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WO2007135226A1 - A method for taking a liquid sample - Google Patents

A method for taking a liquid sample Download PDF

Info

Publication number
WO2007135226A1
WO2007135226A1 PCT/FI2007/000138 FI2007000138W WO2007135226A1 WO 2007135226 A1 WO2007135226 A1 WO 2007135226A1 FI 2007000138 W FI2007000138 W FI 2007000138W WO 2007135226 A1 WO2007135226 A1 WO 2007135226A1
Authority
WO
WIPO (PCT)
Prior art keywords
filtering
filtering element
filter
sample
liquid
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.)
Ceased
Application number
PCT/FI2007/000138
Other languages
French (fr)
Inventor
Erkki RÄSÄNEN
Pekka Savolahti
Pentti Pirkonen
Antti GRÖNROOS
Hanna KYLLÖNEN
Jorma Ihalainen
Hannu Mursunen
Hannu Sekki
Teemu TYÖPPÖNEN
Pertti VASTAMÄKI
Jouko Rakkolainen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
VTT Technical Research Centre of Finland Ltd
Original Assignee
VTT Technical Research Centre of Finland Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by VTT Technical Research Centre of Finland Ltd filed Critical VTT Technical Research Centre of Finland Ltd
Publication of WO2007135226A1 publication Critical patent/WO2007135226A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/10—Devices for withdrawing samples in the liquid or fluent state
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/15—Filters with filtering elements which move during the filtering operation with rotary plane filtering surfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/44—Regenerating the filter material in the filter
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2201/00—Details relating to filtering apparatus
    • B01D2201/08—Regeneration of the filter
    • B01D2201/085—Regeneration of the filter using another chemical than the liquid to be filtered
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/40—Concentrating samples
    • G01N1/4077—Concentrating samples by other techniques involving separation of suspended solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/10—Devices for withdrawing samples in the liquid or fluent state
    • G01N2001/1006—Dispersed solids
    • G01N2001/1012—Suspensions
    • G01N2001/1025—Liquid suspensions; Slurries; Mud; Sludge

