US2867991A

US2867991A - Invertible evaporator

Info

Publication number: US2867991A
Authority: US
Inventors: Makowski Jerzy
Original assignee: Fairchild Engine and Airplane Corp
Current assignee: Fairchild Engine and Airplane Corp
Priority date: 1957-07-18
Filing date: 1957-07-18
Publication date: 1959-01-13
Anticipated expiration: 1976-01-13

Description

Filed July 18, 1957 INVENTOR JERZY MAKOWSKI i l H 15 ATTORNEYS INVERTIBLE EVAPORATOR N. Y., assignor to Fairchild Hagerstown, Md, a

Jerzy Makowski, Babylon,

Engine and Airplane Corporation, corporation of Maryland This invention relates to an apparatus in which vapor is evolved from a liquid and which is capable of operating in either an upright or an inverted position.

In evaporative cooling systems, installed in aircraft, the cooler is capable of functioning satisfactorily in an upright position, during which the vapor formed by the evaporation of the coolant passes from the evaporator through a discharge passage at the top thereof. When, however, a cooler of this type is inverted, as sometimes happens when an airplane is maneuvering, the coolant is free to escape through the discharge passage, with the result that a valuable supply of the coolant is lost. This not only imposes a weight penalty on the aircraft by necessitating that it carry a greater reserve of coolant, but, even more important, it may interrupt the operation of the cooler, causing overheating of certain equipment, or necessitating its shutdown for a time.

The principal object of the present invention is to provide an apparatus from which vapor is readily withdrawn when operating in either an upright or an inverted position, but without substantial loss of the liquid.

In the invertible type vapor evolving apparatus of the present invention, a pair of relatively movable perforated plates is interposed between the upper level of the liquid and the vapor discharge passage. The perforations in one of the plates are laterally offset with respect to the perforations in the other of the plates, but in the upright position of the apparatus the plates are spaced apart so that the vapor is free to pass through the perforations in the plates in passing to the vapor discharge passage. When the apparatus is inverted, however, the plates come together and, due to the laterally offset perforations in the two plates, the liquid is prevented from flowing, at

I least in substantial quantities, through the plates toward the discharge passage.

The apparatus also includes an auxiliary passage which connects the lower portion of the apparatus with the vapor discharge passage. In the upright position of the apparatus, the entrance to this passage is blocked by the liquid coolant. In the inverted position, however, the auxiliary passage permits vapor which is evolved from the liquid coolant to be discharged through the vapor discharge passage.

Additional features of the present invention are concerned with the means for supplying the liquid coolant to the apparatus in both the upright and inverted positions.

For a complete understanding of the present invention, reference may be made to the detailed description which follows and to the accompanying drawings in which:

Figure 1 is an elevation view showing the invertible vapor evolving apparatus of the present invention in cross-section; and

Figure 2 is a perspective view of the evaporator housing, with a portion thereof broken away.

Referring to the drawings, an evaporative cooler embodying the present invention is shown as comprising a United States Patent "ice housing 10 containing a heat exchanger, generally designated 11, through which one or more fluids can be circulated in out-of-contact heat exchange relationship with a liquid coolant 12 which, for present purposes, will be assumed to be water. In the type of evaporator cooler illustrated, the heat exchanger 11 is divided into two parts--one for cooling the cabin air and the other for cooling a lubricant. The cabin air is admitted into the heat exchanger through an inlet conduit 13 and discharged from the heat exchanger through a conduit 14. The lubricant is admitted into the heat exchanger through a conduit 15 and discharged therefrom through a conduit 16. It is, of course, understood that the air and lubricant are not intermingled with each other within the heat exchanger 11.

The liquid coolant or water is admitted into the housing 10 through a conduit 18 when the evaporator is in upright position, or through a passage 17 when the evaporator is in inverted position.

Steam or vapor evolved from the water or liquid coolant 12 passes upwardly through the housing 10 and is exhausted therefrom through a vapor discharge vent 20 in the upper portion ofthe housing. Two perforated

baflie plates

21 and 22 are accommodated in the upper region of the housing 10 intermediate the liquid level of the coolant 12 and the entrance to the discharge vent 20. The perforations 21a in the upper baffle plate 21 are staggered or offset in relation to the perforations 22a in the lower baffle plate 22. The upper bafiie plate is fixedly mounted to the walls forming the interior of the housing, and the lower baflie plate 22 is movable relatively thereto. When the housing is in upright position, the lower perforated plate 22 is supported on a ledge 23 which projects inwardly from the walls forming the interior of the housing. When the perforated bafiie plate 22 is supported on the ledge 23, the

baffle plates

21 and 22 are spaced apart, so that, notwithstanding the fact that the perforations in each are staggered or offset laterally in relation to each other, the vapor evolved from the liquid coolant 12 is free to pass through the perforations to the discharge vent 20. However, when the housing 10 is inverted, the perforated plate 22 falls by gravity against the upper perforated plate 21, bringing the plates into face-to-face contact, and when this takes place the perforations in each bafiie plate are closed by the other plate. As a consequence, the liquid coolant will be prevented from flowing, at least in substantial quantities, from the housing through the discharge vent 20.

The effectiveness of the seal may be increased by various means such as by afiixing flexible gaskets to the adjacent sides of the baffle plates around each of the perforations therein.

