VAPOR GENERATING AND RECOVERY APPARATUS INCLUDING CONTINUOUS CONVEYING MEANS THROUGH A VAPOR ZONE

Abstract: An apparatus for vaporizing a liquid and condensing the vapor includes at least one chamber in which the liquid is vaporized and at least one chamber in which the vapor is condensed. The apparatus has a conveyor inlet channel preferably at one end of the vaporizing chamber, and a con­ veyor outlet channel preferably at the opposite end of the vaporizing chamber. A conveyor for moving items to be treated through the apparatus extends through the con­ veyor inlet channel into the vaporizing chamber and out of the vaporizing chamber through the conveyor outlet chan­ nel. The appatatus includes a heat emitting device in the va­ porizing chamber for vaporizing the liquid therein, and a cooling device in the condensing chamber for condensing the vapor.

Description: The invention relates to a vapor generating and recovery apparatus comprising the features as indicated in the precharacterizing part of claim 1. In such a vapor generating and recovery apparatus as disclosed in US-A-4,389,797, objects to be surface treated will be moved by conveyor inlet means into and by means of conveyor outlet means out of the vapor chamber. Heat emitting means located at the bottom of the vapor chamber heat a liquid to a temperature such that liquid vaporizes. Cooling coils which are located at the top side of the vapor chamber and at openings of the conveyor inlet and outlet means are provided to retain vapor in the surface treating zone. It is the object of the invention to improve a vapor generating and recovery apparatus such that substantially all of the vapor generated in the operation will be recovered. In accordance with the invention, this object is solved by the features as claimed in the characterizing part of claim 1. In the inventive vapor generating and recovery apparatus, vapor chamber and condensing chamber are separated from one another by a wall. An aperture in said wall is located laterally to one side of conveyor means. Such a path for vapor is defined in a general direction away from and beneath the conveyor inlet and outlet openings into the condensing chamber. In a further development of the inventive vapor generating and recovery apparatus, vapor traps are arranged at conveyor inlet and outlet means in order to prevent vapor flow out of the openings. Other further developments of the invention are claimed in the subclaims. A preferred embodiment of the invention will be explained in accordance with the drawing, in which: Figure 1 is a side view in schematic representation, partially broken away, of an advantageous embodiment of a vapor generating and recovery apparatus of the present invention; Figure 2 is a top view of the apparatus of Figure 1; Figure 3 is an enlarged view of a portion of the apparatus of Figure 1 as viewed in the direction of arrows 3-3 in Figure 1; and, Figure 4 is a schematic of the refrigeration system for the apparatus of the present invention. DETAILED DESCRIPTION With reference to Figures 1 and 2, there is shown a vapor generating and recovery apparatus, generally denoted as the numeral 10, for vaporizing and recovering a treating liquid 12. The apparatus 10 can be used, for example, for cleaning objects 40 of oil, grease, wax or particulate matter, or for heat treating an object 40 for shock testing or metal reflow. The examples, however, are only given by way of illustrating some end uses of the apparatus 10 and are not to be considered in any way as limitations. The apparatus 10 has virtually endless applications, and the composition of the liquid 12 will, of course, depend upon a particular end use. The vapor generating and recovery apparatus 10 includes a housing 14 having spaced apart side walls 16 and 18, spaced apart end walls 20 and 22, and a floor 24. A partition wall 26 spans the distance between the end walls 20 and 22 dividing the interior of the housing 14 into at least one vaporizing chamber 28 wherein a treating liquid 12 is vaporized to create a vapor zone 31 above the liquid 12 and at least one condensing chamber 30 wherein the generated vapor 31 is condensed. A path of vapor communication from the vaporizing chamber 28 to the condensing chamber 30 is defined by means of, an aperture 32 formed in the partition wall 26. The aperture 32 is located at the upper level of the vapor zone 31 in the vaporizing chamber 28 and functions in the manner of a weir for the flow of vapor from the vaporizing chamber 28 into the condensing chamber 30. The apparatus 10 also includes conveyor inlet means illustrated as a channel or tunnel 34 located at one end of and open to the vaporizing chamber 28, and conveyor outlet channel means illustrated as a channel or tunnel 36 located at the opposite end of and open to the vaporizing chamber 28. As shown, the inlet and outlet tunnels 34 and 36 are formed by closed ducts which extend into the vaporizing chamber 28. Conveyor means, such as, for example, an endless belt conveyor device 38 extends through the conveyor inlet tunnel 34 into the vaporizing chamber 28, across the vaporizing chamber 28, and out of the vaporizing chamber 28 through the conveyor outlet tunnel 38. The portion of the conveyor 38 extending across the vaporizing chamber 28 is disposed at an elevation below the vapor aperture 32 in the partition 26 and, therefore, below the upper level of the vapor zone 31 in the vaporizing chamber 28. The conveyor 38 is used to continuously move objects 40 through the vaporizing chamber 28 wherein they are surface treated by the vapor 31. The apparatus 10 further includes heat emitting means 42 located in the vaporizing chamber 26 for heating the treating liquid 12 to a temperature above the vaporizing temperature