CN202700162U

CN202700162U - Scum board

Info

Publication number: CN202700162U
Application number: CN 201220378842
Authority: CN
Inventors: 纪佳渊; 梁佳博
Original assignee: Xian University of Architecture and Technology
Current assignee: Xian University of Architecture and Technology
Priority date: 2012-08-01
Filing date: 2012-08-01
Publication date: 2013-01-30
Anticipated expiration: 2022-08-01

Abstract

The utility model provides a logarithmic spiral type scum board which has a logarithmic spiral shape. The scum board has the logarithmic spiral shape, and particles in a sedimentation tank and the like can move at a certain speed to an edge as far as possible along a linear path under the action of the scum board, so that the scum efficiency is obviously increased.

Description

A kind of scum board

Technical field

The utility model belongs to environmental project and sedimentation basin, depositing reservoir etc. and scrapes the slag process field, is specifically related to a kind of logatithmic spiral type scum board.

Background technology

Scum board is to strike off scum silica frost (oil slick) device for the sedimentation basin of the other fields such as sewage disposal and petrochemical industry and depositing reservoir surface.Take sewage treatment plant's secondary sedimentation tank (second pond) as example, existing scum board only is a simple straight plate, and it overlaps substantially with the second pond radial direction, yet that this class scum board is scraped the slag effect is but also bad.The general speed of rotating of scum board is slower, if rotating speed is very fast, it is unstable that fluid flow pattern can become, the formation of impact precipitation, and middle lower floor water body also can the difficult precipitation that forms under the stirring action of scum board, and settled mud also can mix with water again.Although yet the formation that lower velocity of rotation is conducive to precipitate is unfavorable for precipitating and the collection of scum silica frost.

Cross certain point on the second pond edge and make the tangent line of second pond newel, present scum board just has been installed in this tangent position, and the diameter of newel generally is very little with respect to second pond, so can think that it overlaps with radial direction.The scum silica frost particle at certain some place is as example in the second pond: suppose to have a circle, the center of circle is the second pond center, and radius is to the distance of this particle from the center of circle, so any moment, under the effect of scum board, this particle has been subject to the power perpendicular to scum board, namely along this round tangential direction.Particle can produce the speed of a tangential direction and move along this direction under the effect of this power, and this moment, water can produce resistance to particle.Again because the power of scum board is the tangential direction along this circle all the time, so the resistance of the water that is subject to when particle is offset laterally can not be cancelled.If consider inertia, this particle still can be offset in the process of motion laterally, but because the speed of scum board is slow, thrust is very little to the driving velocity that particle produces, and the quality of adding particle is very little, and effect of inertia almost can not embody.To sum up analyze, surface scum is done approximate circular motion at the uniform velocity often along the center of second pond, and can not enter the scum silica frost collection bucket of second pond edge.Each sewage treatment plant has also proved this deficiency, only has wind energy to make scum silica frost around to the edge in actual conditions, but the having or not of wind, size and direction but are not subjected to artificial control.(annotate: suppose that scum board directly acts on the particle the power of scum silica frost particle, but in most cases scum board is not that power is directly acted on particle, but acts on water first, pass to particle by water again.）

In the second pond, scum board is installed on the mud scraper crane span structure.

The utility model content

The purpose of this utility model is to provide a kind of scum board, and this scum board can improve slagging-off efficient.

For achieving the above object, the utility model has adopted following technical scheme.

A kind of scum board, the logatithmic spiral type that is shaped as of this scum board.

The angle of deciding of described logatithmic spiral is greater than 0 degree, less than 90 degree.

The angle of deciding of described logatithmic spiral is preferably 30 degree.

Be provided with on the described scum board for the support that connects the mud scraper crane span structure.

Link to each other with the mud scraper crane span structure respectively after the described scum board segmentation.

The area part scraped of adjacent two sections scum boards overlaps to form jointly can scrape the zone.