When the housing 10 is in inverted position, the vapor evolved from the liquid coolant is still free to be withdrawn from the housing 10 through the discharge vent 20 by flowing through an auxiliary passage within a conduit 24. The lower end of the conduit 24 communicates with the lower portion of the housing 10, and the upper end thereof communicates with the vent 20. When the housing is in upright position, as shown in the drawings, the liquid level of the coolant is at a level higher than the entrance to the conduit 24, so that the entrance is closed to vapor evolved from the surface of the liquid coolant.

To prevent unnecessary ltms of the liquid, a filter or gauze layer 25 may be accommodated within the housing above the 'baffle plate 21. In addition, a baflle plate '26 may be placed at the entrance end of the discharge vent 20. The gauze layer 25 and the baffle plate 26 prevent moisture particles 01' drops from being discharged with the vapor through the vent 20, thereby preventing unnecessary dissipation of the liquid coolant. The gauze layer"25 also absorbs moisture which seeps through the perforated -baflie plates 21' and 22 when the housing is inverted. The vapor, .however, is free to pass readily through the gauze laye'r'25.

In the upright position of the housing 10, the liquid coolant is admitted thereto through a conduit30, a. float valve 31 accommodated within a chamber 32, and the conduit 18 which. connects the interior of the chamber 32 with the interior of thehousing. Thefloat valve31 comprises a float 31a connected to one end of a lever 31b pivoted at 31c,- and a valve head 31d connected to the lever31b on the opposite side'of the pivot. 'The' chamber 32 is supported beside the'housing at a'heightwhich is determined by the-level at 'which it is'desired to maintain the liquid within the'housing ltl. The weight of the float 31a will lift the valvehead-31d-to open-position, thereby admitting liquid into the'housing through the conduit through theconduit 17. .In the upright position of the housing, gravity maintains the :weighted valve 36 closed, so that the level of the liquid withinthe housing is regulated by..the float valve 31., :However,:, inthe inverted position. of the housing, the valve. 36-.opens and permits the flowof liquid into the housing 10 at a rate which is determinedby the calibrated orifice 37. The longitudinal movement of the valve 36 within the chamber 35 is guided by a group of parallel members 39 surrounding the valve.

A connection 38 between the conduit17-on the downstream side of the orifice 37 and the chamber 32 permits the liquid entrapped withinthechamher 32 to flow into the housing when the housing is .inverted. However, as soon as this entrappedliquid is'withdrawn from the chamber, the weight of .the float 31a. willholdthe valve head 31d closed. Since it is not .expected that the cooler will be operating in inverted position for a substantial period of time, it is not likely. that a sufiicient quantity of the liquid will be admitted into the housing 10 via the conduit 17 such that the level of the liquid therein would be raised high enough tolift the float 31a and thereby open the valve 31d.' This, however, can be prevented even in the event of prolonged operation in the inverted position by limiting the size of the restricted orifice 37.

The invention has been shown in preferred form and by way of example only, and obviously many variations and modifications may be made therein withoutdeparting from the spirit of the invention. The invention, therefore, is not to be limited to any specified form or embodiment, except in so far as such limitations are set forth in the claims.

I claim:

1. An apparatus in whichvapor is evolved from a liquid comprising a housing for the liquid, a vapor discharge passage, and a pair of relatively movable perforated plates separating the liquid in the housing and the vapor discharge passage, each perforation in one of the plates being offset with respect to each perforation in the other of the plates, said perforated plates being spaced apart in one position of the evaporator to permit the evolved vapor to pass through both of said perforated plates and to be discharged from the housing through the vapor discharge passage, and said perforated plates being movable together when the evaporator is inverted to stop the flow of the liquid through said perforated plates.

2. An apparatus as set forth in claim 1 including means forming an auxiliary passage between the vapor discharge passage and the interior of the housing on the opposite side of the perforated plates, said auxiliary passage permitting-vapor to be discharged from the housing when the housing is inverted, the entrance to the auxiliary passage being below the usual-level ofthe vapor evolving liquid when the housing is inupright position, thereby preventing the flow of vapor through saidauxiliary passage in the upright position of the housing.

.3. Anapparatus as set forth in claim 1; including a .passage foradmitting liquidinto the housing in .the upright. position of l the housing, a passageforadmitting liquid into the housing in the inverted position'of the housing, means. for closing lone. passage in the. upright position of. the housing, and means for closing the other passage in the inverted position of .the housing.

4. An apparatus as set forth;in claim 1. including means for maintaining apredeterminedlevelof the liquid .in the housing 'whenthe housing is in:one position and means for feeding aregulated quantity, of. the liquid to the housing whenqthe housing is. in inverted position.

5. An invertible apparatus inwhich' vapor is evolved from a liquid comprising a housing for the; liquid, a discharge passage communicating with the upper region of the housing when the housing is. in upright position, a pair of perforatedplates accommodated in the housing separating the liquid and the discharge passage, the perforations in one plate being offset laterally in relation to the perforations inthe other 'plate, and means for supporting the lower of the plates spacially 1 separated from the upper plate in the upright position of the housing, permitting the vapor evolved from the liquid to pass through the perforations of both plates to, thedischarge passage, said lower. plate falling by gravity into contact with the upper plate when the housing is inverted to stop theflow of the liquid throughsaid perforated plates.

6. An invertible apparatus as set forth in, claim 5 including means forming an auxiliary passage, the upper end of which communicates with. the region above the perforated plates and the lower. end of. which communicates with the region below the perforated plates and below the usual level of the liquid in the housing, said auxiliary passage permittingthe vapor to be. removed from the housing. when the,housing is inverted.

No references cited.