US2103723A - Refrigerating construction - Google Patents

Description

Dec. 28, 1937. F. H. HIBBERD 2,103,723

REFRIGERATING CONSTRUCTION Filed March 23, 1954 INVENTOR.

lz a c t/vlllfiliberd UNITED STATES PATENT OFFICE 2,103,723 REFRIGERATING CONSTRUCTION Frederick H. Hibberd, Bayside, N. Y., assignor to Inger-soll-Rand Company, Jersey City, N. 1., B corporation of'New Jersey Application March 23,1934, Serial No. 716,947

9 Claims.

This invention relates to a refrigerating construction, and particularly to a device and method for controlling a refrigerating system in which a liquid refrigerating agent or medium is employed to bring about the required cooling effect.

The invention is adapted for use with a multiple unit type of refrigerating apparatus in which refrigeration by evaporation is accomplished in one or more units according to the load requirements. An object of the invention is to provide means whereby the refrigeration output of the system may be controlled by shutting down or starting up one or more units without excessive manipulation of valves.

For refrigerating systems employing a nonvolatile substance, such as water, as the refrigerant or'cooling medium, an evaporator in the' form of a container for water to be chilled is employed. The pressure in this evaporator is kept at a relatively low point, so that when water is admitted thereto at a given temperature, some of p the water is vaporized at once. -In this way aaccomplished by a steam ejector which exhausts to a condenser wherein the discharge of the ejector is liquefied. With an evaporator having a single chamber and steam ejector such a system' will serve quite well at approximately fixed or predetermined loads, but it is quite unsuitable for practical operation when the load varies. Hence if such a system is built for a rated load it cannot be operated advantageously to give a reduced output, and if it is built for a small load the output cannot greatly be increased. This is due to the fact that the capacity of the steam ejector or steam jet booster, that is, the pounds of water vapor evacuated thereby at fixed suction pressure determined bythe pressure in the evaporator itself, is substantially constant, regardles of the amount of steam being used. Further, it is a characteristic of the steam jet booster that its steam flow must be maintained at the rated value so long as the suction pressure (or the chilled water temperature) in the evaporator and disremain at their normal values. But with a reprises several evaporator chambersand steam ejectors, connected in multiple and adapted to work with either all of its evaporator chambers and ejectors, or less than all of said chambers and ejectors in operation, the load can be varied within quite widely separated limits, steam can be saved under conditions of reduced load and the consumption or expenditure of power is thus adjusted to the quantity of refrigerating effect that is actually obtained.

This invention is especially designed to be employed with refrigerating systems including a plurality of chambers for evaporating and cooling water and a steam ejector for each chamber, with proper connections for the operation of one or more of said chambers; a further object thereof is to provide a refrigeratingsystem having multiple evaporator chambers-with supply means disposed in permanent free communication with said chambers and so arranged that water to be chilled is admitted to only the chambers of the evaporator which really are in operation and use, the inflow of water to any chamber which is cut out being automatically interrupted so that said chamber remains virtually empty until the operation thereof is resumed.

Another object of the invention is to provide a refrigerating system, having a water evaporator comprising a chamber or chambers of such interior design that the admission of water thereto is at once prevented whenever the evacuation of water vapor therefrom is stopped. This mode of action is obtained solely as the result of working conditions in any chamber which is thus put out of operation, and no valves or the like elements to be manipulated in the water supply connections are needed.

An additional object of the invention is to provide a refrigerating construction embracing an evaporator with one or more chambers in which part of a liquid refrigerant is vaporized to cool the main body of said refrigerant, and with another chamber in which no substantial refrigerating effect is produced and which has for its function the automatic maintenance of the proper level of the chilled water in the other chambers.

The objects and advantages of the invention are completely set out in the following description, but the disclosure is explanatory only, and many changes that are embraced within the principle of the invention can be made, as indicated by the broad terms in which the appended claims are expressed.

In the drawing, Figure 1 shows an outline of a refrigerating construction according to the invention, partly in section,

Figure 2 is a sectionalview taken on the line 2-2 of Figure 1, and

Figure 3 is a view similar to Figure 2 showing an evaporator chamber that is not operating.

In the drawing the same numerals identify the same part throughout.