Definitions

  • the invention relates to the sampling of a liquid containing solids by filtering the liquid.
  • the invention relates to the method used herein, the sampling filter, and their use.
  • the sampling filter according to the invention has a rotatable filtering element, a liquid containing solid matter being led parallel to the surface of the element so that a sample is continuously filtered through the element at one point and that the element is continuously cleaned at another point.
  • the filtering element is preferably plate-shaped. Liquid is thus led past the surface of the filtering ele- ment so that only a part of the liquid, in practice actually a very small part, travels through the filtering element.
  • the filtering element is preferably cleaned by directing a cleaning agent flow through the element upstream in relation to the filtering.
  • the cleaning agent can be liquid or gaseous.
  • the liquid can be water or, for example, an acid or alkali solution, or an oxidising solution, such as a permanganate solution.
  • several cleaning agents can be used simultaneously.
  • the apparatus can also have several successive washing stations. In addition to cleaning agents, physical cleaning, such as ultrasonic, electric or thermal cleaning can be used.
  • the filtering element can be rotated all the time or continuously.
  • the material of the filtering element can be, for example, metal, polymer, com- posite, or glass.
  • the pore size can be, for example, 0.1 - 200 ⁇ m.
  • the pores are preferably holes travelling essentially straight through the plane of the element so that the liquid is prevented from moving in the transverse direction of the element.
  • the holes can be, for example, cylindrical or conical.
  • the holes can be located, for example, at an interval of 10 ⁇ m - 1 mm.
  • the diameter of the filter plate can be, for example, 5 - 15 cm, and the diameter of the filtrate chamber can be, for example, 2 - 5 cm.
  • the filtering speed for the sample can be, for example, 1 - 100 ml/min.
  • the feed channel for the suspension contains as few and as gradual bends as possible, a sample can be taken even from a very thick suspension.
  • the feed channel for the suspension inside the filter is in this case preferably essentially straight.
  • the feed channel has preferably a protruding opening, which is connected to the filtering element. The suspension flow travels best against the direction of rotation of the filtering element.
  • the filtering speed can be adjusted by altering the pressure difference. This can be done in the filtrate exhaust channel either by suction or restriction.
  • a continuously identical, as representative a sample as possible can be obtained.
  • liquid is fed with a constant flow speed
  • sample is obtained with a constant flow speed.
  • the flow speeds of the suspension, the sample and the solutions in the cleaning steps and the pressure settings are kept the same, a continuously and reliably repeatable and exact sample is obtained.
  • the invention is suitable for the use especially in the process industry and for taking samples to such analyses (e.g. capillary electrophoresis, ion chromatography), in which only a small amount of sample is needed, for example, a few mi- cro litres per analysis. Thus, a capacity of approximately 1 ml/min is sufficient for many purposes.
  • analyses e.g. capillary electrophoresis, ion chromatography
  • the invention can be used, for example, in the pulp and paper industry, mineral industry, food industry, and in water purification plants. Drawings
  • FIG. 1 is a side view of a filter
  • Fig. 2 is a top view of the filter in Fig. 1
  • Fig. 3 is a side view of a second filter
  • Fig. 4 is a front view of the filter in Fig. 3
  • Fig. 5 is a top view of the filter in Fig. 3.
  • the filter according to Figs 1 and 2 has a circular filter plate 1, which is fitted to be rotated on an axis 2 by means of a motor 3.
  • the filter plate is located tightly between an upper support part 4.1 and a lower support part, 4.2.
  • the filter plate is made of a material with desired porosity.
  • the other half of the upper support part 4.1 is radially provided with a suspen- sion chamber 5, through which the filter plate 1 travels and to the lower edges of which it has been sealed.
  • a feed channel 6 for the suspension leads to the suspension chamber from above, and a suspension exhaust channel 7 leads upwards from it in direction of the radius.
  • the lower support part 4.2 has below the filter plate 1, at the place of the filtering chamber, respectively a filtrate chamber 8, from which an exhaust channel 9 for the filtrate sample leads downwards from the outer edge.
  • the filter plate 1 On the other half of the filter plate 1 below it there is located in the lower sup- port part 4.2 radially a feed chamber 10 for the cleaning solution, a feed channel 11 for the cleaning solution leading to its inner edge and an exhaust channel 12 for the cleaning solution leading away from its outer edge.
  • the upper support part 4 has at the respective place an exhaust chamber 13 for the used cleaning solution, from the outer edge of which there leads away an exhaust channel 14.
  • the feed chamber has a higher pressure than the exhaust chamber, cleaning solution will flow through the filter plate.
  • part of the filter plate 1 filters the sample all the time, and part of it is being cleaned all the time.
  • the filter plate can be rotated all the time or periodically.
  • the rotatable filter plate 1 is respec- tively located between an upper support part 4.1' and a lower support part 4.2'.
  • the other half of the upper support part 4.1' includes a suspension chamber 5', which is formed of the downwards protruding opening of a feed channel 6' parallel to the filter plate l.
  • the trailing edge of the feed chamber is chamfered downwards and, respectively, the leading edge is chamfered upwards.
  • the lower support part 4.2' has three cleaning agent feed chambers 10' placed at equal intervals with the filtrate chamber 8'.
  • a cleaning agent feed channel 11' leads to the inner edge of the feed chamber, with a cleaning agent exhaust channel 12' leading away from the outer edge of the feed chamber.
  • the exhaust channel has a pressure regulating valve 15.
  • three successive washing steps can be performed, such as, for example, acid wash, water wash, and air drying.
  • the materials for the equipment can be, for example, steel, plastic (such as Teflon), or ceramic.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biochemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Hydrology & Water Resources (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The invention relates to a sampling method and filter for taking a liquid sample from a suspension containing liquid and solid matter by filtering. The filter has a rotatable filtering element (1), filtering means (6, 5, 8, 9) not rotating in relation to the filtering element for the continuous filtering of the liquid through the filtering element and cleaning means (11, 10, 13, 14) not rotating in relation to the filtering element for the continuous cleaning of the filtering element. The invention is especially suitable to be used in the process industry and in such applications in which only a small amount of the sample is needed.

