US3593729A

US3593729A - Vapor degreaser

Info

Publication number: US3593729A
Application number: US754140*A
Authority: US
Inventors: David Goldware
Original assignee: David Goldware
Current assignee: CYCLO-TRONICS Inc
Priority date: 1968-07-29
Filing date: 1968-07-29
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20

Abstract

A portable degreaser comprising two concentric tanks separated by a perforated wall. The concentric tanks are an immersion tank located within a solvent-boiling tank which serves as an offsetvapor-generating sump. The rinse and spray area above the immersion tank is surrounded by a perforated wall. Boiling solvent is on the other side of the wall. Condensing coils encircle the perforated wall at the top of the spray area and thus, are exposed to the vapor an all sides. A gutter immediately below the condensing coils returns the condensed liquid into a separate distillate tank equipped with a water separator. The spray jets are supplied with the distilled solvent from the distillate tank. The distillate is kept hot since the lower portion of the tank is positioned within the boiling sump.

Description

United States Patent Primary Examiner-Daniel Blum AttorneyAlter, Weiss & Whitesel ABSTRACT: A portable degreaser comprising two concentric tanks separated by a perforated wall. The concentric tanks are an immersion tank located within a solvent-boiling tank which serves as an offset-vapor-generating sump. The rinse and spray area above the immersion tank is surrounded by a perforated wall. Boiling solvent is on the other side of the wall. Condensing coils encircle the perforated wall at the top of the spray area and thus, are exposed to the vapor an all sides. A gutter immediately below the condensing coils returns the condensed liquid into a separate distillate tank equipped with a water separator. The spray jets are supplied with the distilled solvent from the distillate tank. The distillate is kept hot since the lower portion of the tank is positioned within the boiling sump.

PATENIED JUL2 0 ran SHEET 1 BF 3 FIG! INVENTOR DAVID GOLDWARE ATTORNEYS PATENTEU JUL20 ISYI SHEET 2 OF 3 INVENTOR DAVID GGLDWARE ATTORNEYS VAPOR DEGREASER The invention relates to vapor degreasers, and more par ticularly, to degreasers that provide a combination dip, spray and vapor cleaning facility as well as solvent vapor dryers.

A problem with present day vapor degreasers is the loss of solvent which escapes past the condenser coils due to penetration of the interface between boiling and refrigeration temperatures. This occurs due to vapor-air diffusion caused by the boiling action of the solvent within a completely open top tank. The perforated wall separating the two concentric tanks virtually eliminates this vapor-air diffusion. Also, the interfacing capacity of refrigerate coils on the presently available degreasers are limited because the coils are located on the ex terior walls of the degreaser tank and thus, present only a limited surface to the vapor as it passes the coils.

Also encountered by present day vapor degreasers is restricted working volume in the degreaser for handling products to be degreased. The inefficiency in the use of the cleaning area of the presently available vapor degreasers is caused by the method of separation of the immersion tank and the boiling tank. A baffle is used to divide one tank. The baffle, of course, limits the length of the product being degreased as well as the width.

A further problem encountered by vapor degreasers is the spraying of cold distilled solvent. The temperature of the condensing coils is thermostatically controlled. Should cold solvent be sprayed upon the condensing coils when it is about to call for refrigeration, an unbalanced temperate condition is set up. Hot vapors surrounding these coils demand refrigeration at the right time otherwise the vapors escape past the coils and are lost. This is costly as well as uncomfortable due to the escaping fumes. A further disadvantage is that cold solvent is not as efficient a cleaning agent as hot.

Accordingly, an object of this invention is to provide a unique vapor degreaser.

A related object of the tank is to provide vapor degreasers wherein the refrigerate coils are not mounted on any closed walls.

Yet, another object of this invention is to provide vapor degreasers wherein no baffle is required between the immersion tank and the boiling tank. Thus, no baffle is located within the rinse and spray working area.

Yet, another object of this invention is to provide a vapor degreaser having a heated reserve distillate tank equipped with a water separator that is connected directly to gutters located below the refrigerate coils so that only clean, freshly distilled solvent is pumped through the sprays.

Another object of this invention is to create a double boiler effect wherein the boiling action is restricted to the outer con centric tank only, by means of-slightly elevating the inner concentric tank.

