RU68236U1 - DEVICE FOR BIOLOGICAL TESTS OF FILLING MATERIALS AND COATINGS - Google Patents

Abstract

The device, rotating around the vertical axis (9) when the flow direction is changed due to the vane mechanism, was created on the basis of a similar device for exhibiting fouling plates (4) by replacing plates of inert materials used for research purposes with test materials or coatings. It allows you to increase the speed and accuracy of tests of fouling of materials and coatings, as well as to optimize tests through the use of special design gratings (1), which differentially affect fouling, reinforcing it. Improving the reliability of the device is achieved by fixing the vertical axis (9) on a rigid support (16). 1 s and 6 n.a.s. f-ly. Fig. 6. Tab. four.

Description

The proposed utility model relates to the field of environmental protection, and more specifically to devices for studying fouling communities, which include both microorganisms (bacteria, unicellular algae, unicellular animals), and macroorganisms (sponges, hydroid polyps, barnacles, mollusks, bryozoans, echinoderms, ascidia and others). It can be used in the field of technical hydrobiology in flowing and still waters, in seas and inland freshwater bodies (rivers, lakes, canals, ponds, reservoirs) for research purposes, as well as for determining the fouling (and biodeterioration) of materials used in the aquatic environment , in biological tests of the effectiveness of protective anti-fouling coatings. It can also be useful in biomonitoring the quality of water (natural, purified, prepared for drinking) due to the high rate of fouling processes and the presence of indicator species in it.

Fouling communities develop on natural and artificial substrates in the aquatic environment, including on the bottoms of ships, in pipes supplying water to enterprises to provide technological cycles, on deep-water cables, on the underwater part of oil and gas platforms operated on the shelf, on fishing nets , on plants for growing aquatic organisms in mariculture, etc. The fouling of materials leads to the loss of a number of important operational qualities by them, to the development of bio-corrosion and biodeterioration.

There is not a completely resolved practical problem: how to efficiently and quickly assess the fouling of materials used in the aquatic environment, and the effectiveness of anti-fouling coatings used to protect technical objects from biological fouling and biodeterioration?

In the proposed utility model, to solve this problem, an approach is used based on the use of devices for exhibiting fouling plates, which allow various materials to be placed in the reservoir at a given depth and time in the form of plates and held there (expose) with respect to the conditions of the reservoir: settlement forms organisms fouling, flow, light and others. Fouling plates, which can simulate surface areas of technical objects operated in or in contact with an aqueous medium, are usually made of inert materials for research purposes: glass, plastic, tile, metal, etc. These materials may be dyed, for example with anti-fouling paint.

Known devices [1] - [4] for exhibiting fouling plates in flowing waters, similar in technical solution to the proposed utility model. In principle, any materials, including anti-fouling coatings, can act as fouling plates in them. Therefore, they can be used for biological testing of materials and coatings used in the aquatic environment.

Known devices [1] - [4] for exhibiting fouling plates include a support element mounted on a vertical rod and holders on which cassettes are mounted with fouling plates placed on them.

A device [1] is known in which a horizontal support element is freely mounted on a vertical rod, on which a cassette with fouling plates oriented parallel or perpendicular to the flow is rigidly fixed, and the horizontal position of the support element is achieved by the vertical position

rod and four braces in the form of chains, one end of which is fixed to the supporting element, and the other to the bottom of the reservoir.

In the known device [1], the features common with the proposed utility model are: a vertical rod on which the support element is freely mounted, a cassette for accommodating fouling plates, mounted on the support element, additionally performing the function of a holder.

However, the known device [1] has a low information content, which is due to the possibility of simultaneously exhibiting on it up to 20 fouling plates (slides). In addition, the use of the device [1] is limited by streams and narrow rivers, which is associated with the peculiarities of fastening a vertical rod in water. In addition to this, it can be used to study only fouling in the bottom layer, which significantly limits the possibility of its use. The device [1] cannot be adequately used for testing the fouling of plates in a flow that is variable in direction, since it does not allow the plates to be exposed at a constant angle to the direction of the flow, which changes its direction. At the same time, the abundance of fouling (density and biomass of fouling) substantially depends on the direction and speed of flow around the plates.

