SU1221476A1 - Method of cleaning vessel internal surface - Google Patents

Description

The invention relates to a method for cleaning the inner surface of capacitances from deposits of mineral and biological origin and can be used in heat and power engineering, for example, at thermal power plants, in particular, steam turbine condensers.

The purpose of the invention is to increase the efficiency of the process and its efficiency.

The proposed method consists in cleaning the inner surface of the containers by pumping water through them with a filler in the form of ice balls obtained by supplying air cooled to minus 5 to minus 10 ° C,

The drawing shows schematically an apparatus for carrying out the proposed method.

The device contains a condenser I of a steam turbine with tubes 2, an air pipeline 3 with a regulating valve 4, for supplying air: and to the generator 5 is cold, a pressure pipe 6 for supplying cooling water to a condenser equipped with a valve, To the main pipeline 6 a bypass pipeline 8 is connected to a valve 9 connected by a pipe 10 to an input chamber of the condenser I. The cold generator 5 is connected by a pipe P to a bypass pipe 8.

The inner surfaces of the tubes are cleaned as follows.

Cooling water with a temperature of 5-25 C flows through the pressure pipe 6 through the valve 7 into the tubes 2 of the condenser 1. Part of the cooling water is discharged through the valve 9 through the bypass pipe 8, into which cold air is fed through the nozzle 11, regulating the flow air by valve 4. When cold air and water are mixed in pipe 10, ice balls are formed, which then flow with cooling water and cold air into tubes 2 of condenser 1,.

Cleaning the inner surfaces of the tubes from the existing deposits occurs due to the friction of the ice balls against the walls of the tubes and the washing of the walls with a turbulent air-water system.

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flow, water-air flow, organic (soft) sediments, and ice balls clear the surface of both organic and mineral (solid) sediments.

In addition, due to a sharp decrease in temperature in the cooling tubes due to ice balls, the sediment layer is rapidly cooled. is given, which leads to thermal deformations of the sediments, causing their cracking, scalding and further entrainment by the air-water flow.

 The temperature of the cooling water entering the condenser through line 6 is 5-25 ° C, and its flow rate is determined by the type and mode of operation of the steam turbine. For example,

20 for turbine T-100-130 with condenser KG2-6200, the maximum flow rate of cooling water is 16000 m / h. The flow rate of water drawn through the bypass conduit 8 is up to 0.5% of the flow through the main pipeline fS,

The volumetric flow rate of the cooled air entering through the nozzle 11 is 8-10 per 1 kg of water,

30 flowing through conduit 8. The temperature of the cooled air in the nozzle 11 is (-5) - (). The diameter of the ice balls formed in the nozzle 10 is equal to O, 5-1SO mm,

35 and their number is determined by the flow rate of water through pipe 8 and cold air through pipe 11.

When using chilled

q.,

air above the temperature of -5 ° C ice — No balls are formed, and lowering the temperature below requires considerable costs for creating an installation that generates a cold, besides, at air temperatures of -10 ° C, thermal deformations of the cooling tubes themselves are possible.

The proposed method has a number of advantages compared to the known,

The cleaning efficiency of the internal surfaces of the tubes in a heat exchanger using cleaning elements is largely determined by the uniformity of their distribution throughout

55 tubes of the apparatus and the distribution density of the filler throughout the internal volume of the tubes in the flow of cooling water.

In the proposed method of cleaning tubes with ice balls, having a density close to the density of water and equal to Р 920 kg / m at Р 0.093 MPa and t 0 ° С, ice balls in a turbulent water-air flow will be distributed over the whole internal volume of the tube and, therefore, the entire inner surface of the tubes of heat exchangers, such as steam turbine condensers, will be cleaned.

According to a known method, the use of dry ice granules, the density of which is equal to Р 1560 kg / m with Р 0.1 MPa, is 1.56 and 1.7 times greater than the density of water and ice balls, respectively. As a result, the dry ice granules will always be mixed and mixed with a moving stream of cooling water in the lower part of the inner surface of the tubes, and therefore only this part will be cleaned.

For the same reason, the distribution of ice balls among individual tubes in the water chambers of turbine condensers will be more uniform compared with the distribution of dry ice granules, which also affects the efficiency of cleaning the tubes of the apparatus.

The noted drawbacks of the known method of cleaning tubes will be especially apparent with the widely used intermediate operating modes of heat exchangers with reduced speeds and consumption of cooling water, for example, in condensers of heat-generating turbines.

the cost-effectiveness of which increases with decreasing steam and cooling water consumption in the condenser tubes. The cost effectiveness of the proposed

cleaning of tubes is significantly higher than the efficiency of the method of cleaning hollow articles by a known method, since the costs associated with the formation of ice balls and their introduction

into the heat exchanger, significantly lower costs associated with the generation of dry ice, granulating it and putting these granules into the inside of the apparatus to be cleaned. The formation of ice balls in the proposed method takes place inside a pipeline intended for transporting and supplying the air-flow together with ice balls in

This unit's camera.

Thus, the creation and insertion of ice balls into the condenser in the proposed method does not require special devices, in contrast to the known cleaning method, in which the production of granules from dry ice and their supply into the heat exchanger requires the use of special additional devices or mechanisms.

If dry ice is used and evaporated in the water supply path of the heat exchangers, an excessive amount of carbon monoxide is formed, which has a negative effect on the micro and macro flora of the water basins, which is not acceptable in thermal power plants using

heat waste waters for the creation and development of fish farming.

Editor Y. Sereda

Compiled by V. Shimanska

Tehred V. Kadar Proofreader E. Sirohman

1601/46 Circulation 589 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, Proektna St., 4

Soda

Claims (1)

. METHOD FOR CLEANING THE INTERNAL SURFACE OF TANKS by pumping water with an ice filler through them, characterized in that, in order to increase the efficiency of the process and its efficiency, ice balls obtained by supplying air cooled from minus 5 to minus are used as filler 10 S.