Method of recovering solid particulate material from a liquid

Claim 2

This apparatus includes two basic parts, a precoating device 11 and a vacuum filtration unit 12. The precoating device includes a housing 13 which contains a power driven mixer and a pump, neither of which is shown, a water inlet pipe 14, a door 16 (FIG. 1) for charging the housing with filtering material, a pump outlet pipe 17 and a distributor head 18 mounted on the discharge end of the outlet pipe. In accordance with this invention, copper particulate material which is of the same type as the material 10 which is to be recovered from the contaminated rinse water, initially is mixed with water in the precoating device 11 to form a relatively thick slurry. Referring to FIGS. 1, 2 and 3, the precoating device 11 then pumps the slurry to the distributor head 18, which is positioned above a portion of a suitable filter media 19, such as an indexable continuous strip of cellulose paper, in the vacuum filtration unit 12. As the water from the slurry passes through the filter media 19, a major portion of the copper particulate material in the slurry is filtered out and becomes deposited on the media in a layer 21, as is illustrated in FIG. 4. Subsequently, as the filter media 19 is periodically advanced to the left, as viewed in FIG. 5, the deposited copper particulate material 21 is leveled to a uniform depth by a blade member 22 of the vacuum filtration unit 12, to provide a relatively thin filter aid layer 23, preferably on the order of one-sixteenth to one-eighth of an inch in thickness, on the media. The contaminated rinse water then is sprayed from a distributor head 24 of the filtration unit 12 over the filter aid layer 23 and the filter media 19, whereby they cooperate to remove the copper solids 10 from the contaminated water, as indicated by the material layer 26 in FIG. 6. Ultimately, referring to FIGS. 1 and 2, the removed copper solids layer 26, together with the copper solids forming the filter aid layer 23, are scraped from the filter media 19 by a blade 27 in a container 28, with the filter media passing into a separate container 29. The vacuum filtration unit 12 includes a dual reservoir 31, one side of which is designed to receive contaminated rinse water through an inlet pipe 32. A pump 33 has an inlet connected to the contaminated water side of the water reservoir 31 and an outlet connected to a riser pipe 34, on which the filtration unit distributor head 24 is mounted. The water level in the contaminated water side of the reservoir 31 is regulated by a suitable float device 36 which is connected to control the flow of water into the reservoir from the inlet pipe 32 in a well known manner. The other side of the dual reservoir 31 receives filtered clean water after it has passed through the filtration process in a manner to be described, and is connected to a pump 37 for discharginG the clean water through suitable piping for reuse in manufacturing operations or to a sewer. As is best shown in FIG. 2, the two sides of the reservoir 31 are separated by a vertically extending wall 38, over the top of which excess water in the clean water side of the reservoir may flow back into the contaminated water side of the reservoir. Above the dual reservoir 31, a tank 39 is mounted on a suitable framework. A continuous mesh belt 41, made of an inert material such as stainless steel, is supported in the tank on rollers 42 adjacent the opposite upper ends of the tank, with the belt and the rollers being suitably meshed with one another so as to preclude relative movement therebetween. The roller 42 at the upper left hand side of the tank 39, as viewed in FIG. 2, is driven by a motor 43 mounted on top of the tank, for intermittently advancing the belt 41 counterclockwise in this figure. The lower pass of the belt 41 travels beneath a plurality of transversely extending plate members 44 which are secured to opposite side walls of the tank 39 to form a bottom and opposite ends of a vacuum chamber 46, the sides of the chamber being formed by the tank side walls. A supply roll 19S of the filter media 19 is suitably mounted on one end wall of the tank 39 with the filter media extending upward from the supply roll and over a guide roller 47 at the tank''s adjacent upper corner. Intermediate the ends of the tank 39, the filter media 19 is supported on the upper pass of the mesh belt 41. In operation, the filter media 19 is retained in engagement with the belt 41 so as to be advanced thereby, by the weight of the copper solids 21, 23, 26 on the media and by the vacuum in the vacuum chamber 46. Referring to FIGS. 5 and 6, as the contaminated water from the distributor head 24 is filtered by its passage through the filter aid layer 23 and the underlying portion of the filter media 19, the thus produced clean effluent passes into the vacuum chamber

Claim 4

The method as defined in claim 3, in which: the slurry is deposited on the unitary filter media to build up a porous, filter aid layer having a thickness on the order of one-sixteenth to one-eighth of an inch.