A device [2] is known for exhibiting fouling plates in fluid, in particular in marine, waters. It includes a vertical rod mounted on the bottom of the reservoir, on which a horizontal support element is freely mounted, which acts as a single fouling plate.

In the known device [2], the features common with the proposed utility model are: a vertical rod on which the support element is freely mounted, it is also a vertical keel and fouling plate.

The known device [2], in contrast to the device [1], provides adequate exposure of the plates at a constant angle to the direction of flow, variable in

direction. Therefore, it can be used in reservoirs with a variable direction of flow, including in the seas, and is used for testing, for example, antifouling coatings.

However, the known device [2] has low information content, which is due to the possibility of simultaneously exhibiting on it only one fouling plate. In addition, the use of the device [2] is limited to the study of fouling near the bottom of the reservoir, due to the fastening of the device to the bottom using a rod, which significantly limits the possibility of its use. An additional disadvantage is the possibility of exhibiting fouling plate on the device only in a vertical plane, since it simultaneously serves as a vertical keel.

A device [3] is known for exhibiting fouling plates in fluid, in particular in marine, waters. It includes a support plate mounted on a vertical rod in the form of a disk with radial holders made in the form of brackets on which cassettes are mounted to accommodate fouling plates. The device is suspended in water on a carrier cable. To increase the accuracy of testing the fouling of the plates under flow conditions, the support disk is mounted freely on the vertical rod to ensure its rotation, the cassettes are mounted on holders at equal angles to the vertical plane, while the device is equipped with clamps to change the angle of inclination of the cassettes and hold them in a given position.

In the known device [3], the features that are common with the proposed utility model are: a vertical rod mounted on a carrier cable, used to install the device in a pond, mounted with the possibility of rotation around a vertical rod supporting element, on which are mounted cassettes with fouling plates.

The known device [3] is devoid of the main disadvantages of devices [1] and [2]: it has high information content, allows you to simultaneously exhibit 10 times

a larger number of plates than the device [1] and 100 more than the device [2], adequate when used in waters with a variable direction of flow, provides exposure of fouling plates at different depths (at the surface, in the water column and at the bottom).

However, it is not without flaws. On the known device [3] the abundance of fouling (in density and biomass) depends on the position of the fouling plates on the device. Experimental studies have shown that the closer the plates are placed to the vertical rod, the less abundance of fouling (in terms of abundance and biomass) is achieved. Therefore, using the device [3], the accuracy of determining the abundance of fouling has been reduced, and, therefore, adequate tests, for example, anti-fouling coatings or water quality, are not provided.

The known device [4] for exhibiting fouling plates is the closest in technical essence to the proposed utility model. It contains a rotatable support element in the form of a rectangular-shaped frame with positive buoyancy, equipped with a vertical keel rigidly attached to it and cassettes with fouling plates, rotating around a vertical rod mounted on a carrier cable, which serves to install the device in a pond. In addition, the frame is equipped with guy wires connected to the supporting cable by means of a washer, which ensures the turn of the guy wires relative to the cable.

The functioning of the device is ensured by the effect of the weather vane due to the fact that when the direction of flow is changed on the keel, a moment of forces is created that unrolls the support element with cassettes and fouling plates around a vertical rod mounted on the support element until the vertical keel is set in a position parallel to the direction currents.

The known device [4] provides uniformity of fouling of the plates located in different parts of the device, and the achievement of statistically uniform results of biological tests, for example, the degree of fouling of the same materials.

In the known device [4], the features common with the proposed utility model are: a rotatable support element in the form of a rectangular-shaped frame with positive buoyancy, equipped with a vertical keel rigidly attached to it and cassettes with fouling plates rotating around a vertical rod mounted on a carrier a cable used to install the device in a pond.

Despite the significant advantages of the known device [4] over devices [1] - [3], it is not without drawbacks. The device [4] does not provide a sufficiently high speed of biological tests under flow conditions, since it does not allow to obtain the maximum amount of fouling on the fouling plates, which is especially important when testing antifouling coatings and other materials for fouling, as well as when assessing water quality. Additionally, the device [4] does not allow to optimize biological tests by creating conditions for obtaining a predicted abundance of fouling.

