Filter for removing particulate matter from drained off liquids

The subject of the invention is a filter for removing particles from wastewater.

A filter for removing particles from a effluent is known which includes a grate with a number of parallel fixed and sliding bars forming a plane inclined downwards in the direction of water flow. The edges of the bars face the water that is being drawn in and form steps. The sliding rods are connected in parallel in at least one set, which is activated by a drive mechanism located at the upper end of the filter above the water flow and causing movement on a closed circuit in a plane perpendicular to the sliding rods. The movement path of sliding bars has a vertical component that exceeds the height of the bar steps.

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This type of filter is used, for example by wastewater treatment plants, to separate particles from wastewater and is among others disclosed in Swedish Patent SE 448106.

Due to the presence of hair and other fibers, as well as abrasive particles in the liquid, it is preferable to position the drive mechanism and those moving parts that are attached thereto, above the surface of the effluent. This has a drawback, resulting from the need for a relatively high and bulky stand for installing the filter. During installation, it is necessary to level the stand and make an exact alignment for the support of the sliding part of the filter so that the shafts are parallel. By placing bearings for sliding rods much higher above the lower end of the filter, leverage is generated as a result of water pressure on the lower part of the filter, which causes stresses in the structure that must be compensated by improving the quality of the bearings and the thickness of the material.

There are also simpler design filters that use drive means to clean the bottom of the sliding filter, but avoids a closed loop to reduce production and installation costs. Therefore, this part of the filter only moves back and forth and does not effectively contribute to the upward movement.

The filter for removing particles from the wastewater according to the invention, comprises a grid structure consisting of parallel fixed rods and sliding rods forming a plane inclined in the direction of water flow, and having edges forming the steps facing the water inflow, the sliding rods being connected in parallel in at least one set, which is connected to the driving mechanism located in the upper end of the filter, above the water level, causing the movement of the sliding bars on a circular path in a plane perpendicular to the sliding bars, with a pitch greater than the height of the bar steps.

The filter according to the invention is characterized in that the driving mechanism is connected, through at least one winding element, to a connecting mechanism which is located at the lower end of the filter and on which the lower ends of the sliding rods are based.

The winding element is in the form of a chain, wire or rod.

The sliding rods are connected with spring elements forcing their movement down the filter.

The connecting mechanism comprises a first connector that is located between the first attachment point on the filter structure and the lower end of the tension element and a second connector which is located between the lower end of the tension element and a second attachment point located on the filter structure at the lower ends of the sliding rods.

The winding element is connected to the drive mechanism via an eccentric pin located parallel to the axis of the output shaft of the drive mechanism. The winding element is connected to the eccentric pin via a crankshaft, the axis of which is offset by several degrees relative to the eccentric pin.

The linker is preferably in the form of a chain.

The connecting mechanism and the winding element are connected to two side beams located on both sides of the filter.

Each side beam is connected to a support beam on which the sliding rods are based.

The filter for removing particles from the wastewater according to the invention is easy to use and install, is cheaper and effectively removes all types of solid particles from the wastewater.

The object of the invention is shown in the embodiment in which the drawing in which Fig. 1 is a side view filter for removing particles from a sewage system, Fig. 2 - the filter in Fig. 1 in a front view, Fig. 3 - the filter in Fig. 1 in a top view, showing its drive mechanism, FIG. 4 - bottom end of the filter in a side view, enlarged, FIG. 5 - a housing of the filter connection mechanism in a side view.

The filter for removing particles from the wastewater shown in Figs. 1-4 includes a grid 12 which is sandwiched between two side beams 11. The grid 12 alternately comprises

174 445 fixed rods 13 and sliding rods 14 (see Fig. 4) that form a plane inclined downwards towards flowing water. Fixed and sliding bars 13 are folded into steps. The set of fixed 13 and sliding bars 14 thus forms a grid 12. The sliding bars 14 can move in a plane perpendicular to them on a closed circular track with a vertical pitch greater than the height of the steps of the fixed and sliding bars 14. Step lines are horizontal or slightly tilted backwards in front of them when the filter is installed in the channel in the operating position shown in Fig. 1.

