Method for the continuous thermal hydrolysis of sludge with a high dryness value

Abstract

The invention relates to a method for the continuous thermal hydrolysis of sludge to be treated containing organic matter, and to a facility for implementing said method, said method comprising at least: a. a step of destructuring said sludge to be treated, producing destructured sludge; b. a step of thermal hydrolysis of said destructured sludge in a thermal hydrolysis reactor, producing hydrolysed sludge; and c. a step of cooling said hydrolysed sludge. According to the invention, said destructuring step consists in: introducing said sludge to be treated into a dynamic mixer; and heating said sludge from said dynamic mixer, the heating being generated by introducing, into a heat exchanger, both said sludge from the dynamic mixer and said hydrolysed sludge, this then inducing said cooling.

Description

technical field 1. Field of invention [0001] The field of the invention is that of treating sludges comprising organic matter, such as sludges from purification stations. More particularly, the present invention relates to a process for continuous thermal hydrolysis of sludge containing organic matter, with or without mixing with other waste materials containing organic matter. These sludges or wastes can e.g. originate from the treatment of domestic wastewater (e.g. sludge from digested or undigested purification stations, from pre-treated grease...), or from the treatment of industrial wastewater (e.g. wastewater from the agro-food processing industry, slaughterhouse effluents, spent molasses...), or consists of effluents from grease tanks. The term "sludge" will be used hereinafter to denote these sludges and / or wastes. Background technique [0002] 2. Existing technology [0003] Sludges from the treatment of wastewater, whether of domestic or industrial origin, can...

AI Technical Summary

Problems solved by technology

[0008] This batch method has the disadvantage of the need to manage the treatment cycles of different batches of sludge to be treated and the need to run certain equipment repeatedly, such as opening-closing e.g. valves, which leads to premature wear

When the maximum dryness limit value of 10% is exceeded, the observed pressure drop of the order of several bars depending on the dryness of the sludge to be treated and the difficulty in operating the exchanger make the method economically unprofitable

[0018] Another disadvantage is that these exchangers are also limited in capacity: therefore multiple exchangers need to be arranged in series to handle sufficient volume

Therefore, the energy consumption of the engine running the exchanger increases, which is disadvantageous in terms of energy

[0019] Another disadvantage of these exchangers that have a scraper shaft or use additional mechanical devices is related to their maintenance

Fouling associated with paste sludge recycling requires regular maintenance and is difficult to implement

Images