Tubular elements for cake filtration and method of providing a filtration cake

Patent metadata

Field	Value
Publication number	US-10919793-B2
Application number	US-201515540208-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Dec 30, 2014
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

The present invention relates to a filtering device for a water treatment system comprising a biological treatment device adapted to provide a sludge from wastewater or filtrated wastewater, and/or the biological treatment device being fluidic connectable to or in fluidic connection with the filtering device for receiving filtrated wastewater from the filtering device and for delivering sludge to the filtering device. The filtering device is a cake filtration device comprising a fluid penetrable support structure and the support structure is provided as one or more tubular elements having a filtration cake provided on the inside of the fluid penetrable support structure. The filtering has device an inlet being connectable to receive liquid to be filtered so that the flux of liquid to be filtered is from the inside of the support structure, through the filtration cake and to the outside of the support structure thereby providing a filtrate, an outlet for outletting liquid from the interior of the tubular element, and a filtrate outlet for outletting filtrate from the filtering device. The filtration cake is being provided by deposition of solids from the sludge formed in the biological treatment device.

First claim

The invention claimed is:

1. A water treatment system comprising a filtering device, the water treatment system comprising:
a biological treatment device configured to provide a sludge from wastewater or filtrated wastewater and a digester adapted to provide digester sludge, the biological treatment device being fluidic connectable to or in fluid communication with the filtering device for receiving filtrated wastewater from the filtering device and/or for delivering sludge to the filtering device, and the digester being in direct fluid communication with the filtering device for delivering digester sludge directly from the digester to the filtering device,
wherein
the filtering device is a cake filtration device comprising a fluid penetrable support structure, the support structure being provided as one or more tubular elements, the filtering device comprising:
an inlet being connectable to receive liquid to be filtered so that the flux direction of liquid to be filtered is from an interior of the tubular element, through the filtration cake and to the outside of the tubular element thereby providing a filtrate,
an outlet for outletting liquid from the interior of the tubular element,
a filtrate outlet for outletting filtrate from the filtering device, and

the filtration cake being provided on the inside of the fluid penetrable support structure during use by deposition of solids from the sludge formed in the biological treatment device and in the digester, wherein the solids comprise digester sludge and at least one of activated sludge flocs and coagulated substances.

2. The water treatment system according to claim 1 , wherein the filtering device further comprises a fluid tight casing encapsulating the support structure and providing a cavity outside the support structure in fluid communication with the filtrate outlet.

3. The water treatment system according to claim 1 , wherein each of the tubular elements comprising an inner layer and an outer layer being concentrically arranged, wherein each layer comprises through-going openings, and the through-going openings in the inner layer has a larger cross sectional area than the through-going openings in the outer layer.

4. The water treatment system according to claim 1 , wherein the tubular element(s) is(are) cylindrical element(s) having an internal diameter less than 15 mm.

5. The water treatment system according to claim 1 , comprising a plurality of tubular elements, which are arranged in parallel having a common inlet for receiving wastewater to be treated.

6. A water treatment system comprising the filtering device according to claim 1 , wherein the filtrate outlet of the filtering device is fluidic connected to a downstream biological treatment device.

7. A water treatment system comprising the filtering device according to claim 1 , wherein the inlet of the filtering device for receiving liquid to be filtered is fluidic connected or fluid connectable to an upstream biological treatment device.

8. The water treatment system according to claim 6 , wherein the system further comprises a screening device arranged upstream of the filtering device, said screening device being configured to carry out a filtering-out of objects above a pre-selected size from the wastewater prior to be fed into the filtering device.

9. The water treatment system according to claim 6 , wherein the water treatment system comprises a separator separating the sludge formed in the biological treatment device into an effluent and activated sludge having a higher dry matter content than the effluent.

10. A method for providing a filtration cake on a support structure of the filtration device according to claim 1 , comprising:
feeding solids comprising digester sludge and at least one of activated sludge flocs or coagulated substances,
an accumulation phase comprising accumulating activated sludge flocs and/or coagulated substances on the interior surface of the tubular elements by inducing a pressure difference to generate a flow of sludge, towards and through fluid penetrable support structure until a layer of flocs has been established on the interior surface of the support structure,
a compression phase comprising increasing the pressure difference to a level being sufficient to compress the layer of accumulated flocs on the support structure into a filtration cake,
wherein,
the filtration cake is provided from activated sludge flocs and/or coagulated substances formed in a biological treatment device arranged upstream or downstream of the support structure.

11. The method according to claim 10 , wherein the sludge fed into the interior of the tubular elements are provided by separating the sludge formed in the biological treatment device by use of a separator into an effluent and activated sludge having a higher dry matter content than the effluent.

Assignees

• Grundfos Holding As

Inventors

• Jaeger Tom
• Dominiak Dominik Marek
• Gausmann Marcel

Classifications

• C02F3/1215

  Combinations of activated sludge treatment with precipitation, flocculation, coagulation and separation of phosphates · CPC title

• Y02W10/30

  Wastewater or sewage treatment systems using renewable energies · CPC title

• C02F2209/001

  Upstream control, i.e. monitoring for predictive control · CPC title

• C02F3/302

  Nitrification and denitrification treatment (C02F3/308 takes precedence) · CPC title

• C02F2303/20

  Prevention of biofouling · CPC title