Briefly, an exemplary embodiment of this invention accomplishes these and other objects by means of an immersion tank that is located within a boiling tank. The boiling tank serves as an offset-vapor-generating sump. Since the vapor-producing tank is located outside the immersion tank within the complete degreasing unit, vapor pressure tends to rise around the immersion tank as well as the spray area and is reduced by 60 percent before flowing through the perforated wall towards the opening at the top of the degreaser through which the product to be degreased is put into the degreasing spray and rinse area. The spray and rinse area is surrounded by this perforated wall. The perforated wall is surrounded by the refrigerate coils at some point near the top thereof. Thus, while the refrigerate coils are exposed to vaporized solvent on all sides the vapors within the rinse and spray area are relatively static and perform much more efficiently. Vapor-air diffusion is minimized. A gutter located beneath the refrigerate coils catches the distilled, condensed solvent and returns it to a reserve distillate tank that is equipped with a water separator. Sprays are supplied from the reserve distillate tank.

The abovementioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood, by reference to the following description of an embodiment of an invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 pictorially shows the complete inventive vapor degreasing unit;

FIG. 2 is an exploded view of that portion of the tank into which the work product being degreased may enter;

FIG. 3 is a semisectional front view of the complete degreaser showing the assembly of the central units of the degreaser;

FIG. 4 is a top sectional view of the degreaser unit looking in the direction of the arrows 4-4 of FIG. 3; and

FIG. 5 is a sectional view of the distillate reserve tank look ing in the direction ofthe arrows 5-5 in FIG. 3.

Similar characters of reference indicate corresponding parts and features throughout the several views, and referring now to the same; the character 10 indicates the complete vapor degreasing unit. The degreaser unit as best shown in FIG. 1, comprises a unit which may be mounted on casters, such as caster l], for portability. The complete unit is made up of two r sections, the degreasing section llll and the control and refrigerating section 12. The control and refrigerating units are located beneath panel 114. The degreasing section lll comprises a cover 15 closing the opening of the freeboard above the spray and rinse area. The cover has in the middle thereof a handle 17 enabling its easy removal from the opening.

The degreasing area of the vapor degreaser unit as best shown in FIG. 2, comprises a freeboard section 118, a rinse and spray area wall separator 19 comprised of perforated material and an immersion tank 21. The rinse and spray area wall 19 is encircle near the top thereof by condenser or refrigerate coils 22. Apertures, such as apertures 23, are provided in the perforated wall 19 to enable spray from the jets 25 to pass therethrough. The tubing 24 leads to spray jets, such as spray jet 25 shown in FIGS. 3 and 4.

The control panel 13 comprises switches and indicators for controlling the degreaser unit. Thus, there is shown a boiling tank liquid level indicator 26 and a reserve distillate tank liquid level indicator 27. The switches include: switch 28 for controlling an idling heater strip, switch 29 which controls a main heater strip, and switch 31 which controls the refrigerator unit. A spray control switch, such as switch 32, is shown. A spray cycle timer, if one is desired, is controlled by switch 33. Red warning light 34 is in conjunction with a low solvent level safety mechanism which automatically shuts off all heaters.

A drain cock is provided as illustrated at 36 for removing all of the solvent from the unit. Alternatively, a drain cock 36a is provided for purifying and reclaiming dirty solvent through distillation.

As is apparent in FIGS. 2 and 3, the freeboard section 18 rests on top of the outer cabinet 16 on its flange 38. A peripheral offset 39 is located at the bottom of the freeboard section. The peripheral offset 39 fits over the top of the perforated wall section 19. The wall section 19 fits within the peripheral offset section 41 of the immersion tank 21. A drain 42 covered by stainless steel mesh filter is located near the bottom of the immersion tank 21, to facilitate draining the tank, during cleaning operations, for example.

The operation and the assembly of the combined units is best seen in FIG. 3. A vapor-generating boiling tank, 43 extends upward to the middle portion of freeboard l3 and surrounds most of the assembly of the units shown in FIG. 2.

Means are provided for capturing the condensed fluid. More particularly, gutter 44 extends beneath the condensing coils 22 and is coupled into a separate distillate reserve tank 46 through piping 47. The distillate reserve tank 46 is positioned so that it is partly submerged within the boiling sumps, as indicated by boiling level line A-A.

