PL116800B1 - Combined vertical-and horizontal-flow sedimentation tank of radial type for sedimenting liquid suspensions,in particular sewages - Google Patents

Description

The subject of the invention is a radial sedimentation tank with a horizontal flow, intended for sedimentation of liquids, especially sewage or water containing a filamentous suspension, eg post-coagulation sludge, activated sludge, biological deposits.

Previously used settling tanks with horizontal flow, made in the form of a cylindrical tank with a cone-shaped bottom and a sediment funnel located in the middle of the bottom, and equipped with drainage channels on the periphery - do not provide optimal conditions for the sedimentation of the above-mentioned suspensions.

The effect comparable to the effect obtained by the use of the settling tank according to the invention has so far been obtained in vertical settling tanks, since the sedimentation of the rhizome suspension is determined by the vertical flow causing the agglomeration of the filly.

The cost of building the settling tank, which is the subject of the invention, is, however, about 25% lower than the cost of building the known vertical settlers.

There are also already known settling tanks with horizontal-vertical flow, nip. Rex settling tanks (rectangular in shape and equipped with a sludge funnel at one end and a series of deflectors inside, below which a chain scraper is placed at the bottom of the settling tank.

- Due to the unreliability of the collecting devices, the drives of which are located under the sewage reservoir, these settling tanks have not been widely used in practice.

Also known from the Polish patent description No. 54631 is the device called "Circular flow separator". This clarifier is equipped with a rotating central two-cylinder head, in which the internal cylinder intended for the supply of contaminated liquid is connected by a feeding trough, and the space between the inner cylinder and the outer cylinder is connected to the trough and is connected to the trough. The feeding trough has holes in its bottom, and the receiving trough has perforated collecting pipes fixed in the bottom. Between the feeding trough and the receiving trough, along the entire length of these troughs there is a partition wall that does not extend to the bottom of the clarifier.

The main feature that distinguishes this solution from the radial settling tanks x is that the horizontal flow in the radial direction has been replaced by the horizontal flow directed parallel to the perimeter of the device. This flow has a relative character, with a stagnant mass of sewage, the inflow and collection of sewage, placed on a movable platform, is carried out. This does not make any significant changes to the technological function of the settling tank and only a small part of the sewage, which flows around the deflector suspended under the platform, has a vertical flow direction. 116 800 116 800 3 A significant disadvantage of the structure of the basin, which worsens the sedimentation effect, is the location of the sewage collection at a considerable depth under their free mirror. Doubtful technological effects with the simultaneous considerable complexity of the device caused that it was not used in the sewage treatment plant.

The aim of the present invention is to eliminate the above-mentioned disadvantages and inconveniences of known solutions and to enable sedimentation of liquids, especially sewage from activated sludge chambers, biological deposits and post-coagulation sludge, while maintaining optimal process conditions obtained so far only on vertical settling tanks. and the technical problem to be solved is the development of the construction of a radial settler that would enable the achievement of this goal.

This goal was achieved by placing inside the cylindrical tank of the system of annular walls ending above the bottom and resting on supports, so that the spaces between the walls constitute the sedimentation chambers, with overflow troughs placed on the upper edge of these walls and on the inner circumference of the tank. They are connected with vertical pipes and a "horizontal pipe" from the sump located outside the settling tank. On the outer perimeter of the tank there is a ring-shaped sediment trough, and at the bottom of the tank there are ring-shaped sediment troughs, and the bottom also has a slope towards means in which the sump is made.

The advantage of the solution according to the invention is simple construction, reliable operation, and the elimination of the need for a sludge recirculation pump.

The subject matter of the invention is shown in an example of an embodiment - in the attached drawing, in which Fig. 1 shows a radial settling tank with a horizontal-vertical flow for sedimentation of liquids, especially sewage in a vertical section, Fig. 2 - this settling tank in a top view.

Inside the tank 1, in the shape of a cylinder, there is a system of annular walls 2 provided on the upper edge with overflow troughs 3. The space between the walls 2 forms annular chambers 4. The walls 2 rest on supports 5. The tank 1 has a trough on its inner circumference. overflow 3 and on the outer periphery a sludge trough 6 passing into a straight trough 7. In the middle of the tank 1 there is a vertical part of the pipeline 8 for feeding sewage T the horizontal part of the pipeline 9 which runs radially from the center of the tank 1 to the outside of the settling tank . A cylindrical deflector 10 is located inside the riser 8 inside the reservoir 1. At the bottom of the reservoir 1 there are single-shaped troughs 11 or the bottom has not shown in the groove; slope towards the center of the sump.

The overflow troughs 3 have vertical pipe connections 12 and horizontal pipe connections 13 with the well 14 outside the reservoir 1. A pipe 5 of pipes 15 leads out of the well 14. The 'settler equipment' is also a known sludge scraper 16 consisting of either a travel platform located radially on the sedimentation basin, vertical pumps and a scraper scraping the sediment or from the road deck and a scraper scraper divided into segments according to the number of chambers 4.

The latter solution is applicable to the conversion of existing horizontal-flow radial settlers to horizontal-vertical-flow radial settlers according to the invention. The operation of the settler in accordance with the invention is shown below. The sewage with "sediment content" flows in a horizontal pipeline 9, which in the middle of the device turns into a vertical pipeline 8. The inlet to chambers 4 is directed by a deflector 10. In the chambers 4, sedimentation takes place. of vertical pipe lines 12, then through the horizontal line 13 flow to the sump (14. The outflow of treated sewage from the sump 14 follows the pipeline 15

The sediment accumulating on the bottom of chambers 4 is removed by means of a scraping and pumping device in such a way that the scrapers collect it into the trough 11, from where it is pumped into the ring trough 6 located on the outer perimeter of the tank 1. From trough 6, the sediment flows out in a straight trough 7 or it is mechanically scraped into a sludge funnel situated in the center of the tank 1, from which it is removed by a pipeline.

Patent Claims "Radial settling tank with horizontal-vertical flow for sedimentation of liquids, especially sewage, equipped with a cylindrical tank and a rotating bridge, characterized in that inside the cylindrical vessel (1) there is a system of thin walls ( 2) terminated above the bottom and based on supports (5), so that the spaces between the walls (2) constitute the chambers (4) of the settling tank, with the upper edge of the walls (2) and the inner circumference of the tank (1) there are overflow channels (3) connected by vertical pipes (12) and a horizontal pipe (13) from the sump (14) located outside the settling tank, while on the outer circumference of the tank (1) there is a ring-shaped trough , sedimentary troughs (6) and in the bottom of the reservoir (1), ring-shaped sediment troughs (11) are made, or the bottom has a slope towards the center of which the sediment funnel is made. y 15 20 25 30 35 40 45 50 55 «• 116 800 ^ P & .1