US 1548288 A
Description (OCR text may contain errors)
Aug. 4, 1925. 1,548,288 H. F. SMITH GAS PURIFICATION Original Filed Dec. 19, 1921 i l lw Patented Aug. 4, 1925.
UNITED STATES PATENT OFFICE.
HARRY 1!. SMITH, OF DAYTON, OHIO, ASSIGNOR TO THE GAS RESEARCH COMPANY,
OF DAYTON, OHIO, A CORPORATION OF OHIO.
Application filed December 19, 1921, Serial No. 523,392. Renewed June 8, 1925. a
To an whom it may concern:
Be it known that I, HARRY F. SMITH, a citizen of the United States of America, residing at Dayton, county of Montgomery,
6 and State of Ohio, have invented certain new and useful Improvements in Gas Purification, of which the following is a full, clear, and exact description. This invention relates to purification of 1 gas, and particularly to the treatment of producer gas to remove impurities such as tar and the like therefrom.
In the patents issued to Harry F. Smith Numbers 1,099,773 and 1,140,198, bearing datesrespectively of June 9, 191 1 and May 18, 1915, is set out a method of purifying gas andh type of apparatus for carrying 1 that method intov effect. The method of purification therein set out is based on the fact that if a gas containing impurities therein, such impurities for example as tar,
is passed through a diaphragm of spun glass, or some analogous substance, at a suitable velocity, a coalescence or agglomeration of the particles .of impurity will take place with the. production of particles of such substantial size that they will readily separate' out under the action of gravity,'when carried out of the diaphragm by the current of gas. Experience seems to show thatthe cleaning effectiveness of such apparatus is in accordance with the velocity of flow of the gas through the diaphragm. The greater the velocity of flow the better the cleaning.
tory cleaning under actual operating conditions, it is apparently necessary to at all times maintain a minimum velocity of flow. The velocity of flow of the gas .within the diaphragm, other conditions remaining constant, is dependent upon the differential pressure upon opposite sides of the diaphragm, and the cleaning effectiveness is, in practice, -maintained by socontrolling the cleaning apparatus that the drop in pressure across the diaphragm shall not, normally,
fall below a predetermined minimum. In practice it has been found that a differential pressure of substantially two; pounds gives very effective cleaning, not less than 99.5 per cent of the tar being removed from the gas under these circumstances. Preferably a pressure of substantially two pounds on one side and four pounds on the other side of the diaphragm is maintained, though to the housing 10. An out-let 12, adapted .And in order to secure sufficiently satisfac-' these pressures may vary so long as the drop in pressure across the diaphragm does not depart materially from the desired differential of two pounds, or whatever differential is found to give the desired cleaning effectiveness.
. In the patent issued to Harry F. Smith May 24, 1921 No. 1,37 9,056 is illustrated and described one method, and apparatus, for effecting the desired cleaning of gas. v
One of the principal objects of the. present invention is to provide another method in connection with this form of purification, by nieansof which the desired cleaning effectiveness maybe maintained. Another object of the invention is to provide suitable apparatus for carrying that method into efiect.
Other objects and advantages of the invention will be apparent from the description set out below when taken in connection with the accompanying drawing, in which -is illustrated in section, a form of purifying apparatus embodying this invention.
In the form ofapparatus shown the numeral 10.designates a drum or housing, having an inlet opening 11, adapted for connection to a main through which the fluid to be cleaned passes from any suitable source in- 8 for receiving'the delivery main, through which the gas is led to any desired place of use or storage, is also provided through which the gas which has been treated passes out from the housing. The upper part of the 9 housing is closed by means of a removable cap 13, the construction being such that access to the interiorof the housing may be" readily had upon removal of the'cap. The lower part of the housing is also preferably made detachable, though it may be made integral if desired. Suitable packing material maybe interposed between this lower closure and the housing, in order to prevent leakage.
Positioned within the housing is a cylindrical sleeve 15, preferably of perforated sheet metal, a second cylindrical sleeve, 16 also, preferably, of perforated sheet metal, being positioned withinthe sleeve 15, the two sleeves being so proportioned that a suitable space is provided which is adapted to receive spun glass, or other suitable fila 'mentous material, which serves as a per- I VlOllS, non-filter1ng, d1aphragm; The sleeve 15 is provided at its upper end without standing lugs 18 having threaded passages therein adapted to receive the adjusting bolts 19, which cooperate with the closure and compression member 20, positioned within the space between the two sleeves 15 and 16, and, preferably, in'substantially gas tight connectionwith these two sleeves, so that there maybe no leakage of gas upwardly between these members. This member 20 not only serves to thus preventthe escape of gas from between the two'sleeves 15 and 16, but also for the primary purpose of compressing the filamentous'inaterial 17 to the desired density.
Slidably mounted within the inside of the inner sleeve 16 is a piston 25, which is in substantially gas tight contact with the cooperating surface of the sleeve 16, and which is in addition, provided with grooves 26, throughout its len h, which serve to prevent the passage 0 untreated gas from the space 27, within the inside of the diaphragm, upwardly between the piston 25 andvtlie sleeve 16.
