US2427446A - Fluid extracting piston press - Google Patents

Description

p 1947- J. J. DE LA RozA, SR 2,427,446

FLUID EXTRACTING PISTON PRESS Filed March 31, 1945 I 4 INVENTOR. '5' e/mqa/ndae ma a.-

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particularly to a which mixtures of to extract the fluid from equipped with cleaning apparatus have Patented Sept. 16, 1947- UNITED, STATES PA'rsrrr OFFICE 1 2,4am44s I Application March 31,3945, Serial No. 586,016

, 4 Claims. (01. 100-50) This invention relates to improvements in a fluid extracting fluid extracting device through fluids and solids are passed the solid material. The press includes a pressure tube through which the fluid-solid mixture is advanced by a reciprocatins piston. The pressure fac of the piston is slotted apertures in which are advanced and retracted cleaning blades. The function of the slotted apertures is to serve as passageways for draining of! the extracted fluid while the cleaning blades prevent solids from clogging or forming an obstruction to passage of fluid through the slots.

The concept has to do primarily with th apparatus or the construction of the device and is therefore not limited to any particular use. In other words, the may be utilized in extracting fluids from fluidsolid mixtures of any kind, whether the solids be of vegetable, animal or mineral matter com bined with' liquids of any kind such as water, hydrocarbons. or chemical solutions. In describing the invention the disclosure is limited to the extraction of water or liquor used in treatment or digestion of vegetable fibers such as wood chips, bagasse, straw, bamboo or other sources of cellulosic material.

In the separation of liquids from liquid-solid cellulosic mixtures difficulties. are encountered due to the separation and entrainment of gums, resinous and thickening susbtances which are carried off with the liquids and tend to obstruct the drains and passageways or ducts for removing the separated liquids. Different types of been devised to main.- tain the drain apertures and ducts clear and open with varying degrees of success. Where high pressures are necessary to satisfactorily extract the liquids from the mixtures the problem of keeping discharge openings for the liquid tree of obstructions becomes a major concern in the operation of the press or extracting device. In a copending application, Serial No. 514,817, now Patent 2,398,135, issued April 9, 1946, there is disclosed a press in which apertures in the piston face or pressure plate constitute ducts which are circular in cross, section and which are cleaned by advancing and retarding cylindrical filter pins. The construction here suggested is to substitute for that structur parallel slotted openings or apertures in theiace of the piston in which are reciprocated cleaning blades.

One of the objects of the invention therefore piston press and refers more fluid extracting piston press upon the is to provide an improved type of fluid extracting piston press in which high pressures are imposed fluid-solid mixture to extract the fluid from the solids.

Another object is to provide a simple rugged type of construction which will withstand heavy pressures without clogging.

A further object is to provide a construction for effectively separating fluids from a fluid-solid mixture wher there is a tendency for resinous and gummymaterials to be drained of! with the fluid.

Other and further objects 0! the invention will appear from the following description.

In the accompanying drawings which form a art or the instant specification and are to be read in conjunction therewith, and in which like reference numerals are used to indicat like parts in the various views,

Fig. l is a plan view ing the invention,

Fig. 2 is an enlarged sectional elevation of the device shown in Fig. 1,

Fig. 3 is a view taken along the line 2 in the directionof the arrows.

Fig. 4 is a view taken along the line 4-4 in Fig. 2 in the direction of the arrows.

Fig. 5 is a iragementary cross sectional view taken along the line 5-5 of Fig. 2 in the direction of the arrows.

Referring to the drawings,'at III is shown a tubular passageway which may beoi any desired shape in cross section. This tube has an outlet on its right-hand end, and is either tapered or has positioned therein a restriction in the form of a valve or other'congesting device to limit the size of the passageway. By compacting, congesting and increasing the density of the mixture pressure is imposed upon the congested mass and liquid extracted from 'the solids. Joined to the tube III at flanges II is a cylinder I2 which has a top inlet port l3. Any suitable type of conveyor or transporting duct such as a hopper or pipe is connected to the inlet port l3 and serves of a piston pressembody- 3-3 in Fig.

to supply the mixture to be separated into the .cylinder.

