US2970603A

US2970603A - Steam trap

Info

Publication number: US2970603A
Authority: US
Inventors: Maeda Chiyomatsu
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-04-17
Filing date: 1957-10-22
Publication date: 1961-02-07
Anticipated expiration: 1978-02-07

Description

Feb. 7, 1961 Filed Oct. 22, 1957 Fig. l

CHIYOMATSU MAEDA STEAM TRAP 2 Sheets-Sheet l If fll lha INVENTOR ATTORNEY Feb. 7, 1961 CHIYOMATSU MAEDA 2,970,603

STEAM TRAP Filed Oct. 22, 1957 2 Sheets-Sheet 2 INVENTOR ATTORNEY .nited States Patent STEAM TRAP Chiyomatsu Maeda, 2-158 Hamakoshien, Nishinomiya, Hyogo, Japan Filed Oct. 22, 1957, Ser. No. 691,583 Claims priority, application Japan Apr. 17, 1957 8 Claims. (Cl. 137-194) This invention relates to steam traps especially adapted for use in power plants and serves as a means for separating liquid from steam and discharging it into a reservoir, the main object of the invention being to provide a construction wherein variations in steam pressure will have substantially no effect upon the operation of the trap.

Another object of the improvement is to produce a simple, effective and convenient device for the purpose stated.

To this end the invention consists in the novel construction, arrangement and combination of parts shown and described, and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts;

Figure 1 is a transverse vertical section taken centrally of a device embodying the principles of the in vention;

Figure 2 is a plan view of the device, and;

Figure 3 is a transverse horizontal section on line 3-3 of Figure l with parts omitted.

As shown in the drawings, and referring particularly to Figure 1 thereof, the illustrated trap 10 has a shell or casing 11 of substantially cylindrical form adapted to be used with its axis upright. It is closed at the upper end by means of an integral end plate 12 over which is secured an upper cover member 14 as by means of suitable bolts 14'. In one side, near the top of the trap casing, is an inlet 17 to which is secured a part of the return line piping through which air, water of condensation, and exhaust steam flow from pipe lines. In the opposite side of the trap casing, near the bottom thereof, is the outlet 18 which in the construction shown is formed as part of a lower cover member which closes the open bottom end of the trap casing and to which it is secured by means of suitable bolts 19. The lower cover member 15 includes an integral end plate 13 which serves to close the open bottom end of the casing 11. The casing 11 is thus divided into three vertical chambers, namely, an upper chamber 41, a middle chamber 42, and a lower chamber 43, the end plates 12 and 13 serving as partition walls between the chambers.

At the bottom of the casing the lower end plate 13 is provided with a central aperture 13' which has fitted therein the removable valve seat member 26. The valve seat member 26 is provided with a centrally disposed valve port 26'. At the top of the casing the upper end plate 12 is provided with a central opening 12' in which is fitted a vertical drain pipe 27 fixed in place by means of a collar 27'. The upper end of drain pipe 27 is formed to provide a valve seat member 25 having a valve port 25' and the arrangement of parts is such that the upper and lower valve ports 25' and 26' are in alignment. Directly above the upper valve port an adjustable stop member 28 is provided. Member 28 may be a bolt fixed to the upper cover member 14. 7

2,970,603 Patented Feb. 7, 1961 A balanced discharge valve cooperates with the ports 25' and 26' and comprises a cone shaped upper valve element 22 adapted to control the upper port 25 and a cone shaped lower valve element 23 adapted to control the lower port 26'. These valve elements are made of the same size and shape, so that diameter d equals diameter d The valve elements are interconnected by means of a stem 24 which is disposed within the vertical drain pipe 27 in coaxial relation therewith. The balanced valve, comprising the stem 24 and the valve elements 22 and 23, is secured to a float 31 by connecting pieces 32 projecting from the stem 24 near the bottom of the stem. The lower end of the drain pipe 27 terminates at a point above the bottom end plate 13 so that the lower part of the valve stem 24 is exposed to permit free up and down movement of the connecting pieces 32.

As shown, the float 31 is annular in form to accommodate within its central hole the vertical drain pipe 27 and the balanced valve.

A plurality of vertical pipes 21 are provided, arranged within the steam trap casing symmetrically relative to the float and externally thereof as indicated in Figure 3. These pipes, which may be termed equalizing pipes, provide communication at all times between the upper chamber 41 and the lower chamber 43 as shown in Figure l. The lower ends of the pipes are screwed into the lower end plate 13 while the upper ends of the pipes 21 are attached to upper end plate 12 by peening the upper ends thereof as seen in Figure 1. The trap casing 11 is also provided with a buffer plate 16 which is located adjacent the inlet 17 and a valve cock 29 for expelling air from chamber 42. The operation of the steam trap is as follows:

The trap is installed vertically as shown in Figure 1 with the unit to be drained connected to the inlet 17 and with the flanged outlet 18 attached to a pipe leading to a suitable drain device. Exhaust steam containing the condensate flows into the middle chamber 42 through inlet 17. As the steam flows into the trap it will be instantly separated from the condensate, the steam remaining in the upper part of the middle chamber and the condensate flowing by gravity into the bottom of the middle chamber. Indicated pressure in the middle chamber is approximately the same throughout. Normally, the upper valve 22 is seated upon its valve seat and the lower valve 23 is seated upon its valve seat. The steam pressure within the middle chamber 42 acts upon the under surface of the upper valve 22 and upon the upper surface of the lower valve 23 equally because as already described both top and bottom valves are identical in shape and size with equal diameters d and d At this time the pressure within the upper chamber 41 acting on the upper surface of the upper valve 22 is the same as the pressure within the lower-chamber 43 acting upon the lower surface of the bottom valve 23. The pressure within the upper and lower chambers is the same since they are in communication by the several equalizer pipes Accordingly, the valves are free from any effect of the pressure even though the steam pressure in the trap may be high or low and even though the difference of pressure between the middle chamber and either the upper or lower chamber may vary. Furthermore, the float 31 will not be affected by variations in the steam pressure. Therefore, the valves 22 and 23 will bear down upon their

respective valve seats

25 and 26 with only the weight of the float 31 and its attachments.

