CN102008847B - Cleaning method of bag filter used in low temperature methanol washing process - Google Patents

Abstract

The invention relates to the technical field of coal chemical industry, in particular to a cleaning method of a bag filter used in the low temperature methanol washing process. Through the combination of the steam condensate at 130 DEG C and the nitrogen back washing, the method can effectively remove the oil stain and impurity adhered on the internal surface of the filter element, enhance the service efficiency of the filter, purify the purity of the solution, protect the heat exchanger and prolong the service thereof. The method provided by the invention simplifies the cleaning work, thereby saving the labor power as well as effectively preventing the damage of the filter element during the manual cleaning process.

Description

The method for cleaning of the bag filter that a kind of low-temp methanol washing process is used

Technical field

The present invention relates to coal chemical technology, particularly the method for cleaning of a kind of low-temp methanol washing process bag filter used.

Background technology

Extensive use along with methyl alcohol and downstream product thereof, a collection of large-scale coal methanol project processed builds up in succession, in the selection of gas purifying technique technology, mostly select low-temp methanol washing process, the efficient wound tube heat exchanger of a large amount of use of this technique, this heat exchanger heat exchange efficiency is high, and an onesize heat exchange area is more than the twice of common tubular heat exchanger.But also there is a deadly defect in this heat exchanger, be exactly that the shell side gap is too little, usually only has 1～2 millimeter, in methanol solution, impurity content is too much, just easily cause heat exchanger to stop up, gently the heat exchanger heat exchange efficiency descends, serious switching heat-exchanger more, not only expensive cost of equipment to be paid, more huge production suspension induced losses will be born.Therefore, namely effective operation of filter of the purification of methanol solution just seems particularly important.

Impurity in recycle methanol solution is from three aspects: the catalyst powder that 1, conversion gas is taken out of, because Ammonic washing tower can't thoroughly be removed, a part will be taken rectisol system to conversion gas.In addition, at the conversion section pressure and temperature, be applicable to generating carbonyl iron, this material also can enter into rectisol system with conversion gas and form impurity.2, in the running of low-temperature rectisol, owing to having water, hydrogen sulfide to exist, electrochemical corrosion forms impurity, particularly when the water content rising, corrosion also can strengthen, and the Another reason of corrosion is to generate carbonyl iron, and the reaction of carbon monoxide and iron is significantly strengthened in the existence meeting of hydrogen sulfide, and the carbonyl iron generated occurs decomposing when the regeneration of methyl alcohol heat, decomposite the solid impurities such as elemental sulfur and iron sulfide.3, system is in general overhaul, and the flushing displacement is not thorough, opens manhole when maintenance, inspection too much, cross-ventilation causes corrosion, be exactly in addition in daily management, do not focus on the clean of on-the-spot funnel, underground pond and solution storage trough, cause some impurity from entering here.

These impurity all must be removed by filter, to prevent from entering wound tube heat exchanger, and cause deposition to stop up.Circulation along with solution, filter resistance will constantly rise, just must stop and carry out the labor cleaning while reaching certain pressure reduction, because solution filter is from outside to inside, the impurity that is attached to the filter core top layer can remove with brush, but the greasy dirt impurity that is accumulated in the filter core the inside can't be removed, the resistance rising of filter is accelerated, clearing times increases, can only walk to pay line when cleaning simultaneously, so ceaselessly cleaning, the in fact real time of filtering is seldom, impurity in solution increases gradually, thereby threatens the stable operation of wound tube heat exchanger.

Summary of the invention

For the deficiency of prior art existence, the object of the present invention is to provide the method for cleaning of a kind of low-temp methanol washing process bag filter used.

Technical solution of the present invention is as follows:

A, preparation steam condensate pipeline, to methyl alcohol filter atmospheric valve, are prepared nitrogen pipeline to methyl alcohol filter outlet end socket place, and all are communicated with filter, all are furnished with hand control valve simultaneously;

B, when methyl alcohol filter pressure reduction is high in limited time to operation, close the filter terminal valve, the gas atmospheric valve that begins to rehearse, open tapping valve, drains solution, closes tapping valve, closes air bleeding valve, drives blowoff valve;

C, drive steam condensate hand control valve and nitrogen pipeline hand control valve, steam condensate outwards constantly recoils inside in conjunction with nitrogen, greasy dirt by the high temperature condensate liquid to filter core inside is diluted, is decomposed, and, by the blowoff valve discharge filter, impurity is thoroughly removed;

D, after recoil completes, close steam condensate pipeline hand-operated valve, continue use the low-pressure nitrogen blowback, until blow clean the interior moisture of filter;

After e, cleaning drying, the row's of closing trench showering guilding valve door, slightly opened filter inlet valve topping up, note slightly beginning to rehearse the air valve exhaust, standard-sized sheet terminal valve after the pressurising exhaust completes, the line valve is paid in pass puts filter into operation.