I show at l a water evaporator having a supply pipe 2 and an exhaust or delivery pipe 3, the water being admitted to the evaporator i, and after being cooled therein, being withdrawn through the conduit or header 3 and carried oif thereby. The evaporator G contains several compartments or chambers 4, 5, 5, and 7, formed by the ends of the evaporator and transverse partitions 8, a portion of the incoming water being vaporized in one or more of these chambers. The water vapor is' removed by means of suitable evacuator members, such as steam ejectors or steam jet boosters 20. The steam ejectors remove the water vapor trom the chambers and in so doing maintain the high vacuum necessary for vaporization and chilling of the incoming water to the temperature desired. These boosterscommunicate with the top of the chambers and discharge into a steam exhaust pipe 9. This exhaust pipe communicates with a conventional type of condenser wherein the evacuated vapors and operating steam are condensed at a somewhat higher pressure than that in any of the chambers where water vapor is thus created. The steam ejectors for all the chambers of the evaporator l are supplied from a common steam line H).

The terminal portion of the water supply pipe 2 is inside the evaporator I, and has sections ll in the chambers 4, 5, 6, and I. It delivers to the chamber 4 through a comparatively small upright branch pipe or well l2, and the other chambers through lateral branches indicated in Figure 2 at l3. The common delivery pipe 3 communicates with the bottom of all the chambers through branches or riser pipes I4 by way of outlet openings l5. The communication between the conduit 3 and any of the chambers of the evaporator is always free because no valves are employed in either the delivery pipe 3 or any of the branches M. So long as the various chamhers are in operation and water is vaporized therein and water vapor removed therefrom, the water in the various chambers will be cooled to the required extent. If, however, one of the compartments is put out of operation by closing the booster steam valve, the level of the cooled water therein will automatically sink, for the chilled contents of this particular chamber will I be forced outbecause the pressure in that chamber rises to condenser pressure. But enough of the water will be trapped in the riser connected to that chamber to seal it and keep it from communicating with the other chambers. As this method is fully set forth in my co-pending application, Serial No. 716,945, for patent on Refrigerating apparatus, flied of even date herewith, that part of the apparatus herein described which gives this function is therefore not recited in 'the claims hereunto appended.

When, one of the boosters is turned on for purposes of saving steam as described above, and condenser pressure is exerted in the corresponding evaporator chamber, the water to be chilled must be prevented from entering this inactive chamber. This is necessary because the inactive chamber is now in free communication with the height.

the chamber which extends longitudinally between the partitions B and one end of the evap-' orator l; Each weir begins at the bottom and extends toward the top. Each of the weirs together with the adjacent portions of the wall of the evaporator I provides a space or well 88 into which the water is admitted through the adjacent branch l3 delivering to the well near the bottom, as shown in Figure 2, and a certain portion thereof will be vaporized at once as it flows over the weir. If desired each weir may have openings ll near the top through which the water therein may be delivered. Such a construction has the advantage that the proper distribution of water to the various chambers is more easily obtained and controlled, as it prevents slight variations of vacuum from interfering with the flow of the refrigerant.

To carry away the water vapor, each of the chambers 4 5, 6, and I has an outlet IS in the top leading to steam ejectors or steam jet boosters 20. These are in the form of L-shaped tubular members which communicate at one end with the outlets l8 and are connected to their opposite ends to the conduit 9 into which they discharge.

Each ejector has a steam nozzle}! connected by pipe 22 to the steam line H! and each branch pipe carries an admission and shut-off valve 23. The ejectors for the chambers 4, 5, 6, and I all discharge into the conduit 9 leading to the condenser (not shown), but the ejector for the chamber 4 is of much smaller size and capacity than the others and serves a special purpose described below. The chamber 4 is not provided with a weir but the inlet pipe I! extends from the bottom as high as the weirs IS in the other chambers. All of the weirs are, of course, of the same In operation, water to be cooled may enter all the chambers through the branches I3 and the inlet pipe [2, and as part of it is vaporized, the water vapor is removed by the steam ejectors through the pipe 9 and compressed to the pressure in the condenser. The water, which is chilled by the vaporization of part thereof, passes out through the risers l4 and the delivery conduit 3 as above set forth. So long as the steam jets are supplied from the line ID the vacuum in the chambers remains low, but if any one of the steam jets is shut oil the absolute pressure in the chamber to which that jet is connected, will increase and become equal to the pressure of the condenser. This pressure will depress the level of the inflowing water in the well l8 below the tops of the weir or openings IT in that chamber,

so that no more water can enter the chamber chambers.

