US2085942A - Refrigerating apparatus - Google Patents

Description

July 6, 1937. P. A. BANCEL ET AL REFRIGERATING' APPARATUS Filed June 28, 1934 m; m y v B am Elli A TORNEY Patented July 6, 1937 UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS Application June 28, 1934, Serial No. 732,826

Claims.

Our invention relates to improvements in refrigerating apparatus, and particularly to means for regulating the power required to operate same.

The invention is of the type in which a non- 5 volatile refrigerant, such as water, is employed as the refrigerant, to be cooled by vaporizing a -part thereof in a closed vessel or evaporator and removing the vapor thus formed by an evacuator,

such as a steam ejector, which carries the vapor to a condenser wherein both the vapor and steam.

are. liquefied. The aim of the invention is to govern the steam consumed while the ejector is maintained continuously in action, so that the amount of steam expended is always no greater than the-conditions demand.

i For the operation of -a refrigerating system of this class, the quantity of steam needed may fluctuate according to variations in either the load or the temperature of the water supplied to the condenser to cool the latter. In either case conditions inside the condenser undergo change, with the result that the performance of the steam ejector is affected, and, if the pressure and temperature within the condenser are increased too much, the steam ejector may even be stopped.

.It is well known that a steam ejector, steam jet booster or a thermo-compressor as it is also called, when used for this purpose, has an approximately constant capacity, that is, the quantity of water vapor drawn by the ejector from the evaporator and compressed for delivery to the condenser, is substantially the same in amount regardless of the quantity of steam used, so long as the suction pressure, which is the pressure in the evaporator, remains unchanged. It is also a characteristic of the steam ejector that it must be used at its full rated capacity so long as the pressure in the evaporator remains at a predetermined degree, that is, the steam ejector cannot be regulated merely by turning it partly on or partly off, but must be turned on full to whatever pressure steam is supplied to it. Hence, a satisfactory means for regulating the steam flowing to an ejector in a refrigerating system like this, in accordance with changes in conditions within the condenser, must influence both the quantity of steam and'the pressure thereof without in any way reducing the maximum discharge capacity of the ejector.

An object of the invention is to ensure efiicient and economical operation of such a system, and

I to govern the amount of steam that is consumed at varying loads, in connection with one or more 55 evaporator chambers, as. by varying the pressure of the steam supplied to each ejector, to prevent waste of energy in operation.

Another object of the invention is to provide regulating means which are responsive as the pressure rises or falls in' the condenser to alter the amount of steam supplied to the steam ejector as conditions require.

The objects andradvantages of the invention are set out in the following description, and the novel features are defined in the appended 10 claims. We reserve the right to make changes in shape,,size and arrangement of the various members Without departing from the principle of the invention, or exceeding its scope and'spirit.

On the drawing, Figure 1 shows in outline a top viewof refrigerating apparatus according to this invention; and I Figure 2 is a side view, partly in section, thereof.

The numeral [indicates an evaporator enclosing two or more chambersto which water flows through a supply pipe 2. This pipe is connected in each of the chambers to a nozzle 3, having a number of openings 4 through which the water issues in the form of jets. The temperature and pressure in the evaporator are low enough so that the water sprayed into the chambers is vaporized in part, and in the process of vaporization enough heat is taken out of the main body of water to cool it down to the required degree. The chilled water is removed through an outlet pipe 5, and the water vapor formed in each chamber of the. evaporator I is carried ofi through an opening '6 in the top by the action of a steam ejector 1. This ejector member is connected to a steam supply pipe 8, and the steam with the entrained water vapor passes'through a tubular casing 9 into the condenser ID. This condenser may be of any suitable type and is cooled by water to liquefy the steam and water vapor delivered thereto.

' The ejector compresses the water vapor, and the mixture of water vapor and steam flows into the condenser at a somewhat higher pressure than that in the evaporator l.

