US2880927A - Compressor for gaseous materials - Google Patents

Description

April 7, 1959 A. T. PLOEGERT COMPRESSOR FOR GASEOUS MATERIALS 2 Sheets-Sheet 1 Filed March 13, 1956 INV TOR.

W eg n v 6 8 m 7 0M 7 6w 2 i C A a L T i w w w H 9 5 I x \A\ 7 E W 5 W Wum- 000 W a e i April 7, 1959 Filed March 13, 1956 A. T. PLOEGERT 2,880,927

COMPRESSOR FOR GASEOUS MATERIALS 2 Sheets-Sheet 2 COMPRESSOR FOR GASEOUS MATERIALS Anatol T. Ploegert, Buffalo, N.Y., assignor to The Wittemann Company, Inc., Buffalo, N.Y.

Application March 13, 1956, Serial No. 571,198

14 Claims. (Cl. 230201) This invention relates to compressors, more particularly of the reciprocating displacement type for gases and stroke, and the space between it and the cylinder head was filled with water, damage to the compressor would result.

It is, consequently, an object of this invention to provide a compressor which is so constructed that there is no danger of damage to the compressor in the event than an excessive amount of water is fed to a cylinder.

A further object is to provide a compressor of this type with valves which are so located that when opened, water will be discharged through the same in advance of compressed gas.

A further object is to provide a two-stage compressor of this type which includes only a single reciprocatory piston and in which the cylinder for the second stage .moves with said piston and cooperates with'a stationary piston.

, t It is also an object of this invention to provide a compressor of this kind with means of improved construction for cooling the gases in the compressor.

i Other objects and advantages will be apparent from United States PQt-mt "O the following description of one embodiment of the invention and the novel features will be particularly pointed .out hereinafter in connection with the appended claims.

In the accompanying drawings:

. Fig. 1 is a longitudinal, central sectional elevation of the upper portion of a compressor embodying this inivention.

a Fig- 2 is a similar view of the lower portion of the compressor showing the mechanism for imparting reciprocatory-motion to the movable piston.

The compressor, which is shown in the drawings to illustrate by way of example one embodiment of my invention, includes a cylinder 5 in which a piston 6 is reciproca ble in a substantially vertical direction. The cylinder is provided at the upper end thereof with a cylinder head 7 containing one or more valves 8, two being shown in the construction illustrated. Above the cylinder head 7 is an inlet chamber 9 to which the gas to be compressed may be conducted in any suitable man- .ner,.for example, through an openinglfl formed therein.

.tion, and since valves of this type can be readily purchased ,andare of more or less standard construction, they are 'notherein described in detail. They are held in 'place by means of a valve-retaining plate 12v and are inlet valves inlet chamber 9 into the interior of the cylinder 5 above the piston 6.

The piston 6 includes the usual head 13 having a sub stantially gas-tight connection with the inner wall of the cylinder 5, and suitable compression piston rings 15 and guide or rider rings 15' may be arranged on the piston head 13 in any usual or suitable manner.

In accordance with my invention, the discharge valves through which compressed gas may be discharged from the cylinderare located below the cylinder head so that near the end of the compression stroke the water or other coolant will be discharged in advance of or simultaneously with the compressed gas. Consequently, in the con struction shown, I have arranged the discharge valve or valves 14 in piston head, and preferably these valves are located in depressed portions of the upper surface of the piston head, for example, in depressions or re cesses 14 in the piston head, into which water will flow by gravity during the up stroke of the piston. 1 Conse' quently, when the discharge valves 14 open, water will flow through these valves before gas passes through the same. The piston is reciprocated by means of a piston rod 16 suitably secured at its upper end to the piston head 13.

The piston 6 has a downwardly extending tubular body or skirt portion 18 which may, as shown in the drawing, be formed integral with the piston head, and for proper guidance of the piston within the cylinder, this skirt portion is provided at the lower end thereof with an outwardly extending flange 20 which is also provided with suitable piston rings 21 and guide rings 21; to form a substantially gas-tight joint with the lower portion of the cylinder 5.