risers, however, will be high enough so that some of the water will be trapped in the riser connected to the chamber which is not working, and will seal the latter from below, and the greater pressure in the non-operating chamber will be prevented from taking effect in any of the other operating chambers. This condition is shown in the chamber 1 on Figure 1.

In practice the evaporator will be operated by including all the chambers or by cutting out one or moreof the chambers 5, 6, and 1. Chamber 4 must always be in operation because it con-.

.rate of outflow. If this water level drops the valve is opened further, and if the water level tends to rise it is moved towards closed position. The

steam jet for the chamber 4 is somewhat smaller than the other steam jets and is so proportioned that it will maintain the same vacuum'in this chamber as in the other chambers which are working.

This is insured by admitting only a small amount of water through the small conduit i2, thereby establishing the temperature and pressure in chamber 4 as substantially the same as that in the other activechambers. I

It should be noted that the pipe i2 and the booster for the chamber 4 are of such relatively small capacity that no substantial refrigerating effect is produced. The sole function of this booster and its chamber 4 is to maintain the proper water level in the active chambers, irrespective of which ones are in use without necessitating the manipulation of any valves for putting any of the chambers into or out of service.

With all the chambers in communication with one another through the risers It, the cooled water therein tends to seek the same level in the chambers that are working, because each working chamber is subjected to the pressure head of the cooled waterin the other working This level will be constant because the vacuum-maintained by the steam jets in all the working chambers is the same. When any chamber is cut out of operation, the admission of further water thereto from the pipe 2 is prevented because the higher condenser pressure in that chamber forces the level of the infiowing water in the well a material distance down below the top, while the water already chilled in that particular chamber is forced out and that chamber is emptied except for a portion which remains in the riser pipe, at the level indicated in the riser M of the chamber 1, for example, in Figure 1, to seal this chamber. The pump 29' in the line of the conduit 3 insures the transmission of the cooled water to the place of use.

The end of the pipe 2 outside of the evaporator is shown as having a flange 30 to facilitate securing it to the outside of the chamber 4, so as to deliver through an inlet 3| to the portion of this supply pipe which is inside of the evaporator i. The valve 26 is in the line of this pipe inside the evaporator, as are also the lever carrying the float, the connecting rod 28 and the arm 21. Hence, no stufiing box or packing need be provided for this rod, such as would be necessary if the valve 26 were outside of the evaporator. The casing for this valve has flanges to enable it to be joined on one side to a flange of a section of the pipe 2 inside the evaporator leading to the inlet 3|, where this section has a similar terminal flange to enable it to be secured to the wall of the evaporator around the inlet 3|, the same as the outside pipe 2, and on the other side to another section leading to the first of the' remaining chambers. The inside partitions it have openings 32 so that the sections H can be secured by similar end flanges to the partitions 8 around the openings 32, and the lateral branches l3 lead to openings 33 in the weirs l6 adjacent the bottoms thereof. Pipe i2 is likewise secured to the pipe' 2 by a flange at its lower end, and the branches is. are similarly united to the weirs around the openings 33, the numeral 38 indicating all of the flanges above mentioned.

It will be seen that, as illustrated in Figure 2, the level of the infiowing water in any chamber which is operating is at a predetermined discharge point in the well thereof, and is higher than the level of the chilled water in the bottom of any working chamber, where it collects before passing out through the risers id. vaporization of part of the water takes place as the incoming water flows downward from the upper portions of the wells iii and the pipe M, which is also, in effect, a well. As long as the water vapor is sumciently evacuated from any chamber by the members it, the level of the incoming water remains high enough to be discharged from the well, and when the vacuum is lessened upon the stoppage of any one of the steam jet boosters, the increase of absolute pressure to condenser pressure within the chamber which is put out of operation empties that chamber because the pressure forces down the level of the incoming waterso that no more vaporization is accomplished and at the-same time it depresses the level of the chilled water therein to the point indicated in connection with the riser M connected to the chamber i.

