FI98096B - Layout for taking of filtrate samples from stock - Google Patents

Description

98096

APPARATUS FOR SAMPLING A PULP FROM PULP

The invention relates to a device for taking a filtrate sample from a pulp stock containing fibers through the wall of a container containing pulp.

5 In the pulp / pulp industry and in the pulp industry in general, pulp samples are taken to monitor and control the process. In connection with the analysis, the pulp-related parameters and the liquid contained in the pulp, i.e. filtrate-10 related parameters, e.g. pH. The present application deals only with the filtration sampling in general and the filtrate sampling device; the application does not in any way deal with the analysis of the filtrate sample, this can be done in any way known per se from the literature. - In the present application, pulp means any pulp containing pulp and water which is processed in the paper, cellulose or wood fiber industry or in the clothing industry, or in general in any fiber or water industry in general, e.g.

At present, the aim is to take samples from the pulp stock at the desired stages of the process in question.

by means of sampling devices. Contained in pulp stock · 1.1. however, lignocellulosic fibers tend to clog the tubes and screens used. Known equipment for cleaning and washing sampling equipment does not meet the requirements set for them, and current sampling equipment is unsatisfactory when used for on-line monitoring of zinc processes.

···: A device is known from patent publication FI 46193. to take a filtrate sample of 35 mm. a rotating piston with a stem piston forming different • ·. from a special sieve plate. The appliance is rinsed with a special • · · .1 · rinsing nozzle and is cumbersome. Patented%% ♦ ♦ · •·· • · 2 98096 FI 57664 discloses a toiner) device for taking a filtrate sample, which includes e.g. a piston and in addition a poppet valve for closing the channels of the device; the device is complex and cumbersome to use.

It is an object of the present invention to obviate the above drawbacks. In particular, it is an object of the invention to provide a novel device for taking a filtrate sample from a pulp stock containing fibers through the wall 10 of a pulp-containing container so that the device can be cleaned manually or automatically if desired. It is a further object of the invention to provide a device for taking a filtrate sample which is suitable for use in any fiber pulp industry for on-line monitoring of filtrate samples of pulp 15 better and more reliably than previous devices.

For aspects of the invention, reference is made to the claims.

The invention is based on a novel structure of a filtrate sampling device. The device includes a special cylinder space limited by walls. The other end of the cylinder is partially or completely open, and the cylinder can be mounted in a container containing pulp so that the open end of the cylinder space opens into the container containing pulp. The cylinder further includes a piston movably reciprocated in the cylinder space and forming a sample passageway from the open * end of the cylinder to the cylinder space behind the piston. The device further includes an actuator for moving the piston • · · * * 30 to the inner position and to the front position. In the inner position, the piston head is depressed a certain distance inside the open end of the cylinder, forming a special pocket at the cylinder end bounded by the cylinder walls and the piston head; the pocket opens into a container containing pulp, whereby ***. 35 The pulp stock accumulates in the pocket and forms a pad-like fiber accumulation in the filter pocket. In the forward position, the piston head is projected at least substantially to the level of the open end of the cylinder to empty the fiber accumulation into the container. In addition, the cylinder is provided with an outlet passage for discharging the fibrous material accumulated in the pocket and the filtrate sample penetrating behind the piston through the sample passage for analysis.

In a preferred embodiment, the piston is arranged to close the discharge passages in the internal position of the piston. In this case, the surface of the piston on the side of the cylinder space behind it can form, for example, a closure which, when the piston 10 is in the internal position, covers the discharge channel and closes it. Alternatively, the piston or piston rod moving the piston in its direction of movement may also be provided with a separate closing member arranged to close the discharge passages in the inner position of the piston and to open it in the front position of the piston.

In a preferred embodiment, the cylinder and piston form a gap therebetween which forms a sample passage. Alternatively, a separate channel 20 may be formed in the piston and / or cylinder wall to form a sample passage from the front to the rear of the piston.

Furthermore, the cylinder is preferably provided with a flushing channel for supplying and washing the wash water to the sample duct and / or the discharge duct. In this case, the piston is preferably arranged to also close the rinsing channel in the rear position of the piston, so that the rinsing water does not then enter the container containing the pulp stock.

Thanks to the invention, a filtrate sample can be taken from the pulp stock contained in the tank, with the piston in the rear position, which is led through the liquid passage: to the discharge passage and further to the analyzer.

: At the end of sampling, the instrument can be cleaned and rinsed with washing water. The device can be cleaned 35 very easily and effortlessly, eg with automatic control *. The device is easy to use and reliable.

