Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
  • B01D35/20—Vibrating the filters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D35/00—Filtering devices having features not specifically covered by groups B01D24/00 - B01D33/00, or for applications not specifically covered by groups B01D24/00 - B01D33/00; Auxiliary devices for filtration; Filter housing constructions
  • B01D35/12—Devices for taking out of action one or more units of multi- unit filters, e.g. for regeneration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/11—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements
  • B01D29/114—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with bag, cage, hose, tube, sleeve or like filtering elements arranged for inward flow filtration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/50—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition
  • B01D29/52—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with multiple filtering elements, characterised by their mutual disposition in parallel connection
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/60—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor integrally combined with devices for controlling the filtration
  • B01D29/606—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor integrally combined with devices for controlling the filtration by pressure measuring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/62—Regenerating the filter material in the filter
  • B01D29/70—Regenerating the filter material in the filter by forces created by movement of the filter element
  • B01D29/72—Regenerating the filter material in the filter by forces created by movement of the filter element involving vibrations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/76—Handling the filter cake in the filter for purposes other than for regenerating
  • B01D29/86—Retarding cake deposition on the filter during the filtration period, e.g. using stirrers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2201/00—Details relating to filtering apparatus
  • B01D2201/04—Supports for the filtering elements
  • B01D2201/043—Filter tubes connected to plates
  • B01D2201/0446—Filter tubes connected to plates suspended from plates at the upper side of the filter elements

