US2593101A - Multiple valve for condenser tube blowers - Google Patents

Description

April 15, 1952 w. s. CAMPBELL MULTIPLE VALVE FOR CONDENSER TUBE BLOWERS Filed Jan. 17, 1946 INVENTOR WZZianvJTUam IJZQZJ BY 7y ATTORNEY Patented Apr. 15, i952 CUNITED STCATE'S PATENT OFFICE MULTIPLE VALVE FOR CONDENSER TUBE BLOWERS William S. Campbell, Astoria, N. Y. Application January 17, 1946, Serial No. 641,776

My invention relates to tube cleaners and in particular to devices for applying high-pressure fluids such as steam directly to flue or condenser tubes for flushing the same.

A number of devices have been proposed and are in use for supplying pressurized fluids to condenser tubes for cleaning purposes. Most of these devices require manual actuation of a valve in order to admit the cleaning fluid. Frequently, the tubes to be cleaned are constricted by excessive deposits, so that application of pressurized fluid may result in the backward ejection of cleaning fluid. When steam is employed, this difliculty can result in serious injury to the user of the device. I

It is, accordingly, an object of my invention to provide an improvedtube cleaner of the character indicated.

It is another object to provide a tube-cleaning device offering improved features of safety and of operating ease.

It is also an object to provide a tube-cleaning device having an improved automatic valving mechanism for readily admitting pressurized cleansing fluid only when the device is properly v fitted to the tube to be cleaned.

to be cleaned only when the device is urged against the pipe.

Other objects and various features of novelty and invention will be hereinafter pointed out or will become apparent to those skilled in the art.

In the drawings which show, for illustrative purposes only, a preferred form of the invention:

Fig. 1 is a cross-sectional elevation of my improved tube-cleaning device, shown with the valving mechanism in its normally closed position;

Fig. 2 is a sectional view of a portion of the device shown in Fig. 1, illustrating the valving mechanism in its open position; and

Fig. 3 is a section taken in the plane 3--3 of Fig. 1. r I

Broadly, my invention resides in the provision of an improved automatic valving mechanism for a tube cleaner having an input chamber 5 and a discharge-orifice member or nozzle 6. The valving mechanism is normally seated to seal oif chamber 5 from orifice member 6. Member 6 is adapted for displacement with respect to chamber 5, and means areprovided for opening the valve mechanism upon displacement of nozzle 6. In operation, nozzle '6 is'displaced only 5 Claims. (Cl. 277-43) when the device is urged against the open end of a tube to be cleaned. This action results in opening the valve-thus admitting pressurized cleaning fluid to the tube to be cleaned. If the device is insufliciently urged against the tube, or if the tube has been flushed and the device is being removed, the pressure of the fluid in chamber 5 over the upstream area of the valve is sufliciently great to forcean immediate closure of the valve. Thus, before the valve is actually removed from the tube, complete closure has been efiected and the danger of fluids escaping from the interfit of discharge member 6 with the tube is very substantially reduced.

In complete form,.the valve means of my invention includes a firstmember which is normally seated to cut off the major part ofthe possible flow between chamber 5' and nozzle 6. A second or pilot-valve member is .normally seated to cut off the remainder of this possible flow, and this second alve is positioned to coact with displacement of member 6. In operation,

since the second valve presents a comparatively small upstream area, the device may be urged with relative ease into operating relation with the tube to be cleaned. Opening of the second valve member admits fluid at high-pressure to the downstream side of the firstvalve member, thus partially balancing the pressures on the main valve and making possible easy complete opening of the valve. j

Referring to the form shown in the drawings, the device is built around a main body or housing 1 having a handle 8 for portability and to facilitate urging the device against a tube to be cleaned. Main body 1 includes chamber 5 at its upstream end and an inlet pipe 9 for connection to a source of supply of cleaning fluid. Orifice member 6 is in sliding engagement with the housing I, and in the form shown this fit is concentric-that is, an outer cylindrical portion I0 is displaceable longitudinally in a sleeve ll forming a part of housing 1. If desired, and par ticularly when high-pressure fluids are employed, sealing'means may be provided to prevent leakage between th'e'sliding surfaces It! and II; in the form shown, a cup l2 threadedly engages housing I to urge packing [3 into relatively tight engagement with surface l0.

