The candle filter (titanium rod filter element) is an efficient vertical deep solid-liquid separation equipment, widely used for precision filtration of media such as urban pyrolysis water. Its core filtration principle and standard operation process are as follows, which are both theoretical and practical, and fit the actual industrial application scenarios.
I. Filtration Principle
Taking the titanium rod filter element as the core filtration unit, the candle filter adopts the “external pressure deep filtration” mode, combined with pre-coating filtration aid (diatomite) technology to achieve efficient solid-liquid separation. The specific principles are as follows:
Pre-coating Filtration Aid
Before filtration, pump the pretreatment liquid mixed with diatomite into the equipment, so that the diatomite adheres evenly to the surface of the titanium rod filter element to form a dense and porous pre-coating filter layer. This filter layer can fill the tiny pores of the titanium rod filter element, improve the filtration precision, and at the same time avoid solid impurities directly blocking the pores of the filter element, extending the service life of the filter element.
Core Filtration
The medium to be filtered (such as urban pyrolysis water) enters from the outside of the filter tank, and passes through the pre-coating filter layer on the surface of the filter element and the titanium rod filter element itself under pressure. The titanium rod filter element has the characteristics of high temperature resistance, corrosion resistance and uniform pores, which can further intercept tiny impurities; the pre-coating filter layer is responsible for intercepting most of the solid particles, realizing double filtration.
Solid-Liquid Separation
Solid impurities are efficiently intercepted on the surface of the filter element (forming a filter cake), while the filtered clear liquid is collected through the central tube inside the filter element and finally discharged from the clear liquid outlet, completing the solid-liquid separation process.
Filter Element Regeneration
When the filter cake on the surface of the filter element accumulates too much and the internal pressure of the equipment reaches the set threshold, the filter cake and residual impurities on the surface of the filter element are removed through steps such as forward blowing, reverse blowing and cleaning, so that the filter element restores its filtration performance and realizes cyclic use.
II. Standard Operation Process
For the filtration of urban pyrolysis water, the candle filter follows a closed-loop operation process of “pre-coating → filtration → slag removal → cleaning → reset”. Each step is closely connected to ensure filtration efficiency and equipment stability. The specific steps are as follows:
Pre-coating Stage
Pump the pretreatment liquid mixed with diatomite into the candle filter, adjust the feed speed, so that the diatomite adheres evenly to the surface of the titanium rod filter element to form a uniform and dense pre-coating filter layer. Stop feeding the pre-coating liquid when the pre-coating effect meets the set standard.
Formal Filtration Stage
Pump the urban pyrolysis water to be filtered into the candle filter, control the feed pressure and flow rate, so that the pyrolysis water stably passes through the pre-coating filter layer on the surface of the filter element and the titanium rod filter element. Solid impurities are intercepted on the surface of the filter element to form a filter cake. The filtered clear liquid is collected through the central tube inside the filter element and discharged from the clear liquid outlet. Monitor the filtration effect and equipment pressure in real time.
Filtration Termination Judgment
With the progress of the filtration process, the filter cake on the surface of the filter element gradually thickens, and the internal pressure of the filter continues to rise. When the pressure reaches the preset threshold, the filtration speed of urban pyrolysis water will decrease significantly. At this time, it is necessary to immediately stop pumping the raw slurry (urban pyrolysis water) to avoid excessive clogging and damage of the filter element or affecting the filtration effect.
Forward Blowing Stage
Enter the slag removal link, first start the forward blowing program, and introduce compressed air from the air inlet of the equipment. On the one hand, it completely discharges the unfiltered raw slurry remaining in the filter tank to the designated container; on the other hand, it uses the air flow to dry the filter cake (solid impurities) attached to the surface of the titanium rod filter element, preparing for the subsequent reverse blowing slag removal and ensuring thorough slag removal.
Reverse Blowing Slag Removal Stage
After the filter cake on the surface of the filter element is completely dried, switch to the reverse blowing mode. Compressed air is blown reversely from the inside of the titanium rod filter element to the surface. With the impact force of the air flow, the filter cake (solid impurities) accumulated on the surface of the filter element is completely blown off, so that the surface of the filter element is restored to cleanliness and the subsequent filtration efficiency is guaranteed.
Slag Discharge Stage
After the solid impurities are blown off by reverse blowing, open the slag discharge valve at the bottom of the filter, centrally discharge the fallen filter cake (solid impurities) to the designated waste collection device. Close the slag discharge valve after slag discharge to ensure good sealing of the equipment.
Filter Element Cleaning Stage
After slag discharge, pump the clear liquid into the candle filter to rinse the titanium rod filter element, thoroughly remove the tiny impurities and diatomite remaining on the surface of the filter element, ensure that the filter element fully restores its filtration performance, and avoid residual impurities affecting the next round of filtration effect.
Equipment Reset Stage
After cleaning, stop feeding the clear liquid, empty the residual clear liquid in the filter, check the sealing of each valve and interface of the equipment. After confirmation, the equipment returns to the standby state, waiting for the next round of filtration operation.
Post time: Mar-13-2026