1 therein. A plurality of bars I! form the pressure face of the piston. These bars are spaced apart by separators l6 shown in cross section in Fig. 3

and are assembled together by bolts I1. and fit into the open end of the piston upon the shoulder mentioned above. The bar assembly is held in place on the shoulder by bolts l8 screwed into threaded apertures drilled axially of the piston walls Behind the bar assembly and within the piston housing is a circular plate i9 the outer diameter of which is slightly smaller than the bore of the housing whereby it is free to slide axially f the housing. On one side of this plate is a threaded aperture into which is screwedstop rod 20. The opposite side of the plate is slotted to receive a plurality of cleaning blades 2|. These cleaning blades are held in position in the of the plate by bolts 22. The free ends of the blades extend into and reciprocate, as will be hereinafter explained, in the slots |5a between bars l5. Spacers i6 which surround bolts l1 and are located between the bars l5 to form the slot ted openings move within the elongated apertures 2|a formed in each of the blades as shown in Fig. 4. Extending through all but the upper bar l5 and adjacent the forward face of the piston areelongated ducts 23 which form a continuous pas geway for draining extracted fluid to thehorizontal pipe 24 in the lowest bar. Fluid extracted with congestion or compacting of the fluid-solid mixture passes through the horizontal slots in'the piston face between'bars I5 into thevertical duct 23. Fromduct 23 it passes through the lowerhorizontal duct 24 from which it is discharged into the space between the bar assembly and plate IS. Agroove 25 extending longitudinally along the bottom of the inner wall of the piston permits the fluid to drain from this space and discharges it into theflexible pipe 28 by means of which it is discharged from the press. To assure a pressure-tight fit between the piston and cylinder adjacent the driven end of thepiston a flanged ring 2'! is bolted to the cylinder and holds in place a sealing ring or gasket 28 in the form of a packed gland between the inner face of the cylinder and outer periphery of the piston housing.

The piston is reciprocated by rotation ofshaft 29 which receives its energy from any suitable source of power not shown. on the end of the shaft is a crank 30 whosecrank pin 3| bears in the end ofyoke 32. Arms 32a of the yoke bear in crosshead 33 bolted to the end of the piston. The arms of the yoke straddle stops 35 and 36.

As previously suggested, there is screwed into one side of plate I9 astop rod 20 whose function is to limit with the aid ofstops 35 and 36 the travel of cleaning blades 2| and plate IS. Agland 31 and stufling box in the end of the piston surrounding the rod prevents leakage.

In operation the fluid-solid mixture from which the fluid is to be extracted is introduced to the press through inlet I3. the piston the material is pressed forwardly (i. e., to the right) through tube l0 toward the outlet and due either to the shape of the tube or a restriction placed in the tube in the form of a valve the material is congested and compacted to a high density in the tube. With reciprocation of the piston fluid is separated from the solids draining through the slots in the face of the piston intovertical duct 23.

