Heavy-Duty Municipal Sludge Dewatering Belt Filter Press - 副本

Heavy-Duty Municipal Sludge Dewatering Belt Filter Press - 副本

Category： Belt Filter
Energy Consumption: <15 kW/h
Water Recycling: Closed-Loop System
Noise Level: <65 dB
Certifications: CE
INQUIRY EMAIL

Belt filter press description

A belt filter press (BFP) provides sludge dewatering by pressing the sludge to force the water through a permeable medium. The process produces a cake (the dewatered product) having a dry solids (DS) content of 30% or more in the case of primary sludge. This is to be distinguished from the lower-energy gravity belt thickener process which achieves a maximum DS content of ~10%.

A BFP combines drainage and mechanical pressure sequentially to remove water. The equipment normally comprises 2−3 recirculating belts, with two belts combining at some point to compress the sludge and squeeze water from it.

Belt filter press principle

Many belt filter press technologies contain a second pressure zone comprising a series of rollers through which the two belts pass with the sludge solids retained between them. The rollers in this high pressure zone apply tensioning (i.e. stretching) to the belts, exerting both shearing and compressive forces on the sludge which further release more water.

Some BFP technologies are based on a three-belt system, where the gravity belt is independent of the two pressurising belts. This allows the recirculation rate for the thickening operation to be separately adjusted from the dewatering operation.

In common with the gravity belt thickener, the belts are subject to cleaning with water spray to limit the plugging of the filter belt pores. The waste washwater is combined with the filtrate.

The overall performance of the BFP is dependent on the feed sludge source and characteristics and the dosing conditions. As with all other thickening and dewatering technologies, primary sludges – both raw and anaerobically digested – are more readily filtered than waste activated sludge (WAS).

Belt filter technical sheet

Sludge Kinds	Input Concentration %	Capacity m³/h	DS Capacity kg/h	Moisture of Cake %	PAM Consumption %(DP/DS)
Unconcentrated Aerobic Sludge	0.5~1.5	15~30	150~300	~80 (+2)	2~5
Concentrated Aerobic Sludge	2~4	6~12	200~300	~80 (+2)	2~5
Digested Sludge	3~6	7~15	300~400	<80	2~5
Unconcentrated Primary Sludge	0.8~2.0	18~35	300~400	<80	2~5
Concentrated Primary Sludge	3~5	6~12	300~400	<80	2~5
Paper-making Activated Sludge	0.5~2.5	15~35	200~400	<78	3~7
Printing and Dyeing Mixed Sludge	1~3	10~25	180~350	75~78	3~10

Model selection

Model	Belt Width	Sludge Concentration	Outlet Concentration	Capacity	Power
DNT-1000	1000mm	2-4%	15-25%	6-12	1.49kW
DNT-1500	1500mm	2-4%	15-25%	12-15	2.05kW
DNT-2000	2000mm	2-4%	15-25%	15-25	2.6kW
DNT-2500	2500mm	2-4%	15-25%	35-50	4.1kW

Belt Filter Press Advantage

A belt filter press is also known for its high capacity throughput, as it is designed to handle excess capacity. It has low initial costs and low energy running costs, however, if throughput is less than 4 million gallons per day, the belt filter press may be less cost efficient than liquid transport, hiring a processing facility, or utilizing non-mechanical dewatering methods such as drying beds or reed beds.

Belt filters are less effective at processing some feeds. Unless the feed is well mixed from a digester, the use of belt filters will be more costly when processing a feed with varying solids content as this requires more operator attention, raising staffing costs. Feeds with high grease and oil content can lower the solids percentage in the cake by blinding the belt filter and all feeds need to be screened to protect the belt from being damaged by sharp objects. The type of feed may also affect the washing process. The belt filter needs to be washed frequently which consumes large amount of water and time. Water and time wastage, as well as the associated costs can be reduced by automating the washing system and using effluents.

Belt filter press features

Belt press filters are designed for solids capacity, by weight or volume, rather than wastewater flow. Solids concentration must be determined based on the concentration of primary solids in the feed and further solids that may precipitate during treatment. Solids concentration for a process will vary, thus the design must have the capacity to deal with varying feed solids concentration.

The feed to a belt press filter depends on the type of solids, desired product and filter design. For most sludge types the feed dry solids concentration is typically in the range of 1-10%. The resulting dewatered sludge (or cake) dry solids concentration typically falls in the range of 12-50%. Dilute feed solids concentration results in a cake of higher moisture content whilst a higher feed solids concentration yields an improved solids filtration rate and drier end product.

Belt filter press applications

The belt filter is mainly used for dewatering of sludge and slurry and juice extraction from apples, pears and other fruits, as well as grapes for winemaking, etc. Belt filters are used both municipally and industrially in a range of areas including urban sewage and wastewater treatment, metallurgy and mining, steel plants, coal plants, breweries, dyeing, tanneries, as well as chemical and paper factories.

Contact Us for a Consultation