Patent Publication Number: US-7901478-B2

Title: Reservoir for a replacement fluid for a device and a device, together with an oil separator fitted with such a reservoir

Description:
This invention relates to a reservoir for a replacement fluid for a device. 
     The term ‘replacement fluid’ is used here to refer to any fluid that is used in a device in order to ensure or optimise the proper functioning of the device, where such fluid needs to be replaced, whether regularly or otherwise, for example liquid coolant, liquid lubricant and so on. 
     It is known that replacing such a replacement fluid in a device is often an onerous and dirty task which is very time-consuming. 
     For example, oil separators are known which are used to remove the oil from the compressed gas which comes from oil-injected compressors. 
     In such oil-injected compressors, oil is injected into the compression chamber during the compression of the gas in order to cool down the gas and lubricate the compressor element&#39;s moving parts. 
     Such oil separators consist, in their known form, of a reservoir shaped like a boiler in which the separated oil is collected at the bottom. 
     In order to change the oil during servicing, a drainage stop is provided at the bottom of such oil separators, via which the used oil can be collected in order to be disposed of. 
     After the oil has been drained off, the reservoir has to be refilled via a fill plug, with a gauge or dipstick being used to determine the right quantity of oil. 
     Obviously, a servicing intervention of this kind for changing oil is relatively laborious and time-consuming, as it is necessary to repeatedly verify whether the correct oil level has already been reached. 
     Moreover, it is nearly impossible to perform this work without making a mess. 
     There are similar disadvantages associated with replacement fluids in other types of devices. 
     Another disadvantage lies in the fact that the replacement fluids are usually available in standard-size packaging units which do not generally correspond to the required quantity of replacement fluid, so that it is usually necessary to purchase more product for a servicing intervention than is strictly necessary, leaving a surplus whose properties can degrade over time. 
     The aim of the present invention is to offer an answer to said and certain other disadvantages. 
     To this end, the invention relates to a reservoir for a replacement fluid for a device, where the reservoir is pre-filled with the desired quantity of the relevant replacement fluid and where this reservoir is equipped with detachable coupling devices which make it possible to mount and dismantle the reservoir on the device and where the reservoir, in its mounted state, serves as a changeable fluid reservoir for the device. 
     One advantage of such a reservoir according to the invention is that the replacement of the fluid can be performed rapidly, accurately and cleanly, in that only this reservoir containing the used replacement fluid needs to be replaced by a new reservoir in which a premeasured quantity of fresh replacement fluid is introduced, so that the reservoir serves as packaging for the replacement fluid for the device, both before and after the use thereof. 
     For example, when such a reservoir according to the invention is used with an oil separator, it is no longer necessary when replacing the oil to measure the correct quantity, of oil by means of a gauge or dipstick, as the required quantity of oil has already been introduced into the new reservoir. 
     Nor is it necessary to provide an extra catchment tray to catch the used oil, as the reservoir which is removed from the oil separator already contains all the used oil and can be removed in its entirety together with the oil, for recycling, for example. 
     The present invention also relates to a device which contains a replacement fluid, where said device is fitted with a reservoir according to the invention which contains at least a portion of the device&#39;s replacement fluid. 
     More specifically, the invention also relates to an oil separator in an oil-injected compressor, where said oil separator consists of firstly a housing with an inlet and an outlet for compressed gas, and secondly, a pre-filled reservoir that is secured detachably against the housing by means of detachable coupling devices and where the chambers in the housing and this reservoir are linked via orifices for the separated oil and where an offtake point is provided via which the reservoir can be connected to a circuit for the injection of the oil from the reservoir into the compressor. 
    
    
     
       With the intention of better showing the characteristics of the present invention in what follows, by way of example and without any limitative character, a number of preferred embodiments are described of a reservoir according to the invention for a replacement fluid for a device, with reference to the accompanying drawings, in which: 
         FIG. 1  is a diagrammatic and perspective representation of a device in the form of an oil separator which is fitted with a reservoir according to the invention; 
         FIG. 2  represents a cross-section along line II-II in  FIG. 1 , but in an exploded view; 
         FIGS. 3 to 5  illustrate the use of a reservoir according to the invention step by step; 
         FIG. 6  represents a variant on  FIG. 2 . 
     
