GB2192381A - Sampling apparatus for free- flowing materials - Google Patents

Abstract

The apparatus comprises a supporting pillar mounted on which is 4 manipulator 2 controlling sampler 3. Sampler 3 has coaxially-arranged outer and inner spirals. The inner spiral has the form of a lead screw whose upper part is connected with a rotation drive 12 installed on manipulator 2. Secured to manipulator 2 are electromagnetic 13 and safety 14 clutches, the latter being connected to the outer spiral of sampler 3, said outer spiral being provided in the lower part with element 20 contacting with the inner spiral while protective cover 17 is arranged coaxially with sampler 3 The apparatus can be employed for taking single-point samples by immersion in containers of free- flowing solid materials, mutual rotation of the two spirals exposing pockets which fill with material, the pockets then being re-closed by rotation of the spirals; the sampler is withdrawn and the samples discharged. <IMAGE>

Description

SPECIFICATION Sampling apparatus for free-flowing materials The present invention relates to instrument engineering and more particularly it relates to the apparatuses for taking samples of freeflowing materials, predominantly fine-grained and dust-like materials, such as concentrates, from containers and other transport vessels used for storage and transportation of freeflowing materials.

Samples are taken from transport containers by hand-operated and mechanized sampling means that provide for taking samples throughout the depth of the sampled material at least at three points equispaced along the diameter. The mass of a single-point sample depends on the size of the maximum lump of the material. The mass variations of individual single-point samples should not be over 20%.

The sampled material, carried in containers by rail or road becomes considerably compacted by the end of transportation and its properties approach those of solid materials.

However, after insertion of the sampler and loosening the compacted material, its properties are restored and it recovers its free-flowing state.

For taking samples, the sampling apparatus has to be inserted into the material to a considerable depth, viz., up to 1.8 m, overcoming the resistance of compacted layers and enabling the samples to be taken throughout the depth of the material.

Samples are taken by said method by means of sampling apparatuses, either handoperated or mechanized types.

Known in the prior art are apparatuses serving the same purposes, for example covered by the US Patent No. 4179930, IPC GO1N 1/00, which describes a sampler comprising a hollow ported shell with valves moving along it and the end face is fitted with a cone for easier insertion into the material. Said apparatus is designed for taking samples of granulated materials.

A disadvantage of said apparatus lies in the impossibility of its insertion into high-density materials.

Another US Patent No. 4252200, IPC E21B 11/02 discloses an apparatus used for taking samples of mineral deposits. The apparatus is comprised of a tubular element with ports arranged along its axis. Said element accommodates a rod installed rotatably therein with a provision for being pulled out of said element.

The rod has chambers, each corresponding in size and arrangement with one of the ports in the walls- of the tubular element. The rod has chambers, each corresponding in size and arrangement with one of the ports in the walls of the tubular element. One end of the rod is provided with a conical point enabling the rod to be inserted into the mineral deposits by virtue of a force applied to the other end of said rod.

Among the disadvantages of said apparatus a noteworthy one consists in difficulties of taking out samples and of cleaning the apparatus before taking the next sample.

The known accepted application of UK No.

1397468 describes an apparatus for taking samples from a pile of coal, ore or some other fine-ground material comprising a shell, a drilling worm rotating in said shell, and a scraper. The scraper may be made in the form of a pulley from a resilient material which fills the space between two turns of the worm and has sharp edges. The apparatus may also have control switches intended to cut off the motor drive when the worm is filled with the material which raises after the scraper in the course of drilling.

The disadvantages of the apparatus include difficult cleaning and checking the cleanliness of the apparatus after extraction of the sample.

Another known accepted application of Japan No. 56-40776, IPC GO1N 1/14 describes an apparatus for taking grain samples. The apparatus comprises a pointed-end probe consisting of a core and a shell. The probe has spaces for- taking samples due to mutual displacement of core hollow and shell holes. As the container with grain moves to the sampling position, the conveyor stops and a certain amount of grain is drawn into said spaces.

Then the shell shifts relative to the core so that the spaces become hermetically closed.

The probe is shifted to a position above the funnel and the shell is shifted again so that grain flows from the probe spaces into the funnel. Then the conveyor is again set in motion with the aid of a control unit.

This known apparatus is designed for taking samples of grain or another material of a comparatively low density and thickness of layer.

