Field of the Invention

This invention relates to removal of solids from liquid, and more particularly, to a tube settler which is into a compact, profile configuration for transport to an installation site and prepare module into an open-tube configuration at the site used for the purpose of clarification.

Background Art

Settlers remove certain materials and particles from liquid, to clarify the liquid. These materials are suspended in the liquid and can be removed by settlement when the flow of the liquid is laminar. Since these materials are generally solid and are said to "settle" out of the liquid, they are referred to as "settleable solids", or "settleable particulates". Settleable solids may include naturally occurring materials (e.g., clay, silts, sand and dirt), chemical precipitants and biological solids. The word "solids" as used herein to describe the present invention refers to such settleable solids and settleable particulates.

Settlers are used, for example, in water and waste water treatment plants. In water treatment, the water drawn from a water supply has various non-settleable colloidal solids therein. When mixed with chemicals, the colloidal solids and chemicals agglomerate to form solids. In waste water treatment, the solids include organic solids, among other wastes. Water and waste water are treated in settlers to remove such solids, thereby making the water clear and suitable for use, reuse, or for further treatment, such as tertiary treatment. The word "liquid" as used herein to describe the present invention refers to water and waste water.

In the prior art, inclined settler plates have been held assembled by stems, as in U.S. Pat. No. 3,903,000 to Miura issued Sep. 2, 1975. However, such plates are expensive relative to the cost of tube settlers. For example, the plate settlers require more structural support than tube settlers and must be bounded by side baffles.

Therefore, numerous designs have been proposed for tube settlers. One type tube settler, as shown in McCann U.S. Pat. No. 3,491,892 issued on Jan. 27, 1970, uses parallel sheets or walls spaced by parallel baffles which form inclined conduits, or the flow channels. The sheets and baffles have been made from rigid plastic or metal, and have been secured to each other to form the tubes and such flow channels, as by use of adhesive to join the plastic sheets and baffles, or soldering or welding of the metal sheets and baffles. In a design based on that of the McCann Patent, U.S. Pat. No. 3,898,164, to Hsiung issued Aug. 5, 1975 describes a self-supporting tube settler using extrusions which are adhesively attached to each other to form the tubes. Other variations of the design of tube settlers include providing connectors having grooves for receiving elements which form the tubes, as in U.S. Pat. No. 3,963,624 to Henderson, et al.
As described above, generally a tube settler provides improved separation performance through the division of the flow path of the raw water into a tubular passages, because such division improves fluid stream therefore, improves settlement. Moreover, tube settler improves settlement area. Conventionally, the cross sectional configuration of the tubular passages of a tube settler are circular, square, triangular, hexagonal, or rhombic. These shapes give not much satisfactory results for several reasons, like hexagonal chevron shape have lowest hydraulic dia and highest surface area In a tubular passage of square cross section or triangular cross section wherein one side surface forms the bottom, the precipitate lies in a thin layer and has a relatively high surface area exposed to the fluid passing through the tube. This means relatively low gravitational forces effected on the precipitate for slip-off and relatively large frictional resistance, and it is likely that some of the precipitate is re-suspended by a fluid stream running opposite to the direction of slip-off. Circular or hexagonal shape does not give sufficient concentration of precipitated matter either. Moreover, square and triangular shapes are having much less surface area compare to product applied for patent.

One general type of tube settler has been designed for assembly at the site. For example, in U.S. Pat. No. 3,951,817, to Snyder issued Apr. 20, 1976, extruded plates have been assembled at the site. Also, in U.S. Pat. No. 3,852,199, to Wachsmuth et al issued Dec. 3, 1974, a minimum number of parts have been used to assemble separate tube settler modules, which modules are smaller than the settler basin in which they are to be used. The separate modules are abutted with other such modules at the site to provide the necessary larger tube settler assembly. However, the settler module there shown is made entirely from rigid planar members and ribbed tube-defining members assembled via slots to define the tubes of the tube settler. Further, much of the success of tube settlers that are designed to be assembled at the site depends on having skilled labours available at the site.

