The present disclosure relates horizontal pressure filters, in which multiple plates, movable away and towards from each other in vertical direction, are placed one above another for forming a horizontal filter chamber. Typically multiple plates form a plate pack which, in turn, form one or more filter chambers. Particularly collector elements and plate elements for such pressure filters are concerned. The disclosure also relates to methods concerning such pressure filters are concerned.
For example, U.S. Pat. No. 3,655,056 concerns a horizontal pressure filter having lateral tubular members partially nested within each other when the filter is in a closed position. In addition, USP 319,673; USP 328,414 and USP 578,229 concern box arrangements for oil presses.
In the following the disclosure will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings, in which
In the closed state of the horizontal pressure filter 8, two adjacent plate elements 6 are pressed against each other, so as to form a closed filtration chamber between each other. Suitably, a subsequent plate element 6, i.e. lower plate element, may be provided with a filter screen 6e for supporting a filter medium 7 on top of it, and enabling filtrate to pass through into a filtrate vat 6a below. A preceding plate element 6, i.e. upper plate element, has a chamber 6d into which the slurry is fed. The chamber 6d is open at its bottom, such that the upper plate element 6 can be pressed against the filter medium 7 supported on the lower plate element. In operation, a filter medium 7 is positioned between the plate elements 6, and subsequently the plate elements are pressed against each other for forming a closed filter chamber 6d. Slurry is fed into the chamber, whereby a solids cake is formed on top of the filter media, while filtrate passes through the filter media 7 and the filter screen 6e into the filtrate vat 6a on the lower plate element 6. After a certain time period, the solids cake formed on the filter medium 7 may be further pressed against the filter medium for squeezing remaining filtrate out of the solids cake. Alternatively, this additional squeezing may initiated by any other parameter, for example after reaching a certain pressure level in the filtration chamber 6d.
As an optional step, a pressurized air flow for drying can be introduced into the filter chamber. The air flows through the solids cake and the filter medium, and further, via the same route as the filtrate.
The filter plate elements 6 are then retracted away from each other in to an open state for removing the solids cake from between. The removal of the solids cake may be done, for example, by forwarding the filter medium 7 provided as a web. However, some residual filtrate will continue to flow out, e.g. of the vats underneath the filter media and filter cake.
Accordingly, in the context of this disclosure, the term horizontal pressure filter is used to describe a pressure filter having multiple plate elements for forming at least one horizontal filter chamber therebetween. Furthermore, the plate elements are arranged to move in vertical direction towards each other and away from each between an open state and a closed state, thus defining a press direction. Such horizontal pressure filters are also known in the industry as tower presses.
Particularly, the horizontal pressure filter according to the disclosure is not to be confused with vertical pressure filters, in which vertical filter chambers are formed in-between vertically disposed plates elements, arranged to move towards and away from each other in a horizontal direction.
A coupling portion 5 extends outwardly from the hollow body 1a, preferably in a direction transverse to the press direction. The coupling portion 5 has a passage 5a for providing fluid communication between an outlet of a plate element and the inside of the hollow body 1a. In other words, the passage 5a, extends between the inside of the hollow body 1a and a distal end of the coupling portion 5.
As can clearly be seen from
Furthermore,
Furthermore,
Naturally, any of the plate elements 6 illustrated in
As can be seen in
The collector elements 1
Also most clearly visible in
Furthermore, the coupling portion 5 may be equipped with a lower surface arranged to abut an upper surface of the second opening portion/and or coupling portion 5 of a subsequent collector element, when the first opening portion 2 of a preceding collector element 1 is fully inserted into the second opening portion 3 of the subsequent collector element. Such an arrangement is advantageous for preventing a preceding collector element from being inserted too deep into a subsequent collector element, and additionally or alternatively, provides for further sealing of the duct.