The inventions that are closest to the claimed apparatus are covered by the Inventor's Certificate of the USSR No. 703757, Cl.

GO1N 1/20 of Sept. 29, 1977 for "Installation for taking samples of free-flowing material from truck body" comprising a supporting pillar situated above the truck loading ramp, said pillar carrying samplers, a conveyor for delivering samples into a sample collector and a laboratory, manipulators for inserting the samplers into the truck body, said samplers consisting of drives, carriages, movable and immovable guides, selector switches controlling the working and idle motions of the samplers, and carriage operating units and by the Inventor's Certificate No. 430306 of the USSR Cl.

GO1N 1/20 of October 24, 1972 for "Sampling Apparatus for Free-Fiowing Materials" comprising outer and inner flat spirals coaxially installed via a turn restrictor and a transverse slot, said spirals mounted with a provision for being turned relative to the axis through half a pitch with the aid of an operating handle.

The disadvantages of hereinabove mentioned apparatuses include no assurance in taking the sample throughout the depth of the material layer in the first mentioned apparatus and the impossibility of manual insertion of the sample through a considerable depth (over 250 mm) in the other apparatus.

An object of the present invention resides in elimination of said disadvantages of hereinabove-mentioned apparatuses.

The primary object of the invention consists in providing an apparatus for taking single-point samples -of free-flowing materials, the design of the sampler providing for extracting the required volume of samples taken uniformly through the depth and ruling out losses of the material.

This object is accomplished by the provision of a sampling apparatus for free-flowing materials comprising a supporting pillar carrying a sampler manipulator which has outer and inner spirals installed coaxially via a turn restrictor and a transverse slot, a rotation drive of said spirals, their relative position transmitters, electromegnetic and safety clutches installed on a barrel secured on- the manipulator, the latter comprising guide rods with a protective cover in which, according to the invention, the inner spiral has the form of a lead screw whose upper part is connected with a drive installed on the manipulator, secured to which are said magnetic and safety clutches, the latter being connected with the outer spiral of the sampler, the lower part of said spiral having an element contacting the inner spiral, and the lower cover is arranged coaxially with the sampler.

One embodiment of the invention has the spaces of the outer and inner spirals in the form of diametrically arranged pockets whose width is equal to half the pitch of the lead screw and which are set at identical angles to the sampler axis. It is expedient that the barrel space be provided with spring-loaded cams, stops and spiral relative position transmitters arranged in parallel planes, and that the spring-loaded cams be connected with the outer spiral while the stops, with the inner spiral of the sampler.

The prdtective cover may be installed on the rods with a provision for reciprocation with relation to the sampler and be provided with flanges and a cleaner.

Such a design provides for taking samples of the material kept in a transport container, uniformly throughout its depth, for cleaning the sampler, and rules out the raising of dust.

The essence of the claimed invention consists in that the apparatus utilizing said invention solves the problem of taking samples from transport containers deeper than 1.2 m which deliver the sampled material to the Customer. In the course of transporation by road or rail the vibrations compact the material to its initial density. The claimed invention meets the problems of inserting the sampler into the material, loosening said material in the sampling zone, taking the samples uniformly throughout the depth and carrying them to the sample collector. Installation of the sampler on the manipulator provided with a programming unit provides for automating the selection of sampling points, stepping up labour productivity and improving the working conditions of the servicing personnel.

The shaping of the inner spiral in the form of a lead screw whose upper part is connected to a drive while the lower part is attached to a drilling bit, makes for combining the ability of the screw spaces to collect the material through the insertion depth with its stiffness both axial and in twisting.

Reliability of sampler operation is improved by tandem connection of the manipulator with the electromagnetic and safety couplings and with the outer spiral, each turning relative to the lead screw so that the particles of the sampled material are constantly present in the gaps between the outer surface of the lead screw and the inner surface of the outer spiral; being of abrasive nature, said particles oppose the relative turning of said parts. To overcome said forces of friction, the electromagnetic clutch builds up a braking force and the safety clutch creates a vibration force, said forces being directed against the force built up by the sampler rotation drive.

The lower part of the element contacting the inner spiral and installed on the outer spiral may have the form of a conical half-ring, said ring overlapping the space of the lead screw at the moment of sampler closing.