The downwardly extending, hollow body or skirt portion 18 is bored to form the second stage cylinder of the compressor and cooperates with a stationary piston 25 which, in the construction shown, is mounted at the upper end of two concentric cylindrical parts 26 and 28 which are formed integral at their lower ends with a lower head 27 of the cylinder 5. The two tubular parts 26 and 28 are spaced apart and the cylindrical part 28 has an upper portion of increased thickness which supports a series of piston rings 30 which cooperate with the cylinder formed by the skirt 18 of the upper piston 6. i

The stationary piston head 25 is provided with one or more valves 31, two such valves being shown in the construction illustrated, through which liquid compressed within the second stage cylinder may pass into the space 32 formed between the two cylindrical piston-supporting members 26 and 28, for discharge from the compressor.

In the compressor as so far described, it will be ob.- vious that on the down stroke of the main piston 6, gas will pass through the valves 8 from the inletchamber ,9 into the interior of the cylinder 5. Upon upward movement of the piston 6, this gas is compressed, and upon reaching a predetermined pressure, the compressed gas vwill be discharged into the second stage cylinder formed second stage cylinder will consequently be discharged valves 8 may be of; any suitable or desired constructhrough vwhich. gas tobe compressed.maypassfrom the ,5,

through the valves 31.

When operating with certain gases such, for example, as carbon dioxide produced in the fermentation process of a brewery, it is, of course, very necessary that the compression of the gas be carried on at a low temperature so that certain taste-imparting ingredients or other constituents of the gas will not be destroyed or damaged. For this purpose, water or other coolant which alsoacts as. atlubricant-for .thecontacting surfaces. of .-the cylinder;

pistons is sprayed through the cylinder head 7 by of a suitable :nozzle 34 'formed on the end of a water inlet pipe 35 which, in the construction shown, extends through the inlet chamber 9 and terminates in the-suitable nozzle 34. Water may be supplied to this pipe 35 in any suitable manner (not shown), and is =s'prayed in finely divided form into the gas which is being compressed. Some of this water will be vaporized, gbut'enough water is injected into the cylinder so that some. of this water also acts as a lubricant for the piston and cylinder. The excess water collects on top of the piston head 13, and as soon as the valves 14 open, this water will be discharged downwardly into the second istage cylinder formed within the skirt 18, and will thus serve to lubricate the second cylinder and the stationary pistonand also act as a coolant for the gas compressed in the second stage. Similarly, when the piston 6 is anoved downwardly by the piston rod 16, and when it :approaches closely to the end of the stationary piston 25, water which has collected above the valves 31, will be discharged through these valves into the space 32 for discharge with the compressed gas to a suitable separator "(not shown), in which the water is removed from the gas.

The base 27 of the cylinder 5 is provided with a gas passage 37 which connects with the space 32 and the gas from this passage is discharged from the compressor through an outlet pipe 38.

The main cylinder 5 may be supported on the compressor in any suitable or desired manner, and in the construction shown, this cylinder is provided with an outwardly extending flange 40 which rests on the upper end of a cylindrical supporting member 41. The piston rod 16 extends through a suitable stuffing boX 42 arranged "in the base 27 and which may be of any usual or suitable construction to prevent any lubricant from the piston reciprocating mechanism from passing into contact with the gas being compressed and to prevent Water or other acoolant from passing down along the rod 16 and contaminating the lubricant used in the mechanism, which :actuates the piston rod. 43 represents a collar secured to the piston rod to prevent lubricant from the actuating mechanism from creeping up along the piston rod.

The discharge pipe 38 extends through a suitable hole or opening 46 formed in the supporting member 41. This supporting member in turn is supported by a suitable case or crank case 48 which rests on any desired foundation. This base houses mechanism for operating the piston rod 16 including a crank shaft 50 journalled in suitable bearings 51 and 52, mounted in opposite walls of the crank case. Rotary motion of the crank shaft 50 is converted into reciprocatory motion in the usual manner by means of a crank 54 which imparts motion to one end of a connecting rod 55, the other end of the connecting rod being pivotally connected with a cross head 56 by means of a cross head pin 57. The cross head =56 is mounted as usual, in a suitable cross head slide which may be formed as a part of the crank case 48.