The objectives of creating the proposed utility model are: increasing the speed and accuracy of biological tests of fouling of materials and coatings under flow conditions, optimizing tests, and improving the reliability of the device.

An increase in the speed of biological tests of fouling of materials and coatings under flow conditions is achieved by the fact that, in the known device, containing a vertical rod mounted on a carrier cable, used to hang the device in a pond, mounted for rotation around

vertical rod supporting element in the form of a rectangular frame with positive buoyancy, equipped with a vertical keel and cassettes with fouling plates rigidly attached to it, in accordance with the proposed utility model, gratings are placed on the supporting element in front of cassettes with fouling plates and vertical keel moreover, the lattices are placed at a distance from the fouling plates, not exceeding the double smallest cross-sectional size of the lattice cells.

An increase in the accuracy of biological testing of fouling of materials and coatings under flow conditions is achieved by the fact that, in the known device containing a vertical rod mounted on a carrier cable, used to suspend the device in a pond, the support element is mounted with the possibility of rotation around the vertical rod in the form of a rectangular frame positive buoyancy forms equipped with a vertical keel rigidly attached to it and cassettes with fouling plates, in accordance with the intended utility model, the sizes of the cells of the gratings installed in front of the cassettes with fouling plates and keel, are selected to exceed the dimensions of the side of the fouling plates directed to the cells, and the fouling plates are placed in a plane passing through the middle of the cells.

The optimization of biological tests of fouling of materials and coatings under flow conditions is achieved by the fact that, in accordance with the proposed utility model, in a known device containing a vertical rod mounted on a carrier cable, used to suspend the device in a pond, mounted to rotate around a vertical rod supporting element in the form of a rectangular-shaped frame with positive buoyancy, equipped with a vertical keel rigidly attached to it and cassettes with plates about plants

in accordance with the proposed utility model, such lattices and fouling organisms are used that give a predicted abundance of fouling.

Additionally, the proposed device differs from the known device [4], the closest in technical essence to the proposed device, in that, in accordance with the proposed utility model, the vertical rod around which the frame rotates can be mounted on a rigid base, for example, on the bottom stand .

The essence of the proposed utility model is illustrated by figures 1-6. Figure 1, placed in the text of the description in example 3, shows turbulent pulsations at different distances from the walls of the laminarizing lattice. Figure 2 shows a General view of the proposed device; figure 3 - turbulent lattice; figure 4 - laminarizing lattice; figure 5 - suspension system of the device in water; figure 6 - node rotation of the device when it is placed on the bottom stand.

The proposed device is devoid of these drawbacks of the device [4], which is achieved through the use of gratings 1 rigidly fixed on the support element 2 and placed on the flow side (free flow) in front of the cassettes 3 with fouling plates 4 mounted on the support element 2 (FIG. .2).

Using in the proposed device gratings 1 provides a change in the characteristics of the incoming flow. This is achieved through the use of gratings 1, enhancing the natural turbulent flow pulsations (turbulent gratings), or, on the contrary, weakening them (laminarizing gratings).

The turbulizing lattice (Fig. 3) includes a system of rods 5 parallel to each other, for example, of a cylindrical shape, rigidly fixed to the slats forming a rectangular frame. The rods 5 are located in a vertical plane, and the thickness of the rods and the distance between adjacent rods are selected so as to provide the desired change in the flow characteristics at a given

flow rates, for example, maximum amplification of turbulent flow pulsations. The rods 5 of the turbulizing gratings together with the strips 6 form rectangular cells 7.

Laminarizing lattice (figure 4) includes rigidly interconnected mutually parallel horizontal and vertical strips 6, together forming a system of cells 7 having the shape of prisms, for example with a square section, as in figure 4. To ensure the required smoothing of turbulent flow pulsations, in accordance with [5], the length L of the cells in the flow direction should exceed the linear dimensions "a" of the cells in their cross section, for example, to maximize smoothing of turbulent flow pulsations by 10 or more times.