Cleaning of the slots between bars i5 is accomplished by reciprocation or sliding movement of the cleaning blades 2| in the slots. This. is made possible by the relative differences in lengths of travel of the stroke of the piston and carrier 4 plate It upon which the cleaning blades are mounted. As the piston is advanced during its pressure stroke bolts l'l slide spacer members l8 forward in slots 2|a of the blades and move the blades forwardly to an advanced position, as shown in Fig. 2. The end ofstop rod 20 extends through the rear piston wall and a hole instop 28. At its end between stops l5 and 86 is a cross pin 38. Abutment of this cross pin on stop 38. limits the forward movement of plate l9 and blades 2|. Rearward movement of the plate and blades is arrested by abutment of the rod and cross pin on stop". In operation when the piston is retracted by action of the crank pin 80 from its advanced position shown in Fig. 2 clea ing blades 2| remain stationary in the piston and travel with it during the initial stages of the return stroke. When stoprod 20 moving with the piston abuts stop 35 further retraction of the blade carrier plate It! is halted and as the piston continues its rearward stroke the blades are advanced in the slots until their forward edges are flush with With the reciprocation of I V through the face of the piston or extend slightly therebeyond. When the blades and'carrier plate'stop, continued rearward reciprocation of the piston moves bolts l1 and spacers I8 through slots 2: until they arrive at their rearward ends. Thus, reciprocation of the piston from an advanced position by crank II in a stroke whose length is determined by the throw of the crank causes the blades to travel with the piston until stopped by abutment ofrod 20 withstop 35. Then the movement of the cleaning blades within the slots is arrested and as the piston continues to move rearwardly the blades are advanced in their slots toward the face of the piston as described. Slots 2 la through which bolts I! pass permit continued rearward movement of the piston after the blades have been stopped.

When the direction of the piston is reversed on its forward or pressure stroke, the cleaning blades in their advanced position in the piston travel with the piston until stopped by abutment of cross pin 38 withstop 36. The piston continues to advance but as the travel of the blades is arrested they are again retracted in the slots of the piston to a position shown in Figs. 2 and 4. Thus, movement 01' the cleaning blades through the slots in the face of the piston is synchronized with the pistons stroke to retract the blades from the piston face during the forward pressure stroke and advance the blades during the rearward stroke. Advancement of the' cleaning blades the slots removes any solid material pressed into the slots during the pressure stroke or carried into the slots with the fluid. When pressures are employed or 1000 pounds or upward during fluid extraction of the mass and when the material being extracted contains resinous and gummy materials the importance of an efllcient cleaning mechanism is appreciated.

In the extraction of fluids from vegetable flbrous materials containing incrustants including waxes, resins, sugars and other substances readily separable from the fibers and drained with the fluids, it becomes of the utmost importance to keep the drains and channels through which the extracted fluids are removed open and free from accumulation of solids.

While the invention has been described in connection with its use in the production of pulp from vegetable fiber, it may as well be used in the extraction of fluids from any substances where it is desired to remove liquids from solids.

From the foregoing it will be seen that the in- As many possible embodiments may be made of the invention it is understood that all matter herein set forth or shown in the drawings is to be interpreted as illustrative and not in a limiting sense;

Having thus described my invention, I claim:

1. A fluid extracting piston press for separating fluids from fluid-solid mixtures comprising a pressure tube, a piston reciprocating therein and means for reciprocating the piston, inlet and outlet ports in the tube for introducing material to be extracted and for discharging extracted materials, slotted apertures in the face of the piston, a drain connected to said apertures, and cleaning blades slidable in the slotted apertures adapted to clean the slots of the piston with each reciprocation thereof and permit free passage of the extracted fluid through the slots and drain.

2. A piston press as in claim 1 having a reciprocating blade assembly on which the cleaning blades are mounted, said blade assembly synchronized with the reciprocation of the piston to retract the cleaning blades from the face of the piston at the forward or pressure end and advance the blades at the rearward stroke of the piston.

3. A piston press as in claim 1 having a reciprocating blade assembly on which the cleaning blades are mounted, said blade assembly recipnested in an opposed direction to the direction or the piston strokes and means for governing the length of the strokes of the blade assembly.

4. A piston press for separating fluids from fluid-solid mixtures comprising a pressure tube having inlet and outlet ports, a piston reciprocable therein and means for reciprocating the piston, a plurality of spaced apart elements in the race of the piston, a drain connecting the slots between said elements, a blade assembly including a plate positioned rearwardly of said elements and cleaning blades mounted on the plate so they extend forwardly therefrom into said slots, and means driven from the piston reciprocating means for advancing and retracting the blade assembly in opposed directions to the travel of the piston.

JOAQUIN J. on LA ROZA, Sn.

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

UNITED STATES PATENTS

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