The supply pipe 2 is connected to the nozzles 3 in the evaporator by means of branches H in which are cut-off valves 12. Similarly the steam pipe 8 is connected to. the steam ejectors 1 by branch pipes l3-in parallel, each having a cutofif valve I4. Also the delivery conduit 5 is connected to the chambers by branches l5. These branches may also contain cut-off valves, or they may be permanently open when the con duit 5 is beneath the chambers and the branches l5 have the form of risers of suflicient height bethe chambers is to be cut out the valve I2 is closed to shut off the water supply and the valve i4 is closed to cut ofi the steam for that chamber. If valves are provided in the branch pipes 15, the branch l5 of the non-operating chamber is also closed, but if these branches .are in the form of risers without valves, the operation is similar to that set forth in the application of Frederick H. Hibberd for patent on a Controlling device for a refrigerating system, Serial No. 716,945,

filed March 22, 1934, the water in the chamber cut out being then forced by the pressure in the condenser out through its open riser pipe l5 and down therein to a point above the conduit 5, where it is trapped and seals this chamber, so that the heat of the condenser does not aiTect the chilled water delivered by the conduit 5 from the other chamber or chambers which are working.

To govern the amount of steam used, a thermostatic device comprising a bulb or element I8 is inserted into the bottom l9 of the condenser II]. This bulb is connected by a tube 20 to the fixed end of an expansible chamber 2|, the other end 22 of which is movable, and is adapted to influence a valve 23 in the line of.the steam pipe 8. The stem 24 of the valve is'surrounded by a spring 25 which presses at one extremity on the movable end 26 of a second expansible chamber 21 and at the other extremity on a head or washer 2B slidably mounted on the stem 24. This stem also passes through an opening in the end of a lever '29, connected at its opposite end to the movable end. 22 of the chamber 2|, and mounted on an intermediate pivot 30. The washer 28, lever 29 and expansible chamber-2| constitute a shifting abutment means for the spring 25. The spring 25 will preferably be under sufiicient compression and be of sufficient length to cooperate with the aforesaid abutment means throughout the entire range of movement of .both expansible chambers. In the bulb I8, the tube 20 and chamber 2| is a suitable expansible fluid which, on an increase of temperature in the condenser It! will force the lever 29 to compress the spring 25 and chamber 21 and cause the valve 23 to, open and allow more steam at higher pressure to pass to the nozzles 1. The chamber 21 has a fixed end connected by a tube 3| to the pipe 8,. on the low pressure side of the valve 23.

This arrangement enables steam to be supplied to the-ejectors at the pressure required by working conditions. The pressure in the condenser opposes the admission of the steam and water vapor and if this pressure exceeds a predetermined value, in relation to the pressure of thevapor and steam, the ejector will break.

back, or cease to function, because it now will be unable to compress'its own burden, or even a small quantity of water vapor, until the evaporation pressure has materially increased. and the temperature of the chilled water hasbecome much higher.

The remedy for this condition is to raise the pressure of the steam at the ejector I. When the pressure in the condenser rises, the temperature of the water in the bottom IQ of the condenser goes up a proportionate amount. The

.liquid in the bulb II, tube 20 and chamber 2! tween these conduits and the evaporator l. A partition 16 is shown in the evaporator l, dividthen expands, the valve 23 opens furtheryand more steam at higher pressure flows through the casing 32 of this valve. The opening of the valve is of course opposed by the pressure in the tube 3| and chamber 21. On the other hand, if the pressure in the condenser drops, less steam at a lower pressure will suffice to compress water vapor created in the evaporator I and force this vapor into the condenser. Upon the pressure in the condenser falling, the temperature of the,

liquid in the bottom l9 decreases, and the valve 23 is then actuated towards closed position by the chamber 21, so that less steam at lower pressure flows past this valve 23. The pressure of the steam in the pipe 8 to the right of this valve will of course, be high enough to meet all demands.

Suppose for example, the apparatus is operating with all chambers and steam ejectors working, and it becomes desirable to cut out one of drop in the load. With the remaining chamber vapor are transmitted to the condenser, and therefore the water flowing through the cooling pipes of the condenser absorbs less heat and the pressure in the condenser drops (i. e. the vacuum increases). Therefore, the temperature of the liquid at the bottom 19 of the condenser formed by condensation of steam and water vapor decreases. The liquid in the tube l8 and chamber 22 becomes cooler, allowing the valve 23 to move toward closed position, with the result that steam at lower pressure and in smaller quantity is supplied to the remaining nozzle or nozzles .1. The reduced load can thus be carried economically and steam is saved. Upon the load increasing, so that all the chambers in the evaporator and all the ejectors have to be used again, the con-- denser will become warmer, the vacuumwill become less in the condenser and the back pressure against the steam and water vapor will be in- 1 creased. Therefore, the water in the bottom of the condenser will be hotter and the regulating means will now open the valve 23 to allow steam at higher pressure and in'greater quantity to pass one or more chambers of the evaporator I, to

permit more or lesssteam at higher or lower pressure to flow to such of the chambers IT as are active, in the manner above described.