Description

A method for taking a liquid sample
Description
Technical field
The invention relates to the sampling of a liquid containing solids by filtering the liquid. The invention relates to the method used herein, the sampling filter, and their use.
Technical background
Many processes require that a liquid sample be taken from a liquid containing solids, continuously by filtering. For filtering particles of colloid size, filters with very small holes are needed, and especially filters like this become easily blocked. The blocking can occur even in minutes. It has been tried to prevent the blocking by removing cake from the surface of the filter by means of a liquid flow (mixing, high flowing speed, rotation of filter pipes, control of the flow) and by ultrasonic cleaners (see, for example, FI100919 B and FI106614 B).
General description of the invention
It has now been invented a sampling method, a sampling filter and the use of these in accordance with the independent claims. The dependent claims disclose some advantageous embodiments of the invention.
The sampling filter according to the invention has a rotatable filtering element, a liquid containing solid matter being led parallel to the surface of the element so that a sample is continuously filtered through the element at one point and that the element is continuously cleaned at another point. The filtering element is preferably plate-shaped. Liquid is thus led past the surface of the filtering ele- ment so that only a part of the liquid, in practice actually a very small part, travels through the filtering element.
The filtering element is preferably cleaned by directing a cleaning agent flow through the element upstream in relation to the filtering. The cleaning agent can be liquid or gaseous. When needed, the liquid can be water or, for example, an acid or alkali solution, or an oxidising solution, such as a permanganate solution. Also several cleaning agents can be used simultaneously. The apparatus can also have several successive washing stations. In addition to cleaning agents, physical cleaning, such as ultrasonic, electric or thermal cleaning can be used.
The filtering element can be rotated all the time or continuously.
The material of the filtering element can be, for example, metal, polymer, com- posite, or glass. The pore size can be, for example, 0.1 - 200 μm. The pores are preferably holes travelling essentially straight through the plane of the element so that the liquid is prevented from moving in the transverse direction of the element. The holes can be, for example, cylindrical or conical. The holes can be located, for example, at an interval of 10 μm - 1 mm. The diameter of the filter plate can be, for example, 5 - 15 cm, and the diameter of the filtrate chamber can be, for example, 2 - 5 cm. The filtering speed for the sample can be, for example, 1 - 100 ml/min.
When the feed channel for the suspension contains as few and as gradual bends as possible, a sample can be taken even from a very thick suspension. The feed channel for the suspension inside the filter is in this case preferably essentially straight. In this case, the feed channel has preferably a protruding opening, which is connected to the filtering element. The suspension flow travels best against the direction of rotation of the filtering element.
The filtering speed can be adjusted by altering the pressure difference. This can be done in the filtrate exhaust channel either by suction or restriction.
According to the invention, a continuously identical, as representative a sample as possible can be obtained. When liquid is fed with a constant flow speed, also the sample is obtained with a constant flow speed. When the flow speeds of the suspension, the sample and the solutions in the cleaning steps and the pressure settings are kept the same, a continuously and reliably repeatable and exact sample is obtained.
The invention is suitable for the use especially in the process industry and for taking samples to such analyses (e.g. capillary electrophoresis, ion chromatography), in which only a small amount of sample is needed, for example, a few mi- cro litres per analysis. Thus, a capacity of approximately 1 ml/min is sufficient for many purposes.