The use of turbulizing or laminarizing gratings 1 during biological tests in flow conditions with the participation of different dominant species of fouling allows increasing the speed of testing and, accordingly, reducing their time by increasing the amount of fouling. Thus, at the same time, when using the proposed device, you can conduct a larger number of tests, such as anti-fouling coatings, than when using the known device [4].

The gratings 1 are placed at a distance from the fouling plates 4, not exceeding the double smallest cross-sectional size of the cells 7. This is due to the significant circumstance that at distances greater than those indicated, the flow practically restores its characteristics [5] and ceases to be a factor that positively affects the speed of testing. Thus, the optimum is the distance of the gratings 1 from the fouling plates 4, equal to one of the smallest cell sizes of the gratings.

To increase the accuracy of biological tests, the cell sizes of the gratings are chosen so that they exceed the size of the fouling plates

4. Otherwise, the change in the freewheel characteristics in different transect sections (sections of the plates on which the abundance of fouling is determined) will not be the same [5], which will lead to different fouling of the plates due to the dependence of the fouling on the speed and flow turbulence [6] . Thus, this circumstance will lead to a decrease in the accuracy of quantitative estimates of the amount of fouling and, therefore, to a decrease in the accuracy of biological tests.

Since normal to the walls of the laminarizing gratings and rods 5 of the turbulizing gratings inside the cells, the variation in the flow characteristics increases according to [5], in the proposed device, in accordance with the formula of the utility model, fouling plates 4 are placed in a plane passing through the middle of the cells along the flow in horizontal or vertical plane.

As it was established earlier [7], there are three groups of fouling species with respect to flow turbulence. Most of the studied species achieve large abundance in turbulent conditions, increased compared to natural. A small number of species achieve greater abundance with smooth turbulent flow pulsations or with natural turbulence. Thus, for different types of fouling, there are their own optimal conditions for flow turbulence for sedimentation, replenishment and growth.

The effect of optimization of biological tests is achieved due to the fact that in solving various scientific and practical problems fouling is required, which reaches different abundance, which can be obtained by using the differential response of fouling to flow characteristics, which are predictably set using gratings with the required characteristics. Therefore, in order to optimize biological tests, in accordance with the formula of a utility model, such lattices are used in the proposed device, and tests

carried out with such dominant species that give a predicted, for example, maximum, abundance of fouling.

In order to improve the reliability of the device, in accordance with the formula of the proposed utility model, the vertical rod 9, around which the frame 2 rotates, can be mounted on a rigid base 16, for example on the bottom stand using a nut 17 (Fig.7). The increase in the reliability of the device is due to the fact that in this case the best conditions are provided for the rotation of the frame 2 and the cassettes 3 rigidly connected to it with fouling plates 4 around the vertical rod 9. Additionally, when the device is deepened into the bottom layer, the wave and wind loads acting on it are reduced. When placing the device on the bottom stand in the proposed utility model, a needle bearing (Fig. 7) is used, which reduces the friction force when the device rotates around a vertical rod 9 when the direction of flow changes.

The proposed device, in accordance with the claims, provides a test of fouling of materials and coatings due to the fact that the fouling plate is made of test materials and coatings. From practice and theory it is known [6] that the smaller the area of the plates, the higher the abundance of fouling on them. Therefore, on the proposed device provides more stringent conditions for testing materials and coatings than on specific products made from or coated with them, since the dimensions of the products are much larger than fouling plates, the dimensions of which usually do not exceed 10-20 cm.

When testing coatings, such as anti-fouling coatings, using the proposed device, in accordance with the claims, they are preliminarily applied to fouling plates made of non-corrosive materials or coated with anti-corrosion compounds. This is necessary in order to experience pure fouling of coatings, such as anti-fouling

coatings, without affecting their fouling of substances released from the plate material, for example, anti-fouling coatings, metal, when it is corrosion in water.

The work of the proposed device is as follows. Under flow conditions, the force of the water pressure acting on the vertical keel 8 deploys the device around the vertical rod 9 until the vertical keel 8 occupies a position parallel to the flow. This will ensure that the position of the gratings 1, in which the plane of the holes of the cells 7 facing the incoming flow, are oriented perpendicular to the direction of flow. It is in this case, as described above, in accordance with the proposed utility model, the highest speed and accuracy of biological testing is achieved. At the same time, optimization of biological tests is additionally ensured, which is associated with a differential improvement in the conditions for settling and growth of specific types of fouling under the influence of changes in flow characteristics by gratings 1 of a certain type (or in their absence).

