CA2190937A1 - Device and process for filtering a liquid - Google Patents
Device and process for filtering a liquidInfo
- Publication number
- CA2190937A1 CA2190937A1 CA002190937A CA2190937A CA2190937A1 CA 2190937 A1 CA2190937 A1 CA 2190937A1 CA 002190937 A CA002190937 A CA 002190937A CA 2190937 A CA2190937 A CA 2190937A CA 2190937 A1 CA2190937 A1 CA 2190937A1
- Authority
- CA
- Canada
- Prior art keywords
- filter
- filtrate
- fact
- rinse
- filter segments
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims description 15
- 238000001914 filtration Methods 0.000 title claims description 6
- 239000000706 filtrate Substances 0.000 claims abstract description 47
- 239000011148 porous material Substances 0.000 claims abstract description 7
- 239000002245 particle Substances 0.000 claims description 14
- 238000005406 washing Methods 0.000 claims description 4
- 230000007423 decrease Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 238000004140 cleaning Methods 0.000 description 7
- 239000012530 fluid Substances 0.000 description 5
- 238000005086 pumping Methods 0.000 description 3
- 239000011362 coarse particle Substances 0.000 description 2
- 239000011859 microparticle Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000010794 food waste Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F39/00—Details of washing machines not specific to a single type of machines covered by groups D06F9/00 - D06F27/00
- D06F39/08—Liquid supply or discharge arrangements
- D06F39/083—Liquid discharge or recirculation arrangements
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47L—DOMESTIC WASHING OR CLEANING; SUCTION CLEANERS IN GENERAL
- A47L15/00—Washing or rinsing machines for crockery or tableware
- A47L15/42—Details
- A47L15/4202—Water filter means or strainers
-
- 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
- B01D29/117—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 outward flow filtration
- B01D29/118—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 outward flow filtration open-ended
-
- 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
- B01D29/54—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 arranged concentrically or coaxially
-
- 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
- B01D29/603—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 flow 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
- B01D29/66—Regenerating the filter material in the filter by flushing, e.g. counter-current air-bumps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2201/00—Details relating to filtering apparatus
- B01D2201/18—Filters characterised by the openings or pores
- B01D2201/188—Multiple filtering elements having filtering areas of different size
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Washing And Drying Of Tableware (AREA)
- Filtration Of Liquid (AREA)
Abstract
A filter combination is used in a washer cycle that circulates the rinse or wash liquid driven by a circulating pump. The filter combination has several filter segments with somewhat different, pore sizes, which the liquid to be filtered goes through in such a way that the size of the individual filtrate streams can be adjusted. Each filter is provided with a separate filtrate line that can be used to back-rinse the filters. The filters are independently back-rinsed according to a sequence controlled by a control device.
Description
21 90937' 1 DEVIC~ AND PROCESS FOR FIL'llERING ~ LIQUID
3 The invention concerns a device and a process foL
4 filtering regular wash or rinse liquid, especially tAe rinse water in a dishwasher or the wash fluid in a washing 6 machine.
7 In a household dishwasher, the return water is usually 8 collected in an outlet tub or sump in the bottom of the 9 compartment of the dishwasher from which the water is pumped into the compartment. This is shown for example in 11 DE-OS 3114 633. On the bottom of this outlet tub there is 12 one suction support each for a circulating pump and a 13 discharge pump respectively. To clean the rinse water, 14 which has varying amounts of food residues in it, a combination sieve with coarse, fine and microfine filters 16 is used in this area.
17 The arrangement of the individual sieve elements is 18 designed so that the outlet tub is covered on top by a 19 funnel-shaped fine sieve with a large aperture, which in the middle turns into a cylindrical fine sieve section that 21 extends to the suction supports on the discharge pump.
22 This fine-sieve cylinder is surrounded by another fine-23 sieve section that is also designed in the form of a 24 cylinder on the periphery.
When the circulating pump is running, the funnel-26 shaped fine sieve filters out coarse and fine particles of 27 dirt in a main stream and flushes it to the fine-sieve 28 cylinder in an auxiliary stream parallel to the surface of 29 the funnel-shaped fine filter. These residues of dirt are ultimately stored near the suction support on the discharge 31 pump. They cannot penetrate the fine-sieve filter because 32 the two fine-sieve models have an almost identical hole 33 size.
2 ~ 90937 1 In addition, a removable coarse sieve is used in the 2 upper section of the fine-sieve cylinder to keep the 3 discharge pump from being clogged with very coarse residues 4 of dirt.