When samples are taken from a moist material (e.g. -with moisture content about 10%), the particles of said material stick to the surface of the lead screw thus calling for the use of additional forces for cleaning said surfaces which, according to the invention, have the form of a cleaner, mounted on the cover reciprocating relative to the sampler.

The standard of cleaning is higher in the case of a surface having the least number of surface irregularities, sharp angles and chinks, Such a surface can be made by machining the outer and inner spirals with, say, a circular milling cutter. The pockets of the spiral are arranged along the line of the lead screw. This line corresponds to a mutually diametral position of the pockets whose width is equal to half the pitch of the screw and to the angle determined by the helix angle of the outer spiral.

The process of filling the spaces of the lead screw or pockets cannot be monitored by any methods since in the course of sampling said spaces are out of sight inside the material.

Therefore, the disclosed invention suggests that complete opening and closing of said spaces be controlled by spring-loaded cams, stops and spiral relative position transmitters installed in the sampler barrel. Introduction of signals of said transmitters into the general control circuit makes for all-round automation of taking and discharging samples, rules out emergency spilling of samples when they are being transferred from the container into the sample collector.

The flanges on the protective cover permit its reliable posifioning above the sampling zone in the container and above the sample collector, ruling out formation of dust and losses of material in the course of sampling.

The claimed apparatus ensures reliable and highly automated sampling of the material in the transport containers, raises output and improves the working conditions at the same time obviating the losses of costly materials.

Now the invention will be described in detail with reference to the accompanying drawings, in which.

Figure 1 shows a general view of the sampling apparatus for free-flowing materials; Figure 2 is a section through Il-Il iri Fig. 1; Figure 3 is one construction of the sampler; Figures 4, 5 are sections through IV-IV and V-V, respectively, in Fig. 2; Figures 6, 7 are versions of the sampler with diametrically-arranged pockets.

The claimed sampling apparatus for freeflowing materials is designed for taking singlepoint samples from transport containers and carrying said samples into a sample collector.

The apparatus (Fig. 1) comprises supporting pillar 1 carrying manipulator 2 of sampler 3 with rotation and feed mechanisms 4 and 5, respectively. Shown sideways of the apparatus is transport container 6 with concentrate material and sample collector 7. Sampler 3 (Fig. 2) has outer 10 and inner 11 spirals coaxially installed via turn restrictor 8 and transverse slot 9, the inner spiral 11 made in the form of a lead screw, spiral rotation drive 12, electromagnetic and safety clutches 13 and 14, accommodated in barrel 15 secured on manipulator 2, the latter comprising guide rods 16 with protective cover 17 installed coaxially with sampler 3 and provided with cleaner 18 and flanges 19. Cover 17 has a provision for reciprocating relative to sampler 3.

Secured in the lower part of outer spiral 10 (Fig. 3) is element 20 in the form of a conical half-ring contacting with inner spiral 11 secured to which is drilling bit 21. At the top, rods 16 (Fig. 1) are interconnected by tie piece 22-and are free to reciprocate in bushings 23.

Figs. 4 and 5 illustrate the parallel-plane installation in barrel 15 of transmitters 24 indicating the relative positions of outer 10 and inner 11 spirals, movable cams 25 with springs 26 and stops 27.

The constructions of sampler 3 shown in Figs. 6 and.7 comprise outer 10 and inner 11 spirals made in the form of diametrically-arranged pockets 28 whose width is A 2 where A= spiral pitch, and which are set at identical angles a to the axis of sampler 3.

The claimed apparatus functions as follows.

A programming unit of any conventional design (not shown in the drawing) is switched on and manipulator 2 turned on supporting pillar 1 (Fig. 1) by rotation mechanism 4 positions sampler 3 above the required point of transport container 6 set by a conveying mechanism e.g. a battery-powered truck, on the same axis with sampler 3. Then commands are given for switching on rotation drive 12 of outer 10 (Fig. 2) and inner 11 spirals 11 whose pockets 28 are closed, and feed mechanism 5 for the downward motion.

Sampler 3 penetrates the sampled material for the preset depth and stops.