The distillate reserve tank 46 is shown in greater detail in FIG. 5. It serves to hold the freshly distilled solvent for use in spraying articles being degreased. The tank is equipped with a float 48. The float in moving varies an impedance; for example, which changes a signal thereacross. The impedance leads to conductors 49, which are connected to reserve distillate tank liquid level indicator 27.

Means are provided within the tank 46 to separate any water from the condensed solvent. More particularly, tank 46 includes a baffle 51 which partitions the water separator por tion of tank 46 from the rest of the tank. The water separator portion 52 is directly under the input pipe 47 through which the condensed solvent flows from gutter 44. Thus, the condensed solvent enters the tank 46 through the water separator portion 52. The solvent is heavier than water so that the water floats thereupon. An outlet 53 is located near the top of the water separator portion 52 of the reserve tank 46 so that when portion 52 fills up with water and solvent sufficiently high to enable the water to flow out of outlet 53, the water is removed from the unit. The water flows through outlet 53 to a shallow evaporator pan (not shown) which is placed in the vicinity of the refrigerator fan unit. Thus, the evaporation of the water is accomplished and the necessity of connecting to external plumbing to carry the water away is obviated. It should be noted that baffle 51 cooperates with smaller baffle 51a to maintain the water in the water separator unit.

Means are provided to enable solvent from tank 46 to flow into tank 43. In greater detail, an overflow outlet 54 is located in the reserve solvent portion of the tank to enable the solvent, when it reaches this level in the tank, to flow directly into the boiling tank 43.

Means are provided for transmitting the freshly distilled solvent to the jet sprays. ln greater detail, at the bottom of the reserve tank is an outlet and piping 56 which leads to pump 57. The pump 57 is then connected to the jet sprays, such as spray through pipe 24. Thus, the sprays are supplied with freshly distilled solvent at all times in the operating cycle of this degreaser.

The sprayed fluid which is emitted from jet sprays, such as jet spray 25, falls into the immersion tank 21. The liquid solvent in the immersion tank is indicated by numeral 58. Thus, flow occurs from boiling tank 43 where the solvent is vaporized, to condenser coils 22 where the solvent is condensed, gutter 44, tank 46, pump 57, spray jets, such as spray jet 25 to immersion tank 21.

When the immersion tank overflows, the solvent falls back into tank 43 and at the same time is filtered through a fine stainless steel mesh at the overflow height in order to prevent any floating particulate matter from entering the outer concentric tank.

Means are provided for preventing solvent 58 in immersion tank 21 from boiling. in greater detail, tank 21 has legs, such as leg 59, which maintain space 60 between the bottom 61 of boiling tank 43 and the bottom 62 of immersion tank 21. The space acts to insulate the immersion tank from the heat of the heating elements; such as element 63 located in the heating compartment 64. The heat generated by the heating element in compartment 64 is sufficient to boil the fluid solvent in tank 43, but is prevented from boiling the solvent in tank 21 by the fact that tank 21 is not directly contiguous to the bottom 61 of the tank 43.

Means are provided in boiling tank 43 for properly locating the immersion tank 21. More particularly,

angle irons

64, 66 located on floor 61 of tank 43 abut the legs, such as leg 59, of

tank 21 to properly locate that tank when it is lowered into position in tank 43.

Means are provided for monitoring the height of the boiling solvent, designated as 67, in the boiling tank 43. More particularly, a float 68 is coupled to variable impedance means 69 which is connected to indicator 26 on the control panel. This provides a feature whereby the height of the boiling solvent is continuously monitored. The impedance means 69 is shown in FIG. 4; switching means could, of course, be used in place of the impedance means. The essential matter is that a safety mechanism is provided for monitoring the level of the boiled liquid. Additional safety features include a thermostat 71 which automatically turns off the heating unit when the boiling solvent 68 becomes too hot.

The outer tank or boiling tank 43 has a bottom floor section 72 which defines the bottom of the heating space 64. Spacers, such as spacer 73, are used to space the boiling tank 43 from the bottom floor 74 ofthe cabinet 16.

Means are provided for completely draining the solvent from the degreaser unit. More particularly, a valve 76 attaches to outlet 42 on the inner tank or immersion tank 21. The valve is controlled by valve control handle 77 which extends through the top section 78 of tank 43. A long stem 79 reaches from handle 77 to valve 76. The immersion tank solvent 58 is emptied into boiling tank 43 through a fine stainless steel mesh filter when it is desired to drain all the fluid from the degreaser unit. Bottom floor 61 of tank 43 has an outlet 81 which leads to drainage pipe 82 and through valve 36 to outlet drain 83. Opening both valves enables the removal of all solvents from the degreaser unit.

