SU885457A1 - Method of thawing loose frozen rock - Google Patents

Description

(5A) METHOD FOR DETERMINING SUSPENDED PERMAFROST

I

The invention relates to the mining industry, in particular, to methods for thawing permafrost underground sand, laid out in dumps on the surface.

There is a known method of thawing frozen rocks due to the heat of solar radiation, which consists in removing the thawed layer by layers and transferring it to the PZ dumps using earth-moving equipment.

The disadvantage of this method is low thawing efficiency and low utilization of the means transporting the rocks and the dump.

Closest to the present invention is a method involving heat exchange between a moving warm gas and a rock laid in a heap. The flue gases formed as a result of fuel combustion, mixed with air, are supplied through the gas outlet

into the common collector and into perforated pipes. Gases are blown out of the pipes by a fan perpendicular to the surface of the soil, which is defrosted and then heated to the required temperature C21.

The disadvantage of this method is the cyclical nature of the work on thawing the cleaning of rocks, large heat losses due to the fact that

10 is heated only slightly. volume top layer of rocks. In addition, to clean the hot layer of rocks, it is necessary to dismantle the gas supply pipe system and mount it again.

15 for subsequent thawing of the rock layer. Thawing of rocks to the full depth is ineffective and long-lasting, since only conductive heat transfer in the thickness of the massif comes off with a significant reflection of heat flux from the surface of the heated section, moreover, drying of the upper layer of rock leads to a sharp decrease in its heat conductivity.

. at the same time for the formation of hot gases requires large expenditures of fuel (electricity),

The purpose of the invention is to increase productivity and reduce energy costs.

This goal is achieved by the fact that heat exchange is carried out by passing atmospheric air through the rock from the surface of the heap to its base to create an estimate of the permanently discharged zone in the latter.

In addition, the thawed layer is periodically removed and the process is intensified by moistening the surface of the blade.

The drawing shows a dump of loose frozen rock and installation for implementing the method.

Before laying out the dump 1, a layer of loose frozen rocks 2 is placed on which perforated tanks 3 are installed, connected by a central duct to the Central duct 4 has an outlet outside the blade 1. After installing the duct system, mine frozen rocks are dumped to the full height of the blade 1.

In the summer, with the onset of a positive air temperature, a fan installation 5 is connected to the output of the central air duct k.

Then, to intensify the thawing process, the outer surface of the blade 1 is moistened, for example, by watering it with water from a jetting machine or from a sprinkler (not shown). The ventilation unit 5 is turned on and a vacuum is created, causing forced directed movement of humidified atmospheric air 6 from top to bottom between the frozen rocks of the dump 1, through the perforated containers 3, the air duct k, the fan 3 and into the atmosphere.

The movement of warm and humid atmospheric air between lumps of the pale rocks promotes intensive heat and moisture exchange between them. Water vapor contained in the air is condensed on the surface of frozen rocks. The resulting heat from condensate and the warmth of atmospheric air heat the rock mass. The most intensive thawing of frozen rocks occurs on the outer surface of the blade 1, since in this area the maximum temperature of the air is positive.

The thawed upper layers of the rocks are periodically removed with a bulldozer or scraper up to the moving boundary of 7 thawed and frozen rocks. The exposed surface of the frozen rocks of the dump 1 is re-moistened to intensify the thawing process.

When air moves through the blade's pores, the air is cooled, and as a result, the thawing of rocks at the base is the last. Such technology eliminates the clogging (plugging) of perforated holes in containers.

The layer of loose rocks 2 below the metal pipes provides drainage of the water that has accumulated as a result of thawing of ice particles in the dump, and prevents flooding of the holes 8 in the perforated containers 3. By increasing the flow of water and air, the time of defrosting the entire blade 1 can be reduced.

In the proposed method, heat and moisture-mass transfer takes place in an array of rocks by combining thawing and rock removal processes, and additional fuel costs for producing hot gases are eliminated, and the amount of combined work during ductwork is significantly reduced.

The use of the invention will give. the ability to significantly increase the intensity of thawing of rocks and reduce the cost of maintenance work 3-A times.

Claims (3)

1. A method of thawing loose, frozen rocks, consisting in heat exchange between a moving warm gas and a rock laid in a dump, is due to the fact that, in order to increase productivity and reduce energy costs, heat exchange is carried out by passing the warm gas through the rock from the surface of the blade to its the base due to the creation in the latter of the zone of constant rarefaction. 2. The method according to claim 1 is also distinguished by the fact that periodically the removal of the crushed rock layer is carried out. 3. Method pop. 1 and 2, characterized in that, in order to increase the intensification of the process, the surface of the blade is moistened. / ;. ° n. / o .j :. 4 - - O -:. Al. /; .- -. . . and . 9; . -. 11.; L .AO P / 1 -V // 4. .1OO OOi. . y / X 100 OO1 -. sr IOO about oh. . . S // - / o-lSfiSiJ O. with oooojcP ool., Q . Lit h I I 543 Sources of information taken into account in the examination 1.Pavlov A.V. Soil heat exchange with the atmosphere in the northern and temperate latitudes of the USSR. Yakutsk, 1975,. 2. USSR author's certificate number 1792 2, cl. E 02 F 5/30, (prototype).