Some of the circulated rinse water goes through coarse 6 and fine-sieve cylinders and reaches the circulating pump 7 through the microfine s,ieve cylinder. Here, very fine 8 residues of dirt, so-called microparticles, are retained.
g The residues of dirt are removed from the appliance both during and at the end of the rinse program by having the 11 discharge pump pump them out. Because of the geometry oE
12 the individual filter components and the stream that is 13 produced, the filter surfaces are continually cleaned 14 thoroughly by cross streams during the rinse process and during the process of pumping off the retained dirt 16 particles. Only the coarse pieces that cannot be carried 17 away must be removed manually.
18 This filter system is suitable for the rinse cycle in 19 households and also works well when the dirt is average to heavy. But if there are a lot of residues on the dishes, 21 deposits can very quickly accumulate on the surface of the 22 sieve, which can, in an extreme case, become blocked and 23 stop the entire rinse cycle.
24 Moreover, the proportion of rinse liquid that flows through the microfine sieve cylinder is small compared to 26 the whole filter throughput, so that the rinse liquid is 27 only cleaned slowly of fine microparticles. This way, the 28 filtrate clarity, which is a measure for the residual 29 soiling of the dishes, is only improved gradually.
The operator must also perform a thorough cleaning of 31 the removable filter system, if possible after each rinse 32 program, but at the latest after five to ten rinse cycles.
33 This is necessary because due to the high suction pressure 34 that the circulating pump produces, the particles of dirt that accumulate on the filter surface are suctioned up by 36 the mesh and holes in the sieve, where they can easily stop 37 and get caught. ~ .
1 If such a filter system is not cleaned over a long 2 period of time, the whole system is adversely affected.
3 To counteract clogging by the dirt particles, it is 4 known to rinse out the filter by reversing the direction of flow several times during the rinse program as shown in D~-6 UM 81 08 815. But, in practice, it has been shown that 7 this method is limited,,and the necessary expense is not 8 justified by the results.
The invention provides a process for filtering rinse 11 water or wash fluid and a filter device. According to the 12 invention the filter is iargely maintenance-free when there 13 is a large quantity of dirt and the rinse water can be 14 cleaned of microfine particles of dirt quickly.
The invention utilizes a device of the type mentioned 16 previously in which the filtrate streams that go through 17 the individual filter segments can be carried off and 18 separated by separate filtrate lines. The size of the 19 individual filtrate streams can be adjusted by the geometry and/or by a choke or control element used.
21 In this way, the filter device is largely maintenance-22 free and must only be dismantled if there are problems.
23 Moreover, because of the especially high filter throughput 24 through the microfine filter, the rinse water is quickly cleaned of microfine particles of dirt.
26 The invention utilizes a process of the type 27 previously mentioned in which filter segments are arranged 28 in a duct and form part of the wall of the duct with their 29 filter surfaces. The filtrate streams going through the individual filter segments can be carried away separately 31 through separate filtrate lines.
32 One special advantage of the invention is that dirt is 33 prevented from clogging the pores by controlling the wash 34 or rinse water to be cleaned so that a sieve that is already dirty or affected need not necessarily be cleaned 1 by the appropriate means, which is not successful in every 2 case when there are stubborn deposits.
3 To ensure this clogging prevention, the filtrate 4 streams of the individual filter segments do not go into a common space and from there to the circulating pump of 6 filtrate pump. Instead, the filtrate streams are first 7 taken away separately in separate filtrate line5, which 8 also can include filtrate guides designed with a preset 9 flow resistance. The self-cleaning function of a filter segment is based on the dependence of the transverse flow 11 of the filter surface on the amount of throughput. For 12 reliable cleaning of particles of dirt filtered out of the 13 filter segments, it is necessary that the filtrate lines be 14 designed by their geometry and/or by a choke or control element in such a way that the speed of the transverse 16 stream flowing parallel to the filter surface is at least 5 17 times greater than the specific filter throughput.
18 Under some circumstances, it is necessary to subject 19 one or more filter segments to cyclic back-rinsing. This depends on the stream ratios of the respective filter 21 segment. A filter with smaller pores and slow transverse-22 flow speed, for example, is affected by this measure, 23 especially if the ratio of the transverse-flow speed to the 24 specific filtrate throughput is in a marginal area or less than 5. Such a filter segment requires in its filtrate 26 line, in addition to the resistance determining the filter 27 throughput, a control device for turning the filtrate 28 stream on and off and a control element for turning a back-29 rinse stream on and off. Conveniently, the filtrate and the back-rinse stream go through the same line between the 31 filter segment and the accompanying switching device.
32 The control devices for turning the filtrate and rinse 33 streams on and off can be, for example, individually 34 controllable valves or rotary control disks with at least one through zone and one locked zone, wherein for each 36 filtrate and back-rinse line, there is one valve or control 37 disk. The control devices for filtrate and back-rinse 1 stream are preferably designed so that they can be mutually 2 locked.