As an alternative to drainage through outlet 81, most solvent may be removed by distillation and pumped out of distillate reserve tank as it is purified.

The refrigerating unit 84 is shown in FIG. 3.

Tubing

22a and 22b lead from the refrigerating unit to refrigerate coils 22 in tank 43. The refrigerating unit may rest on spacers such as spacer 86.

Means are provided for maximizing the operating efficiency of coils 22. That is, the condensing coils 22 are not mounted on a closed wall, rather they are mounted on perforated wall 19 and thus, are exposed to the vapor on all sides.

Means are provided for maximizing the working space available in the rinse and spray area and in the boiling tank. This is accomplished in that the immersion tank is set within the boiling tank. The configuration of the boiling tank 43 surrounding immersion tank 21 does away with baffling in the rinse and spray area. This makes it possible to degrease larger products than would be possible with the normally operated degreasing machines that have baffling between immersion and boiling sections within the tank.

The controls used in this degreasing machine are those which are normally found on similar type degreasing units. Thus, for example, a l0-second spray is available by actuation of the proper switch, such as switch 32, for example. The switch activates a time delay cycle apparatus whereby the machine is automated to give a lO-second spray cycle. This may be changed to a S-second spray cycle, if so desired, or any other useful time delay required.

A foot switch may be provided to operate the spray jets if so desired. Electrical circuitry for these controls is not shown herein because it is believed that it is obvious to those skilled in the art.

A thermostat control 88 is located above condensing coils 22. This thermostat control operates to turn the machine off if the vapor level should rise too high or the refrigeration unit should break down and the condensing coils are not operating. Then vapor would reach thermostat control 88 causing it to heat and turn off the degreasing machine heaters.

All of the degreaser parts are preferably made from stainless steel sheet metal. One of the heating strips is so wired in heating section 64 whereby the degreasing machine can be idled overnight under low wattage without having to turn the machine off. The overnight idle enables the reserve tank to refill, and precludes the necessity of having a warmup time before using the machine.

Of further importance is the fact that while the machine is on idle heat, the vapor zone is maintained. Loss of the vapor zone is a loss of expensive solvent. Idling the machine obviates the necessity to reestablish the vapor zone.

While not shown, an electric cable connects the degreasing machine to a power source. Also not shown are the electrical controls and the connections between the floats and thermostats and the control panel. These details are well known to those skilled in the art.

In operation, the vapor degreaser is turned on. The refrigeration unit sends refrigerant through the condensing coils 22 mounted on mesh perforated wall 19. The heating units, such as heating units 63 causes the solvent in tank 43 to boil. The vapor fills the area outside the perforated wall as well as the rinse and spray area surrounded by perforated wall 19 but is prevented from going higher than the coils 22 by the efiicient condensing action of coils 22. Since the coils 22 are exposed to vapor on all sides it condenses a much greater capacity of vapor than the available units that mount their coils on an exterior wall and thus remove a large portion of the operating area of the coils.

The condensed solvent is fed into reserve tank 46. From there it is pumped through jet sprays mounted in the spray and rinse area. The sprayed solvent returns to the immersion tank 21.

The cover is removed to place articles for degreasing into the machine. The high freeboard, and especially the offset vapor generator as well as the efficient action of the condensing coils prevents any vapor from escaping through the opening at the top of the cabinet H6. The article is held in the vapor below coils 22 or immersed in the tank 41 and then sprayed. Thus, the article for degreasing is subjected to the degreasing eiTects of immersion, vapor and spray. The absence of any baffle in the rinse and spray area or in the immersion tank makes it possible to service larger size articles than could be done in similar-sized degreasing units. In addition, there is no necessity of moving the article, other than lowering and raising it to go from an immersion step to a vapor-processing step and vice versa.

While I have described the above principles of my invention, in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention,

lclaim:

1. A degreaser unit for degreasing articles of manufacture,

said unit comprising an outer cabinet,

said cabinet having therein a vapor-generating tank for converting liquid solvent into vapor,

heating means associated with said vapor-generating tank to provide the heat to cause said solvent to boil and provide vapor,

means for condensing said vapor to prevent the vapor from leaving said degreaser unit,

immersion tank means located within said vapor-generating tank,

said immersion tank means being surrounded on all sides by the solvent in said vapor-generating tank, and

legs on said immersion tank to keep the bottom of said immersion tank separated from said heating means to thereby keep the solvent within said] immersion tank from boiling.