Further, in the type of prior tube settler that is assembled at a factory and shipped assembled to the site, in Applicants' experience, such assembled tube settlers have not been provided with an integral tube settler module assembled at the factory and shipped to the site in a configuration so as to take up minimum space during shipping, and then (still as an integral module) transformed into an open configuration for use. Rather, tube settlers that are fabricated at a factory have integral units having the open tubes formed in place. With the tubes open, such settlers are shipped to the installation site, e.g. a waste water treatment clarifier . With the open tubes formed prior to and during shipment, such integral tube settler modules have a three-dimensional shape which is substantial in each of the three dimensions and takes up substantial volume. For example, a typical tube settler may have overall dimensions of 3.5 feet in height by 10 feet in length (to span the distance between supports) by 4 feet in width. Because much of the volume of these conventional tube settlers is the open tubes (i.e., air), they are relatively expensive to ship, as by containers used for overseas shipments. As a result, there is still a need to provide a factory-assembled tube settler module having a configuration suitable for efficient shipping to the basin in which the tubes are to be used, but which upon arrival at the basin is easily transformable without skilled labor.

SUMMARY OF THE INVENTION

Applicants have studied prior tube settlers in an endeavor to Improved Clarification Efficiency, reduced overall profile weight, reduces the installation time and space occupied in transportation along with a lower Footprint ensuring improved settling of total suspended solid. Such studies indicate that in shipping tube settlers to the site of clarifier, one should not assume that skilled workers will be available at the site to assemble the tube settlers

Applicants have determined that the design of the pre-assembled tube settler must provide for significant reduction in the size of the pre-assembled tube settler during shipping, but be readily and easily module preparation by unskilled workers into such open-tube configuration for use at the site.

It is the principal objective of the present invention to ensure improved fixing sealing with minimal installation times along with a reduced chocking potential through improved hazen velocities resulting in a better laminar flow without compromise on the surface area with a mean hydraulic radius of 17mm.

The present invention provides features in profile type tube settler module having a profile configuration defining a first volume, and a configuration defining a second volume larger than the first volume. The tube settler module is provided with main and side profile. . There are interconnected members between the profiles with tongue and groves arrangement.

Therefore such as herein description there is provided a profile type tube settler module including multiplicity of long and narrow tubular passages having a profile configuration defining a first volume, and a module configuration defining a second volume larger than the first volume wherein the tube settler module is provided with main and side profile, a plurality of inter connected members between the profiles with tongue and grooves arrangement, a plurality of inclined through running passages of hexagonal chevron cross-sectional configuration through the entire length.
This type of multitubes separator can be employed for the settling and separation of suspended particles having a greater specific gravity than the fluid to be treated or for the floating and separation of particles having a smaller specific gravity than the fluid, whichever the case may be. Suspended materials are often in the form of fine solid particles. However, for the purpose of simplification and better understanding, description is made hereinafter mainly with respect to the case where fine solid suspended particles having a greater specific gravity than the fluid being treated are settled and separated from the fluid.
A settling and separating device having above said type of multitubes separators are hereinafter referred to as a tube settler.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will be apparent from an examination of the following detailed descriptions, which include the attached drawings in which:

FIG. 1 is a cross-sectional, schematic view of a tube settler module which is profile according to the present invention;

FIG. 2 is an enlarged three dimensional, schematic plan view of a profile configuration of a portion of the tube settler module in accordance with the present invention;

FIG. 3 is an enlarged three dimensional, schematic isometric view of a module configuration of a portion of the tube settler module in accordance with the present invention.

DETAILED DESCRIPTION

FIG. 1 shows a typical cross-sectional diagram of the tube settler. The tube settler assembly comprises a multiplicity of long and narrow tubular passages having a selected cross-sectional configuration aligned parallel under a certain systematic cross-sectional arrangement and inclined at an angle a to the horizontal. Said water flows slantingly and upwardly through the tubular passages in the tube settler and meanwhile the flocks (solid impurities) adhering to suspended particles are settled.