Definitions

• the present invention concerns a procedure an a means for automatic filtering of liquid substances with a self-cleaning arrangement and possibly simul ⁇ taneous homogenizing of the liquid that is being fil ⁇ tered.
• the procedure and means are based on using filter mesh elements, ultrasonics and compressed air.
• filter mesh elements In a liquid filtering event in which the liquid is passed through filter elements, the elements are soiled down and have to be replaced or cleaned. Since filter element replacing entails many detriments, e.g. the need to keep such elements in stock, the work in- volved in the replacement operation and possibly inter ⁇ ruption of the filtering process, endeavours are gene ⁇ rally aimed at performing doing the cleaning during operation if possible.
• the means of the invention is characterized by that which has been stated in the characteristic fea ⁇ tures part of Claim 1.
• the most important advantages of the invention over other cleaning processes which take place during operation are to be seen in that by the procedure of the invention the filter elements will be more completely cleaned, the risk of damaging the filter mesh is pre- vented and reciprocating running of liquid is avoided.
• the means comprises two identical filter units 1 and 2, these units being alter ⁇ nately one in use and the other in its cleaning cycle, or on conclusion of the cycle in readiness for use, and a switch-over valve assembly 3 with actuating mechanism, and an ultrasonic generator 4.
• a filter unit is composed of a filter body 1.1, a filter element 1.2 which is exchangeable accord ⁇ ing t ⁇ operating meed, a filtering residue removal valve 1.3, a single-action pneumatic actuator 1.4, a pilot valve 1.5, a float chamber 1.6 for air venting, a float- operated switch 1.7, a valve 1.8, a filling valve 1.9, a restriction 1.10, an ultrasonic oscillator 1.11, a compressed air flushing valve 1.12, a differential pres ⁇ sure switch or differential,pressure pick-up 1.13 and a control unit 5.
• the switch-over valve assembly consists of a switch-over valve 3.1 for pure liquid, a switch-over valve 3.2 for impure liquid, a pneumatic actuating means 3.3 common to the foregoing components 3.1 and 3.2, and a pilot valve 3.4 for governing the component 3.3.
• the degree of cleanness of the filter elements is monitored with a differential pressure switch, or pick-up, 1.13 installed across the incoming and outgoing pipelines, and to which may also be connected a dif- ferential pressure indicator means.
• a differential pressure switch or pick-up, 1.13 installed across the incoming and outgoing pipelines, and to which may also be connected a dif- ferential pressure indicator means.
• the valve 3.4 causes with the aid of the actuating means 3.3 the switch-over valves 3.1 and 3.2 to be positioned so that the liquid to be filtered will pass through the filter unit 2, which was in stand-by state heretofore.
• the ultrasonic head 1.11 (2.11) may be operated on low power in order to produce a slight cavitation phenomenon within the liquid to homogenize the liquid that is being filtered.
• the limit switch on the actuator of the switch-over va'lve actuator indicates that the liquid is passing through unit 2
• unit 1 is switched to the clean ⁇ ing cycle
• the ultrasonic head 1.11 being now switched to receive power at a rate higher than the homogenizing power.
• the compressed air valve 1.12 opens and the pilot valve 1.5 causes the filtering residue elimina ⁇ tion valve 1.3 to open, the size of which valve is selectable with a view to obtaining sufficient throt ⁇ tling, as a result of which the filter chamber will be drained within desired time.
• the internal cavitation caused in the liquid by the ultrasonics causes efficient cleaning of the filter elements 1.2.
• the ultra ⁇ sonic generator is switched to lower power and the filter residue elimination valve 1.3 and the compressed air valve 1.12 are closed, whereafter valve 1.9 and valve 1.8 open.
• Liquid replenishment from the main liquid flow line flows through the restriction 1.10 into filter unit 1. Abrupt disturbances caused by lower ⁇ ed main flow pressure can be eliminated with the re- stricted flow.
• the liquid filtering and homogenizing procedure of the invention is mainly characterized in that the power output of the ultrasonic generator is controlled with a signal from the differential pressure switch or pick-up 1.13 connected across the filter units.
• This signal may be a limit value-actuated switch-on signal starting the above-described filter cleaning function, or it may be a continuous differential pressure signal from the dif ⁇ ferential pressure switch 1.13.
• ultrasonics due to the cavitation which they cause have an attritive effect on materials its power has to be optimized in relation to the interaction of ultrasonics promoting the filter ⁇ ing and liquid homogenizing action.
• the efficiency of ultrasonics in aiding liquid filtering and homogenizing is furthermore dependent on a number of factors, e.g the pressure, temperature, viscosity and flow velocity of the liquid, the filter mesh size, and the frequen- cy/frequency spectrum of the ultrasonics.
• the procedure of the invention for filtering and homogeniz ⁇ ing liquids is also mainly characterized in that not only the power but also the frequency of the ultrason- ics is controlled not only by said differential pressure switch or pick-up 1.13 but also by a liquid pressure pick-up 1.14, a temperature pick-up 1.15 or a liquid flow rate meter or pick-up 1.16 determining the flow going through the filter units.
• the procedure of the invention for filtering and homogenizing liquids is further characterized in that endeavours are made to maximize the filter area e.g. as shown in the section A-A in Fig. 1, i.e., by disposing cylindrical filter cartridges in concentric circular configuration in the filter body 1.1, and on the outer circle so that ultrasonic cleaning applied in the filtering process might be needed at intervals as infrequent as possible.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Filtration Of Liquid (AREA)
• Cleaning By Liquid Or Steam (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8525508

Family Applications (1)

Country Status (7)

Cited By (8)

Families Citing this family (19)

Citations (2)

Family Cites Families (12)

• 1987
  • 1987-12-02 FI FI875330A patent/FI79471C/fi not_active IP Right Cessation
• 1988
  • 1988-12-01 WO PCT/FI1988/000193 patent/WO1989005184A1/en active IP Right Grant
  • 1988-12-01 KR KR1019890701279A patent/KR930010759B1/ko active
  • 1988-12-01 DE DE3888348T patent/DE3888348T2/de not_active Expired - Fee Related
  • 1988-12-01 KR KR1019890701279A patent/KR900700174A/ko not_active IP Right Cessation
  • 1988-12-01 US US07/382,639 patent/US5053141A/en not_active Expired - Lifetime
  • 1988-12-01 JP JP1500063A patent/JPH02502353A/ja not_active Expired - Lifetime
• 1989
  • 1989-06-22 EP EP89900125A patent/EP0344262B1/en not_active Expired - Lifetime

Patent Citations (2)

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