3 A filter segment to be back-rinsed is back-rinsed 4 cyclically, so that, for example, one filtrate line is back-rinsed for at least 1 second after approximately 60 6 seconds. This way, all filter segments designed to be 7 back-rinsed are rinsed periodically, and these filter 8 segments are preferably back-rinsed individually and 9 periodically. The individual filter segments are controlled in a fixed sequence, so that they can be cleaned 11 reciprocally, i.e., one filter segment traps dirt particles 12 during the rinse phase of another filter segment. One 13 possible switching sequence for baclc-rinsing individual 14 filter segments is, for example, 11, 14, 12, 15, 13, 16, 11, 14... Depending on the layout of the filter design, it 16 may be necessary to back-rinse one or more filter segments 17 several times one after another during the rinse cycle.
18 This way, the residues of dirt from one filter segment are 19 transported to the next and are ultimately stored in the area of the last filter segment, seen in the direction of 21 flow. From there, they are carried off during the pumping 22 process by the discharge pump and/or drainage devices, 23 potentially with the rinse liquid.
SEVERAL VIEWS OF TIIE DRAWING
26 The invention will be described in greater detail 27 below using two examples of embodiments and the attached 28 drawings.
29 Fig. 1 is a schematic drawing of a dishwasher with a filter integrated in the circulation of the dishwasher;
31 Fig. 2 is a drawing of one embodiment of the filter 32 device;
33 Fig. 3 is a section along line A-A in Fig. 2; and 34 Fig. 4 is an aIternative variation of the embodiment from Fig. 2.
.
21 90~37 2 In a washing machine, such as a household dishwasher 2 3 according to Figure 1, there is a collector 3 in the 4 circulating system for returning rinse water 4" a. filter device 1, a circulating pump 5 and at least one spray arm 6 10 that distributes the,rinse liquid in the dishwasher.
7 There is also a discharge pump 6 to take the rinse liquid 4 8 out of the dishwasher 2.
g The filter device 1 filters out coarse, fine and microfine particles of dirt 7 that are found in the rinse 11 liquid 4 and are loosened from the items to be rinsed. The 12 filter device moves the dirt particles 7 to an interim 13 storage unit 8 in concentrated form. This concentrate of 14 dirt particles 7 is stored immediately upstream of an inlet support 9 of the discharge pump 6 and pumped off during 16 and/or at the end of the rinse program. The filter device 17 1 is designed to guarantee self-cleaning of individual 18 filter segments 11, 12, 13, 14, 15, 16 during operation.
19 The rinse liquid 4 to be cleaned is taken from the rinse water collection device 3 to the filter system 1.
21 The liquid goes through a coarse filter 17, which retains 22 large objects and coarse particles of dirt 18 that cannot 23 be pumped off. The coarse filter 17 can be removed for 24 manual cleaning. The liquid 4 then goes into a duct 20 that is designed to be rectangular, for example. This duct 26 20 is designed so that part of its walls comprise 27 individual filter segments 11, 12, 13, 14, 15, 16. At the 28 entrance to the duct, there are filters 11, 12, 13 with 29 somewhat larger pores and at the end of the duct 20 microfine filters 14, 15, 16. The end of the duct is 31 connected to the inlet support 9 of the discharge pump 6.
32 The fluid 4 that goes into the duct 20 is divided when 33 it gets to the first filter 11. Part of the fluid goes 34 through the first filter 11 in a radial direction in relation to the axis of the duct. ~ere, the particles of 36 dirt 7 that cannot penetrate the filter 11 are filtered out 21 9093?, 1 and move to the next filter 12 with the other part of the 2 rinse liquid 4. The design of the filter system 1 and the 3 streams resulting from it are adjusted so that the filtered 4 dirt substances 7 are rinsed again and cannot stick to the surface of the filter or get caught in the pores. This is 6 achieved by having a transverse stream 25 cleaning the 7 filter surface at a speed at least 5 times greater, 8 preferably at least 10 times greater, than the specific 9 filtrate throughput. On each other filter segment 12, 13, 14, 15, 16 after the first segment 11, in the same way, 11 there is a division of the rinse water 4 in a filtrate that 12 goes through the filter segment 12, 13, 14, 15, 16 and an 13 amount of fluid that flows on in the duct 20, which cleans 14 the surface of the filter by forming the transverse stream 25. For an especially good cieaning effect, the condition 16 mentioned above for the ratio between the transverse stream 17 speed and the filtrate throughput must be complied with on 18 each filter segment 11, 12, 13, 14, 15, 16.