A passage of modified shape of the tube settler 130mmX 45 mm cross-sectional configuration disclosed herein in order to obtain effective settling and separation of suspended particles from fluids, turbulence must be avoided. The settling of suspended particles is substantially hampered under the condition of turbulence. The commonly used tube shapes other than said Hexagonal chevron shape cross-sectional configuration have a relatively high hydraulic radius of 17mm, and the resulting Reynolds number Much lower for flow of a fluid through the tube passages. Thus, with the commonly used tube shapes, it is necessary that the flow rate or through-put rate of fluid must be low in order to keep Reynolds number below the critical Reynolds number and to avoid turbulent flow. Accordingly, the critical upward-flow rate for avoiding obstructions to precipitation without turbulence is governed by the cross-sectional configuration of the tube passage; and with tube passages of the commonly used shapes, except said hexagonal chevron cross-sectional configuration, the critical upward-flow rate is generally low. The hydraulic radius of said 17 mm cross-sectional configuration is low and the critical rate of upward flow through the passages of said configuration is high; so, hexagonal chevron cross-sectional configuration increases the treating capacity of the tube settler.

The above said modified Hexagonal chevron (130 mmx 45mm) cross-sectional configuration has been believed to prove more advantageous as a tube shape than any other cross-sectional configuration from a geometrical point of view, and in fact, exhibits good performance as such. In industrial application, however, it has been found that said configuration still involves a problem requiring cleaning in relation to the effect of a boundary layer in the flow through profile in the cross section of a tube passage. The flow rate of a boundary layer which develops along the passage wall as fluids flow ranges from free to zero. The boundary layer decreases the average flow rate of fluids passing through the tube. From a different point of view, it makes the effective sectional area of the tube smaller than the geometric sectional area thereof. If the cross section of a tube passage presents a zone surrounded by two contour portions intersecting at an acute angle, the boundary layer along the contour portions is apt to grow thicker, resulting in decreased average flow rate. The sides of the modified hexagonal chevron(130 x 45mm) cross-section form an angle between them. It is a motive for this invention to eliminate the acute angle zone present in a hexagonal chevron(130 x 45 mm) cross-sectional configuration under the limitation of certain systematic tube-passage alignment and without prejudice to the uniformity of settling distance and good sludge-collecting function.

The present invention provides an easy to fix modular design with tongue and groove arrangement which is easy to install at site and transport occupying only 1/5th of the original transport space. The product ensures reduced choking and a reduced hydraulic retention time of the clarifier which is ensuring a reduction of clarifier footprint. The tubesettler can also be used for drinking water application taking into consideration that food grade quality material is used as the material of construction of the tubesettler profile.

A variant of the tube settler can also be used for drinking water applications since it is to be manufactured in a food grade quality material. The equipment has uses in clarification of raw water, secondary clarification after aeration systems and has a benefit of the possibility of installation inside a circular clarifier for enhanced space utilization.

A multiplicity of long and narrow tubular passages having this particular cross-sectional configuration is arranged compactly and in parallel to one another under a systematic alignment to form a tube-nest passage assembly. As can be seen in FIGS. 2 and 3, with respect to one particular passage, the center portion of the bottom of the cross section thereof corresponds with the top side of a passage located right thereunder, and the side portions of the bottom of said passage correspond with inclined sides of the cross sections of adjacent lower passages. The inclined sides of the cross section of said passage correspond with side portions of the bottoms of adjacent upper passages. Again, the top side of the cross section of said passage corresponds with center portion of the bottom of the immediate upper passage. Unit assembled modules are connected to a suitable size, are disposed at an angle of 55 or 60 degree to the horizontal. In FIG. 2, said assemblies, as a tube settler assembly.

The settling performance of a tube settler is greatly improved when the tube passages of the settler are of approximate boomerang cross-sectional configuration. The boomerang cross-sectional configuration has advantages over the commonly used passage shapes: it has a low hydraulic radius and accordingly the Reynolds number for flow through the tubular passages of this invention is low. The boomerang cross-sectional configuration prevents turbulence and permits laminar flow through the passages even where flow rates are much higher.