The lower end of the piston rod 16 is rigidly connected "with the cross head 56. 58 represents an oil pump for lubricating the moving parts within the crank case and 59 represents a suitable oil seal to resist the escape of oil from the crank case along the piston rod. Any other means for reciprocating the piston may be provided.

In addition to cooling the compressed gas by means of water or other coolant sprayed into the cylinders, cooling means are also provided about the cylinder 5 in the form of jackets of any usual or suitableconstruc- -tin. 63 represents a cylindrical jacket member extending-about the cylinder and spaced therefrom by outextending ribs 64, 65, ,66 which separate the space surrounding the cylinder into a number of gdifierentcompartments. All but the lowermost of the compartments formed by these ribs are employed for the simulation of the coolant. For example, coolant may harnessed into the compartmentxbetween the ribs .65and 4 66 through an inlet tube or pipe 68 and passes from this compartment through an opening '70 in the cylinder 5 into the space between the piston skirt 18 and the cylinder 5, so that this space is always filled with coolant, which moves up and down with the reciprocations of the piston. The cylinder 5 is provided with a discharge opening 71 through which liquid from the space surrounding the skirt 18 is discharged into the jacket compartment between the outwardly extending flanges 64 and 65, and the flange 64 is provided with an opening 72 through which coolant flows into the upper compartment of the jacket from which it is discharged through pipe 73.

It has been ,found that the coolant discharged from the upper jacket compartment through the pipe 73 is sufficiently cool, so that it may be used for further cooling the gas in the compressor. Consequently, this pipe extends downwardly and terminates in a passage 74 formed in the flange 40 at the lower end of the cylinder 5. This passage leads to an annular passage 75 formed by an annular groove in the lower head 27 of the cylinder .5 and facing the flange 40. This passage 75, consequently, extends about the gas passage 37 and thus acts asa jacket to cool gas flowing in the passage 37.

From the passage 75, the coolant flows into a space 76 between the cylinder 5 and the cylindrical portion 28 of the stationary piston. This space also receives any coolant that may leak past either piston and its cylinder and this coolant, together with that discharged from pipe 73, passes through suitable holes or openings '78 leading to the lowest jacket space, and thence to a discharge passage 79 connected with a discharge pipe 80. The holes 78 are preferably spaced slightly above the surface of the lower head 27 so that a shallow body of coolant will lie on that surface and thus further ab sorb heat from gas in the passage 37.

Since the volume of the chamber or space 76 varies with each reciprocation of the main piston, means are pro vided for preventing any pressure from being generated in this space due to this change in its volume, and this is accomplished by means of an equalizing pipe or duct 83 which connects with the lowest jacket compartment and with the inlet chamber 9, so that gas in the chamber 76 during the down stroke of the piston will pass through the passages 78 into the lowest jacket chamber and then to the pipe 83 into the inlet chamber 9. During the stroke of the piston in the reverse or upward direction, the flow in the equalizing pipe 83 is reversed so that gas is received from the inlet chamber 9 and transmitted into the lowest jacket space. This construction has the advantage that a relatively even flow of gas to be compressed Will enter the inlet chamber 9, since during the downward stroke of the main piston when gas is drawn from the inlet chamber 9 into the cylinder 5, some gas is also discharged from the chamber 76 into the-inlet chamber 9. To compensate to some extent for that which is drawn into the cylinder 5, and during the reverse stroke when no gas is taken into the cylinder 5, a considerable quantity of gas will be drawn into the chamber 76.

By means of the construction described, it will be obvious that damage to the compressor because of excess water or other coolant being admitted into a cylinder is entirely eliminated, since if excess water is passed into a cylinder, it will pass through the discharge valve or valves in advance of the gas which is being compressed and this is equallytrue in both stages of compression. It is, consequently, possible by means of the construction shown to admit more coolant to the cylinders than has heretofore been considered practical, and consequently, more efficient cooling of the gases is efiected, as well as thoroughly tefiicient lubrication of the bearing surfaces between the 'cylindersyand pistons, so that a cooler for the gases be'- tween the two stages of compression is not necessary. The maintaining of a relatively large body of water in the space between the piston head and the lower pistonflange 20 ensures .adequatelubrication of the main piston and its cylinder and also ensures efficient cooling of the second stage cylinder 18.

herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.