The reliability of the operation of the proposed device when it is suspended in the water column on a vertical cable 10 (Fig. 5) is ensured due to the fact that the weight of the device is compensated by the lifting force of the floats 11, which is limited by guy wires 12 connected to the support plate 2 and the lower rotation unit. Additionally, reliable fixation of the proposed device in the reservoir at a given depth is achieved by using the load 13, which serves as a counterweight to the buoy 14, and also due to the anchor 15 located at the bottom. To ensure positive buoyancy of the proposed device, the support plate can be hollow and filled, for example, with air or light gas.

The proposed device allows to expose the fouling plate 4 in a horizontal or vertical plane, for example parallel to the flow. Fouling plates 4 can be displayed in a pond using the proposed

devices, in accordance with the objectives of the study, also at an angle to a horizontal or vertical plane, for example perpendicular to the direction of the flow, which can be done by changing the orientation of the cassettes 3 with fouling plates 4 or the support plate 2 relative to the horizon or direction of flow. However, in this case, the test speed decreases, since the maximum abundance of fouling develops when the plane of the fouling plates is oriented parallel to the incident flow [6], [8].

The proposed device allows you to display fouling plate 4 in any reservoirs at different depths, for example in the coastal zone of the seas, which is achieved using a suspension system with two rotation nodes (figure 5). The need for a second (additional) rotation unit is due to the fact that, as practice has shown, in the absence of the device as a result of repeated turns of the device around the vertical rod 9 under conditions of a flow that is variable in direction, the vertical cable 10 is twisted, which ultimately leads to stopping the device and disrupting its functioning.

When installing the proposed device on the bottom stand, in the bottom layer of water, in accordance with the objectives of the study, there is no need for two nodes of rotation, since the support plate 2 freely rotates around a vertical rod 9, rigidly mounted on the stand (Fig.6). In this case, the design of the rotation unit, which is equipped with a needle bearing that reduces friction of rotation, provides optimal conditions for the functioning of the proposed device.

The assembly of the device is as follows. A vertical keel 8, gratings 1 and cassettes 3 with fouling plates 4, and also a rotation unit including a vertical rod 9 are mounted on the supporting plate 2, and the floats 12 are attracted to the frame 2 by clamps or a rope. Vertical keel 8 is attached to the base plate 2 corners of metal or plastic. Cartridges 3 are rigidly attached to the support element

bolts or otherwise. The floats 11 and guy wires 12 are selected so long as to provide a horizontal (or other predetermined) position of the support plate 2 relative to the horizon. The load 13 must be of such a weight as to balance the buoy 14. The length of the anchor cable 10 is chosen sufficient to keep the buoy 14 afloat even at maximum fluctuations in water level, for example, when the tides in the coastal zone of the seas.

All elements of the proposed device are made of non-corrosive materials in water that do not emit substances that impede the development of fouling, which creates optimal conditions for the functioning of the device and the development of fouling on it.

The technical and economic efficiency of the proposed device in relation to the base object characterizing the world level of technology and operating in the territory of the Russian Federation, for which it was adopted [9], consists in increasing the speed and accuracy of biological tests, as well as in their optimization.

A well-known device for exhibiting fouling plates [9], which is widely used at present in the practice of fouling studies, in which to increase the speed of biological tests using a two-row arrangement of cassettes with fouling plates, the cassettes mounted on a steel frame that is suspended in the water column with a buoy and anchor. The known device [9] does not provide for the possibility of rotation of the device when the direction of flow changes, which does not allow to obtain comparable and statistically homogeneous results of biological tests and reduces both their accuracy and speed. The device [9] also does not contain the possibility of increasing or predictably controlling the abundance of fouling, for example, due to gratings that affect the flow characteristics, as is the case in the proposed useful

models, which does not allow to increase the speed and accuracy of biological tests, as well as to optimize it in relation to specific research tasks.

