goes to the outlet.

 A modified version of FIG. 2 of the secondary capacitor 32 is shown in FIG. 8, where the capture pipe 45 is diverted from the exhaust pipe 30 behind the secondary condenser 32 and connected to the evaporator 15. With this design, the capture pipe 45 returning condensate from the secondary condenser 32 to the evaporator 15 is independent of the exhaust pipe 30 through which the gaseous mixture is discharged from primary condenser 16, and condensate return to the evaporator 15.

 When the distiller 14 is a sealed type distiller that does not have an outlet pipe 30, the pressure in the distiller 14 is controlled by adjusting the energy supply to the heater 18 and the cooling medium to the cooler 20 so that the pressure is not excessively high or low.

 As shown in FIG. 9, the condenser 16 may be provided with a suction pipe 47 and an exhaust pipe 30. The suction pipe 47 has a check valve 48 through which air is discharged into the condenser 16, and the exhaust pipe 30 has a check valve 49 allowing gas to flow into the atmosphere.

 Although the storage tank 3 and the distiller 14 can be made separate from each other, as shown in FIG. 2, the top of the storage tank 3 may be, as shown in FIG. 4, communicated with the upper part of the housing 17 of the evaporator. As shown in FIG. 5, several storage tanks 3 can be connected in series, and a pipe 4 for supplying liquid can be connected to the lowest (or lower upstream) tank 3.

 In the cleaning device shown in FIG. 2, the upper space of the evaporator 15 of the distiller 14 and the upper space of the storage tank 3 are communicated with each other to fill the latter with solvent vapor. As shown in FIG. 6, the upper space of the storage tank 3 can be communicated with the evaporator 34A to supply solvent vapor therein. Evaporator 34A can also be used as evaporator 34 to supply solvent vapor to a purification tank 1. In the upper space of the storage tank 3 shown in FIG. 4, solvent vapor is supplied from the evaporator 15 and therefore no evaporator 34A is needed for the tank 3.

 As shown in FIG. In the second embodiment, the upper space of the cleaning tank 1 is supplied with solvent vapor from the evaporator 34, but the solvent vapor can be supplied by means of a message, as shown in FIG. 7, the upper space of the tank 1 with the upper space of the evaporator 15 of the distiller 14 through a pipe 51 provided with a solenoid valve 50.

 As shown in FIG. 2 of the cleaning device, the vacuum pump 23 serves to remove both air and solvent vapor from the cleaning tank 1, but two vacuum pumps can be used on the respective independent lines communicating with the storage tank 3, one of the vacuum pumps being used for as a pump for discharging air, and another as a pump for discharging solvent vapors.

 Instead of the distiller 14 shown in FIG. 1 and 2, the distiller shown in FIG. 10, in which the condenser 16 is smaller in diameter than the evaporator 15, and is integrated in the latter. In another embodiment, the evaporator 15 and the condenser 16 may be configured as shown in FIG. 11, in the form of separate independent elements. In these modified distillers 14, the liquid solvent located in the storage tank 3 can be sent from it to the evaporator 15 via line 27 (FIG. 2) to recover the solvent contaminated as a result of repeated use.

 In previous cleaning devices in accordance with the present invention, the pressure in the cleaning tank 1 may exceed atmospheric pressure, i.e., it may become positive during the cleaning operation, which will cause leakage of solvent vapor. Therefore, when using an organic solvent such as freon (trade name) as a solvent, a clamping mechanism is needed to press the lid 12 against the seal, which is provided with the upper open end of the tank body for cleaning to ensure tightness. Such a clamping mechanism somewhat complicates the tank 1 for cleaning. In addition, poor tightness of the lid 12 due to loosening of the clamp or damage to the seal can cause leakage of solvent vapor from the tank 1 into the atmosphere, which can lead to the destruction of the ozone layer.

 Also, in the case of using a cleaning fluid other than an organic solvent and sticking of highly infectious bacteria to the part to be cleaned, the tightness of the lid 12 should be quite high, and other problems associated with environmental pollution may occur.

 In FIG. 12 shows a control system that overcomes the aforementioned difficulties. The control system is provided with control means 54 connected to a pressure sensor 53, which provides a pressure detection signal representing the vapor pressure of the organic solvent in the upper part of the cleaning tank 1. In response to the pressure detection signal, the control means 54 controls at least one of the elements including a heater 33 of the vapor supply unit 34 and a pump 8 for pumping the liquid, so that the discharge of the liquid solvent from the tank 1 exceeds the supply of vaporous solvent to it, so that the pressure in the upper space of the cleaning tank 1 will always be negative.