· The device is ideally suited for use in filtration sampling »·» 4 98096 from pulp stock in all process conditions.

The invention will now be described in detail by means of an exemplary embodiment with reference to the accompanying drawing, which schematically shows a side view of a device according to an embodiment of the invention mounted on a process pipe.

The figure shows a side view and a section of a device for taking a filtrate sample from a pulp stock containing fibers 10. The device comprises a cylinder 3 bounded by walls 4. The cylinder forms a cylinder space 6, and the cylinder is mounted in the process vessel 1 through the wall 2 with the open end 5 facing the vessel 1. A piston 7 is movably reciprocated in the cylinder space 6, and the piston forms a fluid passage 8 from the open end of the cylinder to the cylinder space behind the piston. The device further comprises an actuator 9 for moving the piston to the inner position and the forward position. In the inner position, the piston head is depressed a certain distance 20 inside the open end of the cylinder, forming a special pocket 10 bounded by the cylinder walls 4 and the piston head; said pocket opens freely into the container 1. In the forward position, the piston head is projected substantially flush with the open end of the cylinder to empty the pulp stock 25 accumulated in the pocket into the container. In addition, the cylinder ·. is provided with an outlet duct 12 through the sample duct to lead the filtrate penetrating behind the piston * out for analysis, e.g. to an analyzer or ··· · * · collection vessel.

. The purpose of the pocket 10 is to collect the pulp stock in the pocket so that the pulp stock forms a kind of filter through which the sample passage 8 and further to the discharge passage 12 can penetrate only. 35 to a pad-like filter formed by a pulp.

If desired, the piston can be moved to the front position, whereby the fibrous material accumulated in the pocket enters the container 1 and the device is cleaned. At the same time, as the piston moves in the cylinder space, e.g. back and forth when driven by the drive 9, the sample passages 8 are also cleaned. At the same time, a special rinsing agent can be introduced into the cylinder chamber 5 behind the cylinder space via the rinsing channel 13, whereby the remaining fibrous materials remaining in the cylinder or sample passage also leave the vessel 1.

In the embodiment shown, the cylinder 3 and the piston 7 form a gap between the sample passage 8. Further, in the embodiment shown, the cylinder is provided with a special flushing channel 13 for supplying wash water to the sample passage 8 and / or the discharge passage 12 and the 1. The piston is arranged to close the discharge passages in the internal position of the piston; i. a cylinder space 15 surrounding the piston rod 14 forming the outlet passage 12. The walls of the cylinder space 15 surrounding the outlet passage form a seat surface lo 20 against which the rear surface of the piston presses in the inner position of the piston, sealing the outlet passage tightly, i. the filtrate cannot penetrate the outlet duct in the rear position of the piston.

The embodiment is intended to illustrate the invention without limiting it in any way.

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Claims (4)

98096 6 An apparatus for taking a filtrate sample from a pulp containing fibers through the wall (2) of a pulp-containing vessel (1), the apparatus comprising 5 cylinders (3) bounded by the walls (4) and forming a cylinder space (6) opening at one end (5) and being mounted through the wall (2) with the open end (5) facing the container (1); a piston (7) disposed in the cylinder space and forming a sample passage (8) from the open j of the cylinder 10. .from the cylinder space behind the piston; an actuator (9) for moving the piston; and the cylinder is provided with an outlet passage (12) through the sample passage for discharging a sample penetrating behind the piston for analysis; characterized in that the piston (7) can be moved by means of the drive device (9) to a position where the piston head is depressed a certain distance inside the open end (5) of the cylinder (3) forming a fiber closure of the cylinder walls for collecting and forming a pad-like filter (11) in the pocket, and in a forward position with the piston head projecting at least substantially flush with the open end of the cylinder to empty the pad-like filter into the container; and that the cylinder and the • ·: *** piston form a gap between them, which forms a sample channel (8). The device of claim 1,: * · *; characterized in that the piston (7) is arranged • · • j. close the discharge ducts (12) in the piston internal position. ···· Device according to Claim 1 or 2, characterized in that the cylinder (3) is provided with a flushing channel (13) for supplying washing water to the sample channel (8) and / or the discharge channel (12) V * and for washing the sample channel and / or the discharge channel to the container (1). Device according to one of Claims 1 to 3, characterized in that the piston (7) is arranged to close the flushing channel (13). • e • · · • ·· • · 7 98096