The system may be operated so that, when a chamber is cut off the total quantity of refrigerant is correspondingly reduced. Then the same quantity of refrigerant as before flows through each of the remaining chambers and at the same rate. Or the operation may be such that the quantity of liquid remains as before, when one or more chambers are stopped and thus the body of refrigerant passes at an increased rate through the remaining chambers.

I claim:

1. A refrigerating construction comprising an evaporator containing a plurality of chambers, means for supplying a liquid refrigerant part of which is to be vaporized in said chambers, means for evacuating vaporized refrigerant from said chambers, means for delivering the remainder of the liquid refrigerant from said chambers, a valve in the supply means on the inside of said evaporator, and a regulating element in one of said chambers connected to said valve arranged to maintain the liquid in said chambers at a substantially constant level.

2. The method of producing and controlling rcfrigeration which consistsin dividing a liquid refrigerant into separate quantities, supplying each quantity independently from a common source, causing the discharge of each quantity from a predetermined level to a lower level and simultaneously vaporizing a portion thereof, and stopping the discharge and vaporization of any one of said quantities by increasing the pressure upon it and thereby depressing its surface below the discharge level, without interrupting vaporization of portions of the remainder of said refrigerant.

3. The method of producing and controlling refrigeration which consists in treating a liquid refrigerant in separate quantities by suppLving each quantity independently, maintaining a vacuum above each quantity, keeping the surface of each quantity at a predetermined level, causing the discharge of each quantity from saidlevel under the influence of said vacuum and simultaneously vaporizing a portion of said quantity, and stopping the discharge and vaporization of any one of said quantities by decreasing said vacuum and thereby depressing the surface of said quantity below the discharge level without stopping vaporization of portions of the remainder of said refrigerant.

4. The method of producing and controlling.

spaces to vaporize a part of the refrigerant therein, removing and compressing the vapor so 7 formed, and increasing the pressure in any one of said spaces to empty same and suspend the passage of refrigerant ,thereinto while continuing the passage of refrigerant into the other spaces.

5. The method of producing and controlling refrigeration consisting in passing a liquid refrigerant through separate spaces, treating the refrigerant by creating a vaucum in each space and vaporizing a part of the refrigerant therein, removing and compressing the vapor so formed, and subjecting any of said spaces to the increased pressure of the removed vapor from other spaces to empty the space so subjected and stop the passage of refrigerant thereinto to suspend vaporization in the space while continuing the passage of refrigerant into and the vaporization thereof in the remainingspaces.

6. A refrigerating construction comprising'an evaporator containing a plurality of chambers, means for delivering liquid refrigerant to each @Jfisfi'fis chamber, means for withdrawing said refrigerant,

independent evacuating means to facilitate vaporization of part of the refrigerant in each chamber, and connections whereby the pressure in each chamber can be increased to empty same and suspend the delivery of refrigerant thereto and the vaporization therein while the remaining chambers continue to be active.

7. Refrigerating apparatus comprising an evaporator having a plurality-of chambers connected in parallel, evacuating means for each chamber to reduce the pressure therein and to remove vapor therefrom, a well in each chamber having its upper opening above the bottom of the chamber, means common to all the chambers to introduce -refrigerant to the well near its bottom, means to withdraw chilled refrigerant from the chambers, and means associated with the evacuating means toincrease the pressure in a chamber and thereby prevent the admission of refrigerant thereto.

8. Refrigerating apparatus comprislngan evaporator' having a, plurality of chambers, evacuating means for each chamber to reduce the pressure therein and to remove vapor therefrom, means to withdraw chilled refrigerant from the chamber, means to start and stop the action of the evacuator to decrease or increase the pressure in the chamber, and means including aweli in the chamber to admit refrigerating medium to the chamber when the evacuator is operating and to prevent such admission when the evacuator is inoperative, without affecting the operation of any other chamber.

9. Refrigerating apparatus comprising an evaporator having a plurality of chambers, evacuating without interference with the admission of refrigerant to any other chamber.

/ FREDERICK H. HIIBBEBD.

'con'lance with the pressure maintained therein,

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