'such' as finely spun glass, hair, or the like,
at a suitable velocity, and as the gas passes through the pad or diaphragm the very finely divided tar fog therein will be so acted upon as to cause the extremely minute tar particles to agglomerate into drops of subi stantial size, which are carried on out of the diaphragm by the flowing gas and are subsequently separated out through gravity. If the quantity of gas passing through the cleaning apparatus were substantially constant, under all conditions, the problem would be comparatively sm all,for the diaphragm having been arranged at a density' to give the desired differentialpressure on opposite sides thereof, no further'manipulation of the diaphragm would be necessary, but inactual practice the gas is-subject to minor pressure fluctuations withoutany material variation in the quantity of gas passingthrough the cleaning apparatus, perhaps as a result of temporary clogging of'a part of the diaphragm, or for other reasons; and in addition the gas is from time to time subject to wide variations in the quantity passing through the diaphragm, which will in turn be translated into variations in the differential pressure upon opposite sides of the diaphragmv unless means istaken to maintain the differential pressure substan tially constant. .l V v In the use of thedescribed apparatus for removing tar from producer gas, for exam- -ple, the space between the sleeves 15 and 16 is filledwith'the desired filamentous mate-' rial, spun glass say, and the member 20 is thenadjusted to give that compremion of the filamentous diaphragm which is desirable under the normal operating conditions to be met. When the gas is introduced through the inlet 11 into the space 27 under suitable pressure the piston 25 will move upwardly to uncover a portion of the diaphragm, the upward movement of the piston continuing until the pressure within the space 27 is such as tobalance the weight of the piston. If the pressure within the space 27 varies as a result of minor fluctuations during operating conditions, oras a result 10f a material change of the quantity of gas being used, or as a result of'partial clogging of the pad, or for any other reason, the piston 25 will assume a new position corresponding to the changed pressure to maintain that pressure] substantially constant. As a result a substantially constant differential pressure, upon opposite sides of the diaphragm, will be secured, and the cleaning 'effectiveness of theapparatus thus main- V tained. As set out above, when impurities, such -as tar and the like, are tobe removed from Inasmuch as the differential pressure upon opposite sides of the diaphragm is due to the resistance to flow throu h the diaphragm, and that is controlled y the effective cross sectional area of the opening through the diaphragm, which-is in turn dependent, under any given-comp'rssion of 'the diaphragm, u 11 the effectiveyor uncoveredfarea of t e diaphragm, the piston "25 as it moves up or down functions to control the effective area of the diaphragm and thus to control the differential pressure on opposite sides thereof, by varying the total effective area of-the'passa'gesthrough the dia hragm, that is the effectiveo ning throug the diaphragm. The term e ective' opening through the diaphragm, therefore, is used .todesignate the total cross sectional area, the total opening, throughthat part of the diaphragm which is not covered by the iston and which part is therefore, effective in the cleaning 0 eration. a
While the met od herein described, and the form of apparatus for carrying this method into effect, constitute preferred einbodiinents of the invention, it is to be understood that the invention is not limited. to
this precise method and form of apparatus, and that changes may bemade in either without departing from the scope ofthe invention which is defined in the appended claims.
What is claimed is:
1. 'Ihe method of purifying gas which.
consists in passing the gas through a filamentous'diaphragn and varying the effective area'of said diaphragm to keep substantially constant. the differential pressure on opposite sides thereof.
2."The method ofpurifying gas which consists in passing the gas through a fila-.
mentous, non-filtering diaphragm; and varying the effective area of said diaphragm to pressure on opposite sides thereof.
- tous iaphiagm eifectiveness.
4:. In a gas purifying system a filamentous, and means associnon-filtering, diaphragm; ated. with said diaphragm for varying the effective area thereof to control the cleaning 5. In a gas purifying system, a filamentous diaphragm; and means associated with said diaphragm for automatically varying the efiective area thereof to control the cleaning 6. In a gas purifying system, a housing having a cylindrical non-filtering pervious diaphragm therein, said housing having an inlet opening into the space inside the diaphragm and an outlet opening from the space outside the diaphragm; and a slidable piston within the diaphragm, the construction being such that the effective area of the diaphragm is determined by the positioning of said piston.
7. In a gas purifying s stem, a housing havin a cylindrical nonltering, filamentherein, said housing having an inlet opening into' the space within the diaphragm and an outlet opening from the space outside the diaphragm; and a slid-' able piston within the diaphragm, the construction being such that the effective area spaced walls,
side the perforated walls,
of the diaphragm is determined by the positioning of said piston.
8. In a gas purifying system, a housing having inlet and outlet openings;
opening, filamentous material between said 'means for compressing said material to give a desired density thereof; and a piston in slidable, and substantially gas tight, contact'within the inner of said spaced walls, the construction being such that the piston will rise or fall with fluctuations in the pressure existing within the space into increase or decrease the efiective area of filamentous material to maintain substantially uniform the differential pressure on opposite sides thereof.
9. In a gas purifying system, a housing,
having inlet and outlet openings; spaced 7 spaced perforated walls surrounding said inlet perforated walls surrounding said inlet opening, filamentous non-filtering. material between said spaced walls, means for compressing said material to give a desired density thereof; and a piston in slidable, and substantially gas tight, contact within the inner of said spaced walls, the construction being such that the piston will rise or fall with fluctuations in the pressure exist-' ing within the space inside the perforated walls, to increase or decrease the effective area of filamentous material to maintain substantially uniform the cleaning eflectiveness.
In testimony whereof I hereto afiix my signature.
H. G. DUERR, L. G. THOMASSEN.