Beneficial effect of the present invention is:

1, adopt filter manner of cleaning up of the present invention; the effect of recoil is far longer than labor cleaning's effect; the cleaning frequency reduces greatly; make large leap ahead of effective filtration time of filter; this will reduce the content of impurity in solution; better protection wound tube heat exchanger, extend they service life, stablize heat transfer effect.

2, cleaning work is more simple, has both saved manpower, has effectively prevented again the damage of filter core in labor cleaning's process.

The accompanying drawing explanation

Figure is process flow diagram of the present invention.

The specific embodiment

Below in conjunction with drawings and the specific embodiments, the present invention is described in further detail.

It is the example explanation that following examples all be take 400,000 ton/years of coal methanol projects processed.

Prepare the steam condensate pipeline to methyl alcohol filter atmospheric valve from Mathanol regenerating tower reboiler condensate discharge pipe network, from low-pressure nitrogen pipe network preparation nitrogen pipeline to methyl alcohol filter outlet end socket, and steam condensate pipeline and the nitrogen pipeline of preparation all are communicated with filter, all is furnished with hand control valve 1,2 simultaneously.

The methyl alcohol filter is in operation pressure reduction during to the 150kpa left and right, closes the filter terminal valve, after gas blow-down pipe valve 5 pressure releases that begin to rehearse, opens tapping valve 4 the interior solution of filter is entered to underground storage tank, pass air bleeding valve 5 and tapping valve 4 after discharge opeing completes.After methyl alcohol emptying in the methyl alcohol filter, open hand-operated valve 1 and 2, by the 1.0MPa steam condensate (130 ℃) of Mathanol regenerating tower reboiler, in conjunction with nitrogen, recoil, lead pouring 3 from filter bottom and be disposed to trench.Note during recoil controlling the steam condensate valve opening, prevent the excessive filter core that washes out of aperture.Each recoil approximately can thoroughly be removed impurity in 30 minutes.After recoil completes, close steam condensate pipeline hand-operated valve 1, continue to use the low-pressure nitrogen blowback, until the moisture blown clean in filter is closed hand-operated valve 2 again.After the cleaning drying, the row's of closing trench showering guilding valve door 3, slightly opened filter inlet valve topping up, note slightly beginning to rehearse air valve 5 exhausts, standard-sized sheet terminal valve after the pressurising exhaust completes, the line valve is paid in pass puts filter into operation

Claims (1)

1. the method for cleaning of low-temp methanol washing process bag filter used, is characterized in that, comprises the following steps:

A, from Mathanol regenerating tower reboiler condensate discharge Pipe net disposition steam condensate pipeline to methyl alcohol filter atmospheric valve, the configuration nitrogen pipeline, to methyl alcohol filter outlet end socket place, and all is communicated with filter, the while all is furnished with hand control valve;

B, when methyl alcohol filter pressure reduction is high in limited time to operation, close the filter terminal valve, the gas atmospheric valve that begins to rehearse, open tapping valve, drains solution, closes tapping valve, closes air bleeding valve, drives blowoff valve;

C, drive steam condensate hand control valve and nitrogen pipeline hand control valve, steam condensate outwards constantly recoils inside in conjunction with nitrogen, greasy dirt by the high temperature condensate liquid to filter core inside is diluted, is decomposed, and, by the blowoff valve discharge filter, impurity is thoroughly removed;

D, after recoil completes, close steam condensate pipeline hand-operated valve, continue use the low-pressure nitrogen blowback, until blow clean the interior moisture of filter;

After e, cleaning drying, the row's of closing trench showering guilding valve door, slightly opened filter inlet valve topping up, note slightly beginning to rehearse the air valve exhaust, standard-sized sheet terminal valve after the pressurising exhaust completes, the line valve is paid in pass puts filter into operation.

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