Claim 5

The method as defined in claim 3, which comprises the further steps of: recycling a portion of the original filter aid layer and a portion of the particles removed from the suspension to form a slurry containing particles of a number of different sizes but being large enough to form a porous mass which allows water to drain therethrough; depositing the slurry on a clean section of the unitary filter media to form another porous filter aid layer; and then passing additional quantities of the water suspension of copper and copper compound particles through the porous, filter aid layer to remove the particles from the suspension.

Claim 6

As the contaminated water flows through the filter aid layer 23 and the filter media 19 into the vacuum chamber 46, the filter aid layer and the media cooperate to remove the copper solids 10 (FIG. 7) from the water as is illustrated by the material layer 26 in FIG. 6. During the filtration process, the filtered clean effluent flows from the vacuum chamber 46 into the lateral extension 39a of the tank 39 and through the drain pipe 48 into the clean water side of the dual reservoir 31, from which it is removed by the pump 37 for reuse or discharge into a sewer. If the level of the water above the filter aid layer 23 and the filter media 19 rises too high during the filtration process, the excess water flows over the depressed side portion 39b of the tank 39 into the trough 49 and through the drain pipe 51 back to the contaminated water side of the reservoir 31. As the layer 26 of the copper solids 10 builds up on the filter aid layer 23 and the filter media 19, the vacuum in the vacuum chamber 46 increases and when it reaches a preselected value the vacuum sensing switch 56 closes to actuate the drive motor 43 for the roller 42. This causes the mesh belt 41 to be again advanced counterclockwise in FIG. 2, thereby advancing the filter media 19 and the material layers 23 and 26 to the left in FIGS. 5 and 6. During this advancement, as the filter media 19 passes over the driven roller 42 the material layers 23 and 26 are scraped from the media into the container 28 by the blade 27, with the media passing into the container 29. At the same time, the material layer 21 which has been building up on the filter media 19 as a result of the discharge from the slurry distributor head 18, is advanced with the media and leveled by the blade 22 To provide a new filter aid layer 23 in the filtration area for the distributor head 24, as is illustrated in FIG. 5. The vacuum in the vacuum chamber 46 also is progressively decreasing and when it reaches a lower preselected value the vacuum sensing switch 56 opens to turn off the advancing motor 43. The accumulation of another material layer 21 on the filter media 19 from the slurry distributor head 18, and the building up of another material layer 26 of the copper solids 10 on the new filter aid layer 23 and its underlying portion of the filter media, as a result of discharge from the filtration distributor head 24, then are repeated. From the foregoing description, it is apparent that the material 23, 26 which is collected in the container 28 consists primarily of copper solids in various forms and that these solids readily can be subjected to a suitable reclamation process and reduced to pure copper, which then can be reused in manufacturing operations. In the alternative, the material 23, 26 can be used for other purposes, such as a bacterial control agent or as a pigment in certain marine paints. A portion of this material 23, 26 also can be recycled through the process as necessary and used to produce the slurry for forming the filter aid layer 23 on the filter media 19. In addition, while the material 23, 26 removed by the scraper blade 27 constitutes the major portion of the copper solids which were on the filter media 19, by subjecting the filter media in the container 29 to a suitable incinerating process, any of the material 23, 26 embedded in the filter media or adhering thereto also can be recovered, if so desired. In the incinerating operation, since the filter media 19 is almost entirely cellulose, it will be reduced to carbon dioxide and water, thereby producing no significant fumes and only a small amount of ash, which can be readily disposed of. What is claimed is:

