Views: 8 Author: Site Editor Publish Time: 2022-03-30 Origin: Site
Sludge drying refers to techniques that remove moisture from sludge as water vapour. This is distinct from methods in which sludge is dried merely mechanically, such as thickening or dewatering.
This is accomplished by a sludge dryer machine. Let’s look at this in more detail.
Why bother Drying Sludge?
There are three main reasons why drying sewage sludge may be beneficial:
• To reduce the sludge's water (or moisture) content and thus volume, more than mechanical techniques can
• To make the sludge acceptable for treatment using specific thermochemical processes, primarily incineration and pyrolysis
• To generate a stabilised product, that is substantially free of pathogenic organisms and odour and is not susceptible to decay
• The sludge's nature and consistency are also significantly altered when it is dried. Sludge dried to >65% dry solids (DS) can exist as pellets or, at higher solids concentrations of 90% or more, as a powder. Both forms are easier to transport than dewatered sludge with a larger water content, which exists as big lumps that can only be delivered by conveyor belt
• Reduced moisture content raises the organic carbon concentration and hence the calorific content of the sludge, which is generally reported in mega-Joules per kg sludge dry solids (MJ/kgDS)
Sludge Drying Applications
Dried or processed sludge has a wide range of applications, the most common of which is agricultural. When the drying process to make biosolids is done, the biosolids function as a fertiliser for crop harvesting. Crops absorb the organic nitrogen and phosphorus found in biosolids very efficiently since these plant nutrients are supplied gradually during the growing season. As the crop matures, it will be able to absorb these nutrients.
Aside from crop harvesting, processed sludge from a sludge dryer machine can be utilised as top dressing on golf course fairways, soil conditioner for park construction and athletic fields, and so on.
Top 4 Sludge Drying Tips
1) Sludge drying requires precise control. Dryers are often designed to avoid the'sticky' phase in order to generate a free-flowing granular or powdered product. This is accomplished through either back mixing or agitation.
2) Back mixing involves blending the influent dewatered sludge with portion of the dryer's pre-dried granular material to produce a sludge product with an average water content lower than that associated with the sticky phase. This combined product is then sent into the dryer to further reduce the water content.
3) Agitation prevents the creation of sticky sludge by efficiently mixing the sludge during the problematic sticky phase to keep it moving. This guarantees that the lumps disintegrate fast before becoming stuck.
4) Controlling sludge characteristics while drying is crucial. Under specific conditions and for certain sludge properties, sludge dust particles can explode, or solids can self-combust. These dangers can be mitigated by blanketing with an inert gas.
Advantages Of Sludge Dryers
-It has a highly dispersed process. All material surfaces function as effective drying areas.
-The entire system in a sludge dryer machine is computer-controlled; multiple drying temperatures and times can be configured to provide automatic drying based on different drying requirements. This can reduce labour and supplies while also increasing work efficiency.
-The internal construction improves cleaning and heat transfer. It is very adaptable to moisture and viscosity of materials and saves money. It also decreases maintenance costs and drying time.
-These sludge dryer machines have a long service life, which can lower production costs and increase production efficiency.
YKP Dryers can process any sticky, adhesive, or viscous sludge, as well as liquids such as slurry, without clogging. Furthermore, because of its basic structure and affordable cost, the money spent can be recovered by lowering industrial waste disposal costs.