    
    
     In  FIG. 1 , a device  1  is shown according to the invention in the form of an oil separator which is formed by a housing  2  and a reservoir  3  according to the invention, where said reservoir  3  takes the form of a changeable reservoir in which a required, measured quantity of oil is provided and which, as indicated in  FIG. 2 , can be secured against the housing  2  as a separate and changeable element. 
     The housing  2 , which for example can be made by welding or casting, is in this case bell-shaped, encloses a separating chamber  4  and is also provided with a floor  5 . 
     In the side of said housing  2  a tangentially inserted inlet opening  6  is provided, as well as an outlet opening  7  on the top of the housing  2 , which inlet opening  6  is provided in order to be connected to the outlet of an oil-injected compressor, while the outlet  7  is provided in order to be connected to a mains network. 
     Further, the housing  2  is provided with an offtake point  8 , which in this case takes the form of the extremity of a feed-through line  9 , which passes through the wall of the housing  2  and whose other extremity connects to a nipple  10  which is fastened at the bottom to the floor  5  and which is provided with an external screw thread  11 . 
     Likewise, on the underside and across the entire periphery of the floor  5  a downwards-pointing flange  12  is introduced which is provided with an internal screw thread  13  with a pitch greater than that of said external screw thread  11  on the nipple  10 . 
     Finally, in the floor  5  further orifices  14  are provided which extend round said nipple  10 . 
     Said reservoir  3  according to the invention takes the form of a changeable reservoir in which a pre-measured required quantity of replacement fluid  15 , such as oil for example, is introduced. 
     This reservoir  3  mainly consists of a virtually barrel-shaped receptacle  16  which contains a chamber  17  which holds said quantity of oil and which is also bounded by an upper wall  18  with a centrally deepened section  19  with a central opening  20  through which a suction line  21  is introduced which extends axially into the reservoir  3  to a certain distance from the floor of the reservoir  3  and which is provided with a widened section  22  which protrudes through said opening  20  and is provided with an internal screw thread  23  which can mate with the external screw thread  11  of the nipple  10 . 
     In the deepened section  19 , a number of orifices  24  are introduced round the widened section  22  of the suction line  21 . 
     Said suction line  21  is held in place in the reservoir  3  by means of a ring  25  which is introduced round the suction line  21  so that it can be moved but cannot be rotated, and which is secured at its edges on a support  26  in the form of a profiled plate whose edges are fastened to the inner wall of the reservoir  3 . 
     The ring  25  is, in its resting state, fastened securely to the support  26  and is provided with orifices  27 . 
     Between the ring  25  and the support  26 , a snap-off or click-apart mechanism is provided so that, after sufficient axial force has been exerted on the suction line  21 , the ring  25  snaps off or clicks apart from the support  26 . 
     The support  26  is also provided with a short tubular section  28  in which said ring  25 , after it has snapped off, can be moved over a short distance in the axial direction without rotating, after which the ring  25  completely detaches from the support  26 . 
     The reservoir  3  is provided with coupling devices  29  which enable the reservoir  3  to be mounted on and dismantled from the housing  2 , with these coupling devices  29  being formed in this case by the fact that the barrel-shaped reservoir  3  is provided at the top around its periphery with an external screw thread  30  which mates with the internal screw thread  13  on the flange  12  of the housing  2 . 
     In the upper wall  18  of the reservoir  3 , a groove  31  is provided which contains a seal  32 . 
     As shown diagrammatically in  FIG. 2 , the reservoir is covered with a removable lid  33 . 
     The use of the reservoir  3  according to the invention is very simple, and is represented in steps in  FIGS. 2 to 5 . 
       FIG. 2  shows the starting situation, in which an oil change needs to be performed and, after the removal of a used reservoir  3 , a new changeable reservoir  3  needs to be introduced. 
     To this end, after the removal of the lid  33 , the reservoir  3  is mounted on the bottom of the housing  2  by twisting the reservoir  3  with its screw thread  30  in the screw thread  13  on the bottom flange  12  of the housing  2 , as a result of which the widened section  22  of the suction line  21  with its screw thread  23  is simultaneously twisted on the nipple  10 , as shown in  FIGS. 3 and 4 . 