Claim 7

The belt 41 and the filter media 19 then are advanced counterclockwise in FIG. 2 and to the left in FIG. 5, causing a new portion of the media and a new filter aid layer 23 of copper solids to be brought into position in the filtration area for the distributor head 24, and causing a new portion of the media to be brought into position beneath the slurry distributor head 18, as is illustrated in FIG. 5. When the belt 41 and the filter media 19 have advanced sufficiently that the vacuum in the vacuum chamber 46 has dropped back to another preselected level, the sensing switch 56 opens to stop the advancement of the belt and the media. Since the slurry water which drains through the filter media 19 in the formation of the material layer 21 (FIG. 4) is still relatively contaminated, rEferring to FIG. 2, an upper transversely extending diverting member 58 and a lower transversely extending dam 59 are mounted between the side walls of the tank 39 to confine the water from the slurry to the right hand portion of the vacuum chamber 46, as viewed in this figure. From this part of the vacuum chamber 46 the water drains into the contaminated water side of the dual reservoir 31 through a pipe 61 for subsequent filtration as above described. SUMMARY In practicing the disclosed embodiment of the invention, neutralized rinse water containing copper solids 10 (FIG. 7) to be recovered is introduced into the contaminated water side of the dual reservoir 31 through the inlet pipe 32, under the automatic control of the float device 36, and copper solids of the same type are mixed with water in the precoating device 11 to form a relatively thick slurry. Then, with the vacuum producer 52 energized and producing a vacuum in the vacuum chamber 46, the slurry is pumped by the precoating device 11 through the outlet pipe 17 to the distributor head 18 and is sprayed over the portion of the filter media 19 therebeneath. As the water from the slurry filters through the filter media 19, copper solids become deposited upon the media as illustrated by the material layer 21 in FIG. 4. The water from the slurry which passes through the filter media 19, being still relatively contaminated, is confined to the right hand end portion of the vacuum chamber 46, as viewed in FIGS. 1 and 2, by the diverting member 58 and the dam 59, and flows through the drain pipe 61 into the contaminated water side of the reservoir 31 for subsequent recirculation and filtration. The motor 43 then is actuated to advance the mesh belt 41 counterclockwise in FIG. 2, thereby advancing the filter media 19 to the left in FIGS. 4 and 5. During this advancement, the blade 22 levels the layer 21 of copper solids to provide the initial relatively thin filter aid layer 23 on the filter media 19, as is illustrated in FIG. 5. After the formation of the initial filter aid layer 23, the pump 33 is actuated to begin delivery of the contaminated rinse water from the reservoir 31 through the pipe 34 to the distributor head

Claim 8

Referring to FIGS. 1 and 2, this effluent then flows from the vacuum chamber 46 into a lateral extension 39a of the tank 39 and through a vertical drain pipe 48 to the clean water side of the dual reservoir 31. If the level of the contaminated water above the filter aid layer 23 and the filter media 19 rises too high, the excess water flows over a depressed portion 39b (FIGS. 1 and 2) in one side wall of the tank 39 into a trough 49 mounted on the side wall, and then through a drain pipe 51 back to the contaminated side of the dual reservoir 31. As viewed in FIGS. 1 and 2, a vacuum producing device 52 and an associated drive motor 53 are mounted on top of the tank 39 adjacent its left hand end. The vacuum producing device 52 is connected to the vacuum chamber 46 by a suitable conduit 54 and a vacuum sensing switch 56 is connected to the vacuum chamber by a pipe line 57. Thus, as the layer 26 of the copper solids 10 builds up on the filter aid layer 23 and the filter media 19, as illustrated in FIG. 6, the vacuum in the vacuum chamber 46 increases and when it reaches a preselected value the sensing switch 56 closes to actuate the drive motor 43 for the mesh belt