Temperature regulation apparatus and method

Abstract

A machine for a temperature regulation arrangement that includes a closed area within the machine leading a temperature regulating chamber positioned adjacent a heat source, in which there are a number of liquid collectors arranged so that each has a feed take off that provides a elevated passage way from one liquid collector to the next.

Claims

1. A machine with a temperature regulation arrangement therein comprising: a closed area within the machine leading a temperature regulating chamber positioned adjacent a heat source, a liquid in the closed area, a head space within the closed area containing substantially only vapor of the liquid, a liquid collector within the head space configured to hold as a reservoir, wherein some of the liquid in the closed area is at an elevated height in the closed area, a first gooseneck conduit from said liquid collector to direct said liquid from within said liquid collector to a first lower level within the closed area, a feed take off from said first lower level, a second gooseneck conduit from said first lower level to a second lower level, wherein said second lower level is lower than said first lower level by which said liquid from within the first lower level is to be directed to said second lower level, a feed take off from said second lower level, wherein the shape of the second gooseneck conduit provides a height barrier to passage of said liquid there past, and wherein at least one of said first lower level and said second lower level comprises a reservoir.

2. The machine of claim 1, further comprising a condenser to provide a supply of liquid from within the head space to an elevated position within the head space.

3. The machine of claim 1, further comprising a condenser to effect a supply of liquid, wherein said condenser is positioned such that condensed liquid is directed toward the liquid collector.

4. The machine of claim 3, wherein each of said first lower level and said second lower level comprises said reservoir, wherein said feed take offs from each of said first lower level and said second lower level are arranged to maintain a liquid supply within the reservoirs of said first lower level and said second lower level with some excess to feed further levels below the first lower level and the second lower level.

5. The machine of claim 1, wherein said liquid is provided by being elevated through a thermo siphon arrangement.

6. The machine of claim 1, further comprising a pump and wherein said liquid is provided to the liquid collector by said pump.

7. The machine of claim 1, wherein the height barrier is provided by the reservoir having an elevated outlet to a lower level of said first lower level and said second lower level.

8. The machine of claim 7, further comprising a third gooseneck conduit that provides a connection between said first lower level and said second lower level, wherein vapor pressure within the head space is substantially that of the liquid within the head space, such that the liquid will not act in a siphon manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of this invention it will now be described with reference to embodiments which with the assistance of drawings wherein;

(2) FIG. 1 is a perspective view of injection die portion with part cut away in cross section and with a side plate removed,

(3) FIG. 2 is a cross section through the same portion as shown in FIG. 1 with however a side plate in position,

(4) FIG. 3 is a perspective view of the same portion as in FIGS. 1 and 2 with again the side plate removed but otherwise showing visible areas,

(5) FIG. 4 is a perspective view an assembly that is a functional part of the system that will be within a die part to effect uniformity of distributed cooling with some differences according too a second embodiment,

(6) FIG. 5 is a view from the front of the same assembly as in FIG. 4, and

(7) FIG. 6 is a simplified view of the assembly in FIGS. 4 and 5.

(8) FIG. 7 shows a schematic view of the system of a further form of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(9) Referring in detail to the drawings, the invention in its broadest sense can apply to any machine where temperature regulation is called for.

(10) One application that has been found to be particularly relevant relates to molds for injection plastics where extraction after molding of a finished product has to wait until the plastic has cooled sufficiently to be self supporting and therefore able to be extracted as an integral article.

(11) Getting cooling and especially somewhat uniform coiling to all parts of the injected product then becomes very important and can be very critical in obtaining good cycle times.

(12) I have previously disclosed a technique where there is a cooling space adjacent a heat source and within the cooling space there is a liquid and above this only substantially the vapour of the liquid within the space.

(13) There are condensing means appropriately placed at another part within the space or as part of the wall of the space.

(14) The problem to which this invention is being directed relates to this same process although it can apply more broadly to any machine. Nonetheless where some of the liquid is selectively directed to an area this allows for selective control of an amount of liquid directed into an area and therefore it allows for better control of distribution of liquid and leads to better temperature regulation.

(15) If the liquid within the space is fed through a conduit, the pressure applicable to causing such liquid to pass through will be to a significant extent governed by the so called “head of liquid” from which the liquid is being supplied.

