US2039796A - Chilling apparatus - Google Patents

Description

May 5, 1936. N. H. HILLER CHILLING APPARATUS Filed Oct. 31, 1933 -2 Sheets-Sheet- 1 INVENTOR Nico/w 11156713:-

ATTORNEYS Il'l Patented May 5, 1936 UNITED STATES PATENT OFFICE 2.039.790 cmLLmG APPARATUS Nicolai H. Hiller, Carbondale, Pa., asslgnor, by mesne assignments, to Worthington Pump and Machinery Corporation, Harrison, N. 1., a corporation of Virginia The invention in its preferred form is an improvement in chilling apparatus of the general heat interchanger type shown in the Hiller Patent No. 922,898, and adapted for the treatment of liquids to effect congealation andseparation therefrom of certain solid constituents. Such an apparatus, for instance, is adapted for use in the chilling of distillates to separate parafiine, wax or the like. The present invention, in certain of its broader aspects, may be utilized in other types of heat interchangers as well as in the typ of chilling apparatus above referred to.

It has been proposed to provide a heat interchanger comprising one or more vertical series of pipes to which a volatile refrigerant is delivered by gravity from an accumulator disposed above the level of these pipes. In such exchangers, there is a substantial back pressure on the refrigerant liquid, which varies in accordance with the static liquid head of the volatile refrigerant, and which affects the ebullition temperature thereof.

One object of the present invention is to provide a chilling apparatus having improved means whereby the back pressure, due to the liquid head of the volatile refrigerant, is substantially the same in each of the series of evaporator sections disposed at different elevations.

Still another object is to provide an evaporator system having a plurality of passages for the refrigerant arranged in parallel, and having means for insuring the even distribution of refrigerant to said passages,

Another object is to provide new and improved means for preventing leakage in the chilling apparatus.

In my improved apparatus, I provide a plu- Iality of pipe sections disposed at different levels for conducting the liquidto be treated, and a corresponding plurality of evaporator 'sections connected in parallel and respectively disposed in heat exchange relationship with said pipe sections to chill the liquid therein.

As one feature of my invention, 1 separately deliver refrigerant liquid and separately take off refrigerant gas from the separate sections at different elevations.

As another feature, the connections between the pipes of each evaporator section are connected in series at the tops of the pipes to insure against the trapping of superheated gases in the evaporator system.

As still another feature, I provide a circulating pump for circulating the refrigerant agent through the evaporator sections, and a metering device at the inlet to each section to effect even distribution of refrigerant to each of said sections. The circulating pump serves not only to keep all the evaporator sections full of refrigerant, but also increases the circulation. This 5 forced circulation increases the value of the coeflicient of heat transmission.

As a further feature, the circulating pump is disposed below a surge drum or accumulator to insure keeping the pump flooded and to prevent 10 the circulating pump from being gas bound.

In the accompanying drawings, there is shown for the purpose of illustration, one embodiment of the present invention. In these drawings:

Fig. 1 is a perspective view of an apparatus embodying the present invention.

Fig. 2 is a section taken onthe line 2-2 of Fig. 1.

Fig. 3 is a top plan view, partly in section, of a portion of the apparatus shown in Fig. 1.

Fig. 4 is a section showing details of a stufllng box for the scraper shaft.

Fig. 5 is a section taken on the line 5-5 of P18. 3.

Fig. 6 is a section showing details of a portion of Fig. 3, but somewhat enlarged, and

Fig. '7 is a section showing a portion of the apparatus of Fig. 2, but somewhat enlarged.

In the construction illustrated, there are provided three horizontal coils .or connected pipe sections A, B and C disposed in superposed relationship and each comprising a plurality of pipes l0 serving to conduct the liquid to be treated. concentrically mounted with respect to said pipes iii are pipes I l forming annular chambers therewith for the passage of a chilling agent. Adjoining pipes lll of each section are connected together in series at one end by horizontal bends l2 and at the opposite end by horizontal bends 13 arranged in staggered relationship with re- 40 spect to the bends I2, whereby all of the pipes ill of each section are connected together in series.