19 The transverse stream speed and hence also the specific filtrate throughput decreases from the first 21 filter to the last 11, 12, 13, 14, 15, 16. As a result, 22 the transverse stream speed to filtrate throughput ratio 23 also decreases and under some circumstances cannot be kept 24 in the favorable range at the last filters. If the speed/throughput ratio is low and, for example, approaches 26 the limit of 5 to l or falls below the limit, the 27 corresponding filter segment 11, 12, 13, 14, 15, 16 must be 28 rinsed again. For this, a control device 22 for the 29 filtrate stream 23 is inserted in a filtrate line 21. The control device 22 is turned off and a new rinse stream 24, 31 which goes through the filtrate line 21 and the filter 32 segment 11, 12, 13, 14, 15, 16 in the opposite direction is 33 turned on. The control device 21 includes individually 34 adjusted valves, such as rotary control disks, associated with each filtrate line 21. The valves have a flow-through 36 or open position and a closed or locking position. In this 37 way, the particles of dirt 7 on the filter segment 11, 12, 2 1 909~7 1 13, 14, 15, 16 are dislodged and moved by the stream in 2 the duct 20 in the direction of the next filter. one 3 filter segment 11, 12, 13, 14, 15, iS thus cleaned by the 4 next filter segments. This way, the particles of dirt 7 5 gradually make their way to the last filter 16. There they 6 settle, since no cleaning takes place here in the absence 7 of the transverse stream 25. This last filter 16 must, in 8 any case, be periodically rinsed in order to prevent 9 residues of dirt 7 from clogging the pores. The.dirt 7 is carried off and all filter surfaces cleaned at the same 11 time in the pumping-off phase. ~t this pOillt, at least the 12 last filter segment 16 before the discharge pump 6 is back-13 rinsed, preferably all filter segments that can be back-14 rinsed are rinsed during the pumping.
The back-rinse streams 24 are produced by the 16 circulating pump 5. For this, a back-rinse line 26 iS
17 attached to the output of the circulating pump 5 and 18 connected to the control device 22, which has the job of 19 turning the back-rinse stream 24 on and off.
Figs. 2 and 3 show a first embodiment of the filter 21 with the duct 20 and filter segments 31, 32, 33, 34. A
22 duct baffle 27 provides the proper built-in dimensioning.
23 One possible alternate design that is somewhat based 24 on a conventional sieve system is shown in Fig. 4.
Individual filter segments 28, 29, 30 are not made as 26 radially acting filters along a duct 20. Instead the 27 filter 28 is in the known funnel-shaped design with a large 28 angle of aperture, and the filters 29 and 30 are in 29 cylindrical form. All three filters 28, 29, 30 are 30 however, controlled like the one in the invention, i.e., by 31 control and choking of the streams 23, and, if necessary, 3 2 back-rinsing.
33 The embodiments of the invention shown are exemplary.
34 The invention includes modifications within the scope of 3 5 the claims.
7 In a household dishwasher, the return water is usually 8 collected in an outlet tub or sump in the bottom of the 9 compartment of the dishwasher from which the water is pumped into the compartment. This is shown for example in 11 DE-OS 3114 633. On the bottom of this outlet tub there is 12 one suction support each for a circulating pump and a 13 discharge pump respectively. To clean the rinse water, 14 which has varying amounts of food residues in it, a combination sieve with coarse, fine and microfine filters 16 is used in this area.
17 The arrangement of the individual sieve elements is 18 designed so that the outlet tub is covered on top by a 19 funnel-shaped fine sieve with a large aperture, which in the middle turns into a cylindrical fine sieve section that 21 extends to the suction supports on the discharge pump.
22 This fine-sieve cylinder is surrounded by another fine-23 sieve section that is also designed in the form of a 24 cylinder on the periphery.
When the circulating pump is running, the funnel-26 shaped fine sieve filters out coarse and fine particles of 27 dirt in a main stream and flushes it to the fine-sieve 28 cylinder in an auxiliary stream parallel to the surface of 29 the funnel-shaped fine filter. These residues of dirt are ultimately stored near the suction support on the discharge 31 pump. They cannot penetrate the fine-sieve filter because 32 the two fine-sieve models have an almost identical hole 33 size.
2 ~ 90937 1 In addition, a removable coarse sieve is used in the 2 upper section of the fine-sieve cylinder to keep the 3 discharge pump from being clogged with very coarse residues 4 of dirt.
Some of the circulated rinse water goes through coarse 6 and fine-sieve cylinders and reaches the circulating pump 7 through the microfine s,ieve cylinder. Here, very fine 8 residues of dirt, so-called microparticles, are retained.
g The residues of dirt are removed from the appliance both during and at the end of the rinse program by having the 11 discharge pump pump them out. Because of the geometry oE
12 the individual filter components and the stream that is 13 produced, the filter surfaces are continually cleaned 14 thoroughly by cross streams during the rinse process and during the process of pumping off the retained dirt 16 particles. Only the coarse pieces that cannot be carried 17 away must be removed manually.