 In this modified embodiment, the supply of vaporous organic solvent is controlled by adjusting the energy supply to the heater 33 of the solvent vapor supply unit 34, but it can be adjusted by means of a solenoid valve 55 with an adjustable orifice installed in the pipeline 36. The orifice of the solenoid valve 55 is controlled by a control means 54 in response to a pressure detection signal. In this modification, the regulation of the energy supply to the heater 33 is not necessary, but it eliminates the waste of energy. Such a solenoid valve with an adjustable orifice can be used as a solenoid valve 7 in communication with a pump 8 for pumping liquid, to regulate the release of cleaning fluid from the tank 1 for cleaning.

 In order to reliably prevent leakage of the vapor of the cleaning liquid, it is preferable to actuate the vacuum pump 23 (FIG. 2) in the steam exhaust pipe 24 to maintain negative pressure in the tank 1 during cleaning of the cleaning liquid part 2.

 A conventional cleaning tank is obtained by welding a flat plate 60 to the bottom of the tank body, as shown in FIG. 13. As a flat plate 60, a rather thick sheet is used, for example, a steel sheet about 5 mm thick, so that the plate can withstand pressure when the tank 1 is evacuated. However, such a thick plate makes it difficult to transfer the vibrations generated by the ultrasonic generators 11 to the liquid organic solvent to be cleaned in the tank 1, which leads to a decrease in the cleaning efficiency of the part 2. To avoid a decrease in efficiency, it is necessary to use large-sized ultrasonic generators 11.

 The cleaning tank shown in FIG. 14, solves this problem. The body of the tank 1 for cleaning is made in the form of a hollow cylinder with a closed lower end and consists of a hollow cylindrical wall 61 and a bottom 62 welded with its upper open end to the lower open end of the wall 61. Although not shown, the wall 61 is provided with a direction tangential to a hole for supplying cleaning fluid. In addition, in the center of the bottom 62 there is a hole for draining the cleaning liquid (also not shown), communicating with the hole for feeding through the pipeline with or without a filter. During the circulation of the cleaning fluid, it can move in a spiral in the tank 1 around its center line. The body of the cleaning tank is used with a cap at its upper end and with ultrasonic generators mounted on its bottom, as shown in FIG. 1. The bottom 62 has a convex downward shape, and ultrasonic generators 11 are attached to the outer surface of the convex bottom directly or through a mounting plate (not shown). For this purpose, ultrasonic generators or a mounting plate are shaped to correspond to the convex shape of the bottom.

 The body of the cleaning tank is bent outwardly in the bottom region and therefore has sufficient pressure resistance even if the lower part is made thinner than the lower plate 60 of the conventional cleaning tank body. The bottom of the lower part 63 may have a cup-shaped or hemispherical shape. According to the design calculations carried out by the inventors, the lower part 62 having a thickness of 1.5 mm is sufficient to withstand the pressure caused by the evacuation of the tank 1 for the tank body having a cylindrical wall 61 with an inner diameter of 300 mm and a bottom with a radius of curvature 450 mm

 In the cleaning device shown in FIG. 2, before starting the cleaning operation with the lid 12 closed, the vacuum pump 23 is activated to evacuate the cleaning tank 1, so that the organic solvent completely soaks the cleaned part 2. However, due to the performance of the vacuum pump 23, a small amount of air remains in the tank 1. When, under these conditions, an organic solvent is introduced into the tank 1 through line 4, the remaining air is trapped in the upper space of the tank 1 and, therefore, the pressure in erhnem space is increased by a partial pressure of residual air. When using the tank 1 for cleaning, in which the pressure when introducing a solvent, such as freon, etc., becomes positive, it is necessary, as described above, a rather complicated related equipment. In order to maintain a relatively low pressure in the upper space of the tank 1, the volume of the upper space relative to the total volume of the tank 1 can be made large. However, this reduces the volume of the space containing each solvent for cleaning, i.e., the total volume of the tank is 1 minus the volume of the upper space. Therefore, the cleaning tank 1 has a lower upper limit on the volume of the part 2 to be cleaned, or it must be made larger in volume for a given volume of the part 2 to be cleaned.

 This problem is solved by the two methods described below, in which the cleaning operation is carried out at a negative pressure in the tank 1 created by actuating the vacuum pump 23. In accordance with the first method, the lid 12 is opened, the part 2 to be cleaned is loaded into the tank 1, and then hermetically closed lid 12. After that, the organic solvent is fed from the storage tank 3 to the cleaning tank 1 through a pipe 4, and in this state, the vacuum pump 23 for continuous operation is continuously provided. air remaining in the upper space of the tank 1 for cleaning.

 In the second method, the vacuum pump 23 is driven before the solvent is supplied to the tank 1. The air pumped out by means of the vacuum pump 23 is discharged directly into the atmosphere without passing it through the distiller 14. Having reached a certain degree of pumping of air from the tank 1, liquid is fed into the tank 1 the solvent, while the remaining air and vapors resulting from the evaporation of the solvent are passed through a distiller 14.