to create the vapor zone 31 above the liquid 12, and cooling means 44 located in the condensing chamber 30 for cooling the vapor to a temperature below the vaporizing temperature to cause the vapor to condense in the condensing chamber 30. As shown, the heat emitting means 42 comprises at least one heat emitting coil located above the housing floor 24 in the vaporizing chamber 28 and immersed in the treating liquid 12 to be vaporized. As illustrated, the cooling means 44 comprises at least one heat absorbing coil located just below the vapor aperture 32 in the condensing chamber 30. The heat emitting coil 42 and heat absorbing coil 44 can be of virtually any type such as, for example, the heat emitting coil 42 can be an electrically heated coil and the heat absorbing coil 44 can be a water cooled coil. However, it is preferred that the heat emitting coil 42 be a refrigerant condensing coil, and the heat absorbing coil 44 be a refrigerant evaporating coil of a refrigerant system 46, hereinafter discussed. With reference to Figures 1, 2 and 3, in order to prevent vapor from migrating out of the vaporizing chamber 28 through the conveyor inlet and outlet tunnels 34 and 36, thereby resulting in the loss of liquid and contamination of the ambient atmosphere, a vapor trap means 48;50 may be provided at one of the openings in the housing 14 for receiving the conveyor 38. In a preferred apparatus, vapor trap 48;50 means are provided at both the conveyor inlet and outlet 34,36. In the preferred apparatus 10, a first vapor trap 48 is provided at the conveyor inlet tunnel 34, and a second vapor trap 50 is provided at the conveyor outlet tunnel 36. With respect to the direction of travel of the conveyor device 38, the first vapor trap 48 is located upstream of the conveyor inlet tunnel 34, and the second vapor trap 50 is located downstream of the conveyor outlet tunnel 36. The vapor traps 48 and 50 are substantially identical, and, therefore, for the sake of brevity only the first vapor trap 48 will be described, it being understood that the description applies equally to the second vapor trap 50. As can be best seen in Figure 3, the vapor trap 48 comprises an outer compartment 52 open to the conveyor inlet tunnel 34, through which the conveyor 38 traverses, and an inner compartment 54 located within the outer compartment 52 below the path of the conveyor 38 through the outer compartment 52. Vapor or fluid recovery is provided for through the inner compartment 54 and outer compartment 52 by means of, for example, a first aperture 56 formed in the inner compartment 54 defining means to provide fluid flow communication between the inner compartment 54 and outer compartment 52, and a second aperture 58 in the inner compartment 54 defining means at the opposite side of the inner compartment 54 from the first aperture 56 to provide fluid flow communication between the inner compartment 54 and outer compartment 52. Fluid circulates across the outer compartment 52, through the first aperture 56, across the inner compartment 54 and through the second aperture 58 by, for example, a fan 60 located at, for example, the second aperture 58. The vapor trap 48 further includes cooling moans 62 located in the outer compartment 52 for condensing the vapor entrained in the gas stream circulated by the fan 60. The cooling means 62 cools the vapor to a temperature below its vaporizing temperature causing it to condense in the outer compartment 52. The condensate is returned to the vaporizing chamber 28 from the outer compartment 52 of the vapor trap 48 by means of, for example, a conduit 64 having its open inlet end at the bottom region of the outer compartment 52 and its open outlet end in the vaporizing compartment 26. The cooling means 62 comprises at least one heat absorbing coil located at the first aperture 56 in the inner compartment 54, and it can be of virtually any type, such as, for example, a water cooled coil. However, preferably, the cooling means 62 is a refrigerant evaporator coil of a refrigerant system 46 hereinafter described. With reference to Figure 4, there is shown in schematic an example of the refrigerant system 46. The exemplary refrigerant system 46 is illustrated as comprising a refrigerant compressor 66 for compressing a suitable refrigerant. The high pressure side of the refrigerant compressor 66 is in refrigerant flow communication with the refrigerant condensing coil 42 (heat emitting means) through a refrigerant gas conduit 68. The refrigerant evaporator coil 62 of the first evaporator trap 48 is located downstream of the refrigerant condensing coil 42 and is in refrigerant flow communication with the refrigerant condensing coil 42 through conduit 70. A conventional refrigerant receiver 72, dryer 74 and appropriate thermal expansion valve 76 are also operatively disposed in the conduit 70 between the refrigerant condensing coil 42 and the refrigerant evaporator coil 62. The refrigerant evaporator coil 44 of the cooling means is located downstream of the refrigerant evaporator coil 62 of the first vapor trap 48 and is in refrigerant flow communication with the refrigerant evaporator coil 62 through a refrigerant conduit 78. The refrigerant evaporator coil 62 of the second evaporator trap 50 is located downstream of the refrigerant evaporator coil 44 and is in refrigerant flow communication with the refrigerant evaporator coil 44 through conduit 80. The outlet of refrigerant evaporator coil 62 of the second evaporator trap 50 is in refrigerant flow communication with the low pressure side of the compressor 66 to complete the refrigerant circuit. The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications will become obvious to those skilled in the art upon reading this disclosure.

