CN102008847A

CN102008847A - Cleaning method of bag filter used in low temperature methanol washing process

Info

Publication number: CN102008847A
Application number: CN 201010218596
Authority: CN
Inventors: 鲍胜俭; 赵亚文; 吴潇
Original assignee: SHAANXI SHENMU CHEMICAL INDUSTRIAL Co Ltd
Current assignee: SHAANXI SHENMU CHEMICAL INDUSTRIAL Co Ltd
Priority date: 2010-07-02
Filing date: 2010-07-02
Publication date: 2011-04-13
Anticipated expiration: 2030-07-02
Also published as: CN102008847B

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

Background technology

Extensive use along with methyl alcohol and downstream product thereof, a collection of large-scale coal system methyl alcohol project is built up in succession, on the gas purifying technique Technology Selection, mostly select low-temp methanol washing process, the efficient wound tube heat exchanger of a large amount of uses of this technology, this heat exchanger heat exchange efficiency height, 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 has only 1～2 millimeter, impurity content is too much in the methanol solution, just cause heat exchanger to stop up easily, gently then the heat exchanger heat exchange efficiency descends, serious then switching heat-exchanger more, not only to pay expensive cost of equipment, more will bear huge stopping production loss.Therefore, the purification of methanol solution effective operation of filter just just seems particularly important.

Impurity in the recycle methanol solution is from three aspects: 1, the catalyst powder that goes out of the conversion band of gas, because Ammonic washing tower can't thoroughly be removed, a part is taken the covariant ventilation to the low-temperature rectisol system.In addition, be fit to generate carbonyl iron at the conversion section pressure and temperature, this material also can the covariant ventilation enter into low-temperature rectisol system formation impurity.2, in the running of low-temperature rectisol, owing to have water, hydrogen sulfide to exist, electrochemical corrosion takes place form 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 that generates occurs decomposing when the regeneration of methyl alcohol heat, decomposites solid impurities such as elemental sulfur and iron sulfide.3, system is in general overhaul, and the flushing displacement is not thorough, and it is too much to open manhole when maintenance, inspection, cross-ventilation causes corrosion, be exactly in addition in daily management, do not pay attention to on-the-spot funnel, the cleaning of lower storage reservoir and solution storage trough, cause some impurity from entering here.

These impurity all must be removed by filter, to prevent to enter wound tube heat exchanger, stop up and cause to deposit.Circulation along with solution, filter resistance will constantly rise, just must stop when reaching certain pressure reduction and carry out the labor cleaning, because it is from outside to inside that solution filters, impurity 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, when cleaning, can only walk to pay line simultaneously, so ceaselessly cleaning, in fact real filter time is seldom, impurity in the solution increases gradually, thereby threatens the stable operation of wound tube heat exchanger.

Summary of the invention

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

Technical solution of the present invention is as follows:

A, preparation steam condensate pipeline are prepared nitrogen pipeline to methyl alcohol filter outlet end socket place, and all are communicated with filter to methyl alcohol filter atmospheric valve, 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, drain solution, close tapping valve, drive 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, dilute, decompose by the greasy dirt of high temperature condensate liquid, and, impurity is thoroughly removed by the blowoff valve discharge filter to filter core inside;

D, after recoil is finished, close steam condensate pipeline hand-operated valve, continue to use the low-pressure nitrogen blowback, till the moisture in blowing clean filter;

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

Beneficial effect of the present invention is:

1, adopts 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 big leap ahead of effective filtration time of filter; this will reduce the content of impurity in the solution; the better protection wound tube heat exchanger, prolong they service life, stablize the heat exchange effect.

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

Description of drawings

Figure is a 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.

Following examples are the example explanation with 400,000 tons of/year coal system methyl alcohol projects all.

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

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

Claims

1. the method for cleaning of the used bag filter of a low-temp methanol washing process is characterized in that, may further comprise the steps:

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