As the amount of condensate increases and the float is submerged the float will become more buoyant. When the buoyancy exceeds the weight of the float and its attachments, the float will rise giving the lift to the upper and lower valves, allowing the condensate in the middle chamber=to"discharge' from -the upper and lower cham 'bers 43 through the valve openings. ,P,ressur.e vin the middle chamber 42 forces condensate up through the drain pipe 27 and out through the upper valve port 25'. Steam, however, will 'beheld tightly; in the .middle .chamher.

As the action continues, the :condensate in=the middle chamber decreases, the buoyancy of the float decreases also, until the buoyancy becomes less than'the weight of the float itself. Then the float falls and the valves come into close contact with the valve seats againand the discharge of thecondensate is cut ed.

The trap may be utilized in various types of steam lines, including high andlow pressure systems vand the functioning of the trap is not .aflected by changes of atmospheric temperature throughout the year.

Various modifications can be made :in the-em;b,odiment 'of the trap described :above withoutxdeparting from the spirit of the invention, the scope of vwhich is inclicated by the following :claims.

I claim:

1. A steam trap comprising accasing having inlet and outlet openings. upper and lower horizontal partitions dividing said casing into an upper chamber, a middle chamber and a lower chamber, said inlet opening lead ing into .said middle chamber, said outlet opening leading from said lower chamber, a balanced valve assembly in said casing, said valve assembly forming parallel flow paths comprising an upper valveseat in ,said upper horizontal partition and a lower valve :seat in said lower horizontal partition, a balanced valve. cooperating with said valve seats, a float connected to said balanced valvehaving buoyancy with respect to a liquid level in said middle chamber, a drain pipeextending downwardly from said upper valve seat to a point spaced froinsaid lower valve seat for passing the liquid therethrough when pressure applied to said liquid level is greater than the liquid head required to fill said drain pipe, and at least one pressure equalizing pipe providing communication between saidupper and lower chambers.

2. A steam trap as set forth in claimtl, iniwhich the valves'are of the same'shape and dimensions.

3. A steam trap as set forth in claim l,-in which the valves are cone shaped-and of equal area in horizontal cross section.

4. A steam trap asset forth in claim .3, in which the upper chamber has a limit'stop above-the gupper valve for limiting its upwardrmovement.

5. A steam trapxas set forth in claim, 1 ,in which the casing is cylindrical, the float is annular in ?form and coaxial with the cylindergythe .drain pipe is withinthe .float and-coaxial therewith, thexvalve assembly is within the drain pipe and coaxial therewith,:and in which the pressure equalizing pipes are disposed in symmetrical array about the central vertical'axis'ofthe casing.

.end of the drain pipe.

7. A steam trap comprisinga casing; partitions dividing said casinginto upper, middleand lower chambers;

said ".casingthaving an inlet to said middle'chamber-and anoutlet from said lower and upper chambers; afloat in .said middle chamber: valve seats in said upper and lower partitions; balanced valves closing said valve seats, said balanced valves being opened by upward movement of said float ll'l response to a rise of liquid level in said middle chamber and being closed by downward movement of said float in response to a lowering of liquid level in said middle chamber; and a drain pipe extending from the valve seat ;in said upper partition to a level in said middle chamber below a level of vliquid therein at which saidbalanced valve begins to open; the rise of the liquid level in said middle chamber opening said balanced valves to'provide flowvof liquid through the valve seat insaid lower partition even when only the force of gravity actsupon the liquid and provide flow of liquid also through=the .valvegseat in said upper partition when pressure applied to the liquid produces a liquid head in excess of that required for filling the drain pipe and the valve seatin said upper partition.

=8. ,Asteam trap. comprisingacasing having inlet and outlet openings, said inlet opening capable of receiving liquid and steam under pressure, upper and lower partitions dividing said casing into an upper chamber, a middle chamber and a lower chamber, said inlet opening leading into said middle chamber and said outlet opening leadingfrom said lowerchamber, as balanced valve assembly forming parallel flow paths'from the inlet opening to the outlet opening including an upper valve seat in said upper partition and a lower .valve seat in said lower partition and including a balanced valve cooperating with said valve seats-for closing said parallel flow paths, a float responsive to a quantity of liquid in said middlechamber and connected to said balanced valve for opening said parallel flow paths when the liquid level intherniddle chamberreaches a level causing the float-to become buoyant, a drain pipeextending downwardly from said upper valve seat to a point below said level, and a-pressure equalizing pipe providing passage of liquid between said upper and lower chambers, said liquid on opening of said balanced valve being passed through the lower valve seat in the absence of steam pressure in the middle chamber sufficient to produce the liquid head to-fill said drain pipe, and said liquid on opening ofsaid balancedvalvebeing passed through both valve seats in the presence of steam pressure in the middle chambergreater than the liquid head required to fill said drain pipe, which greater pressure during its continuation forces the liquid through the drainpip e, the upper valve seat, and theequalizing pipeto the-outlet opening.

References'Cited in the file of this patent UNITEDSTATES PATENTS 193,938 Edwards Aug. 7, 1877 2,043,074 Simpson June 2, 1936 2,349,938 Burnette May 30, 1944 2,648,347 Fahnoe Aug. 11, 1953 FOREIGN PATENTS 763 G rm y v----r--.--.---iy 2 1894 679,526 Germany Aug.v 8, 1939