     The reservoir  3  is screwed completely tight so that the seal  32  on the top of the reservoir  3  comes into contact with the floor  5  of the housing  2 , as a result of which a completely closed oil separator is obtained which consists of the housing  2  and the replacement reservoir  3 . 
     As the pitch of the outermost screw threads  13  and  30  is greater than the pitch of the innermost screw threads  11  and  23 , the suction line  21  will, when the reservoir  3  is screwed onto the housing  2 , describe a lesser axial movement than the reservoir  3 , and will in consequence lag behind this reservoir  3 . 
     As a result of this, a downwards axial force is exerted on the suction line  21 , due to which said snap-off or click-apart mechanism is activated, causing the ring  25  to snap off or click apart from the support  26 , although the suction line  21  remains connected to the housing  2  via the screw connection between the screw threads  11  and  23 , as shown in  FIG. 4 . 
     In this state, the reservoir  3  is completely mounted and the device can be put into operation, as a result of which compressed gas flows into the oil separator&#39;s tangential inlet  6  from the compressor. 
     As a result of this, the gas flow acquires a turbulent motion, causing, as is known, the oil particles which are included in the gas flow to be flung against walls of the housing  2 , and due to gravity flows along the walls and via the orifices  14 ,  24  and  27  into the reservoir  3  to be collected there. 
     Due to the gas pressure of the oil on the oil surface in the reservoir  3 , oil is forced via the suction line  21  on the reservoir  3  and the connecting feed-through line  9  on the housing  2  outwards via the offtake point  8  to feed the injection circuit with which the compressor is lubricated. 
     Due to the presence of the floor  5  and the upper wall  18 , the oil is prevented from also starting to swirl around in the reservoir under the influence of the gas flow penetrating into the housing  2 , thus preventing gas from also being conducted to the compressor via the suction line  21 . 
     When the replacement fluid  15  eventually needs to be replaced, it is not just the oil that will be replaced, but instead the reservoir  3  will be replaced with a new replacement reservoir with fresh oil. 
     For this, the used reservoir  3  will need to be unscrewed again. 
     Due to the fact that, after the ring  25  has been snapped off or clicked free from the support  26 , the ring  25  is held in the support  26  in such a way that it can be moved but cannot be rotated, the ring  25  together with the suction line  21  will turn with the reservoir  3 , as a result of which the suction line  21  is unscrewed from the nipple  10 . 
     Once the suction line has been completely unscrewed from the nipple  10 , it can simply slip out from the short tubular section  28  of the support  26 , and hence fall into the reservoir  3 , as shown in  FIG. 5 . 
     This makes it impossible for the used reservoir  3  to be reused. 
     The reservoir  3  can then be closed again by means of the lid  33  so that it can be taken away and where appropriate recycled in a suitable manner. 
     A new reservoir  3  with fresh replacement fluid  15  can then be connected to the housing  2  in the same way as described earlier, starting once again from a situation as depicted in  FIG. 2 . 
     In  FIG. 6 , a variant is shown of a device  1  as in  FIG. 2 , in which a fluid filter  34  has been introduced on the bottom free end of the suction line  21 . 
     The advantage thereof is that, when the reservoir  3  is replaced, the filter  34  for the purification of this replacement fluid  15  will be replaced at the same time. 
     It is clear that said coupling devices  29  need not necessarily take the form of a screw connection, but that they can also consist of any other connecting system, which can preferably though not necessarily be manually activated, such as a bayonet fitting. 
     It is clear that said removable lid  33  can take many different forms which prevent leaks of replacement fluid  15  from the reservoir  3 , such as a screw top, a snap-off section or a removable film. 
     It is likewise clear that said snap-off or click-apart mechanism can take many different forms. An example of another such mechanism is described in BE 1.011.567 by the same applicant. 
     The present invention is in no way limited to the embodiments described by way of example and shown in the figures, but a reservoir according to the invention for a replacement fluid for a device and a device and oil separator fitted with such a reservoir can be produced in many different forms and dimensions without departure from the scope of the invention.