As can most clearly be seen from
The collector element 1 may also be provided with a concave section on the outer surface of the hollow body for ensuring a sufficient space between the passage 5a of an subsequent collector element and the preceding collector element 1 for allowing filtrate and/or possible airflow to flow from the passage 5a to the inside of the hollow body 1a. As can be seen in
The collector element 1 may be provided with a sealing means 3a for sealing the duct formed by adjacent collector elements 1, when positioned so as correspond to their mutual positions in horizontal pressure filter 8 in the closed state. Advantageously, the sealing means 3a are provided as a sealing strip surrounding the second opening portion as illustrated in
The collector elements 1 of
Moreover, the collector elements 1 of
In the above, particularly with reference to
Moreover,
Contrary to the single-sided-type plate elements discussed earlier, the double-sided-type plate elements 6 illustrated in
This enables two layers of the filter medium 7 to be provided in to the filter chamber 6d, such that filtrate is introduced into between the two separate layers of filter medium 7. As a result, the surface area of the filter medium 7, through which the filtrate separated from the slurry will flow, is doubled. In other word, such an arrangement enables filtrate to flow through the filtrate medium 7 into a filtrate vat both on the upper and lower surfaces of the filter chamber 6d. This is particularly advantageous if the slurry is difficult to filter and only thin solids cakes can be formed.
It should also be noted, that in the context of both single-sided and double-sided plate elements, a filtrate vat can be implemented in various ways. Hence, any construction in a plate element 6 used to receive and collect filtrate from the filter medium 7, and further to guide the filtrate towards a drainage outlet of the plate element, can be considered as filtrate vat. For example, the filtrate vat may be implemented as one or more recessed portions or grooves forming a common channel for receiving filtrate from the associated filter medium 7.
According to a first aspect of the disclosure, a horizontal pressure filter 8 filtrate collector element 1 for forming a vertical conduit between adjacent filter plates 6 is provided. The collector element 1 comprises a hollow body 1a forming a first opening portion 2, a second opening portion 3, and an intermediate portion 4.
The intermediate portion 4 forms, within the hollow body 1a, a conduit 4a in a press direction between the first opening portion 2 and the second opening portion 3. In this context, the press direction refers to the direction in which the pressure filter's 8 plate elements 6 are pressed towards and retracted away from each other. In other words, the press direction corresponds, in a horizontal pressure filter 8, when in use, to the vertical direction.
The collector element 1 further comprises a coupling portion 5 for coupling the collector element 1 with a pressure filter plate element 6. The coupling portion 5 extends from the body 1a, preferably at the intermediate portion 4, in a direction transverse to the press direction. The coupling portion 5 has a passage 5a for providing fluid communication between the inside of the hollow body 1a and a drainage outlet 6b of a pressure filter plate element 6. Suitably, the passage 5a extends from the inside of the hollow body 1a, preferably at the intermediate portion 4, within the coupling portion 5 up to a distal end of the coupling portion 5.
The first opening portion 2 and the second opening portion 3 are arranged such that a first opening portion 2 of a preceding collector element 1 can be at least partly nested in the second opening portion 3 of a subsequent collector element 1″. Particularly, the outer dimension first opening portion 2 is smaller than the inner dimension of the second opening portion 3. This enables a continuous duct to be formed by the conduits 4a of adjacent collector elements 1.
According to a second aspect of the disclosure, the coupling portion 5 may be equipped with mounting means for mechanically attaching the collector element 1 to a pressure filter plate element 6 in a rigid manner. For example, one or more through holes, threaded blind holes, pins, clamps, etc. may be provided for attaching the collector element 1 to a pressure filter plate element 6. Preferably, the mounting means are arranged, for example by positioning, such that attaching the collector element 1 to a plate element 6 will result the passage 5a being connected to a drainage outlet 6b of the plate element 6 so as to provide fluid communication.