18 This filter system is suitable for the rinse cycle in 19 households and also works well when the dirt is average to heavy. But if there are a lot of residues on the dishes, 21 deposits can very quickly accumulate on the surface of the 22 sieve, which can, in an extreme case, become blocked and 23 stop the entire rinse cycle.
24 Moreover, the proportion of rinse liquid that flows through the microfine sieve cylinder is small compared to 26 the whole filter throughput, so that the rinse liquid is 27 only cleaned slowly of fine microparticles. This way, the 28 filtrate clarity, which is a measure for the residual 29 soiling of the dishes, is only improved gradually.
The operator must also perform a thorough cleaning of 31 the removable filter system, if possible after each rinse 32 program, but at the latest after five to ten rinse cycles.
33 This is necessary because due to the high suction pressure 34 that the circulating pump produces, the particles of dirt that accumulate on the filter surface are suctioned up by 36 the mesh and holes in the sieve, where they can easily stop 37 and get caught. ~ .
1 If such a filter system is not cleaned over a long 2 period of time, the whole system is adversely affected.
3 To counteract clogging by the dirt particles, it is 4 known to rinse out the filter by reversing the direction of flow several times during the rinse program as shown in D~-6 UM 81 08 815. But, in practice, it has been shown that 7 this method is limited,,and the necessary expense is not 8 justified by the results.
The invention provides a process for filtering rinse 11 water or wash fluid and a filter device. According to the 12 invention the filter is iargely maintenance-free when there 13 is a large quantity of dirt and the rinse water can be 14 cleaned of microfine particles of dirt quickly.
The invention utilizes a device of the type mentioned 16 previously in which the filtrate streams that go through 17 the individual filter segments can be carried off and 18 separated by separate filtrate lines. The size of the 19 individual filtrate streams can be adjusted by the geometry and/or by a choke or control element used.
21 In this way, the filter device is largely maintenance-22 free and must only be dismantled if there are problems.
23 Moreover, because of the especially high filter throughput 24 through the microfine filter, the rinse water is quickly cleaned of microfine particles of dirt.
26 The invention utilizes a process of the type 27 previously mentioned in which filter segments are arranged 28 in a duct and form part of the wall of the duct with their 29 filter surfaces. The filtrate streams going through the individual filter segments can be carried away separately 31 through separate filtrate lines.
32 One special advantage of the invention is that dirt is 33 prevented from clogging the pores by controlling the wash 34 or rinse water to be cleaned so that a sieve that is already dirty or affected need not necessarily be cleaned 1 by the appropriate means, which is not successful in every 2 case when there are stubborn deposits.
3 To ensure this clogging prevention, the filtrate 4 streams of the individual filter segments do not go into a common space and from there to the circulating pump of 6 filtrate pump. Instead, the filtrate streams are first 7 taken away separately in separate filtrate line5, which 8 also can include filtrate guides designed with a preset 9 flow resistance. The self-cleaning function of a filter segment is based on the dependence of the transverse flow 11 of the filter surface on the amount of throughput. For 12 reliable cleaning of particles of dirt filtered out of the 13 filter segments, it is necessary that the filtrate lines be 14 designed by their geometry and/or by a choke or control element in such a way that the speed of the transverse 16 stream flowing parallel to the filter surface is at least 5 17 times greater than the specific filter throughput.
18 Under some circumstances, it is necessary to subject 19 one or more filter segments to cyclic back-rinsing. This depends on the stream ratios of the respective filter 21 segment. A filter with smaller pores and slow transverse-22 flow speed, for example, is affected by this measure, 23 especially if the ratio of the transverse-flow speed to the 24 specific filtrate throughput is in a marginal area or less than 5. Such a filter segment requires in its filtrate 26 line, in addition to the resistance determining the filter 27 throughput, a control device for turning the filtrate 28 stream on and off and a control element for turning a back-29 rinse stream on and off. Conveniently, the filtrate and the back-rinse stream go through the same line between the 31 filter segment and the accompanying switching device.
32 The control devices for turning the filtrate and rinse 33 streams on and off can be, for example, individually 34 controllable valves or rotary control disks with at least one through zone and one locked zone, wherein for each 36 filtrate and back-rinse line, there is one valve or control 37 disk. The control devices for filtrate and back-rinse 1 stream are preferably designed so that they can be mutually 2 locked.