 In accordance with these methods, solvent vapors formed as a result of evaporation of the liquid solvent in the tank 1 continuously enter the upper space of the cleaning tank 1 and no air enters. Consequently, the relative air content in the gaseous mixture in the upper space gradually decreases and in the end the upper space is filled only with solvent vapor. Since the vapor pressure of the solvent in the upper space does not exceed 1 atmosphere (if the temperature in the upper space of the tank 1 is kept below a predetermined one), it is easy to maintain a pressure in the upper space below 1 atmosphere (negative pressure). The solvent vapor in the gaseous mixture, which is fed by means of a vacuum pump 23 to the distiller 14 via lines 24 and 40, is condensed by means of a cooler 20 and the condensate is returned, as described above, back to the storage tank 3.

 In the cleaning device shown in FIG. 2, the solvent vapor remaining in the cleaning tank 1 is sucked off by activating the vacuum pump 23, but the performance of the vacuum pump 23 necessarily causes the problem that a small amount of solvent vapor remains in the cleaning tank 1. If, in this condition, air is sucked in through the suction pipe 25 into the tank 1 to increase the atmospheric pressure therein and then open the cover 12 to remove the cleaned part 2, then the residual solvent vapor will be released into the atmosphere. Using a vacuum pump having a higher capacity can significantly reduce the amount of solvent vapor released into the atmosphere, but this increases the cost of the equipment and therefore is practically not applicable.

 This problem is solved in accordance with the present invention in the following two ways. According to the first method, after cleaning, the liquid solvent is discharged from the cleaning tank 1, as described previously, and then the vacuum pump 23 is activated, while air is introduced into the tank 1 through the suction pipe 25. This operation allows almost complete discharge residual vaporous solvent from the tank 1 through the pipe 24.

 In the second method, before the air is sucked in through the suction pipe 25, a vacuum pump 23 is activated to discharge residual solvent vapor from the tank 1. After pumping out the residual solvent vapor to the capacity limit of the vacuum pump 23, a suitable amount of air is sucked into the tank 1 through the suction pipe 25 to obtain a gas mixture consisting of residual vapor of the solvent and air.

 With these methods, by opening the solenoid valve 26, a continuous supply of air through the suction pipe 25 is provided, but solvent vapor is not supplied. Therefore, the relative vapor content in the gas mixture in the tank 1 for cleaning gradually decreases and in the end only one gas will be in the tank 1 - air. Vapors of the solvent in the gas mixture supplied to the distiller 14 by means of a vacuum pump 23 through lines 24 and 40 are condensed using a cooler 20 located in the upper part of the distiller 14, and then returned to the storage tank 3. With this design, in addition to the fact that the vapor of the organic solvent is heavier than air, the introduction of air into the tank 1 for cleaning does not leak the vaporous solvent into the atmosphere during operation of the vacuum pump 23.

 In FIG. 15 shows a modified embodiment of the cleaning device shown in FIG. 2. In this modified device, a drain pipe 6 supplying liquid solvent from the cleaning tank 1 to the storage tank 3 is removed and a drain pipe 64A is used instead to pass the liquid solvent from the cleaning tank 1 to the distiller 14, where the liquid solvent is distilled and then returned as a regenerated solvent to the storage tank 3, as described above.

 In the cleaning devices shown in FIG. 2 and 15, after the cleaning of the part 2 is completed, the liquid solvent from the cleaning tank 1 is fed to the distiller 14, where it is evaporated by means of the heater 18 and then condensed by means of a cooler 20. This causes a pressure drop in the distiller 14, as a result of which air is sucked into distiller 14 through conduit 30. Vapors in the air condense into water droplets by passing a secondary cooler 31 or by contacting it with a cooler 20 in distiller 14. I mix the water droplets thus obtained Xia solvent and fed to the reservoir 3 for storage. Thus, the water, mixed with the solvent, affects the quality of the solvent to be fed into the tank 1 for cleaning.

In FIG. 16, a distiller 14 is shown containing a moisture removing unit, which serves to prevent such a deterioration in solvent quality. The unit for removing moisture comprises a hermetic container 65 containing liquid solvent 66. The sealed container 65 is located at the bottom of the evaporator 67, which is part of the cooler 64. The evaporator 67 cools the solvent in a sealed container 65 up to about ^-20 ° C, thereby freezing water in a very short time. 68 indicates a suction pipe, one end of which communicates with the atmosphere, and the other is connected to a porous element 69 immersed in a solvent in an airtight container 65. A perforated pipe or an element made of a porous material is used as the porous element 69. The sealed container 65 is connected by its upper space 70 to the upper closed space 71 of the capacitor 16 by means of a communication pipe 30. The communication pipe 30 is equipped with a check valve 72, allowing gas to pass through it only from the sealed container 65 in the direction of the upper closed space 71 of the capacitor 16. Towards the lid 12 of the condenser 16 is connected at one end by an exhaust pipe 74 for discharging a portion of the gas in the confined space 71, with increasing pressure in the confined space 71. The exhaust pipe 74 is equipped with a secondary cooler 75 (near one end of the pipe) for cooling the gas containing solvent vapor, for condensation of these vapor in order to return the solvent. A different check valve 76 is mounted between the secondary cooler 75 and the other end of the discharge pipe 74. The other end of the discharge pipe 74 can be connected to the atmosphere with or without an activated carbon filter to filter solvent vapor.