As indicated above, my improved valving mechanism comprises essentially two parts. A first or main valve member M is normally seated at the downstream end of the chamber 5. Inthe form shown, valve member l4 includes passages 15 permitting fluid communication between chamber 5 and discharge member '6. Normally, however, this communication is prevented by the seated relation of a second or pilot-valve member it over openings l5. In the form shown, valve member I4 is provided with an inner sleeve l1,

slidably accommodating both the stem it of pilot valve I6 and a rod IQ for a purpose which will later be clear. Valve member l4 also includes a cylindrical guide section 20 to promote axial alinement of the entire valve mechanism with housing I and a free sliding relation between these elements. Once pilot valve l6 has been displaced to an open position, a number of openings 2| between an inner annular space 22 (at the downstream end of orifices I) and an outer annular space 23 permit communication of pressui ized fluid to substantially the entire downstream cross-sectional area of valve member l4, thus partially balancing the forces acting on main valve J4.

To" improve alinement of parts andto retain orifice member 6 in unit-handling relationship with the tube-cleaning device as a, whole, valve member I4 is provided with a further cylindrical portion or sleeve 24 extending in sliding engagement substantially down a sleeve 25 machined in orifice member 6. Sleeve 24 is formed at its downstream end with a pair of diametrically opposed slots '26 accommodating-an anchoring pin 21 ,held in member 6. Pin 21 may be secured in member 26 .by conventional methods, and in the form shown, a spring wire or snap ringZtl extends circumferentially about member 5 in a groove 29 machined'in a plane containing'pin 21.

P1112! also carries rod I9, and the location of slots 25 is suchthat, inthe normal extended position of member 6, rod l9, will be spaced from stem J8 to permit theconcurrent seating of pilot valve l5 andof valve member [4. It will be noted that discharge-orifice member or nozzle 6 is provided with a shoulder 30 and that this shoulder may abut the lower end of cup i2, thus limiting the upstream displacement of member 6. The extent of slots 26 should be such that pin 2'? will engage cylindrical portion '24 to unseat valve member i4 prior to abutment of shoulder 35 with cup [2.

The length of rod I 9 should be such with respect to the length of slots 26 that valve I6 is un seated before the above-mentioned operation of valve 14.

As explained, the parts of my tube-cleaning device are. normally arranged as shown in Fig. 1, the high-pressure cleaning fluid serving to keep both valves I and I6 seated automatically. The device is adapted for use by insertion of nozzle member ,6 into the tube to be cleaned (see the dot-dashed element in Fig. 2). Depending upon its size, the end of the tube .will abut one of shoul- ,ders 31-32 on member 6. By thrusting against handle 8, the user can readily force an opening of pilot valve lfi-thus admitting a restricted flow of cleaning fluid to the tube and, more particularly, to the downstream effective areaof valve l4. This condition necessarily means a relatively small force diiferential tending to keep valve I4 seated; this differential may be readily overcome .by an additional thrust on handle 8, whereby pin 21 engages the cylindrical portion 24 of valve 14 to unseat the same. Both valves l4 and I6 are then unseated and admit through orifices 2| and I5, respectively, full flow of cleaning fluid at high pressure.

In removing the device, when it is considered that a cleaning operation has been completed, a first decrease in thrust will disengage pin 21 from sleeve portion 24 and permit the above-mentioned pressure differential to seat main valve I4thus substantially cutting ofi the flow of cleaning fluid. With subsequent decreases in thrust, and since pilot valve l6 presents a larger efiective area upstream than downstream, the fluid-supply pressure in chamber 5 immediately forces a closure of valve I6: Thus, just before the thrust is removed from handle 8, the entire valving mechanism has been automatically closed and a harmful escape of cleaning fluid is not possible from the interfit of member 16 (at shoulder 3| or 32) with the pipe that has just been cleaned or that it was not possible to open by this method.