According to a third aspect of the disclosure, a recess 4b may be formed within the hollow body 1a, such that the passage 5a is arranged at the recess 5b. That is, the passage 5a is arranged to provide fluid communication between the recess 4b and a drainage outlet 6b of a pressure filter medium 6. Suitably, the passage 5a extends between the hollow body 1a, via the recess 4b, and a distal end of the coupling portion 5. In other words, an opening of the passage 5a, on the hollow body 1a side thereof is positioned at the recess 4b. Suitably, the recess 4b is formed at the intermediate portion 4.
Providing a recess 4b, and arranging the passage 5a therein, prevents a first opening portion 2 or an intermediate portion 4 of a preceding collector element 1, when inserted into a second opening portion 3 of an subsequent collector element 1, from blocking the opening of the passage on the inside of the hollow body 1a, and thus from preventing filtrate flow into to the conduit. Furthermore, this ensure that less splashing towards the second opening portion 3 occurs
According to a fourth aspect of the disclosure, the passage 5a may preferably be arranged so as to open towards the first opening portion 2. Alternatively, or additionally, the recess 4b may be arranged to open towards the first opening portion 2. Such arrangements further ensure that a first opening portion 2 or an intermediate portion 4 of a preceding collector element 1, when inserted into a second opening portion 3 of a subsequent collector element 1, can not obstruct the flow of the filtrate from the passage 5a into the hollow body 1a. In addition, as such arrangements effectively direct the filtrate flow from the passage 5a directly towards the first opening portion 2, the filtrate flow is less restricted and less splashing towards the second opening portion 3 occurs.
According to a fifth aspect of the disclosure, the first opening portion 2 and the second opening portion 3 may be arranged eccentrically with respect to each other. This ensures that, when a first opening portion of a preceding collector element 1 is inserted into a second opening portion of a subsequent collector element 1, a space having an eccentric annular or crescent cross-sectional shape is formed between an outer surface of the hollow body 1a of an preceding collector element and an inner surface of the hollow body 1a of the of the subsequent collector element 1. Such a space between successive collector elements 1 ensures an adequate flow route for filtrate flowing from the passage 5a. Preferably, the first opening portion 2 is positioned eccentrically with respect to the second opening portion 3 in a direction away from the passage 5a.
Preferably, but not necessarily, a curved section is arranged on the hollow body 1a such that a concave section is arranged on the outer surface thereof. Most suitably such a curved section is arranged on a transition region between the first opening portion 2 and the intermediate portion 4.
It is preferred that such a curved surface is arranged so that, when a collector element 1 is inserted into a subsequent collector element 1, the curved section opposes the passage 5a of the subsequent collector element 1. This provides flow route having a continuous shape for the filtrate from the passage 5a to the inside of the hollow body 1a. Flow properties of the filtrate are further improved and less spillage occurs.
According to a sixth aspect of the disclosure, the first opening portion 2, the second opening portion 3, or both may be equipped with a sealing means for sealing a connection between a first opening portion 2 of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element 1. Preferably such sealing means are arranged to seal a connection between a first opening portion 2 of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element 1 when the collector elements are in a closed position with respect to each other. This prevents leakage from between the adjacent opening portions 2, 3 even when the filtrate in the conduit 4a is pressurized. The sealing means may be provided, for example, as a sealing strip surrounding the respective opening portion 2, 3.
It should be noted, that the features of any two or more of the collector element aspects discussed above may be combined without departing the scope of the disclosure.
According to a seventh aspect of the disclosure, a horizontal pressure filter plate element 6 is provided.
The plate element 6 comprises a filtrate vat 6a for receiving filtrate during operation of a horizontal pressure filter 8. The filtrate vat 6a does not need to be a separate component, but is suitably formed on the plate element 6, as a portion thereof. The plate element 6 further comprises a drainage outlet 6b having a drainage duct 6c for providing fluid communication between the filtrate vat 6a and the drainage outlet 6b. Suitably, the drainage outlet 6b is formed on a side of the plate element 6 and the drainage duct 6c is formed within the plate element 6. The plate element 6 is equipped with a collector element 1 as discussed in connection with any of the preceding collector element aspects, such that the coupling portion 5 of the collector element 1 is coupled with the drainage outlet 6b of the plate element 6 for providing fluid communication between the filtrate vat 6a and the inside of the hollow body 1a of the collector element 1. Particularly, the passage 5a of the collector element is coupled with the drainage outlet 6b. Preferably, the collector element 1 is also mechanically fixed to the plate element 6 by the coupling portion 5.