 When the pressure drops in the confined space 71 of this modified distiller 14 as a result of condensation of solvent vapors located in this confined space 71 through the cooler 20, air is sucked into the sealed container 65 through the suction pipe 68 as a result of the pressure drop in the upper space 70. Air, thus sucked into the solvent 66 in an airtight container 65 through the porous element 69 in the form of small air bubbles. Passing through solvent 66, the air is sufficiently cooled, as a result of which water vapor in the air freezes in ice, which is left in an airtight container 65. Thus, the air in the upper space 70 of the airtight container 65 contains a small amount of water vapor and is therefore dry. This air is directed through a check valve 72 into a closed space 71 in the upper part of the condenser 16, as a result of which the pressure in the closed space 71 rises to atmospheric. Since the air in the enclosed space is as dry as possible, the cooler 20 condenses a few vapors in the air, as a result of which little water is mixed with the solvent flowing down into the trough 21. Thus, there is practically no possibility of deterioration of the quality of the solvent due to mixing water with it.

 When the pressure in the confined space 71 rises, it is reduced to atmospheric by releasing the gas mixture in the confined space 71 into the atmosphere through the exhaust pipe 74. When the pressure in the confined space 71 decreases, the vapor of the organic solvent leaves the atmosphere through the exhaust pipe 74 because the solvent located in the gas mixture is captured by condensation by means of both a primary cooler 20 and a secondary cooler 75.

 In FIG. 17 shows a modified version of the distiller 14 shown in FIG. 16, wherein the outlet pipe 74 is connected at its other end to a second moisture removing unit that is the same in design as the first moisture removing unit, except that the check valve 72A has a flow direction that allows only gas to pass through and which opposite to the flow direction of the check valve 72 of the first moisture removal unit. In this modified embodiment, with increasing pressure in the confined space 71, it is reduced by passing the gas mixture in the confined space 71 through the exhaust pipe 74 into a second sealed container 65, from which it is released through the pipe 68 into the atmosphere. At the same time, little solvent vapor is released into the atmosphere. The main part of the solvent vapor in the gas mixture is captured in the trough 21 by condensation by means of a cooler 20 located in a confined space 71. The remaining part of the solvent vapor, which is not captured by the cooler 20, is condensed by passing through a cryogenic solvent in the second sealed container 65, where and catch her.

 The first and second units for removing moisture can be placed in a common sealed container.

 Below is described with reference to FIG. 18 is another way to prevent deterioration in the quality of the organic solvent due to condensation of water droplets caused by a pressure drop in the distiller 14. In this modified distiller 14, two dehumidifiers 80A and 80B are connected in parallel through a non-return valve 72 with a closed space 71 of the condenser 16. Each of the dehumidifiers 80A and 80B is charged with a regenerative drying agent such as silica gel and zeolite. The dehumidifiers 80A and 80B are connected to the atmosphere through the suction pipes 81A and 81B, respectively, and are also connected to the check valve 72 via the corresponding exhaust pipes 82A and 82B. Outlet lines 82A and 82B are provided with solenoid valves 83A and 83B, respectively. The dehumidifiers 80A and 80B are in communication with the heater 86 for receiving hot air through respective ducts 84A and 84B for supplying regenerating hot air, each of which has a solenoid valve 85A and 85B. The enclosed space 71 of the condenser 16 is connected to the secondary cooler 32 via a check valve 87.

 When the solenoid valve 83A of one desiccant 80A is open in such a device and the solenoid valve 83B of the other desiccant 80B is closed, air is sucked into the closed space 71 through the desiccant 80A, which compensates for the pressure drop in the closed space 71 caused by condensation of the organic solvent. Meanwhile, the solenoid valve 85A is closed and the solenoid valve 85B is open. Therefore, the hot air heated by the heater 86 enters the dryer 80B, where it regenerates the drying agent by evaporating moisture, which is then released into the atmosphere through the pipe 81B. When the drying agent in the dryer 80A becomes wet as a result of the drying operation, the control device opens the solenoid valves 83A and 85A and closes the solenoid valves 83A and 85B to regenerate the drying agent. In this case, air is also sucked into the enclosed space 71 through the second dryer 80B, which compensates for the pressure drop in the closed space 71, while the drying agent is regenerated in the first dryer 80A. Switching between the first and second dehumidifiers 80A and 80B is done automatically, by counting the number of cleanings, or by means of a timer included in the control device.