(16) Accordingly, according to traditional techniques, such head while it might be appropriate for one level below say a condenser within the space, nonetheless, where a take off might be somewhat lower than another take off, the difference in head could cause significant differences in the extent of fluid flow being effected through a similar take off and this can therefore reduce the uniformity that one can obtain between the take offs.

(17) The solution has been to provide a form of overflow where the liquid can be supplied to a selected level and any excess within that level then fed to a lower level but in such a way that this will not unnecessarily build up an excessive head of liquid to the further lower levels.

(18) This can be achieved by use of a simple conduit in the form of a gooseneck where, because the environment within the space above liquid is only or at least substantially only the vapour of that liquid, then this will ensure that a continuity of liquid needed for a siphon effect will not be maintained.

(19) In other words, the atmosphere within the space is the vapour pressure of the liquid so that a gooseneck will not in the ordinary sense therefore siphon.

(20) The arrangement also provides in this embodiment that there be provided in effect reservoirs at selected heights within the die and the take off tubes which can be one or two or more, are chosen to have a size that will function sufficiently with the given head of water. In practice there will be excess water which will flow through in the case of the application to lower reservoirs and of course such that each of the reservoirs is adequately supplied by this overflow.

(21) This action is shown in the embodiments which are described in the drawings where the drawing itself shows a die or mold where the part shown is one part only of a two part die where there is another part which is also equally configured to effect such cooling but as the die parts separate, they are individually cooled.

(22) Accordingly, referring to FIGS. 1, 2 and 3 there is a body 1 which has enclosed cooling area 2 which contains though this is not specifically shown in the drawings a liquid which in this case is water or water with additives as has been explained in earlier patents of mine, where the space 2 is defined by a backing plate 3 and a molding portion 4.

(23) Within portions of the molding surface 4 are take off tubes shown typically at 5 and 6, 7 and 8, 9 and 10, 11 and 12.

(24) In each case those shown in FIG. 2 are duplicated by further take offs behind these shown.

(25) Each of the take off tubes are fed from respective reservoirs which are shown 13, 14, 15, 16, 17.

(26) At an upper location within the space 2 is a condenser with a number of fins and having running therethrough a conduit through which cooling liquid can be passed to keep the temperature of the condenser 19 at a selected condensing temperature.

(27) In this case, the liquid resulting from condensation of vapour rising condenses and causes liquid to flow into a first reservoir area 21 from whence it is directed through a first conduit 22 to a first reservoir area 13.

(28) At the same time, there is a further conduit which feeds to a lower reservoir area 14 through a gooseneck shaped conduit at 24 through a conduit 23.

(29) From the reservoir 14, there is a conduit rising 25 that then follows a gooseneck with the apex of the gooseneck at 26 so that liquid then is overflowing through the gooseneck 26 and conduit 27 to reservoir 15.

(30) Because the atmosphere within the space is generally comprised only substantially only of the vapour of the liquid within the space, this will cause any break in syphoning effect that otherwise might occur so that the head of water effective for the respective lower reservoirs eg. 14 or 15 or others, is only that defined by the head of water within the down side of the respective gooseneck.

(31) In this case there are of course further reservoirs and further goosenecks where for instance gooseneck 28 is fed from reservoir 15 and feeds through conduit 29 to reservoir 16. Reservoir 16 in turn feeds gooseneck 30 into reservoir 17 which in turn feeds gooseneck 31. This in turn feeds into reservoir 18.

(32) In respect of each of the reservoirs there are the four take offs in each case and for the sake of clarity the number of these not separately identified.

(33) Inlets occur at spaced apart locations and have in each case a relatively consistent common size inlet.

(34) Such aspects can of course be varied so that there is some control as to the amount of liquid available and be used at each level.

(35) Further aspects of the die or mould include a thermo siphon to lift liquid into the upper space as needed this being shown at 32 where there is a lower conduit not specifically shown from lower space area 33.

(36) In the further drawings FIGS. 4 and 5 these show simply the functional part within a die part which incorporates this invention.

(37) Accordingly there are a plurality of cascade reservoirs 40 through 45 where each is of elongate shape so that the effect of separating heads of liquid are achieved by having a raised overflow that acts then as a cascade overflow shown at 46 through 50.

(38) This in effect then acts as a weir.

(39) The inlets to conduit feeds are arranged as shown typically at 51.

(40) There are shown especially in FIG. 4 return passageways for evaporated vapour at typically 52.