According to an eighth aspect of the disclosure, a horizontal pressure filter 8 having multiple plate elements 6, is provided. The horizontal pressure filter 8 has an open state and a closed state.
In the closed state, adjacent plate elements 6 are pressed substantially against each other. That is, the plate elements are pressed against each other, while some components, such as filter media 7 and sealing means, may be located between the adjacent plate elements 6. The horizontal pressure filter 8 is further arranged, in the closed state, for separating filtrate from a slurry, thus producing a solids cake between adjacent plate elements 6.
In the open state, adjacent plate elements 6 are retracted to a distance from each other for enabling removal of the solid cake from between adjacent plate elements.
Particularly, at least one of the plate elements used is a plate element 6 according to the preceding plate element aspect, as discussed above.
According to a ninth aspect of the disclosure, in the horizontal pressure filter 8 according to the pressure filter aspect discussed above, the collector elements 1 of each plate element 6 are arranged such that, both in the closed state and the open state, conduits 4a of the collector elements in adjacent plate elements form an effectively continuous filtrate duct in the press direction between each adjacent plate element 6. That is, the insides of the hollow bodies 1a of each collector element 1 form, both in the open state and the closed state, an effectively continuous filtrate duct in the press direction between each adjacent plate element 6. Particularly, in the open state, the first opening portion 2 of a preceding collector element does not necessarily need to be within a second opening portion 3 of a subsequent collector element 1, but the opening portions 2, 3 may be retracted up to a distance from each other. That is, the term effectively continuous is used in this context to describe that filtrate from a first opening portion 2 will flow into a second opening portion 3 without splashing or contaminating the surroundings. This can be achieved even if the respective first opening portion 2 and the second opening portion 3 are at a distance from each other, as the diameter of the first opening portion 2 is smaller than that of the second opening portion 3. Consequently, the filtrate from preceding collector element 1 will have a characteristic cross sectional dimension of the first opening portion 2. Further, as the flow direction between adjacent collector elements 1 is vertical, the characteristic cross sectional dimension of the filtrate flowing between adjacent collector elements 1 will remain substantially the same at the interstice between the opening portions 2, 3, even if the respective opening portion 2, 3 are retracted up to a distance from each other.
According to a tenth aspect of the disclosure, in the open state, a first opening portion 2 of a preceding collector element 1 extends preferably at least up to the level of a second opening portion 3 of subsequent collector element 1, thus forming an uninterrupted filtrate duct in the press direction between each adjacent plate element 6. In other words the first opening portion 2 of a preceding collector element 1 does not need to be within the second opening portion 3 of the subsequent collector element 1, but is preferably not at a distance therefrom, either.
According to an eleventh aspect of the disclosure, in the open state, a first opening portion 2 of a preceding collector element preferably extends within a second opening portion 3 of a subsequent collector element 1, thus forming a contiguous filtrate duct in the press direction between each adjacent plate element 6. In other words, a filtrate duct is formed by the conduits 4a of the successive collector elements 1 connected throughout in an unbroken sequence. It should be noted, that in the open state, the consecutive collector elements 1 do not need to be in physical contact with each other, but the contiguous duct is formed as the first opening portion 2 of a preceding collector element extends within a second opening portion 3 of subsequent collector element.