The invention can be used, for example, in the pulp and paper industry, mineral industry, food industry, and in water purification plants. Drawings
The enclosed drawings are a part of the written description of the invention, and they illustrate some sampling filters according to the invention. In the drawings Fig. 1 is a side view of a filter; Fig. 2 is a top view of the filter in Fig. 1; Fig. 3 is a side view of a second filter; Fig. 4 is a front view of the filter in Fig. 3; and Fig. 5 is a top view of the filter in Fig. 3.
Detailed description of an embodiment of the invention
Next, examples of some sampling filters according to the invention will be illustrated.
The filter according to Figs 1 and 2 has a circular filter plate 1, which is fitted to be rotated on an axis 2 by means of a motor 3. The filter plate is located tightly between an upper support part 4.1 and a lower support part, 4.2. The filter plate is made of a material with desired porosity.
The other half of the upper support part 4.1 is radially provided with a suspen- sion chamber 5, through which the filter plate 1 travels and to the lower edges of which it has been sealed. A feed channel 6 for the suspension leads to the suspension chamber from above, and a suspension exhaust channel 7 leads upwards from it in direction of the radius. Thus, the suspension is led along the surface of the filter plate 1. The lower support part 4.2 has below the filter plate 1, at the place of the filtering chamber, respectively a filtrate chamber 8, from which an exhaust channel 9 for the filtrate sample leads downwards from the outer edge. When the filtrate chamber has a lower pressure than the suspension chamber, liquid is filtrated through the plate.
On the other half of the filter plate 1 below it there is located in the lower sup- port part 4.2 radially a feed chamber 10 for the cleaning solution, a feed channel 11 for the cleaning solution leading to its inner edge and an exhaust channel 12 for the cleaning solution leading away from its outer edge. The upper support part 4 has at the respective place an exhaust chamber 13 for the used cleaning solution, from the outer edge of which there leads away an exhaust channel 14. When the feed chamber has a higher pressure than the exhaust chamber, cleaning solution will flow through the filter plate. In this way, part of the filter plate 1 filters the sample all the time, and part of it is being cleaned all the time. The filter plate can be rotated all the time or periodically.
In the equipment according to Figs 3 - 4, the rotatable filter plate 1 is respec- tively located between an upper support part 4.1' and a lower support part 4.2'.
The other half of the upper support part 4.1' includes a suspension chamber 5', which is formed of the downwards protruding opening of a feed channel 6' parallel to the filter plate l.The trailing edge of the feed chamber is chamfered downwards and, respectively, the leading edge is chamfered upwards. Below the filter plate 1 there is a filtrate chamber 8', from which a filtrate sample exhaust channel 9' leads downwards from the middle. The suspension flow travels over the filtering surface against the direction of rotation of the filter plate.
The lower support part 4.2' has three cleaning agent feed chambers 10' placed at equal intervals with the filtrate chamber 8'. A cleaning agent feed channel 11' leads to the inner edge of the feed chamber, with a cleaning agent exhaust channel 12' leading away from the outer edge of the feed chamber. The exhaust channel has a pressure regulating valve 15. At the place of the filtrate chamber in the upper support part 4' there is an exhaust chamber 13' for used cleaning agent, from the outer edge of which there leads away an exhaust channel 14' and from the inner edge an exhaust channel 14.1'.
In the equipment according to Figs 3 - 4 three successive washing steps can be performed, such as, for example, acid wash, water wash, and air drying.
The materials for the equipment can be, for example, steel, plastic (such as Teflon), or ceramic.