Scum board of the present invention has the shape of logatithmic spiral type, makes particle in sedimentation basin etc. under the scum board effect, moves to the edge with a certain speed along straight line path, has improved significantly slagging-off efficient.

Description of drawings

Fig. 1 is one of structural representation of the present utility model (not segmentation);

Fig. 2 is two (segmentations) of structural representation of the present utility model;

Fig. 3 is fundamental diagram of the present utility model (not segmentation);

Fig. 4 is the structural representation of existing straight-plate-type scum board;

Fig. 5 is that existing scum board is to the mechanics analysis figure of particle;

Among the figure: 1 support, 2 mud scraper crane span structures, 3 can scrape the zone jointly.

The specific embodiment

The utility model is described in further detail below in conjunction with drawings and Examples.

Referring to Fig. 1 and Fig. 2, the logatithmic spiral type that is shaped as of scum board described in the utility model, the angle of deciding of described logatithmic spiral is greater than 0 degree, less than 90 degree, the angle of deciding of described logatithmic spiral is preferably 30 degree, be provided with on the described scum board for the support 1 that connects mud scraper crane span structure 2, link to each other with mud scraper crane span structure 2 respectively after the described scum board segmentation, the area part scraped of adjacent two sections scum boards overlaps to form can scrape zone 3 jointly.

Referring to Fig. 3, the most important character of logatithmic spiral is that the radius vector at place, arbitrfary point and the angle of tangent line are definite value, and this angle is the angle of deciding of corresponding logatithmic spiral.Namely scum board will point to same direction all the time to the direction of the power of particle, and scum board is identical to the action direction of the particle of central area and neighboring area, like this, along with scum board uniform speed slow ground rotates, particle will move to edge (not considering that plate is to the faint agitaion of the water surface and the postulated particle initial velocity without other directions) along straight line path with a certain speed, make that scum silica frost in the sedimentation basin (or depositing reservoir) is more efficient to move on to the pool side edge, and finally scrape into slag gathering hopper to remove.

Referring to Fig. 4, can find out that from the shortcoming of straight plate scum board the scum board that only changes is to the thrust direction of scum silica frost, scum silica frost could easier being removed.As seen from Figure 5, originally straight plate scum board is to the F direction among Fig. 5 that act as of particle, particle moves along the v direction under the effect of F direction power, and when scum board and diametric angle are τ, at this moment scum board is F ' to the force direction of particle, particle will be along the motion of v ' direction, and the angle of F and F ' is τ, and it also is the angle of v and v '.Although compare with straight plate scum board, particle can be shifted onto the edge by scum board, this scheme also has weak point, along with particle outwards moves, the angle of F and F ' changes, and more outside this angle is less, and particle is also just less along the power on the radial direction so.In this case, the efficient of scum board is not the highest, and if the τ value at any point place all is a definite value, the power that particle is subject to is along a direction all the time, the power that this like-particles is subject at radial direction also is certain.Can find a kind of curve to satisfy the certain condition of τ value, that is exactly logatithmic spiral.

Logatithmic spiral is determined: in logatithmic spiral type scum board, a value namely is the radius value of sedimentation basin centered cylinder in the corresponding logatithmic spiral equation, and the b value is determining the angle of deciding of logatithmic spiral.Be 45m to diameter, mud scraper perimeter line speed is that the sedimentation basin of 1.7m/min uses fluent software to simulate, and decides the angle and is defined as respectively 0 °, 30 °, 45 °, 70 °, 80 °, does not consider resistance and the surface tension of water surface, it is the most suitable relatively to obtain 30 ° of logatithmic spirals of deciding the angle, namely