The technical and economic efficiency of the proposed device in comparison with the prototype and the base object is illustrated by examples.

Example 1. Comparison of the effectiveness of the proposed device with the base object.

In the summer of 2004 (from August 29 to September 17) in the Chupa Bay of the Kandalaksha Bay of the White Sea, biological tests of devices for exhibiting fouling plates of the proposed device and the base object were performed. On the proposed device placed 3 cassettes, each of which had 7 plates, on the base object - 2 cassettes (3-4 plates in each). At the base site, half of the cassettes were oriented primarily in the direction of the tidal current, half - of the tidal current, i.e. the plates were exposed at different angles to the direction of flow at high tide (series 1-3) and at low tide (series 4-6), since this device did not rotate. In total, 3 devices were used that correspond to the base object. On the proposed device, the plates were exposed along the stream, since the principle of the weather vane was implemented in this device. Viniproz wafers (26 × 76 mm) were located at a depth of 1 m. At the end of the experiments, the wafers were transported to the laboratory, fixed with formalin to stop the development of fouling, and then the number of micro-fouling (diatoms) was determined on each wafer in 30 fields of view of the Biolam microscope "at 600x magnification with a water-immersion lens. Based on the primary data thus obtained, the statistical indicators of fouling were calculated: the arithmetic mean and its error. The uniformity of fouling on the proposed device and the base object was judged on the basis of the Fisher criterion F during analysis of variance. As is known, for F> F _{0.01, the} statistical population is not homogeneous and does not actually constitute a single

sampling. Such aggregates (in our case, a series of experiments) on this basis cannot be compared with other series of experiments and can be considered as artifacts.

It was found that during the testing period, the dominant species in plankton and on the plates were diatoms, not counting bacteria. The results of a statistical analysis of the obtained material showed that in the case of the base object in 4 out of 6 series of experiments there is heterogeneity according to the Fisher criterion (F> F _0.01 ). This means that on different plates located in the same cassette, the plates grow in different ways, although it would seem that they are in the same exposure conditions. As a result, in 67% of cases, when comparing different series by the abundance (number) of fouling, it turns out that they reliably differ from each other, i.e. fouling on different cartridges is different.

At the same time, the results of a statistical analysis of the obtained material showed that the fouling on the proposed device was very uniform both within the cassettes and when comparing the abundance of diatoms on the cassettes. Thus, on all 14 plates grouped into two cassettes, uniform fouling was observed, i.e. the plates almost fouled in the same way and formed one aggregate uniform in abundance.

Comparison of diatom fouling shows that the proposed device exceeds the base object by 3 times (100%: 2/6) in speed of testing, and also by 3 times (100% :( 100-67)% in accuracy).

Table 1.
Comparative data of the diatom fouling of the plates on the proposed device and the device corresponding to the base object (H is the percentage of pairs of series of experiments that reliably differ in the abundance of fouling by Student's criterion).

Experiment Series Number The average number of fouling, cells / cm ² N% F F _0.01 Base object one 112570 ± 9310 3.2 4.0 2 123930 ± 8040 8.5 4.9 3 153420 ± 6540 8.5 4.9 four 82 620 ± 8670 6.7 4.0 5 64990 ± 5510 10,4 4.0 6 98 140 ± 9120 3,5 4.9 In total 105950 ± 7650 67 6.3 4.6 Proposed device one 220600 ± 8600 1,1 2.9 2 251000 ± 11200 0.2 6.9 In total 0 0.2 6.9

Similar experiments were carried out in the same area during the period of mass sedimentation of larvae of the bivalve mussel mussel Mytilus edulis on the device adopted as the base object and on the proposed device. Mollusks were taken into account on the entire surface of vertically oriented plates exposed at a depth of 1.5 m in August 2006. The plates were made of plexiglass and sanded to better fix mollusks on them. At the base facility, 6 cassettes were placed (5 plates in each): 3 were oriented primarily towards the tide, the rest toward the low tide. On the proposed device, the plates were exposed parallel to the flow. Table 2 summarizes the data on the fouling of the plates with mussels.