The upper horizontal pipe section A is connected in series with the lower pipe section B by 5 means of a vertical bend it connecting the vertically adjoining end pipes l0 of the two sections, and the pipe section B is similarly connected in series with the section C by a vertical bend [5. End pipes ll! of the sections A and C are provided respectively with an inlet l6 and an outlet ll so that liquid to be treated flows into the inlet l6 and successively through the three sections. This particular arrangement of pipe sections is not important as various other arrangements may be employed as to the number of sections at different elevations and the number of pipes in each section, and all of the pipes may be connected in a single series or in two or more series in parallel.

For scraping the congealed portions of the liquid from theinner surface of the pipe 10, the bends l2, l3, l4, and I5 have journal-ed therein shafts l8 which extend axially of the pipes I 0, and which carry spiral, screw or ribbon conveyors l9 having the outer peripheries thereof close to the inside surface of said pipes. These may be of the type shown in the Torrance Patent No. 1,796,772, issued March 17, 1931.

'The shafts |8may be rotated by any suitable means. Merely as an example I have shown sprocket wheels 20 connected to one set of shaft ends, and engaged by one or more chains (not shown) disposed in zig-zag relationship between vertically adjoining wheels, the chain or chains being driven from any suitable source of power.

As a feature of the present invention, the pipes ll form a plurality of evaporator sections connected in parallel and respectively disposed in heat exchange relationship with the'pipe'sections A, B and C. Forthat purpose, there are provided pipes 2| connecting the ends of horizontally adjoining .pipes II, and arranged in staggered relationship to connect the pipes I I of each section together in series. The volatile refrigerant is, introduced into each evaporator section by means of an inlet pipe 22 connected to an end pipe H of each of said sections and extending from a vertical inlet header 23. The opposite end pipe of each evaporator section is provided with an outlet pipe 24 connected to a vertical re turn header 25. By means of this arrangement,

' while the liquid to be treated flows successively downwardly through the three pipe sections A, B,

and C, and the volatile refrigerant is delivered from the inlet header 23 and horizontally through the three separate evaporator sections, so that each pipe section is chilled by a different batch of volatile refrigerant.

As an important feature of the present invention, the pipes 2| and 24 forming the outlets of the pipes H are connected to the tops of said pipes I I, while the inlet pipes 22 are connected to the bottoms of said pipes H to insure against the trapping of superheated gases in the evaporator sections, thereby preventing the cutting down of chilling surface.

The bottom of the return header 25 is connected to the top of a surge drum or accumulator 26 disposed below the level of the lowest evaporator section. By means of this arrangement, the returns from all the outlets of the three evaporator sections have free vents, the gas and liquid refrigerant falling into the accumulator 26 and thus preventing any back pressure due to liquid hea'd.

means of a connection 29 connected'to the hottom ofthe drum, said pump being disposed below the surge drum to insure keeping the pump flooded and to prevent it from being gas-bound. The discharge side of the pump 21 is connected to the bottom of the inlet header 23 by means of a pipe connection 30.

The drum 26 is provided with an inlet pipe 32 leading from a condenser or other source of liquid refrigerant, this inlet being controlled by means of a valve actuated by a float 33 so as to plate 35 (see Fig. 7) disposed in each of the inlet Y pipes 22. In the form shown, each inlet pipe 22 is formed of two sections 36 and 31 coupled together at their ends, the section 36 haying at its coupled end the orifice plate 35. Bymeans of this arrangement, the even distribution of volatile refrigerant to each of the evaporator sections is assured, and the liquid pressure at the discharge side of each orifice plate may be the same regardless of differences in the elevation thereof.

The outer pipes II are sealed around the pipes ID to prevent leakage of the volatile refrigerant. For that purpose, the pipes I I at one end may be welded 'circumferentially to the inner pipes III, while at the other end they are provided with stufling boxes 46 (see Fig. 6). Each stufling box 40 includes a metal ring 4| weldedor otherwise secured to the inner surface of each pipe II, and having a central opening large enough to permit easy slippage of the pipe l0 therein. Abutting the ring 4| is a metal washer 42 closely embracing the outside. of the pipe l0. Also encircling the pipe ID is a gland 43 having a cylindrical hub 44 adapted to slide axially in the interior of the pipe ll. Disposed between the inner end of the hub 44 andthe washer 42 are a number'of packing rings 45. The gland 43 is forced axially inwardly in the interior of the pipe II by means of bolts (not shown) passing through an outwardly extending flange 41 of the gland 43, and

a collar 41a welded or otherwise secured on the outside of the pipe ll.

