CS270508B1 - Method of glass-maker's melting sets' towing paths cleaning - Google Patents

Abstract

The solution relates to a method of cleaning the exhaust of glass melting pathways deposition by dosing the feedstock containing calcium oxide CaO to the flue gas stream leaving melting aggregates. raw material containing CaO is dosed in such an amount that the resulting mixture of deposit and a feedstock containing the same calcium oxide CaO consisted of 30 to 60% SiO 2, 10 to 40% by weight alumina Al 2 O 3 and 25 to 50% by weight calcium oxide CaO and at given temperatures 1573 up to 1773 K was in liquid form stiect to lower parts of the exhaust routes where it is mechanically removed.

Description

The invention solves a method for cleaning the exhaust paths of glass melting aggregates from deposits containing silica, alumina and calcium oxide.

In the production of glass, raw materials with a strong chemical and particle size distribution are used. These raw materials react with each other at certain temperatures to form vigorous intermediates, the final product of which is glass. The melting of these raw materials usually takes place in melting aggregates heated by a mixture of thermal medium and air. The flue gases generated after the transfer of part of the heat to the raw materials are discharged through the exhaust paths into the chimney. Flow:

The flue gases in the smelting aggregates are entrained particles of raw materials into the exhaust routes, where under certain conditions they can react to form a deposit. These deposits in the operation of melting units cause problems of a technological nature. Clogging the exhaust paths of the melting units with exhaust shafts and ducts, recuperators or regenerators applied by reducing the permeability of these parts for flue gases and air, which deteriorates the combustion of the mixture of heat medium and air, increases pressure in the melters, increases corrosion of the melter when melting glass. The resulting deposits and the associated shortcomings and problems in the operation of the melting units are eliminated in vigorous ways. A mechanical cleaning method using specially adapted equipment is used to remove deposits in less heat-exposed and more accessible to the operator of the melting units in the places of the exhaust paths. This involves drilling, piercing or reflecting a deposit that is “in a loose or slightly sintered but non-sticky form. Removing a deposit that is sticky.

form, accompanied by a local increase in temperature at the site of deposition, e.g. additional burner

By increasing the temperature, the flow temperature of the deposit is reached and the deposit flows into the lower part of the exhaust paths, where it is mechanically removed. The disadvantage of this method is the higher corrosion of the grout at a given location due to the increase in temperature and the higher consumption of thermal medium. In many cases, even the desired flow temperature of the coating by local temperature increase cannot be achieved due to the fact that it is very high. The method of cleaning ceramic recuperators is the subject of Czechoslovakia. AO no. 158 340. It is characterized in that a low-melting compound is formed with the basic component of the high-melting coating, which is sodium sulphate, by adding sodium chloride in a given ratio, which is discharged in liquid form into the recuperator exhaust ducts, from which it is mechanically removed. The disadvantage of the method according to the Czechoslovak. AO no. 158 340 is that the addition of sodium chloride in a given ratio can only be used for deposits whose main component is sodium sulfate.

The resulting deposit consisting of 30 to 70% by weight of silica SiO 2, 15 to 50% by weight of alumina Al 2 O 3 and 10 to 25% by weight of calcium oxide CaO and the associated problems in operating melting units are best eliminated or substantially reduced by using a method According to the invention, the essence is that a raw material containing calcium oxide CaO is metered into the flue gas stream leaving the melting aggregates so that the resulting mixture of deposit and metered raw material containing calcium oxide CaO consists of 30 to 60% by weight of silica SiO 2. up to 40.% by weight of alumina with ^z >;

Al 2 O 3 and 25 to 50% by weight of calcium oxide CaO and at temperatures of 1573 to 1773 K was in liquid form capable of flowing into the lower parts of the exhaust paths, where it is mechanically removed.

The implementation of the invention ensures less laborious and more economical removal of the deposit, which is in an adhesive form, even from places which are inaccessible to the operator of the melting units.

The effect of the addition of calcium oxide CaO on the formation of the liquid form of the deposition is able to be seen from the following table, which shows the results of laboratory tests in which model deposits with the stated chemical composition were subjected to heat exposure for one hour and the formation and amount of the flowing form were monitored. . The results obtained from laboratory tests confirm that the deposit consisting of 30 to 60% by weight of silica SiO2, 10 to 40% by weight of alumina Al 2 O 3 and 25 to 50% by weight of calcium oxide CaO at temperatures of 1573 to 1773 K is in liquid form capable of flowing.

CS 270 508 Bl

Chemical composition Mass concentration Flow temperature model deposition components model deposition ^si ° 2 49% At ₂ ° 3 32% > 1773 K. CaO 19% ^s i ° ₂ 41% At ₂ ° 3 27% 1623 K CaO 32% · sio ₂ 38% At ₂ ° 3 25% 1573 K CaO 37% ^s i ° ₂ 32% ^A1 2 ° 3 21% 1623 K CaO 47 4 SiO ₂ 26% At ₂ ° 3 17% > 1773 K. CaO 57%.

Examples

During the melting of the E-glass, a sticky layer formed in the exhaust part above the recuperator.

containing -47% by weight of silica SiO ₂ , 29% by weight of alumina Si

AljOg and 24% by weight of calcium oxide CaO. Holes were drilled in the excavation of the side wall of the exhaust part, above the recuperator, in the place above the deposit. A dosing device consisting of a hopper for the dosing raw material was built into one of these openings:

. dispenser and control device. The device fed a raw material containing calcium oxide CaO into the flue gas stream leaving the melter, which in this case was:

nec. The device worked in a cycle: 25 seconds dosing, 105 seconds non-dosing. The metered limestone, in contact with the coating, formed a mixture consisting of 38% by weight of silica SiO ₂ , 25% by weight of alumina Al ₂ O ₃ and 37% by weight of calcium oxide CaO.

This mixture, in the temperature at the given point of the exhaust part above the recuperator equal to 1633 K, got into the liquid form and gradually flowed down and / or dripped under the recuperator, where it was mechanically selected. The dosing of limestone through this opening took place until the deposit at the reach of the dosing device was removed to the extent that it was determined to be suitable. Then, the dosing device was moved to other openings and the limestone was metered in the manner already mentioned until such a final state that it did not cause and difficulties in operating the melting unit. _;

Claims (1)

OBJECT OF THE INVENTION i * í Process for cleaning the exhaust paths of glass melting aggregates from a deposit containing 30 to 70% by weight of silica SiO ₂ , 15 to 50% by weight of alumina Al ₂ O ₃ and 10 to 25% by weight of calcium oxide CaO, characterized in that into the flue gas stream from - raw materials coming from melting aggregates, the raw material containing calcium oxide CaO is dosed so that at a temperature of 1573 to 1773 K at the given application point the mixture formed from the dosed raw material and the deposit consists of 30 to 60% by weight of SiO ₂ , 10 to 40% by weight alumina Al ₂ O ₃ and 25 to 50% by weight of calcium oxide CaO.