For improved performance of my valving mechanism, I prefer to employ a material such as brass ;for the members and I6 and steel or other hard materialfor rod l9. Under these circumstances, repeated abutment of rod I!) with the stem l8 of the pilot valve would cause excessive wear of the brass member. To reduce this wear Ihave, in the form shown, embedded a steel ball 34 in valve stem l8.

When the described tube-cleaning device is not in operation and is to be stored, the absence of a pressure-differential across pilot valve [5 means that this element will freely float in valve 14. To prevent permanent dislocation of these valve parts, there is provided in chamber 5 a ledge 35 against which pilot valve 16 may abut, if necessary. It will be clear that even if both valves have become unseated while not in use, reapplication of high pressures to the inlet chamber 5 will effect immediate valve closure-thus readying the device for use.

While the invention has been describedin considerable detail and a preferred form illustrated. it is to be understood that various changes and modifications may be made within'the scope of the invention as defined in the appended claims.

I claim:

1. In a tube-cleaning device, a housing including a sleeve, a discharge member slidable in said sleeve, a main valve, a pilot valve, lost-motion means connecting said discharge member to said pilot valve, said lost-motion means being operative to open said respective valves in response to displacement of said discharge member in one direction, and lost-motion means connecting said discharge member to said mai valve, the motion lost by said second-mentioned lost-motion means being greater than the motion lost by said firstmentioned lost-motion means, whereby first incremental displacement of said discharge member with respect to said sleeve in said one direction is effective to take up lost motion only, further incremental displacement in said one direction is efiective to open said pilot valve and still further incremental displacement is effective to open said main valve.

2. In a tube-cleaning device, a housing including a sleeve and "an inlet for pressurized fluid, a discharge member slidable in said sleeve, a generally annular main valve having portions slidable in said sleeve and in said discharge member, a pilot valve seatable on said main valve, said main valve and said pilot valve being between said inlet and said discharge member, first lostmotion means between said discharge member and said pilot valve, and second lost-motion means between said discharge member and said main valve.

3. In a tube-cleaning device, a housing having a longitudinal bore, a discharge member and a main valve slidable in said bore, a pilot-valve member positioned on said main valve to be unseated by a displacement of said discharge member relatively to said housing when the discharge member isinserted into a tube to be cleaned, said main valve and said pilot-valve member being disposed so as to be urged into closed position by pressure in said housing, and a lost-motion connection between one of said members and 7 said main v alve, whereby after said pilot-valve member has been opened by a first displacement of said discharge member in one direction, said main valve may be opened upon a further displacement of said discharge member in said one direction, said housing sealingly encasing said main valve and one end of said discharge member, whereby said main valve and said pilot-valve membermay be self-closing upon removal of said discharge member from a tube, and further whereby in the case of a constricted tube to be cleaned there may at all times be a safe containment of pressures within said housing.

4. A device according to claim 3, in which abutment means on said discharge member serves to limit outward longitudinal displacement of said discharge member relatively to said housing.

5. A device according to claim 3, in which there is a further lost-motion relation between said discharge member and said pilot-valve member, and in which there is a substantial effective cross-sectional area of said discharge member facing generally upstream within said device, said substantial area exceeding the effective downstream-facing cross-sectional area of said discharge member that is to be inserted in a tube to be cleaned, whereby the pressure Within said device may exert a resultant force tending to displace said discharge member in the opposite direction to the extent of said further lost-motion upon withdrawing said device from a tube and after said pilot-valve member has closed itself.

' WILLIAM S. CAMPBELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 223,040 Gohr et al. Dec. 30, 1879 620,608 Ogletree Mar. 7, 1899 848,999 Kratzenstein Apr. 2, 1907 1,215,146 Haeseler Feb. 6, 1917 1,821,206 Caswell Sept. 1, 1931 FOREIGN PATENTS Number Country Date 221,655 Germany May 2, 1910

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