Claims

Claims
1. A method for taking a liquid sample from a suspension containing liquid and solid matter by filtering with a filtering element (1), characterised in that the filtering element (1) is rotated, liquid containing solid matter is led in the di- rection of its surface, and sample is continuously filtered through it by means of filtering means (6, 5, 8, 9; 6', 5', 8', 90 not rotating in relation to the filtering element and that the filtering element is continuously cleaned by means of cleaning means (11, 10, 13, 14; 11', 10', 13', 140 not rotating in relation to the filtering element.
2. A sampling filter to be used in the method according to claim 1 for taking a sample from a suspension containing liquid and solid matter by filtering, characterised in that the filter has a rotatable filtering element (1), filtering means (6, 5, 8, 9; 6", 5', 8', 90 not rotating in relation to the filtering element for continuously filtering liquid through the filtering element and cleaning means (11, 10, 13^14; 11', 10', 13', 140 not rotating in relation to the filtering element for the continuous cleaning of the filtering element.
3. A filter according to claim 2, characterised in that the filtering element (1) is plate-shaped.
4. A filter according to claim 2 or 3, characterised in that the cleaning means (11, 10, 13, 14; 11', 10', 13', 140 are used for leading cleaning agent through the filtering element (1) upstream in relation to the filtering direction.
5. A filter according to claim 3 or 4, characterised in that it has the first support part (4; 40 on the one side of the filter plate (1) and a second support part (5; 50 on the other side.
6. A filter according to one of the claims 3 - 5, characterised in that it has at least two successive cleaning means (H', 10', 13', 140.
7. A filter according to one of the claims 3 - 6, characterised in that the pores of the filtering element (1) are holes going through the plate.
8. The use of a method according to claim 1 or the use of a filter according to one of the claims 3 - 7 for taking a sample in a processing plant.
PCT/FI2007/000138 2006-05-24 2007-05-23 A method for taking a liquid sample Ceased WO2007135226A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20060512A FI20060512A0 (en) 2006-05-24 2006-05-24 Sampling Filters
FI20060512 2006-05-24

Publications (1)

Publication Number Publication Date
WO2007135226A1 true WO2007135226A1 (en) 2007-11-29

Family

ID=36539959

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2007/000138 Ceased WO2007135226A1 (en) 2006-05-24 2007-05-23 A method for taking a liquid sample

Country Status (2)

Country Link
FI (1) FI20060512A0 (en)
WO (1) WO2007135226A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013098487A1 (en) * 2011-12-30 2013-07-04 Kemira Oyj Method and device for taking samples and use of the method and the device
WO2017104260A1 (en) * 2015-12-14 2017-06-22 株式会社村田製作所 Filtration device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3618767A (en) * 1968-11-06 1971-11-09 Boehringer Mannheim Gmbh Process and apparatus for continuous liquid sampling
SU911236A1 (en) * 1980-06-12 1982-03-07 Предприятие П/Я Р-6930 Liquid impurity pickup (its versions)
SU1262329A1 (en) * 1985-04-29 1986-10-07 Астраханское Специальное Конструкторско-Технологическое Бюро С Опытным Производством Sampler for continuous extraction of filtrate
FI95839B (en) * 1993-02-19 1995-12-15 Keskuslaboratorio Method and apparatus for sampling solid media
US5516426A (en) * 1995-02-21 1996-05-14 Hull; Harold L. Self-cleaning filter system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3618767A (en) * 1968-11-06 1971-11-09 Boehringer Mannheim Gmbh Process and apparatus for continuous liquid sampling
SU911236A1 (en) * 1980-06-12 1982-03-07 Предприятие П/Я Р-6930 Liquid impurity pickup (its versions)
SU1262329A1 (en) * 1985-04-29 1986-10-07 Астраханское Специальное Конструкторско-Технологическое Бюро С Опытным Производством Sampler for continuous extraction of filtrate
FI95839B (en) * 1993-02-19 1995-12-15 Keskuslaboratorio Method and apparatus for sampling solid media
US5516426A (en) * 1995-02-21 1996-05-14 Hull; Harold L. Self-cleaning filter system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013098487A1 (en) * 2011-12-30 2013-07-04 Kemira Oyj Method and device for taking samples and use of the method and the device
WO2017104260A1 (en) * 2015-12-14 2017-06-22 株式会社村田製作所 Filtration device

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Publication number Publication date
FI20060512A0 (en) 2006-05-24

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