Segmentation: need the support grown on the crane span structure because one whole section logatithmic spiral type scum board is installed on, such as Fig. 1, measure a wherein the longest support with AutoCAD, obtain its length above 4.5 meters, this being connected on the engineering is irrealizable, therefore logatithmic spiral type scum board need to be carried out segmentation, and the second pond internal diameter is 45 meters in this example, for making the stent length that respectively protrudes all be no more than 2 meters, rough estimate can be divided into 2 sections.During segmentation, definition pond central point is initial point, and this logatithmic spiral starting point coordinate under rectangular co-ordinate is (1,0), use straight line x=0 that 30 ° of helicals are divided into two sections, two sections scum boards that separate are all rotated under the crane span structure, through calculating and measuring, the stent length that connects by this way is all within 2 meters, referring to Fig. 2, in addition, the outside scum board 25cm that extends internally, the inboard scum board 25cm that stretches out has to guarantee two sections scum boards that 50cm's can scrape zone (referring to Fig. 2) jointly.Segmentation is in order to satisfy the requirement on the engineering, and the diameter length that support stretches out below 30 meters time the in pond can not surpass 2 meters, does not need segmentation, and the pond diameter then needs segmentation greater than 30 meters, and segments and point-score need decide according to concrete pond diameter.The height of scum board is generally 20-30cm.

Material is selected: because scum board need to be draped and be fixed on the crane span structure and can keep good structure, its material requirements gently, not yielding and intensity and hardness is high, has good physical characteristic; Because the scum board long period of soaking is in water, its material require is difficult for oxidized or corrosion, and good chemical stability is arranged; Because the scum board major function is to scrape off the water surface scum silica frost, so the material of scum board can not be easy to adhere to the scum silica frost particle; Consider that from the making aspect this material require good manufacturability is easy to pressure manufacturing, casting and welding.

Because the scum board span is larger, is difficult to produce a monoblock scum board, and for convenient transportation, scum board will be with the loose mail production and transport.Should do suitable reinforcement protection measure in the process of transportation and installation, prevent that it from deforming.

After the mud scraper installation scum board can be installed, motor and cleaning brush can installed thereafter.Before the installation, need to be ready to all required instruments, the contrast drawing finds separately opposite position with the scum board loose mail.During installation, will connect first scum board and the support of crane span structure and be fixed on the crane span structure (all be connected all adopt Stud connection), then each scum board loose mail and support be coupled together, and will couple together between each loose mail.Tailgate is installed at last, and tailgate only is connected with support, is not connected with the scum board main body, and it just can have the rotary moveable space of certain limit like this, so that it scrapes scum silica frost into slag gathering hopper.The slag-scraper of installing should guarantee to exceed design liquid level line 100mm.

After installing, advanced line space load running, be anhydrous dry run, adjust mud scraper and scum board, the double-screw bolt on coarse adjustment support and scum board, each scum board assembly this moment, make each assembly substantially be in the same level height, then operational outfit after the water filling in the pond, the fine tuning double-screw bolt is further adjusted each component height, and observe and adjust height or the position of tailgate and slag gathering hopper, make scum silica frost successfully be collected in the slag gathering hopper and tailgate does not splash spray when leaving slag gathering hopper along the gentle slope.

After above all working was finished, scum board is successful installation just, treat the mud scraper adjustment finish after second pond just can try out.

Claims

1. a scum board is characterized in that: the logatithmic spiral type that is shaped as of this scum board.

2. described a kind of scum board according to claim 1 is characterized in that: described logatithmic spiral decide the angle for greater than 0 degree, less than 90 degree.

3. described a kind of scum board according to claim 1, it is characterized in that: the angle of deciding of described logatithmic spiral is preferably 30 degree.

4. described a kind of scum board according to claim 1 is characterized in that: be provided with on the described scum board for the support (1) that connects mud scraper crane span structure (2).

5. described a kind of scum board according to claim 4 is characterized in that: link to each other with mud scraper crane span structure (2) respectively after the described scum board segmentation.

6. described a kind of scum board according to claim 5, it is characterized in that: the area part scraped of adjacent two sections scum boards overlaps to form can scrape zone (3) jointly.