 With this design, the air introduced into the enclosed space 71 through the suction pipe 30 to increase the pressure in the enclosed space 71, is dried in the way it moves, as a result of which it is always dry. Therefore, the cooler 20 condenses little water vapor in the intake air, and therefore, little water is mixed with the liquid solvent flowing down into the trough 21. Thus, the deterioration of the quality of the solvent due to the ingress of water is prevented.

 In the cleaning devices shown in figures 2 and 15, after cleaning the part 2, liquid solvent is discharged from the cleaning tank 1. Then into the tank 1 serves from the unit 34 for supplying vapor vapor solvent for steam cleaning. In this case, there is a risk of instant boiling (pulsating boiling) of the liquid solvent in the unit 34 due to a significant pressure drop in the tank 1 for cleaning. The pressure in the tank 1 is reduced by draining the liquid solvent from it by means of a pump 8 for pumping liquid, and finally the pressure in the tank 1 drops to the vapor pressure (elasticity) at the temperature of the liquid solvent. If in this case to make the pressure in the unit 34 the same as the pressure in the tank 1 for cleaning by opening the solenoid valve 35 (the pressure in the unit 34 decreases), then the pressure in the unit 34 becomes lower than the vapor pressure of the solvent at its temperature. This causes a pulsating boiling of the liquid solvent in the vapor supply unit 34, resulting in droplets of the liquid solvent. Therefore, it is possible for such droplets of solvent to enter the cleaning tank 1. If these droplets come into contact with the part 2 to be cleaned in the tank 1 during steam cleaning, the parts of the part in contact with the droplets will not be subjected to steam cleaning, which reduces the effect of steam cleaning.

This problem is solved by the pulsating boil prevention system shown in FIG. 19, in which, after cleaning the part 2, the liquid solvent is withdrawn from the cleaning tank 1 in the storage tank 3 by operating the pump 8 for pumping the liquid in the same manner as in the previous embodiments. At this stage of cleaning, the temperature T _{2 of the} liquid solvent in the cleaning tank 1 is increased, making it slightly higher than the temperature T _{4 of the} liquid solvent in the vapor supply unit 34. In particular, the output of the temperature sensor 90, which senses the temperature T _{2 of the} liquid solvent in the cleaning tank 1, and the output of the temperature sensor 91, which senses the temperature T _{4 of the} liquid solvent in the unit 34, is supplied to a control device 92 for controlling the energy supply to the heater 33 of the unit 34 for supplying vapor. The control device 92 compares the received signals and, in accordance with the comparison result, controls the energy supply to the heater 33, as a result of which the temperature T ₂ becomes slightly higher than the temperature T ₄ . In this state, open the valve 35 in the pipe 36 for supplying solvent vapor from the unit 34 to the tank 1 for cleaning. When the pressure in the unit 34 becomes equal to the pressure in the tank 1, it will not be lower than the vapor pressure of the liquid solvent in the unit 34 at a temperature of T ₄ . Thus, pulsating boiling of the liquid solvent in the unit 34 does not occur, and therefore there is no possibility of entering into the tank 1 for cleaning through the pipe 36 droplets of solvent formed as a result of pulsating boiling.

After the flow of solvent vapors from the unit 34 for supplying vapors to the cleaning tank 1, as described above, starts, the control device 92 increases the energy supply to the heater 33 to increase the temperature of the solvent vapors supplied to the tank 1. In this case, the temperature difference between the solvent vapors which are fed into the tank 1, and the surfaces of the part to be cleaned increase, resulting in an increase in the degree of condensation of solvent vapor on the surfaces of the part, which increases the efficiency of the vapor oh cleaning. With increasing temperature T _{4 of the} liquid solvent in the unit 34 by means of the heater 33, the valve 35 is open, and therefore, the pressure in the unit 34 does not become lower than the vapor pressure (elasticity). Thus, there is no possibility of the appearance of a pulsating boiling solvent.

 In FIG. 20 shows another modified embodiment of a cleaning device in accordance with the present invention. In this figure are used the same as in previous embodiments, item numbers to indicate the same or equivalent elements or parts. A pipe 4 for supplying a solvent with a solenoid valve 5 and a drain pipe 6 with a solenoid valve 7 and a pump 8 for pumping liquid are connected to the cleaning tank 1.

 According to this modified embodiment, the cleaning tank 1 and the distiller 14 are connected by means of a steam outlet pipe 24 provided with a hermetically sealed container 100. A tubular cooler 101 is placed in the container 100 to cool the solvent vapor supplied to the container 100 from the tank 1 for cleaning through the steam discharge pipe 24 The pipe 24 has a solenoid valve 22 and a three-way solenoid valve 102.