to a bend 12. The bracket 48 includes a bearing 49 supporting a portion of the shaft l8 near the last mentioned end, and a tubular member or stuffing box 50 having an end wall 5| which is apertured to receive the shaft l8. Encircling the shaft I8 and threaded into the open end of the chamber 50 is a gland 52. Disposed centrally in the tubular member 56 is a coil spring 53. Disposed on opposite ends ofthe coil spring 53 are packing rings 54'and 55. By means of this arrangement, the packing rings on opposite sides of the spring 53 are subjected to substantially equal pressure.

The recess surrounding the spring 53 is adapted to receive any of the liquid which leaks from the pipes I 0, through the packing rings 54. In order to remove the liquid from the recess, there is provided an opening 56 leading into the interior of said recess and having'a pipe connection to a suitable reservoir. Any leakage .of liquid rsigst the recess is prevented by the packing rings At the opposite end of the shaft l8, each bend is. provided with counter bores .51 for receiving anti-friction bearings 58.' In. order to prevent leakage through this end of the shaft", there is provided a cap gland 59 having an outwardly extending flange 60 through which passes bolts 6| adapted to screw into the body of the bend and thereby force the cap 59 against said body. This cap 59 forms a chamber 62 which may be used as a grease chamber, and is provided at the outer end with a plug 63 which permits the inspection of the end of the shaft it when any breakage or other disturbance takes place, and permits the insertion of a rod to push out the shaft or a section thereof if the shaft breaks. Between the bend and the cap gland 59 there is provided a suitable packing washer 84 which seals the connection between the bend and the cap gland.

The apparatus illustrated constitutes only one embodiment of my invention, and various changes may be made without departing from the spirit of my invention or the scope thereof as defined in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A liquid chilling apparatus including a plurality of vertically spaced substantially horizontally extending pipes connected in series for conducting the liquid to be treated, a jacket encircling each of said pipes, an inlet header connected to certain of said jackets, a vertical return header connected to certain of said Jackets, 9. receiver connected to the outlet end of said return header below the lowermost jacket, and means for delivering volatile refrigerant to said inlet header, said means being controlled by the level of the refrigerant in said receiver.

2. A heat interchanger including a plurality of vertically spaced horizontal pipe sections for conducting liquid to be treated, a plurality of evaporator sections connected together in parallel and disposed respectively in heat exchange relationship with said pipe sections, means for circulating volatile refrigerant through said sections, and a receiver disposed below the lowest evaporator section, and connected to the outlets of said evaporator sections.

3. A liquid chilling apparatus including a plurality of vertically spaced horizontal pipe sections for conducting liquid to be treated, a plurality of evaporator sections connected together in parallel and disposed respectively in heat exchange relationship with said pipe sections, a receiver disposed below the lowest evaporator section and connected to the outlets of said evaporator sections, and a pump disposed below said receiver and having its suction side connected to said receiver for forcing volatile refrigerant to said evaporator sections.

4. A liquid chilling apparatus including a plurality of vertically spaced substantially horizontally extending pipes connected in series for conducting the liquid to be treated, a jacket encircling each of said pipes, an inlet header connected to nected in series, a corresponding plurality of evaporator sections connected in parallel and disposed respectively in heat exchange relationship with said pipes, a circulating pump for forcing volatile refrigerant to said evaporator sections, a liquid receiver disposed below said evaporator sections and connected to the inlet of said pump,

means for maintaining a substantially constant liquid level in said receiver, and metering devices for controlling the amount of refrigerant entering each of said evaporator sections from said pump.

6. A liquid chilling apparatus including a series of horizontal substantially parallel pipes for conducting liquid to be treated, a jacket encircling each of said pipes to form therewith an annular chamber for the passage of volatile refrigerant, said jackets each having an inlet of fixed flow area near one end and an outlet larger than the inlet and leading from the top of the jacket at the other end thereof, and separate headers connecting said inlets and said outlets whereby said jackets are connected in parallel for the circulation of separate portions of refrigerant therethrough.