I claim as my invention:

1. A compressor including an upright cylinder having a cylinder head at the upper end thereof, a valve in said cylinder head for admitting gas into said cylinder, a piston reciprocable in said cylinder for compressing gas between said piston and said cylinder head, said piston having a second cylinder fixed thereon on the face thereof opposite to said cylinder head, a stationary piston fitting within said second cylinder, a discharge valve in said reciprocatory piston for discharging gas compressed thereby downwardly into said second cylinder for further ,com-

piston for discharge of the compressed gas, and a reciprocable piston rod secured to said first mentioned piston and extending downwardly lengthwise through said stationary piston.

2. A two-stage compressor including a cylinder having a cylinder head on the upper end thereof containing a valve for admitting gas into said cylinder, a piston reciprocable in said cylinder for effecting the first stage of compression between said piston and said cylinder head, a second stage cylinder fixed to the lower face of said pistoncoaxially therewith, a vvalve in said piston through which gas from the first stage of compression is discharged into saidsecond stage cylinder, a stationary piston fitted 'withinsaid second stage cylinder and cooperating therewith duringreciprocation of said first mentioned piston,

a valve in said stationary piston through which gas from the second stage is discharged, said first mentioned piston being provided with an enclosure surrounding said second stage cylinder, means in said cylinder head for supplying liquid coolant to said enclosure, and means for imparting reciprocation to said first mentioned piston.

3. A compressor according to claim 2, in which said enclosure is formed by a flange extending outwardly from the lower part of said second stage cylinder into sliding contact with said first mentioned cylinder and spaced from the head of said first mentioned piston.

4. A compressor according to claim 2, in which openings are provided in said first mentioned cylinder for admitting cooling liquid into and discharging the same from said enclosure.

5. A two-stage compressor including a cylinder having a cylinder head containing a valve for admitting gas into said cylinder, a piston reciprocable in said cylinder for effecting the first stage of compression between said piston and said cylinder head, said piston including a head and a flange which cooperate with said cylinder and which are spaced apart and connected by a second stage cylinder of smaller diameter than said head and flange, to form an enclosure for coolant between said first mentioned cylinder and said second stage cylinder, a valve in said piston through which gas from the first stage of compression is discharged into said second stage cylinder, a stationary piston which said second stage cylinder is fitting and which cooperates during reciprocation of said first mentioned piston, a valve in said stationary piston through which gas from the second stage is discharged, means in said cylinder head for supplying coolant to said enclosure, and means for reciprocating said first mentioned piston.

6. A two-stage compressor including a first stage cylinder having annular spaced ribs extending outwardly therefrom, a jacket member extending about said cylinder and engaging said ribs and forming therewith a water jacket divided by said ribs into a plurality of compart ments, a piston for reciprocation in said cylinder and having a head engaging with said cylinder, a second stage cylinder 'formed integral withsaid piston and extending downwardly. therefrom, an outwardly extending 'flange on said second stage cylinder, spaced from said cylinder head, said head, flange and said second stage cylinder forming between them an annular space, said first stage cylinder having an opening communicating with one of said compartments of said jacket for admitting coolant to the space in said piston and having another opening communicating with another compartment for discharging coolant from said space, a stationary piston fitted within said second stage cylinder, and means for reciprocating said first mentioned piston.

7. A two-stage compressor including a first stage cylinder having a piston arranged therein, said piston comprising a head at the upper end thereof and a flange at'tlie lower end thereof, said head and flange being connected by a cylindrical skirt which forms the cylinder for the secondstage and which is of smaller diameter than said head and flange, means for admitting coolant into'a'nd discharging coolant from the space between said head and said flange and said first and second stage cylinders from.

8. A two-stage compressor including a first stage cylinder, 'an inlet chamber arranged above said cylinder, a piston in said cylinder, said piston having a downwardly extending skirt portion forming a cylinder for the second stage, a stationary piston fitted within said second stage cylinder, said first mentioned piston having a head at the upper end thereof cooperating with said first mentioned cylinder and La flange at the lower end of said skirt spaced from said head and also having a sliding engagement with said first mentioned cylinder, said stationary piston being supported on a head secured on the lower end of said cylinder, the space between said lower head and said flange of said piston being variable in volume during the reciprocation of said first mentioned piston, a tube connecting said space with said inlet chamber, valves on said compressor controlling the flow of gas through said compressor, the space above said flange at the lower end of said skirt forming the space for coolant, jackets for coolant extending about said first stage cylinder, and openings in said first stage cylinder for conducting coolant from said jacket into said space and for discharge of coolant from said space into said jacket.