Rotation drive 12 of sampler 3 is reversed and electro-magnetic clutch 13 is switched on to restrain the rotation of outer spiral 10 with relation to inner spiral 11. Electromagnetic clutch 13 continues its operation until one of stops 27, turning through 1800 jointly with the shaft of inner spiral 11, presses its movable cam 25 secured on outer spiral 10 and until said movable cam 25 rotating together with sampler 3 in barrel 15 comes in contact with one of transmitters 24. Simultaneously with cutting off electromagnetic clutch 13, the control circuit of manipulator 12 recieves a signal indicating complete opening of intake pockets 28 of sampler 3 and, correspondingly, their filling with sampled material, i.e. concentrate.

The repeated reversing of drive 12 and engagement of electromagnetic clutch 13 till the operation of the second position transmitter 24 interacting with can 25 and stop 27 will send a signal for closing of pickets 28, switching off of electromagnetic clutch 13 and permission for pulling sampler 3 with the sample from container 6.

Sampler 3 is lifted above container 6 by feed mechanism 5, is turned found supporting pillar 1 by turning mechanism 4 and comes to a stop above sample collector 7. Then the sampler goes down into sample collector 7 where pockets 28 are opened and closed 2 or 3 times to ensure their thorough emptying.

The open sampler 3 rotated continuously by drive 12 is lifted from sample collector 7, passes through cleaner 18 located in protective cover 17 and gets cleaned from the remaining material stuck to the sampler and failing to be discharged into sample collector 7, this cleaning being ensured by centrifugal forces and vibrations arising in the sampler on operation of safety clutch 14. Then sampler 3 is positioned above the new point of container 6 and the sampling cycle is repeated over again until the required number of single-point samples have been taken and transferred into sample collector 7. In the course of sampler operation, protective cover 17 is successively fixed by flange 19 on the sampled material and in sample collector 7, closes the sampler insertion zones, reducing the amount of raised dust and simultaneously cleaning the sampler surfaces.

The fixed 1800 turn of outer 10 açnd inner 11 spirals relative to each other and their further joint rotation are enabled due to the movement in transverse slot 9 of restrictor 8 which, turning, comes to bear against the wall of the slot in the outer spiral.

Secured in the lower part of outer spiral 10 is element 20 which seals off hermetically the spaces of inner spiral 11 underneath and makes it possible to secure drilling bit 21 on said spiral.

The claimed apparatus enables the samples of materials to be taken from- the transport containers without taking them apart thus facilitating control of the chemical compositon and properties of said materials and settling of mutual accounts between the Supplier and Customer.

Claims (6)

1. Apparatus for sampling free-flowing materials, comprising a support carrying a manipulator, the manipulator controlling a sampler having inner and outer coaxially mounted spiral members and means for limiting relative rotation of the spiral members, the inner spiral member being a screw member carrying a lower-element for cooperation with outer spiral member the manipulator including means for- rotating the spiral members with respect to the månipulator and for rotating one spiral member relative to the other spiral member, means for sensing the positions of the spiral members with respect to one another, and guide rods carrying a protective cover surrounding the sampler.

2. A sampling apparatus for free-flowing materials comprising a supporting pillar carrying a manipulator controlling a sampler which has an outer and an inner spirals installed coaxially via a turn restrictor and a transverse slot, the rotation drive of said spirals and the transmitters of their relative positions as well as electromagnetic and safety clutches installed in a barrel which is secured on the manipulator, the latter comprising guide rods with a protective cover; the inner spiral has the form of a lead screw whose upper part is connected to the drive mounted on the manipulator secured to which are said electromagnetic and safety clutches, the latter being connected with the outer spiral of the sampler, said spiral having in its lower part an element contacting with the inner spiral, and the protective cover is installed coaxially with the sampler.

3. The apparatus as claimed in Claim 2 wherein the spaces of the outer and inner sprials have the form of diametrically-arranged pockets whose width is equal to half the pitch of the lead screw and which are set at identical angles to the sampler axis.

4. The apparatus as claimed in Claim 2 or 3 wherein the space of the barrel accommodates spring-loaded cams arranged in parallel planes, stops and transmitters indicating the relative positions of spirals, the spring-loaded cams being connected with the outer spiral and the stops, with the inner spiral of the sampler.

5. The apparatus as claimed in Claim 2, 3 or 4 wherein the protective cover is installed on the rods with a provision for reciprocating motion relative to the sampler and has flanges and a cleaner.

6. The apparatus as claimed in any one of the above Claims, explained in the description and illustrated in the drawings.