According to a twelfth aspect of the disclosure, at least one preceding collector element 1 and a subsequent collector element 1 of a horizontal pressure filter 8 are preferably equipped with an expandable sealing means 3b, suitably of the bellows type, extending between a preceding collector element 1 and a subsequent collector element 1. For example, the expandable sealing means 3b may extend between a first opening portion 2 of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element 1. Alternatively, the expandable sealing means may extend between an outer surface of the hollow body 1a of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element. Preferably, but not necessarily, each of the successive collector elements 1 are equipped with such expandable sealing means 3b. Particularly, the expandable sealing means may be provided so as to reduce, during the open state, fumes emissions of the filtrate flowing in the filtrate duct from contaminating the surroundings. For example, bellows made from rubber or other elastomers may be used as the expandable sealing means.
According to a thirteenth aspect of the disclosure, the expandable sealing means 3b may be gas-impermeable, in which case such fume emission may be avoided all together.
According to a fourteenth aspect of the disclosure, collector elements 1 of adjacent plate elements 6 in a horizontal pressure filter 8 are advantageously arranged such that, at least in the closed state, the preceding collector element 1 is spaced apart from the passage 5a at the inside of the hollow body 1a of an subsequent collector element 1. Such arrangement ensures the preceding collector element, particularly, the first opening portion 2, intermediate portion 4, or both, thereof does not obstruct filtrate flow from the passage 5a of the coupling portion 5 to the conduit 4a of the subsequent collector element 1.
It should be noted, that the features of any two or more of the pressure filter aspects discussed above may be combined without departing the scope of the disclosure.
According to a fifteenth aspect of the disclosure, a method for providing a continuous filtrate duct between adjacent plate elements 6 of a horizontal pressure filter 8 is provided. In the method, a horizontal pressure filter 8 having multiple plate elements 6 is provided. Further, the pressure filter 8 has a closed state and an open state.
In the closed state, adjacent plate elements 6 are pressed substantially against each other for separating filtrate from a slurry, thus producing a solids cake between adjacent plate elements 6. It should be noted, that additional components such as filter media and sealing means may be located between the adjacent plate elements
In the open state, adjacent plate elements 6 are retracted to a distance from each other for enabling removal of the solids cake from between adjacent plate elements.
Each plate element 6 is provided with at least one collector element according to any of the collector element aspects, as discussed above
The coupling portions 5 of the collector elements 1 are attached to the plate elements 6, such that the passage 5a of the coupling portion 5 is coupled with the drainage outlet 6b of the plate element 6, so as to provide fluid communication between the filtrate vat and the hollow body 1a of the collector element 1.
According to a sixteenth aspect of the disclosure, in the method for providing a continuous filtrate duct, each of the collector elements 1 are suitably arranged such that, both in the closed state and the open state, conduits of the collector elements 1 in adjacent plate elements 6 form an effectively continuous filtrate duct in the press direction between each adjacent plate element 6. That is, the insides of the hollow bodies 1a of each collector element 1 form, both in the open state and the closed state, an effectively continuous filtrate duct in the press direction between each adjacent plate element 6. Particularly, in the open state, the first opening portion 2 of a preceding collector element 1 does not necessarily need to be within a second opening portion 3 of a subsequent collector element 1, but the opening portions 2, 3 may be retracted up to a distance from each other. That is, the term effectively continuous is used in this context to describe that filtrate from a first opening portion 2 will flow into a second opening portion 3 without splashing or contaminating the surroundings. This can be achieved even if the respective first opening portion 2 and the second opening portion 3 are at a distance from each other, as the diameter of the first opening portion 2 is smaller than that of the second opening portion 3. Consequently, the filtrate from a preceding collector element 1 will have a characteristic cross sectional dimension of the first opening portion 2. Further, as the flow direction between adjacent collector elements 1 is vertical, the characteristic cross sectional dimension of the filtrate flowing between adjacent collector elements 1 will remain substantially the same at the interstice between the opening portions 2, 3, even if the respective opening portion 2, 3 are retracted up to a distance from each other.
According to a seventeenth aspect of the disclosure, in the method for providing a continuous filtrate duct, each of the collector elements 1 are suitably arranged such that, in the open state, a first opening portion 2 of a preceding collector element 1 extends at least up to the level of a second opening portion 3 of subsequent collector element 1, thus forming an uninterrupted filtrate duct in the press direction between each adjacent plate element 6. In other words the first opening portion 2 of a preceding collector element 1 does not need to be within the second opening portion 3 of the subsequent collector element 1, but is preferably not at a distance therefrom, either.