3 A filter segment to be back-rinsed is back-rinsed 4 cyclically, so that, for example, one filtrate line is back-rinsed for at least 1 second after approximately 60 6 seconds. This way, all filter segments designed to be 7 back-rinsed are rinsed periodically, and these filter 8 segments are preferably back-rinsed individually and 9 periodically. The individual filter segments are controlled in a fixed sequence, so that they can be cleaned 11 reciprocally, i.e., one filter segment traps dirt particles 12 during the rinse phase of another filter segment. One 13 possible switching sequence for baclc-rinsing individual 14 filter segments is, for example, 11, 14, 12, 15, 13, 16, 11, 14... Depending on the layout of the filter design, it 16 may be necessary to back-rinse one or more filter segments 17 several times one after another during the rinse cycle.
18 This way, the residues of dirt from one filter segment are 19 transported to the next and are ultimately stored in the area of the last filter segment, seen in the direction of 21 flow. From there, they are carried off during the pumping 22 process by the discharge pump and/or drainage devices, 23 potentially with the rinse liquid.
SEVERAL VIEWS OF TIIE DRAWING
26 The invention will be described in greater detail 27 below using two examples of embodiments and the attached 28 drawings.
29 Fig. 1 is a schematic drawing of a dishwasher with a filter integrated in the circulation of the dishwasher;
31 Fig. 2 is a drawing of one embodiment of the filter 32 device;
33 Fig. 3 is a section along line A-A in Fig. 2; and 34 Fig. 4 is an aIternative variation of the embodiment from Fig. 2.
.
21 90~37 2 In a washing machine, such as a household dishwasher 2 3 according to Figure 1, there is a collector 3 in the 4 circulating system for returning rinse water 4" a. filter device 1, a circulating pump 5 and at least one spray arm 6 10 that distributes the,rinse liquid in the dishwasher.
7 There is also a discharge pump 6 to take the rinse liquid 4 8 out of the dishwasher 2.
g The filter device 1 filters out coarse, fine and microfine particles of dirt 7 that are found in the rinse 11 liquid 4 and are loosened from the items to be rinsed. The 12 filter device moves the dirt particles 7 to an interim 13 storage unit 8 in concentrated form. This concentrate of 14 dirt particles 7 is stored immediately upstream of an inlet support 9 of the discharge pump 6 and pumped off during 16 and/or at the end of the rinse program. The filter device 17 1 is designed to guarantee self-cleaning of individual 18 filter segments 11, 12, 13, 14, 15, 16 during operation.
19 The rinse liquid 4 to be cleaned is taken from the rinse water collection device 3 to the filter system 1.
21 The liquid goes through a coarse filter 17, which retains 22 large objects and coarse particles of dirt 18 that cannot 23 be pumped off. The coarse filter 17 can be removed for 24 manual cleaning. The liquid 4 then goes into a duct 20 that is designed to be rectangular, for example. This duct 26 20 is designed so that part of its walls comprise 27 individual filter segments 11, 12, 13, 14, 15, 16. At the 28 entrance to the duct, there are filters 11, 12, 13 with 29 somewhat larger pores and at the end of the duct 20 microfine filters 14, 15, 16. The end of the duct is 31 connected to the inlet support 9 of the discharge pump 6.
32 The fluid 4 that goes into the duct 20 is divided when 33 it gets to the first filter 11. Part of the fluid goes 34 through the first filter 11 in a radial direction in relation to the axis of the duct. ~ere, the particles of 36 dirt 7 that cannot penetrate the filter 11 are filtered out 21 9093?, 1 and move to the next filter 12 with the other part of the 2 rinse liquid 4. The design of the filter system 1 and the 3 streams resulting from it are adjusted so that the filtered 4 dirt substances 7 are rinsed again and cannot stick to the surface of the filter or get caught in the pores. This is 6 achieved by having a transverse stream 25 cleaning the 7 filter surface at a speed at least 5 times greater, 8 preferably at least 10 times greater, than the specific 9 filtrate throughput. On each other filter segment 12, 13, 14, 15, 16 after the first segment 11, in the same way, 11 there is a division of the rinse water 4 in a filtrate that 12 goes through the filter segment 12, 13, 14, 15, 16 and an 13 amount of fluid that flows on in the duct 20, which cleans 14 the surface of the filter by forming the transverse stream 25. For an especially good cieaning effect, the condition 16 mentioned above for the ratio between the transverse stream 17 speed and the filtrate throughput must be complied with on 18 each filter segment 11, 12, 13, 14, 15, 16.