 The sealed container 100 is connected in its upper part to the condenser 16 by means of a connecting pipe 103 having a solenoid valve 104, whereby solvent vapor can be supplied from the condenser 16 to the container 100. The container 100 is also connected in its lower part to the evaporator 15 by means of another connecting pipe 105 having a solenoid valve 106, so that the liquid solvent contained in the container 100 can be fed into the evaporator 15.

 A three-way valve 102 is connected to the suction pipe 108 of the vacuum pump 23, the discharge pipe 109 which communicates with the sealed container 100.

 To clean the part in the tank 1, it is placed in the tank 1 and subjected to ultrasonic cleaning by means of generators 11. After the cleaning is completed, the pump 8 is pumped to pump the liquid in order to return the used liquid solvent in the storage tank 3 (not shown) through a drain pipe 6. After all the liquid solvent has been pumped into the storage tank, a vacuum pump 23 is activated to suck off the solvent vapor from the cleaning tank 1.

 In this case, the valve 22 is first closed in the steam outlet 24 to interrupt the communication between the cleaning tank 1 and the sealed container 100, and the valve 104 is opened to allow solvent vapor located in the condenser 16 to flow into the container 100 through the connecting pipe 103. Three-way valve 100 through the connecting pipe 103. The three-way valve 102 is switched to a state in which the suction pipe 108 does not communicate with the steam exhaust pipe 24.

 After the solvent vapor has been introduced into the container 100 in the manner described above, the valves 104 and 106 are closed and a cooling agent (refrigerant) is passed through the pipe cooler 101 to cool and condense the solvent vapor in the container 100. As a result, the pressure in the container 100 decreases.

 After that (valves 104 and 105 are closed), valve 22 is opened, as a result of which a reduced pressure in the container 100 causes the solvent vapor remaining in the cleaning tank 1 to flow into the sealed container 100.

 The induced flow of solvent vapors into the container 100 occurs only for a short time, as a result of which the pressure in the tank 1 drops sharply, which causes instant boiling of a liquid solvent adhering to the part to be cleaned, entailing blowing off of the dirt on the part, and therefore cleaning parts.

 The solvent vapor sucked into the container 100 is cooled by means of a tube cooler 101 and condensed into a liquid solvent, as a result of which even with the sucked solvent into the container 100, the pressure therein will increase only slightly, due to which the flow of vaporous solvent from the tank 1 to the container 100 continues and therefore, the pressure in the reservoir 1 decreases.

 When the pressure reduction in the cleaning tank 1 as described above is not sufficient, the three-way valve 102 is switched to a position where the steam outlet 24 communicates with the suction pipe 108 and the vacuum pump 23 is activated. Then, the solvent vapors in the cleaning tank 1 are sent to the container 100 through the steam exhaust pipe 24, the suction pipe 108, the vacuum pump 23 and the discharge pipe 109, and the solvent vapor is condensed in the container 100. During the supply of solvent vapors from the tank 1 to the container 100, the pressure in the container 100 is maintained due to the operation of the cooler 101 at a rather low level, as a result of which the pressure difference between the tank 1 and the container 100 is small, and therefore, a sufficiently high vacuum can be provided in the tank 1 . This means that to obtain a high degree of vacuum in the tank 1 for cleaning it is not necessary that the vacuum pump 23 has a high capacity. It should be noted that this modified version of the cleaning device is advantageous in this regard.

 In the cleaning device shown in FIG. 20, the liquid solvent accumulated in the lower part of the container 100 is sent to the distiller 14 by opening the valve 106. After the liquid solvent is withdrawn from the container 100 in this way through the pipe 105, solvent vapor is sucked from the distiller 14 into the container 100 through the pipeline 105. The internal volume of the container 100, under vacuum, is large enough to cause a sharp drop in pressure in the tank 1 for cleaning. Therefore, the amount of vaporous solvent sucked from the distiller 14 into the container 100 when the valve 106 is open is also large enough. Therefore, the opening of the valve 106 causes the flow of solvent vapor from the distiller 14 to the container 100 with a high flow rate for a short period of time, which entails a pressure drop in the distiller 14 and, therefore, the absorption of atmospheric air through the exhaust pipe 30 into the distiller 14 to compensate for the pressure drop .

 The solvent vapors formed during the operation of the heater 18 displace the atmospheric air sucked in as described above from the distiller 14 through the exhaust pipe 30, and the solvent vapor in the distiller 14 is released through the exhaust pipe 30 into the atmosphere. Exited solvent vapors can be trapped by filter 29, but some of the solvent vapor can be released to the atmosphere, or filter 29 can deteriorate quickly.