Table 2.
Comparative data on the fouling of plates with mussels on the proposed device and the device corresponding to the base object (H is the percentage of pairs of series of experiments that reliably differ in the abundance of fouling by Student's criterion). Device N% F F _0.01 Base object 67 5.7 3.9 Proposed device 0 0.01 4052

Thus, in this case, the proposed device exceeded the base object in speed and accuracy of testing 3 times.

Example 2. Comparison of the proposed device with the prototype. The increase in the speed of biological tests using the proposed device.

In the summer of 2005 (from July 15 to September 12) in the Chupa Bay of the Kandalaksha Bay of the White Sea, biological tests of devices for exhibiting fouling plates — the prototype and the proposed device — were carried out. Plates 5 × 10 cm in size, made of plexiglass and sanded, were exposed on these devices in a horizontal position on the bottom stand, at a distance of about 1 m from the bottom. The total number of mass species on the upper and lower sides of the plates collected in cassettes was taken into account. Each cassette had 7 plates placed one above the other.

The significance of differences in average abundances was determined using Student's criterion.

During the test period, the species of bivalves (mussels, hiatel, and heteronomy) and polychaetes of the family Spirorbidae (Spirorbis sp. And Circeis armoricana) were widespread. It was these species that gave the largest numbers

Table 3.
Comparative fouling data (ind./m ² ) on the proposed device and the device corresponding to the prototype. Wrap Mode Compared to Natural Kinds natural more laminarized More turbulent Upper side of the plates Mytilus edulis 26840 ± 3680 10760 ± 2290 42360 ± 7620 Hiatella arctica 1360 ± 640 760 ± 280 2000 ± 550 Bottom side of plates Mytilus edulis 11560 ± 1400 7520 ± 1500 15200 ± 3200 Hiatella arctica Spirorbis sp. 360 ± 190 120 ± 60 440 ± 230 Circeis armoricana 9240 ± 1420 - 3480 ± 1320 4680 ± 1160 21800 ± 2360 -

fouling on the plates. The device corresponding to the prototype corresponds to the natural flow regime, whereas in the case of the proposed device, it was either more laminarized or more turbulized (compared to the natural one) due to the use of appropriate gratings.

As can be seen from the data in table 3, the proposed device gives a significant increase in the speed of testing, compared with the device adopted for the prototype. So for Circeis armoricana it is about 4.5 times, for Spirorbis sp. - almost 3 times, for Mytilus edulis and Hiatella arctica - about 1.5 times.

Example 3. The increase in the accuracy of biological tests using the proposed device.

To determine the optimal position of the fouling plates relative to the walls of the cells of the gratings, experiments with laminarizing gratings were performed. The cross-sectional size of the cells of the gratings was 25 × 25 mm, the length of the gratings in the flow direction was 250 mm. The experiments used a small wind tunnel of St. Petersburg State Technical Marine University. To record flow characteristics, a Diza hot-wire anemometer was used. Disturbances were introduced into the flow created by the wind tunnel. The air flow rate corresponded to a water flow rate of 7.5-10 cm / s, which is quite comparable with the tidal flow velocities at the place of field testing of the devices.

As it was found, the amplitude of the turbulent pulsations at the exit from the laminarizing lattice, smoothing the turbulent pulsations of the flow, varies from the cell walls to their middle (figure 1). It is maximum on the wall (0.25, 50 mm on the abscissa axis) and minimum in the middle of the cell (12.5; 37.5; 63 mm on the abscissa axis).

Since, as was shown in Example 2, the abundance of fouling depends on pulsations in the flow (experiments with turbulent gratings), the abundance of fouling will also depend on the position of the plates relative to the cell walls. Thus, the results of physical experiments show that the optimal position of the fouling plates behind the gratings, at which the most accurate estimates of fouling are achieved, corresponds to the position of the plates in the middle of the cells.

Example 4. Optimization of biological tests using lattices.

Biological tests were carried out, as described in example 1, from June 10 to September 10, 2006, removing plates from the sea once a month and determining the number of fouling on them. Tests made it possible to establish that according to the dependence of the fouling abundance on the turbulent flow characteristics, there are three groups of organisms (Table 4): some achieve greater abundance under conditions of increased turbulence (turbulent gratings), others - under conditions of reduced turbulence (laminarizing gratings), and others - in fact independent of changes in the turbulent flow characteristics (without gratings, which corresponds to the prototype). A total of 16 species were studied that were most often found in fouling.