19 The transverse stream speed and hence also the specific filtrate throughput decreases from the first 21 filter to the last 11, 12, 13, 14, 15, 16. As a result, 22 the transverse stream speed to filtrate throughput ratio 23 also decreases and under some circumstances cannot be kept 24 in the favorable range at the last filters. If the speed/throughput ratio is low and, for example, approaches 26 the limit of 5 to l or falls below the limit, the 27 corresponding filter segment 11, 12, 13, 14, 15, 16 must be 28 rinsed again. For this, a control device 22 for the 29 filtrate stream 23 is inserted in a filtrate line 21. The control device 22 is turned off and a new rinse stream 24, 31 which goes through the filtrate line 21 and the filter 32 segment 11, 12, 13, 14, 15, 16 in the opposite direction is 33 turned on. The control device 21 includes individually 34 adjusted valves, such as rotary control disks, associated with each filtrate line 21. The valves have a flow-through 36 or open position and a closed or locking position. In this 37 way, the particles of dirt 7 on the filter segment 11, 12, 2 1 909~7 1 13, 14, 15, 16 are dislodged and moved by the stream in 2 the duct 20 in the direction of the next filter. one 3 filter segment 11, 12, 13, 14, 15, iS thus cleaned by the 4 next filter segments. This way, the particles of dirt 7 5 gradually make their way to the last filter 16. There they 6 settle, since no cleaning takes place here in the absence 7 of the transverse stream 25. This last filter 16 must, in 8 any case, be periodically rinsed in order to prevent 9 residues of dirt 7 from clogging the pores. The.dirt 7 is carried off and all filter surfaces cleaned at the same 11 time in the pumping-off phase. ~t this pOillt, at least the 12 last filter segment 16 before the discharge pump 6 is back-13 rinsed, preferably all filter segments that can be back-14 rinsed are rinsed during the pumping.
The back-rinse streams 24 are produced by the 16 circulating pump 5. For this, a back-rinse line 26 iS
17 attached to the output of the circulating pump 5 and 18 connected to the control device 22, which has the job of 19 turning the back-rinse stream 24 on and off.
Figs. 2 and 3 show a first embodiment of the filter 21 with the duct 20 and filter segments 31, 32, 33, 34. A
22 duct baffle 27 provides the proper built-in dimensioning.
23 One possible alternate design that is somewhat based 24 on a conventional sieve system is shown in Fig. 4.
Individual filter segments 28, 29, 30 are not made as 26 radially acting filters along a duct 20. Instead the 27 filter 28 is in the known funnel-shaped design with a large 28 angle of aperture, and the filters 29 and 30 are in 29 cylindrical form. All three filters 28, 29, 30 are 30 however, controlled like the one in the invention, i.e., by 31 control and choking of the streams 23, and, if necessary, 3 2 back-rinsing.
33 The embodiments of the invention shown are exemplary.
34 The invention includes modifications within the scope of 3 5 the claims.
Claims (18)
1. A device for filtering a wash or rinse liquid of a washing machine having a rinse or wash container and a collector in the bottom, for the liquid, the device comprising a coarse sieve to retain large foreign bodies;
several filter segments designed as fine or microfine sieves with different pore sizes; a circulating pump to circulate the liquid from the collector to the container; a discharge device to remove liquid and materials filtered off by the filter segments; and a device for back rinsing the filter segments, characterized by the fact that filtrate streams (23) that go through the filter segments (11, 12, 13, 14, 15, 16) flow separately through separate filtrate lines (21) connected to each of the filter segments in such a way that the flow of the individual filtrate streams (23) can be adjusted.
several filter segments designed as fine or microfine sieves with different pore sizes; a circulating pump to circulate the liquid from the collector to the container; a discharge device to remove liquid and materials filtered off by the filter segments; and a device for back rinsing the filter segments, characterized by the fact that filtrate streams (23) that go through the filter segments (11, 12, 13, 14, 15, 16) flow separately through separate filtrate lines (21) connected to each of the filter segments in such a way that the flow of the individual filtrate streams (23) can be adjusted.
2. A device according to Claim 1, characterized by the fact that the individual filter segments (11, 12, 13, 14, 15, 16) are arranged one after the other on a duct (20) having an inlet connected to the collector and an outlet connected to the discharge device (6) in such a way that filter surfaces of the filter segments form part of walls of the duct (20).
3. A device according to Claim 2, characterized by the fact that a speed of a transverse stream (25) flowing in the duct is at least 5 times greater than a specific filtrate throughput at the first filter segment (11) in the direction of flow.
4. A device according to Claim 2, characterized by the fact that the transverse stream speed in the flow direction decreases along the length of the duct (20) and is equal to zero at the duct outlet except during operation of the discharge device.
5. A device according to Claim 1, characterized by the fact that the filtrate lines (21) flow into a control device (22) with which the individual filtrate lines (21) are controlled independently of one another to adjust filtrate streams (23) and back-rinse streams (24).
6. A device according to Claim 5, characterized by the fact that the control device (22) is adapted to turn on, turn off and back-rinse the respective filter segment (11, 12, 13, 14, 15, 16).
7. A device according to Claim 5, characterized by the fact that the control device (22) for adjusting the filtrate streams comprises individually adjustable valves with at least one flow-through and at least one locking position, wherein one valve is provided for each filtrate line (21).