 These problems are addressed by the modification shown in FIG. 21. In this modification, a hermetically sealed container 100 is connected in its lower part to an auxiliary sealed container 111 by means of a connecting pipe 112 having a solenoid valve 113. The auxiliary container 111 has a significantly smaller capacity than the container 100. A pipe 114 is connected to the bottom of the auxiliary container 111, equipped with a solenoid valve 115 and leading to the lower part of the evaporator 15. The auxiliary container 111 is also connected in its upper part with a pipe 116 having a solenoid valve 117 and going to the evaporator 15.

 The liquid solvent accumulated in the lower part of the sealed container 100 is discharged into the distiller 14 through the auxiliary container 111. In particular, when the liquid solvent accumulates in the container 100, the valve 113 is opened and the valves 22, 104, 115 and 117 are closed. As a result, the liquid solvent in the container 100 flows out of it by gravity down to the auxiliary container 111 through a pipe 112. At the same time, the solvent vapors located in the auxiliary container 111 are sucked up into the container 100, which is under vacuum.

 After that, the valve 113 is closed, the valve 115 is opened, as a result of which the liquid solvent located in the auxiliary container 111 flows downstream of it through the pipe 114 to the evaporator 15. At the same time, a certain amount of vaporous solvent located in the evaporator 15 is sucked into the auxiliary container 111 However, the amount of sucked vapor solvent is small because the auxiliary container 111 has a small capacity.

 At the beginning of the operation of the cleaning device, the valves 22 and 117 are closed and the valves 104, 113 and 115 are opened, whereby the container 100 and the auxiliary container 111 are filled with a vaporous solvent. Since the vaporous solvent is heavier than air, when the valves 104, 113 and 115 are opened, as described above, the vaporous solvent located in the distillation unit 14 flows from it into the auxiliary container 111 and then into the container 100, displacing from the containers 100 and 111 in them, air through a conduit 103 to the upper part of the distiller 14. Consequently, there is an exchange of air in the vaporous solvent between the containers 100 and 111 and the distiller 14. Due to the difference in the specific gravity between the air and the vaporous solvent, this exchange occurs slowly, and the amount of vaporous solvent consumed does not exceed to a significant degree the amount of vaporous solvent produced by heating with the heater 18. Therefore, the position of the interface between the vaporous solvent and air in the distiller 14 does not change much: due to which the amount of solvent leakage from a cleaning device can be minimized.

 In the cleaning device described with reference to figures 1, 2 and 15, a vacuum pump 23 is activated to suck off the solvent vapor remaining in the cleaning tank 1 after the cleaning operation is completed. However, a very small amount of solvent vapor remains inevitably in the tank 1 for the cleaning. Therefore, when the lid 12 is opened to remove the cleaned part 2 from the tank 1 after increasing the pressure in the tank 1 to atmospheric by sucking air into the tank 1 through the suction pipe 25, the solvent vapor remaining in the tank 1 will be released into the atmosphere. The amount of solvent vapor released into the atmosphere can be reduced by increasing the productivity of the vacuum pump 23, but there is a limit to reducing this amount.

 In FIG. 22 shows an improved embodiment of a cleaning device. As shown, the device includes a connecting pipe 120, communicating with each other a capacitor 16 and the upper part of the tank 1 for cleaning. The connecting pipe 120 may be connected, as shown, to the air suction pipe 25 and has a solenoid valve 121 and a cooler 122 through which a cooling agent can pass.

 This improved device provides suction into the tank 1 for cleaning the air that is in the upper space of the distiller 14. Since this way it is possible to avoid the introduction of atmospheric air into the tank 1 for cleaning, the total amount of gases in the device for cleaning does not increase. Therefore, there is no displacement of gases from the distiller to the filter 29, which makes it possible to reduce the amount of solvent vapor (heavier than air) discharged into the atmosphere from the distiller 14. The cooler 122 is cooled and the solvent vapor flowing through the connecting pipe 120 is condensed to return the solvent into the distiller 14, thereby reducing the amount of solvent flowing into the cleaning tank 1 through a connecting pipe 120. (56) USSR Copyright Certificate N 626842, cl. B 0 B 3/12, 1977.