2. The degreaser unit of claim ll, wherein a rinse and spray area is provided above said immersion tank, and

wherein said rinse and spray area is surrounded by perforated wall means.

3. A degreaser unit for degreasing articles of manufacture, said units comprising an outer cabinet,

said cabinet having therein a vapor-generating tank for converting liquid solvent to vapor,

heating means associated with said vapor-generating tank to provide the heat to cause the solvent to provide vapor, means for condensing said vapor to prevent the vapor from leaving said degreaser unit,

immersion tank means located within said vapor-generating tank, legs on said immersion tank to keep the bottom of said immersion tank separated from said heating means to thereby prevent the solvent within said immersion tank from boiling,

a rinse and spray area located above said immersion tank,

said rinse and spray area being surrounded by perforated wall means, and

said means for condensing said vapors comprising refrigerate coils attached to said perforated wall means, thereby maximizing exposure of said coil means to the vapor.

4. The degreaser unit of claim 3 wherein gutter means are provided below said coil means to trap solvent condensed by said coil means, and

reserve distillate tank means for receiving said condensed solvent,

spray jet means in said spray and rinse area, and

means for passing said condensed solvent from said reserve distillate tank through said spray jet means under pressure to provide a spray of condensed solvent.

5. The degreaser unit of claim 4 wherein the distillate tank is so positioned as to be partly submerged within the liquid solvent in the vapor-generating tank.

6. The degreaser unit of claim 5 wherein said reserve distillate tank is provided ti ith water separator means to assure a spray of pure solvent.

7. The degreaser unit of claim 6, wherein level indicator means are provided to indicate the level of solvent in said vapor-generating tank.

8. The degreaser unit of claim 7 wherein said perforated wall means is located and held between said immersion tank and a freeboard section, and

flange means on said freeboard section whereby said freeboard section rests on the top of said cabinet at an article insertion opening.

Claims

1. A degreaser unit for degreasing articles of manufacture, said unit comprising an outer cabinet, said cabinet having therein a vapor-generating tank for converting liquid solvent into vapor, heating means associated with said vapor-generating tank to provide the heat to cause said solvent to boil and provide vapor, means for condensing said vapor to prevent the vapor from leaving said degreaser unit, immersion tank means located within said vapor-generating tank, said immersion tank means being surrounded on all sides by the solvent in said vapor-generating tank, and legs on said immersion tank to keep the bottom of said immersion tank separated from said heating means to thereby keep the solvent within said immersion tank from boiling.

2. The degreaser unit of claim 1, wherein a rinse and spray area is provided above said immersion tank, and wherein said rinse and spray area is surrounded by perforated wall means.

3. A degreaser unit for degreasing articles of manufacture, said units comprising an outer cabinet, said cabinet having therein a vapor-generating tank for converting liquid solvent to vapor, heating means associated with said vapor-generating tank to provide the heat to cause the solvent to provide vapor, means for condensing said vapor to prevent the vapor from leaving said degreaser unit, immersion tank means located within said vapor-generating tank, legs on said immersion tank to keep the bottom of said immersion tank separated from said heating means to thereby prevent the solvent within said immersion tank from boiling, a rinse and spray area located above said immersion tank, said rinse and spray area being surrounded by perforated wall means, and said means for condensing said vapors comprising refrigerate coils attached to said perforated wall means, thereby maximizing exposure of said coil means to the vapor.

4. The degreaser unit of claim 3 wherein gutter means are provided below said coil means to trap solvent condensed by said coil means, and reserve distillate tank means for receiving said condensed solvent, spray jet means in said spray and rinse area, and means for passing said condensed solvent from said reserve distillate tank through said spray jet means under pressure to provide a spray of condensed solvent.

6. The degreaser unit of claim 5 wherein said reserve distillate tank is provided with water separator means to assure a spray of pure solvent.

8. The degreaser unit of claim 7 wherein said perforated wall means is located and held between said immersion tank and a freeboard section, and flange means on said freeboard section whereby said freeboard section rests on the top of said cabinet at an article insertion opening.