During the movement of the set of sliding rods 14, objects and particles are picked up and moved through successive steps up until they can pass over the highest step to the next, not shown conveyor, for example a conveyor belt.

The side beams 11 are connected by means of two lower and 15 upper beams 16 located above the water surface 10. Also, a number of crossbars 17 connect both side beams 11 along the length of the rods 13, 14. The crossbars 17 support the solid rods 13.

A drive mechanism 18 is mounted on the side beams 11 and the upper crossbeam 16, which is shown in more detail in Fig. 3. The drive mechanism 18 comprises an electric motor 19, a reduction gear box 20 and an output shaft 21. The output shaft 21 is connected to the flywheels 23, which are pivoted in the housing 22 at each side beam 11. The eccentric pivot 24 is mounted on each flywheel 23 forming the axis of the support beam 25, sliding outwardly of each side beam 11. The support beam 25 extends downwards to the lower end of the filter and is mounted on it with sliding rods 14 via crossbars 26.

The upper part of the support beam 25 moves eccentrically around the output shaft 21 and transfers the movement to the upper part of the set of sliding rods 14. Such eccentric movement would normally cause the lower parts of the sliding rods 14 to move downwards, then backwards and forwards. However, in their lower part, the sliding rods 14 are suspended respectively on a connecting mechanism, which in the embodiment shown includes a first and a second connector 28. The connection point of the first and second connectors 28 is connected to the eccentric pin 24 through a tensioning element 29, which in the example shown is in the form of a rod.

The tensioning element 29 is connected to the eccentric journal 24 through a crankshaft 24a, whose axis is slightly shifted relative to the eccentric journal 24. Therefore, the movement of the tensioning element 29 is shifted by several degrees in phase relative to the movement of the supporting beam 25. Due to the symmetrical arrangement of the first connectors 27 and the second 28 and the movement of the winding element 29, the lower part of the sliding rods 14 is moved along the curve 30 shown in Fig. 4. The first connector 27 is in the form of a bushing chain running from the first attachment point 31 located on the filter structure, preferably on each side beam 11, to the handle 32, which is slidably mounted through the opening 33 (see Fig. 5) on the connecting element 29 and is locked with threaded nuts 34. The second connector 28 is a bushing pin chain, running from the handle 32 to the second attachment point 35 on the filter structure at the lower ends of the sliding rods 14, preferably on each of the individual support beams

25. Both bushing pin chains are encased in flexible sections of a pipe 36, which is preferably clamped and contains lubricant.

By elastically suspending the lower part of the sliding rods 14 on the first and second chain links 28, the stress in the drive mechanism 18 is reduced if, for example, a small stone would get with the water jet on the bottom of the channel to the bottom of the filter. Otherwise, this would lead to interruptions in the filter's operation if it were to operate completely with forced motion.

In order to avoid filter clogging, preferably the sliding rods 14 have saw teeth 37 on their edges facing downwards, in those parts which are placed in front of the crossbars 17 of fixed rods 13. Each time the sliding rods 14 make a working stroke, the saw teeth 37 tear hair and other materials that adhere to the crossbars 17.

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Due to its simple self-supporting construction with strong side beams 11, the filter is simple to produce installations.

In the filter according to the invention, the chain links can be replaced by ordinary rigid arms. In addition, the fasteners may cooperate in a different manner than shown, for example, the first fastener 27 may be positioned between the first and second fastening points 31 and the second fastener 28 may connect the fastening point 35 to the lower end of the winding element 29. It is also not necessary to use articulated mechanism on each side of the filter. It can be replaced with a mechanism located centrally between two V-shaped and inclined grates towards each other.

The filter according to the invention is installed as an inclined plane in a channel or trough in such a way that it reaches the bottom with its lower end in the stream of sewage to be treated. The lower end of the filter rests on the bottom of the channel, the fluid level normally reaching approximately to the level of line 10 in Fig. 1.

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UP Department of Publications. Circulation of 90 copies

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