Another function 'of the device is to control. *the system in the event that the cooling-water supplied to the condenser for lfi uefying the steam and vapor changes in temperature. In that case the pressure in the condenser changes and the regulating device will now act as before.

The valve 23 thus operates tovary the pressure and quantity of steamdelivered to the nozzle or nozzles 1, according as the condenser pressure increases or diminishes. For greater condenser pressure,'steam at higher pressure and in greater amount is furnished to the nozzles and for small condenser pressures both the quantity and pressure of the steam are reduced.

The liquid of condensation formed in the condenser can be removed through a pipe 33 and transferred to any desired point by a pump 34.

the chambers of the evaporator, because of a With this construction a great saving in the supply of steam in the operation of the apparatus effected, and the cost of'operation is-corresp0ndingly reduced.

While we have described herein an expansible fluid type of thermostatic control, this arrange- 'ment is obviously only one of several means for realizing the end desired. Other forms of :regu-.

. connections for the valve 23 is to Operate this valve in response to pressure changes in the condenser and the temperature of the interior of the condenser is a function of the vapor pressure in the condenser. Hence the temperature responsive element I8 is merely a convenient form of device for giving the resultsought for, and a member responsive directly to the vapor pressure in the condenser may of course, be substituted.

The regulating means herein set forth can, of course, be used with various types of apparatus, such as systems" having sectionalized condensers and steam ejectors with various types of valves therefor. I

1. In a refrigerating system, an evaporator, an evacuator removing vapor from the evaporator, a condenser to which the evacuator delivers, means conducting a power medium to the evacuator, means controlling the flow of medium through the conducting means, a device to actuate the control means in response to the force of the medium, "a device responsive to condenser temperature, and spring-pressed means through which the second device opposes operation of the first device and actuates the control means in response to variations in condenser temperature.

2. In a refrigerating system, an evaporator,

an evacuator removing. vapor from the evaporator, a condenser to which the evacuator delivers,

meansconducting a power medium to the evacu-.

- ator, means controlling the flow of medium through the conducting means, a device to actuate the control means in response to the force of the medium, a spring member having oneend means to alter the position of the spring member device. I I e 5. In a refrigerating system, an evaporator, a fluid operated evacuator removing vapor from the and to actuate the control means in response to variations in condenser temperature.

3. In a refrigerating\.. system, an evaporator wherein a refrigerant is chilled by partial evaporation, .a thermo-compressor to remove vapor from the evaporator, a condenser to which the thermo-compressor delivers, a fluid supply pipe for thethermo-compressor, a valve in the pipe, I

a stem on the valve, a device connected to-the stem to actuate the valve in response to the pressure of the fluid, .a spring around the stem having a fixed abutment at one end, shifting abutment means for the other end of the spring, and a second device adapted to engage the shifting abutment means to apply pressure to the springthereby to actuate the valve in response to variations in condenser temperature.

4. In a refrigerating system, an evaporator wherein a refrigerant is chilledby partial evaporation, a. steam ejector to withdraw vapor from the evaporator, a condenser to which the ejector discharges, a steam supply pipe for the ejector, a valve in the pipe, a device to actuatethe valve in response to the pressure of the steam, a device responsive to condenser pressure, and means con-- necting the devices whereby the second device also actuates the valve and bothdevices cooperate to govern the pressure and quantity of steam supplied to the ejector said means including a spring member in fixed'abutment with the first device and. in shifting abutment with the second evaporator, a condenser to which the evacuator delivers, a fluid supply. pipe-for the evacuator, a valve in the pipe, '9; device to actuate the valve in response to the pressure of the fluid, a spring in fixed abutment with saiddevice, a device responsive to condenser pressure, said springbeing in shifting abutment with the second, device,

whereby upon rising condenser pressure the spring is compressed to actuate the valve to open position and upon falling condenser pressure the spring is released to enable the first device to actuate the valve towards closing position, said devices thereby cooperating to maintainaffixedpressure differential betweenevacuator and condenser.

PAUL A. BANCEL. 7 a Y FREDERICK H. HIBBERD.

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