Research On The Theory And Technology Of Foamed Gel Using For Fire Prevention

As coal spontaneous ignition and gas outburst accident pose a serious threat to the mine production and the safety of miners, the techniques like grouting, inert gases, inhibitor and gel were used to prevent coal spontaneous ignition. Although there are some disadvantages. The study provides a new foamed gel which combines the advantages of gel and foam to meet the coal mine practical demands and specific applications. Foamed gel formed by the exiting pouring system can fill the gob or the tunnel top collapse to extinguish the mine fire more efficiently for its ability of wide spread and upwards cumulated and its outstanding plugging capability makes it possible to enwrap coal, plug cranny and prevent air leak. The foamed gel can effectively prevent the coal spontaneous ignition as well as plug coal to prevent gas from release.The foamed gel formation mechanism has been studied, which based on the theories of surface chemistry, fluid mechanics, physical chemistry, thermodynamics, and polymer chemistry. Basing on the unique formation mechanism of foamed gel, the formula has been developed, which has the advantages of strong foaming ability, time-controllable for making gel, high quality of foam strength, long stabled time of foam, adaptable to wretched condition, and low cost, etc. The preparation system, simulates the field investigation, was set up to provide data for the application. The effects of foam height, reaction time and temperature of the foam viscoelasticity was analyzed by the rheology experiments,and the constitutive model was established to get the most influential parameter to the foamed gel viscoelasticity. The mathematics model of foamed gel's flowing in the pipeline was also established to calculate the parameters. The theory of foamed gel's preventing coal spontaneous ignition obtained from the analyses for the affections to coal spontaneous ignition. The high inhibit effect of foamed gel was proved by the inhibit experiments when the temperature decrease, oxygenation restrain and CO release restrain of the coal sample treated by foamed gel was obvious, and foamed gel shows different inhibit effects during different temperature. The outstanding plugging capability was also testified by the plugging test results. The foamed gel, combines the gel technique with foam technique, takes the advantage of gel's preservation of water, foam's accumulation and spreading out to prevent coal spontaneous ignition. Compared to the normal coal water sprager, the foam carried foamed gel overcasts large areas and has a upwards accumulation to solve the fire prevention and extinguishing problems such as covert fire in gob, perch fire, fire in tunnel top collapse and large-scale fire prevention and extinguishing in gob, etc. The system for pouring three-phase-foam, safe and reliable, convenient, successive flux poured, was set up to adapt a series of fire prevention and extinguishing problems.