Claims (22)

 1. The method of cleaning parts with a solvent, including placing the workpiece in a cleaning tank, sealing the latter, feeding the solvent in a liquid state from the storage tank to the cleaning tank, cleaning the part with solvent, removing the solvent in a liquid state from the cleaning tank to the tank for storage for raising the level of liquid solvent in the storage tank so as to force solvent vapor into the condenser to condense them, removing it from the cleaning tank and a workpiece, characterized in that, in order to increase the efficiency of the cleaning process by preventing the emission of solvent vapor into the environment, the condensed solvent from the condenser is fed through a connecting pipe to a storage tank.  2. The method according to p. 1, characterized in that the condensation of the solvent vapor is carried out in an additional tank-condenser.  3. The method according to p. 1, characterized in that it further includes a step providing for the additional use of the unit for supplying steam to the tank for cleaning, while during the removal of the solvent in the liquid state from the tank for cleaning with a gradual decrease in the level of liquid solvent serves vaporous solvent from the steam supply unit to the cleaning tank to ensure that the vaporous solvent contacts the surface of the part.  4. The method according to p. 3, characterized in that it further comprises the step of maintaining greater than supplying the solvent in a vapor state to the cleaning tank, removing the solvent in a liquid state for cleaning to the storage tank to maintain negative pressure in the cleaning tank during steam cleaning.  5. The method according to p. 3, characterized in that before supplying the solvent in a vapor state from the unit for supplying vapor to the cleaning tank, further include the step of raising the temperature of the liquid solvent in the cleaning tank so that it becomes higher than the temperature of the liquid solvent in the unit for vapor supply to prevent the impact of the liquid solvent in the vapor supply unit.  6. The method according to p. 1, characterized in that air is introduced from the condenser into the tank for cleaning.  7. The method according to p. 6, characterized in that air is introduced into the cleaning tank, the latter being cooled in order to return the solvent vapor contained in the air to the condenser.  8. A device for cleaning parts with a solvent, comprising a cleaning tank, an ultrasonic generator mounted on the bottom of the cleaning tank, a solvent storage tank, means for supplying a solvent in a liquid state from the storage tank to the cleaning tank, means for removing the solvent to liquid state from a cleaning tank to a storage tank, a condenser, means for removing the solvent in a vapor state to a condenser, characterized in that, in order to increase the efficiency the efficiency of the cleaning process due to the obstacle to the emission of solvent vapors into the environment, the solvent storage tank is connected in its upper part to the condenser through a connecting pipe to ensure the removal of vaporous solvent and the return of the condensed solvent in the condenser to the storage tank, and the means for removing the solvent in liquid The condition of the storage tank is equipped with a pump.  9. The device according to p. 8, characterized in that it further comprises a reservoir-condenser.  10. The device according to p. 9, characterized in that the solvent condenser contains an exhaust pipe in communication with the atmosphere, and the exhaust pipe has a filter for filtering air.  11. The device according to p. 10, characterized in that the exhaust pipe is equipped with a secondary condenser for condensing the vapors supplied from the solvent condenser through the exhaust pipe.  12. The device according to p. 8, characterized in that the unit for supplying vapor to the tank for cleaning contains a heater for heating the liquid solvent and is connected to the tank for cleaning through means for passing solvent vapor.  13. The device according to p. 12, characterized in that it further comprises a pressure sensor for sensing pressure in the tank for cleaning and generating a pressure signal and control means for controlling, in response to the pressure signal, the heater and / or means for removing the solvent so that the liquid is discharged solvent increased the supply of solvent vapor to maintain negative pressure in the tank for cleaning.  14. The device according to claim 8, characterized in that the cleaning tank has a suction pipe for introducing air in communication with the atmosphere, with a cleaning tank and having a valve for opening and closing it.  15. The device according to p. 8, characterized in that it further comprises air venting means in communication with the tank for cleaning.  16. The device according to p. 8, characterized in that it further comprises a solvent distiller, including an air-suction means and means for removing moisture contained in the air by cooling this moisture below its freezing point with the possibility of solidification of the moisture.  17. The device according to p. 16, characterized in that each means of removing moisture has a sealed container with a solvent, freezing means for cooling the solvent in the sealed container to a temperature below the freezing point, and means for passing the suction air through an air-suction means through a cooled solvent using a freezer.  18. The device according to p. 16, characterized in that the solvent distiller has a desiccant of air that is sucked in using an air-suction means.  19. The device according to p. 16, characterized in that the solvent distiller has means for sucking in air after a pressure drop therein with a check valve and means for discharging air having a check valve for venting the pressure in the distiller.  20. The device according to p. 8, characterized in that it further comprises a sealed container having cooling means, piping means connecting the container and the cleaning tank and having a valve, and piping means connecting the container and the distiller and having valve means.  21. The device according to p. 20, characterized in that it contains a vacuum pump having a suction and supply pipelines, while the suction pipe is connected to piping means connecting the container and the cleaning tank through the valve, and the supply pipe is in communication with the container.  22. The device according to p. 20, characterized in that it further comprises an auxiliary container, smaller in volume than the sealed container, while the auxiliary container is located below the sealed container, and connected to the latter through a pipe provided with a valve, and the auxiliary container is connected to distiller through piping means having valve means. Priority on points:
06/26/89 for PP. 1.6 - 8,
10.20.89 PP 2-5, 9-22.

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