According to this invention, the cross section of the tubular passages constituting the tube settler gives a uniform height throughout all sections in crosswise direction, except small side-end portions. This insures that the distance which suspended particles in the fluid being treated must fall until they reach the bottom of the cross section does not exceed a certain value throughout the most part of the cross section in crosswise direction. Accordingly, the precipitation of suspended particles is substantially uniform throughout the entire area over the bottom. This allows effective utilization of settling area inside the tube passage. Moreover, the bottom side is of V shape and precipitates on the bottom gather in center portion thereof to form thick condensed precipitate layers. This facilitates the slip-off of precipitates on the inclined plane and decreases the possibility of precipitates being resuspended in fluids owing to the backflow of fluids, thus resulting in satisfactory separation operation.
The cross section of the tubular passage of this invention has a substantially lower hydraulic radius than those of commonly used tube passages. Its hydraulic radius is very close to that of the 17 mm of this cross-sectional configuration. This results in a low Reynolds number below 2000 (a number expressed as a function of flow rate to geometric dimensions, and accordingly a high critical flow rate as substantially determined from the critical Reynolds number which avoids turbulent flow, a factor preventing settling of suspended particles (whose rate of settling is low) and which maintains laminar flow. This means increased treating capacity and more compact apparatus).

No acute-angle zone is present in the cross-sectional configuration of the tubular passage of this invention. Accordingly, there is no risk of a stagnant flow zone developing due to a boundary layer. This results in increased average flow rate and virtual gain in treating capacity.

Tests were made under the following conditions.

1.Overall migration test as per EU-10
2.Overall migration test as per IS 9845-1998
3. Overall dimension check

TECHNICAL SPECIFICATION
Dimensional Specification 42.50(130x45)+_ 1.5
Thickness 1mm thick +_0.1
Fixing Arrangement Glued
Material Stabilization UV stabilized
food grade & non toxic
Color Black / White
SA at 55degrees 13m2
SA at 60degrees 11m2

According to this invention, the cross section of the tubular passages constituting the tube settler gives a uniform height throughout all sections in crosswise direction, except small side-end portions. This insures that the distance which suspended particles in the fluid being treated must fall until they reach the bottom of the cross section does not exceed a certain value throughout the most part of the cross section in crosswise direction. Accordingly, the precipitation of suspended particles is substantially uniform throughout the entire area over the bottom. This allows effective utilization of settling area inside the tube passage. Moreover, the bottom side is of V shape and precipitates on the bottom gather in center portion thereof to form thick condensed precipitate layers. This facilitates the slip-off of precipitates on the inclined plane and decreases the possibility of precipitates being resuspended in fluids owing to the backflow of fluids, thus resulting in satisfactory separation operation.

The above embodiments of the present invention is only expressed in several embodiments, and detailed description thereof is more specific, but can not therefore be understood as limiting the scope of the present patent disclosure. It should be noted that those of ordinary skill in the art, without departing from the concepts of the present invention is the premise of the present invention a modifies 120 mm X 44 mm configuration to the 130mm X 45 mm tube precipitation tube assembly may be made of several different types and sizes and variations thereof and modifications, which are within the scope of protection of the present invention. Accordingly, the scope of the present invention should be defined by the appended patent claims.

Although the foregoing description of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration by way of examples and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

We Claim :

1. A profile type tube settler module including multiplicity of long and narrow tubular passages having a profile configuration defining a first volume, and a module configuration defining a second volume larger than the first volume wherein
the tube settler module is provided with main and side profile,
a plurality of inter connected members between the profiles with tongue and grooves arrangement,
a plurality of inclined through running passages of hexagonal chevron cross-sectional configuration through the entire length.
2. A profile type tube settler module as claimed in claim 1, wherein the hexagonal chevron cross- sectional configuration is of 130 x 45mm.
3. A profile type tube settler module as claimed in claim 1, wherein the said the cross section of the tubular passages constituting the tube settler gives a uniform height throughout all sections in crosswise direction, except small side-end portions.
4. A profile type tube settler module as claimed in claim 1, wherein the hydraulic radius is around 17mm.
5. A profile type tube settler module as claimed in claim 1, wherein the said cross-sectional configuration includes no acute-angle zone inside the tubular passage, thereby nullifying the risk of a stagnant flow zone developing due to a boundary layer and results in increased average flow rate and virtual gain in treating capacity.
6. A profile type tube settler module as claimed in claim 1, wherein said tube settler modules are installed at an angle of 55 or 60 degree to the horizontal.
7. A profile type tube settler module as claimed in claim 1, wherein the parallel tubes are of thickness 1mm and are glued.
8. A profile type tube settler module as claimed in claim 1, wherein the tubes are UV stabilized with are of non-toxic food grade.