(41) FIG. 6 shows the same insert portion as in the first embodiment with gooseneck conduits 53 feeding successive reservoirs 54 from an upper area 55.

(42) This then illustrates how the invention will operate.

(43) With reference to FIG. 7 an embodiment of the present invention is shown in which there is a system 60 having a mould with an internal cavity within which plastic material can be injected to form a predefined shape, referred to as injection moulding. The mould is typically formed from two parts as those skilled in the art would know. In this figure the schematic only shows one half of a mould as a′ representative section and the invention is not to be limited by this.

(44) FIG. 7 shows the at least one internal cooling chamber 62, chamber cover not shown. The cooling chamber 62 further has an coolant inlet pipe 64 and a coolant outlet pipe 66 to provide entry and exit for a cooling liquid/refrigerant. The shape and size of the cooling chamber 62 may vary according to specific needs of design as required.

(45) The evaporator 67 is connected to the cooling chamber 62 of the mould via the coolant inlet pipe 64 to feed liquid refrigerant 68 at a predefined temperature to the cooling chamber 62.

(46) A compressor 70 has an inlet pipe 22 through which it receives refrigerant 72 in the vapour phase and then compresses the vapour phase 72 to produce a liquid phase refrigerant 73.

(47) The heat exchange unit 74 is fluidly connected to the compressor 70 by the pipe 76, the heat exchanger 74 removes the bulk of any heat within the liquid phase refrigerant 73 and then the liquid phase refrigerant 77 is then passed through a pressure control valve 78 and directed to the evaporator unit 67 for cooling to the predetermined temperature to provide recycled liquid phase refrigerant 68.

(48) In use, the liquid phase refrigerant 68 is a refrigerant material suitable for the purpose and can be selected from any suitable refrigerant material such as ammonia, butane, propane, ethane and CO.sub.2 for example. Other suitable low boiling point liquids can be employed and the person skilled in the art without departing from the scope of the present invention.

(49) The liquid phase refrigerant 68 is then supplied to the cooling chamber 62 of the mould. As hot plastics material is injected into the mould cavity, the heat from the hot plastics material is transferred to the walls of the mould cavity and this then is transferred to the liquid phase refrigerant 68, which then evaporates to produce a vapour phase refrigerant 72 thus producing an evaporative cooling effect.

(50) The temperature of the vapour phase refrigerant 72 is substantially the same as the liquid phase refrigerant 16 that has entered the cooling chamber 62, the absorbed thermal energy of the plastics material being used to convert the liquid phase refrigerant 68 to the vapour phase refrigerant 72.

(51) The vapour phase refrigerant 72 is then drawn off to an upper portion of the cooling chamber and is channelled to the compressor 70 where the vapour phase refrigerant 72 is compressed back into a liquid phase refrigerant 73. The liquid supply temperature from the compressor is under the control of a thermostat. At this stage there is a substantial build up of temperature in the liquid phase refrigerant 73.

(52) This hot liquid phase refrigerant 73 is than channelled to a heat exchanger unit 74 to take of the bulk of the heat in the liquid phase refrigerant 73 from conversion of the vapour phase refrigerant 72 to the liquid phase refrigerant 73. A cooling section 75 is operatively connected to the heat exchanger 74 to then dispose of any excess heat in the heat exchanger 74.

(53) The liquid phase refrigerant 77 from the heat exchanger 74 is still typically at a temperature that is greater than the temperature at which it is required to be in order to be used as a cooling liquid for the mould. As such, the liquid phase refrigerant 77 is passed through a pressure control valve 78 to regulate the feed of liquid phase refrigerant 77 into the evaporator unit 67, which cools the liquid phase refrigerant 34 to a temperature suitable for cooling use in the mould. Any excess vapour phase refrigerant is then directed towards the compressor via pipe 69.

(54) The use of such a system and method as described results in a simpler system that is presently used in mould cooling setups that employ water as the cooling liquid. The internal architecture of the cooling chamber is therefore less complicated than those of previous designs that might use a condenser.

(55) This new system and method also provides for increased cooling efficiency of the mould, allowing for potentially a decrease in time between cycles due to the efficient heat take off from the mould.

(56) Such a system can be employed in such apparatus as moulding machines, as described above, and other machines or systems in which there is build up of heat and there is a need to remove the heat away from the system, for, example in engines.