Claims: A vapor generating and recovery apparatus (10) comprising : means defining at least one vaporizing chamber (28) in which a liquid (12) is vaporized ; heat emitting means (42) located in the vaporizing chamber (28) for heating the liquid (12) to a temperature above the vaporizing temperature to create a vapor zone above the liquid ; cooling means (44) for cooling the vapor to a temperature below the vaporizing temperature ; at least one opening in the apparatus (10) providing conveyor inlet and outlet means (34, 36) and conveyor means (38) extending through the conveyor inlet (34) into the vaporizing chamber (28), across the vaporizing chamber, and out of the vaporizing chamber through the conveyor outlet (36) ; CHARACTERIZED BY means defining at least one condensing chamber (30) adjacent to the vaporizing chamber (28) in which said cooling means (44) is located and the vapor (31) is condensed and separated from the vaporizing chamber (28) by a wall (26) ; and an opening (32) disposed within said wall (26) spaced from said at least one opening (34,36) in the housing (10) whereby vapors to be condensed are drawn away from said at least one opening (34,36) in the housing (10) and said opening (32) in said wall (26) definis a path for vapor communication from the vaporizing chamber (28) to the condensing chamber (30) through the wall (26), which is located laterally to one side of the conveyor means (38). The apparatus of claim 1, said conveyor inlet means (34) being on the opposite side of said apparatus (10) from said conveyor outlet means (36). The apparatus of claim 1, further comprising a vapor trap means (48, 50) disposed at said at least one opening (35, 36). The apparatus of claim 3, wherein the vapor trap means (48, 50) comprises : means defining an outer compartment (52) having openings therein for receiving conveyor means (38) therethrough and through which the conveyor means traverses ; means defining an inner compartment (54) within the outer compartment (52) ; means (56, 58) providing for fluid circulation through the inner and outer compartments (54, 52) ; and cooling means (62) disposed within the trap means (48, 50) for condensing the fluid flowing out of the vaporizing chamber (28). The apparatus of claim 4, wherein the cooling means (62) of the vapor trap means (48, 50) is located in the outer compartment (52). The apparatus of claim 4, wherein the means (56, 58) providing for fluid circulation through the inner and outer compartments (54, 52) of the vapor trap means (48, 50) comprises : a first aperture (56) in the inner compartment (54) defining means providing flow communication between the inner and outer compartments (54, 52) ; a second aperture (58) in the inner compartment (54) defining means at the opposite side of the inner compartment from the first aperture (56) providing flow communication between the inner and outer compartments (54, 52) ; and, means (60) for moving fluid across the outer compartment (52), through the first aperture (56), across the inner compartment (54), and through the second aperture (58). The apparatus of claim 6, wherein the fluid moving means of the vapor trap (48,50) comprises fan means The apparatus of claim 4, wherein : the heat emiting means (42) in the vaporizing chamber (28) comprises at least one refrigerant condensing coil of a refrigerant system ; the cooling means (62) of the vapor trap means (48, 50) comprises at least one refrigerant evaporator coil of the refrigerant system ; and the cooling means (44) in the condensing chamber (30) comprises at least one refrigerant evaporator coil of the refrigerant system. The apparatus of claim 1, further comprising : first vapor trap means (48) located upstream of the conveyor inlet means (34) for capturing and condensing vapor (31) flowing out of the vaporizing chamber (28) through the conveyor inlet means (34) ; second trap means (50) located downstream of the conveyor outlet means (36) for capturing and condensing vapor (31) flowing out of the vaporizing chamber (28) through the conveyor outlet means (36) ; means (64) for returning condensate from the first trap means (48) to the vaporizing chamber (28) ; and means (64) for returning condensate from the second trap means (50) to the vaporizing chamber (28). The apparatus of claim 1, wherein said opening (32) defines weir means located at the upper level of the vapor zone (31) in the vaporizing chamber (28). The apparatus of claim 1, wherein the cooling means (44) in the condensing chamber (30) is located below said opening (32). The apparatus of claim 1, further comprising means for circulating condensate from the condensing chamber (30) to the vaporizing chamber (28). The apparatus of claim 1, wherein : the heat emitting means (24) comprises at least one refrigerant condensing coil of a refrigerant system ; and the cooling means (44) comprises at least one refrigerant evaporator coil of a refrigerant system. The apparatus of claim 1, wherein the at least one opening (34, 36) in the housing (14) includes a tunnel through which said conveyor (38) passes. The apparatus of claim 2, wherein the opening (32) in the wall (26) is disposed substantially equi-distant between the conveyor inlet means (34) and the conveyor outlet means (36).

Inventors: MCCORD, JAMES W.
Applicants: DOVER CORPORATION
Application year: 1985
Main classification: B01D1
IPC codes: B01D1, B01D3, B23K1, C23G5, B08B3, B01D5