8. A device according to Claim 5, characterized by the fact that at least the last filter segment (16) before the discharge pump (6) is back-rinsed periodically.
9. A device according to Claim 5, characterized by the fact that the control device (22) for adjusting the back-rinse streams (24) comprises individually adjustable valves with at least one flow-through and at least one locking position, wherein there is one valve for each filtrate line (21).
10. A device according to Claim 5, characterized by the fact that the filtrate stream (23) assigned to a filter segment (11, 12, 13, 14, 15, 16) and the accompanying back-rinse stream (24) both go through the filtrate line (21) between the filter segment (11, 12, 13, 14, 15, 16) and the accompanying control device (22).
11. A device according to Claim 5, characterized by the fact that adjustment of the filtrate (23) and the back-rinse streams (24) by the control device is mutually interlocked.
12. A device according to Claim 7, characterized by the fact that the control device for adjusting a filtrate (23) and a back-rinse stream (24) includes a one-piece control disk.
13. A process for filtering wash or rinse liquid from a washing machine having filter segments (11, 12, 13, 14, 15, 16) arranged in a duct (20) and filter surfaces of the filter segments forming part of a wall of the duct (20), characterized by the steps of directing liquid flow through the duct (20); filtering the liquid through the individual filter segments; and directing filtrate streams (23) that go through the individual filter segments (11, 12, 13, 14, 15, 16) through separate filtrate lines (21).
14. A process according to Claim 13, characterized by the fact that the filter segments (11, 12, 13, 14, 15, 16) are back-rinsed periodically for at least one second.
15. A process according to Claim 14, characterized by the fact that the filter segments (11, 12, 13, 14, 15, 16) are back-rinsed individually.
16. A process according to Claim 15, characterized by the fact that the filter segments are back-rinsed in a fixed sequence.
17. A process according to Claim 13, characterized by the fact that particles of dirt (7) in the duet are removed during a rinse or wash program by turning on a discharge pump (6).
18. A process according to Claim 13, characterized by the fact that during a discharge cycle, at least the last filter segment (16) in the direction of flow is back-rinsed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19543809 | 1995-11-24 | ||
| DE19543809.4 | 1995-11-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2190937A1 true CA2190937A1 (en) | 1997-05-25 |
Family
ID=7778305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002190937A Abandoned CA2190937A1 (en) | 1995-11-24 | 1996-11-21 | Device and process for filtering a liquid |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2190937A1 (en) |
| DE (1) | DE19636014B4 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107993810A (en) * | 2017-11-03 | 2018-05-04 | 国家电网公司 | A kind of drying means and drying device of for transformer insulating oil |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10010879A1 (en) * | 2000-02-29 | 2001-08-30 | Adam Krecisz | Washing machine filter has perforated housing in machine drum, filter movable freely or rotatably fixed in housing with filter surface(s) in lower part, water inlet/outlet openings in top part |
| DE102007056919B4 (en) * | 2007-11-27 | 2020-07-02 | BSH Hausgeräte GmbH | Water-bearing household appliance |
| DE102007060193A1 (en) * | 2007-12-14 | 2009-06-25 | BSH Bosch und Siemens Hausgeräte GmbH | Water-conducting household appliance |
| DE102007060195A1 (en) * | 2007-12-14 | 2009-06-18 | BSH Bosch und Siemens Hausgeräte GmbH | Water-conducting household appliance |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3807419A (en) * | 1972-05-12 | 1974-04-30 | Gen Electric | Dishwasher having means for collecting and removing food soil |
| DE8108815U1 (en) * | 1981-03-26 | 1981-08-06 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | "DISHWASHER" |
| DE3114663C2 (en) * | 1981-04-10 | 1992-11-26 | Bosch-Siemens Hausgeräte GmbH, 7000 Stuttgart | Sieve arrangement in the drain pan of the washing compartment of a dishwasher |
| DE9415486U1 (en) * | 1994-09-24 | 1994-11-17 | Bauknecht Hausgeräte GmbH, 70563 Stuttgart | Dishwasher with a rinse water circuit and a filter device with a cleaning device |
-
1996
- 1996-09-05 DE DE19636014A patent/DE19636014B4/en not_active Expired - Fee Related
- 1996-11-21 CA CA002190937A patent/CA2190937A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107993810A (en) * | 2017-11-03 | 2018-05-04 | 国家电网公司 | A kind of drying means and drying device of for transformer insulating oil |
| CN107993810B (en) * | 2017-11-03 | 2024-04-26 | 国家电网公司 | Drying method and drying device for transformer insulating oil |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19636014A1 (en) | 1997-05-28 |
| DE19636014B4 (en) | 2006-03-02 |
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| Date | Code | Title | Description |
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| FZDE | Dead |
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