7. A liquid chilling apparatus including a plurality of vertically spaced horizontal pipes for conducting liquid to be treated, a jacket encircling each of said pipes to form an annular chamber for the passage of volatile refrigerant, an inlet near one end of each of said jackets, an outlet connected to the top of each of said jackets near the other end thereof, a surge drum located below the lowermost jacket level to receive refrigerant from all of said outlets and deliver separate portions of refrigerant to each of said inlets, and means for maintaining a substantially constant liquid level in said drum.

8. A liquid chilling apparatus including a plurality of horizontal substantially parallel pipes connected in series for conducting the liquid to be chilled, said pipes being arranged in groups at different elevations, a jacket encircling each of said pipes, and forming a passage therewith for a volatile refrigerant, a separate inlet to an end jacket in each group, a supply pipe connected to all of said inlets, tan outlet connected to the other end jacket of each group and extending rality of horizontal pipe sections disposed in superposed relationship for conducting the liquid to be chilled, horizontal bends connecting the pipes of each section in series in a zig-zag manner, vertical bends connecting the pipe sections in series, the top section being provided with an inlet and the bottom section being provided with an outlet, whereby the liquid'to be chilled travels horizontally in zig-zag fashion through each section and successively downwardly through the lower sections, a jacket encircling each of said pipes to form a passage for a volatile refrigerant, couplings connecting the jackets in each section in series to form a plurality of evaporator sections, an inlet header, connections between said header and the inlets of said evaporator sections, a return header, connections between the outlets of said evaporator sections and said return header, whereby said evaporator sections are conof each of said evaporator sections for predetermining the amount of volatile refrigerant forced into said lattersections. q

10. A liquid chilling apparatus including a pipe for conducting the liquid to be treated, a jacket connected to said shaft, acap gland connected to said bearing, and a removable plug at the outer end of said cap gland to permit inspection of the shaft.

11. A liquid chilling apparatus including a series of pipes for conducting liquid to be treated, a jacket encircling each of said pipes to forma chamber for passage of refrigerant, refrigerant inlet pipes opening tangentially into certain of said chambers at their lowermost portions, refrigerant outlet pipes opening from said chambers at their highest points, a receiver disposed below the lowermost of said series of pipes for receiving refrigerant from said outlet pipes, a pump for pumping refrigerant from said receiver to said inlet pipes, means for maintaining a substantially constant liquid level in said receiver, and metering device for controlling the amount of refrigerant enteringeach of said evaporator sections from said pump.

12. A liquid chilling apparatus including a series of horizontal substantially parallel pipes for conducting liquid to be treated, said pipes arranged in vertically spaced sets, a jacket encircling each of said pipes to form an annular chamber for the passage of refrigerant, refrigerant inlet pipe communicating with the lowermost portion of the chamber at one sideof each vertically spaced set of pipes, a refrigerant pipe communicating with the highest portion of the chamber at the other'side of each of saidvertically spaced sets of pipes, and refrigerant conducting pipes establishing commlmication between the chambers of each vertical set of pipes.

13. A liquid chilling apparatus including a series of horizontal substantially parallel pipes for conducting liquid tov be treated, said pipes arranged in vertically spaced sets, a jacket encircling each of said pipes to form therewith an annular chamber for the passage of refrigerant, refrigerant inlet pipe communicating with the lowermost portion of the chamber at one side of h each vertically spaced set of pipes, a refrigerant pipe communicating with the highest portion of the chamber at the other side of each of said vertically spaced set of pipes, refrigerant conducting pipes establishing communication between the chambers of each vertical set of pipes, and a receiver disposed below the lowermost of said series of pipes and receiving refrigerant from said outlet pipes.

14. A liquid chilling apparatus including a series of horizontal substantially parallel pipes for conducting liquid to be treated, said pipes arranged in vertically spaced sets, a jacket encircling each of said pipes to form therewith an annular chamber for the passage of refrigerant, refrigerant inlet pipe communicating with the lowermost portion of the chamber at one side of each vertically spaced set of pipes, a refrigerant pipe communicating with the highest portion of the chamber at the other side of each of said vertically spaced sets of pipes, refrigerant conducting pipes establishing communication between the chambers of each vertical set of pipes,

and restrictionsformed in said refrigerant inlet pipes for controlling the amount of refrigerant entering each of said chambers.

- NICOLAI H. HILLER.

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