According to an eighteenth aspect of the disclosure, in the method for providing a continuous filtrate conduit, each of the collector elements 1 are arranged such that, in the open state, a first opening portion 2 of a preceding collector element extends within a second opening portion 3 of subsequent collector element 1, thus forming a contiguous filtrate duct in the press direction between each adjacent plate element 6. In other words, a filtrate duct is formed by the conduits 4a of the successive collector elements 1 connected throughout in an unbroken sequence. It should be noted, that in the open state, the consecutive collector elements 1 do not need to be in physical contact with each other, but the contiguous duct is formed as the a first opening portion 2 of a preceding collector element extends within a second opening portion 3 of subsequent collector element.
According to a nineteenth aspect of the disclosure, in the method for providing a continuous filtrate conduit, expandable sealing means 3b, suitably of the bellows type, are advantageously provided such that at least one preceding collector element 1 and a subsequent collector element 1 are equipped with said expandable sealing means 3b extending between a preceding collector element 1 and a subsequent collector element 1. For example, the expandable sealing means 3b may extend between a first opening portion 2 of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element. Alternatively, the expandable sealing means 3b may extend between an outer surface of the hollow body 1a of a preceding collector element 1 and a second opening portion 3 of a subsequent collector element. Preferably, but not necessarily, each of the successive collector elements 1 are equipped with such expandable sealing means 3b. Particularly, the expandable sealing means 3b may be provided so as to reduce, during the open state, fumes emissions of the filtrate flowing in the filtrate duct from contaminating the surroundings. For example, rubber bellows may be used as the expandable sealing means. Preferably, the expandable sealing means 3b are gas-impermeable, in which case such fume emission may be avoided all together.
According to a twentieth aspect of the disclosure, in the method for providing a continuous filtrate conduit, each of the collector elements 1 of adjacent plate elements 6 in a horizontal pressure filter 8 are advantageously arranged such that, at least in the closed state, the preceding collector element 1 is spaced apart from the passage 5a at the inside of the hollow body 1a of an subsequent collector element 1. Such arrangement ensures the preceding collector element, particularly, the first opening portion 2, intermediate portion 4, or both, thereof does not obstruct filtrate flow from the passage 5a of the coupling portion 5 to the inside of the hollow body 1a of the subsequent collector element 1.
It should be noted, that the features of any two or more of the aspects concerning a method for providing a continuous filtrate conduit, as discussed above, may be combined without departing the scope of the disclosure.
According to a twenty-first aspect of the disclosure, a method for operating a horizontal pressure filter 8 is provided. In said method, a horizontal pressure filter 8 according to any of the preceding pressure filter aspect is provided.
A filter chamber 6d is formed by positioning the plate elements 6 in a closed state. While in said closed state, a slurry feed is provided into the filter chamber 6.
At a predetermined instance, said slurry feed into the filter chamber 6d is suspended.
After said slurry feed has been suspended, the plate elements 6 are positioned in an open state. While in said in said open state, a solids cake formed during the closed state is removed from between plate elements.
It is apparent to a person skilled in the art that as technology advances, the basic idea of the disclosure can be implemented in various ways. The disclosure and its aspects are therefore not restricted to the above examples, but they may vary within the scope of the claims.
Number | Date | Country | Kind |
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20165241 | Mar 2016 | FI | national |
This application is a continuation of PCT International Application No. PCT/FI2017/050202 filed Mar. 22, 2017, which claims the benefit of Finnish Application No. 20165241 filed Mar. 23, 2016, the disclosure of each of these applications are expressly incorporated herein by reference in their entirety.
Number | Date | Country | |
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Parent | PCT/FI2017/050202 | Mar 2017 | US |
Child | 16134283 | US |