9. A compressor including a cylinder having a cylinder head, a piston reciprocable in said cylinder and having an enlarged head, a secondstage cylinder formed integral with said piston and reciprocable therewith, a stationary piston fitted within said second stage cylinder, and means for passing coolant about the exterior of said second stage cylinder including a flange at the lower end of said second stage cylinder which extends into sliding engagement with said first mentioned cylinder and which forms a space within said first mentioned cylinder and about said second stage cylinder between said piston head and said flange, and on said compressor means for circulating coolant through said space.

10. A compressor including a cylinder, a piston reciprocable in said cylinder, said piston having a downwardly extending skirt portion forming a second stage cylinder, a stationary piston fitted within said second stage cylinder, a hollow cylindrical member supporting said stationary piston, and terminating at its lower end in a head, said head closing the lower end of said first mentioned cylinder, a valve in the upper end of said stationary piston through which compressed gas enters into the space within said cylindrical member, said lower cylinder head having openings therein through which the compressed gas passes for discharge from the compressor, said lower cylinder head having a groove formed therein fyhich lies adjacent to said ifirst mentioned cylinder and drums a passage for coolant for absorbing heat .from .the

'mitt-ing gas into said cylinder, a piston reciprocable in said cylinder and having a head, means mounted on said .rcylinderforsupplying a coolant into said cylinder above :said piston, 'a valve in said piston head through which coolant and compressed gas pass, and a second stage cylinder on the lower face of said piston into which said coolant and compressed gas are delivered by said last mentioned valve.

12. vA two-stage compressor including a vertical cylindBr having a cylinder head, a valve in said head for adrmitting gas into said cylinder, a piston reciprocable in said cylinder, means mounted on 'said cylinder for supplying a coolant into said cylinder above said piston, a valve in saidpiston through which coolant and compressed gas gpass, a second stage cylinder fixed to the lower face of said piston and into which gas and coolant pass downwardly from said valve in said piston, a stationary piston fitted within said second stage cylinder, a valve in the upperend of said stationary piston through which gas and coolant are discharged downwardly, and means for imparting reciprocatory motion to said first mentioned piston.

13, A compressor including an upright cylinder having a cylinder head at the upper end thereof, a valve in said cylinder head for admitting gas into said cylinder, a

piston.reciprocable in said cylinder for compressing gas between said piston and said cylinder head, said piston having a second cylinder fixed thereon on the face thereof opposite .to said cylinder head, a stationary piston fitting masons? reciprocatory piston for discharging gas compressed thereby downwardly into said second cylinder for further com-- .pression, a discharge valve mounted "on said stationary piston for discharge of the gas, and means for supplying "a coolingand lubricating liquidfto the gas in said first mentioned cylinder, which is discharged through said discharge valve into said second cylinder in advance of the gas compressed in said first mentioned cylinder.

14. A compressor including an upright cylinder having a cylinder head at the upper end thereof, a valve in said second cylinder fixed thereon on the face thereof opposite to said cylinder head, a stationary piston fitting within said second cylinder, a discharge valve in said reciprocatory piston for discharging gas compressed thereby downwardly into said second cylinder for further compression, a discharge valve mounted on said stationary piston for discharge of the gas, said cylinders and pistons being arranged on a substantially vertical axis with said cylinder head uppermost, and means for discharging 'a cooling liquid into the gas above said first mentioned piston, whereby said liquid will flow by gravity in advance of the compressed gas through said discharge valves when the same are open.

References Cited in the file. of this patent UNITED STATES PATENTS 495,348 Lawson Apr. 11, 1893 1,113,873 Boring ---a Oct. 13, 1914 1,681,280 Bruckner Aug. 21, 1928 1,791,364 'Lewis Feb. 3, 1931 1,998,264 Aikman Apr. 16, 1935 jaw;

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