Table 4.
Conditions ("+" sign) under which the greatest abundance is achieved by different types of fouling.
In brackets it is indicated on which side of the plates, when they are horizontally oriented on the proposed device, the abundance of fouling was greatest. Dachshund natural Turbulence Increased lowered 1. Diatom + Berkeleja rutilans (top) 2. Red algae + + Polysiphonia, Ceramium (top) (top) 3. Brown algae + + Pylaliella, ectocarpus (top) (top) 4. Brown algae + Fucus vesiculosus (top) 5. Brown algae + Laminaria saccharina (top) 6. Green algae + Enteromorpha (top) 7. Ciliates + Folliculina producta (bottom) 8. Hydroid polyps Gonothyraea loveni +

Dynamena pumila (top) 9. Polychaeta + Circeis armoricana (bottom) 10. Shellfish Mytilus edulis, Hiatella + arctica (top) 11. Clam + + + Heteronomia squamula (bottom) (bottom) (bottom) 12. Ascidia + Molgula citrina (bottom)

An analysis of the data presented in Table 4 shows that different species achieve the greatest abundance under different conditions of flow turbulization, although the most common case should be the achievement of the greatest abundance of fouling with increased turbulence. With the maximum abundance of fouling, the speed of biological tests is also maximum.

Therefore, the optimization of biological tests is achieved, in accordance with the proposed utility model, using such gratings and such fouling organisms that give a predicted abundance of fouling, for example, maximum.

Literature

1. Munteanu N., Maly E. J. The effect of current on the distribution of diatoms settling on submerged glass slides // Hydrobiologia. 1981. Vol. 78, N 3. P.274-275.

2. Mullineaux L.S., Garland E.D. Larval recruitment in response to manipulated field flows // Mar. Biol. 1993. Vol. 116, N 4. P.667-683.

3. Railkin A.I., Gudkov A.V. A device for exhibiting fouling plates. RF patent No. 1066514, priority 11.06.82, MKI ⁴ A01K 61/00.

4. Railkin A.I. A device for exhibiting fouling plates. RF patent No. 1242081, priority 07.01.85, MKI ⁴ A01K 61/00.

5. Schlichting G. Theory of the boundary layer. M .: Nauka, 1974. 712 p.

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Claims (6)

1. A device for biological testing of fouling of materials and coatings, containing a support element in the form of a rectangular-shaped frame with positive buoyancy, equipped with a vertical keel rigidly attached to it and cassettes with fouling plates, rotating around a vertical rod mounted on a carrier cable, used to install the device in a reservoir, characterized in that, in order to increase the speed of biological tests in the flow, on the support element in front of the cassettes with plates fouled Nia and the keel has a lattice modifying the flow characteristics, the grating placed at a distance from the fouling plates not exceeding the double of the smallest size sections gratings cells. 2. The device for biological testing of fouling of materials and coatings according to claim 1, characterized in that, in order to increase the accuracy of biological tests in flow conditions, the sizes of the cells of the gratings are chosen to exceed the dimensions of the sides of the fouling plates directed to the cells, and the fouling plates are placed in the plane passing through the middle of the cells. 3. The device for biological testing of fouling of materials and coatings according to claim 1, characterized in that, in order to optimize biological tests in the flow, use such lattices and such fouling organisms that give a predicted amount of fouling. 4. The device for biological testing of fouling of materials and coatings according to claim 1, characterized in that, in order to increase the reliability of the device, the vertical rod around which the frame rotates is mounted on a rigid base. 5. A device for biological testing of fouling of materials and coatings according to claim 1, characterized in that for determining the fouling of materials and coatings, fouling plates are made of test materials and coatings. 6. The device for biological testing of fouling of materials and coatings according to claim 1, characterized in that, when testing coatings, for example anti-fouling coatings, they are preliminarily applied to fouling plates made of non-corrosive materials or coated with anticorrosive compositions.