RU2297959C1 - Method of warming and draining of high viscosity products from transport and stationary reservoirs - Google Patents

Abstract

FIELD: materials handling facilities.

SUBSTANCE: according to proposed method of warming and draining of high-viscosity products, some product is taken out of reservoir and is heated in external fire heating device. Warm product is returned into reservoir, and recirculation of product in reservoir is carried out until all product is heated to required temperature. Then product is drained from reservoir. Initial cycle of taking out of mixture of cold product and heated product is done using preliminarily heated product which is filled in starting reservoir before warming and draining process. Initial cycle of taking out of product is done after filling pipeline of recirculation system with heated product from starting reservoir. Mixture of cold and heated product from reservoir is taken out and delivered into receiving manifold along low-temperature pipeline and directed into fire tube oven. Cold product is heated in fire tube oven at preset rate of product passing along tubes. Part of heated product is returned into reservoir through outlet, pump, pressure manifold and high-pressure pipeline.

EFFECT: reduced power consumption of pump and technological layout of plant.

5 cl, 1 dwg

Description

The invention relates to the unloading of highly viscous and highly hardening products (petroleum products, molasses, fats, etc.) from containers for storage and transportation.

There are various ways to increase the fluidity of a product, including dissolving a viscous or solidified product with a low viscosity liquid solvent, adding a depressant to lower the pour point of the product, etc.

In Russia, for example, the largest distribution for the discharge of viscous oils and oil products from railway tanks was heated by saturated steam supplied directly to the oil product.

However, this method is not only ineffective and harmful to the environment, but also reduces the commercial quality of the petroleum products themselves.

Known are the technologies for heating and draining the product without mixing it with the heat carrier, based on heating the product taken from the tank in an external heat exchanger, where the heated product is not in direct contact with the heat carrier, and returning the heated product to the tank (circulation heating). However, in the proposed methods in the heat exchangers use superheated steam, through which the oil is heated. In this case, it is necessary to install expensive equipment in the form of a boiler room, a complex system of heat exchangers through which steam is passed under high pressure, which significantly increases the cost of the process of heating and draining highly viscous products.

The invention is known "Tubular heater", patent RU No. 2256846, publ. 2005.07.20, IPC F 22 B 7/00, in which there is a heat exchange element in the form of a food coil. The invention provides an expansion of the arsenal of technical means used in the oil and chemical industries for the heat treatment of thermolabile and thermally unstable liquids having technological and other restrictions on the maximum heating temperature. However, this heater is used only for complex technological processes of demulsification and stabilization of oils in oil fields. The technical task to be solved is the fight against overheating of media prone to thermal decomposition due to the heterogeneity of the heat flux density in the furnace.

The invention is known "Cylindrical tube furnace", application RU No. 92014598, publ. 1995.01.27, IPC F 22 B 21/26, F 27 B 5/00, in which the heated medium passes sequentially through the furnace coils, and then it is sent to the consumer. However, the invention does not solve the problem of heating and draining highly viscous products from transport tanks.

The invention is known "Device for heating and draining viscous liquids from a container", patent RU No. 2114041, publ. 1998.06.27, IPC B 65 G 69/20, B 65 D 88/74, using a suction pipe, a pump, a pressure pipe with a heat exchanger connected in series and equipped with an impermeable partition of any shape. However, the process of heating the liquid in the tank is based on the organization of recirculation with the help of an impenetrable partition in a small volume: in the zone of supply and selection of liquid, and not using the heating of the liquid in a cylindrical fire furnace.

The invention is known "Method of heating and draining fuel oil from railway tanks", patent RU No. 2112733, publ. 1998.06.10, IPC B 65 G 69/20, B 65 D 88/74, in accordance with which the fuel oil is pumped from the tank by the pump through the heat exchanger and the heated oil is fed after the heat exchanger back to the tank. The invention solves the technical problem of the possibility of pumping cold fuel oil from the tank, and also allows to increase the thermal power supplied to the tank during the heating process, to simplify and make the pump control system more reliable. However, it does not solve the technical problem of reducing energy consumption, since the pump transfers cold fuel oil from the tank, as a result of which the high viscosity of cold fuel oil greatly reduces consumption due to the high hydraulic resistance of the pump inlet line when cold oil is fed into the system, which means that the energy consumption increases and the pump consumables worsen due to increased viscous friction inside it. This problem is partially solved due to the fact that part of the fuel oil after the heat exchanger is passed into the suction pipe, however, the pressure manifold with the pump is installed on the low-temperature pipe, which worsens the pump operation mode. In addition, the heat exchanger is used according to the traditional scheme, namely, passing superheated steam through the heat exchanger, which significantly increases the cost of the installation for implementing this method.

The invention is known "A method of heating and draining highly viscous products from a container and a device for its implementation", patent RU No. 2204514, publ. 2003.05.20, IPC B 65 D 88/74, B 65 G 69/20, B 67 D 5/04, according to which the product in a mixture with a preheated product is taken from one part of the tank, this mixture is passed through an external heat exchanger, where it is heated to a predetermined temperature, and the heated product is returned to the same container, recirculating the product until the product is heated in the container to the desired temperature, followed by complete draining of the product from the container. The invention allows to reduce the heating and draining times of highly viscous products having a high pour point, such as cold fuel oil. However, it does not allow to solve the technical problem of reducing energy consumption, reducing the cost of the recirculation plant, as well as improving the environmental friendliness of the method.

Closest to the proposed technical solution is the invention "A method of heating and draining highly viscous products from a container and a device for its implementation", patent RU No. 2260552, publ. 2005.09.20, IPC B 65 D 88/74, B 65 G 69/20, in accordance with which a cold product is taken from the bottom of the tank, heating it in an external heat exchanger, returning the heated product with a pump to the tank with product recirculation to heating the product in the tank to the required temperature at which the product is drained from the bottom of the tank, and the initial cycle of selection of a mixture of cold product with a heated product is carried out using a pre-heated product, which before starting the heating and draining process filling a starting capacitance that is installed in a product recirculation system. The invention solves the technical problem of ensuring the continuity of the selection of cold product from the bottom of the tank due to the continuous supply of heated product to the bottom of the tank during the entire process of heating it. However, it does not allow to solve the technical problem of reducing energy consumption, reducing the cost of the recirculation plant, as well as improving the environmental friendliness of the method.

Due to the fact that all the proposed recirculation systems use traditional heat exchangers, in which superheated steam is circulated, with the help of which fuel oil is heated, the fuel oil recirculation system is significantly complicated when it is drained from the tanks. It is required to install a boiler room in front of the heat exchanger, which ensures the production of superheated steam. In such systems, the quality of the drained fuel oil is significantly impaired, and the method is not environmentally friendly, since the mixture of water and fuel oil enters the environment during operation of the circulation system. Known tubular fire furnaces for heating fuel oil are used only for a complex technological process of heating fuel oil, for example, demulsification and stabilization of oils. When heating and draining highly viscous products from transport tanks, such fire ovens are not used due to the use of the traditional operating mode of the furnace, which can lead to uneven heating of the oil, and therefore increase the flammability of the system. In addition, in traditional schemes, the pressure header is located directly behind the transport capacity, which complicates the operation of the pumping station and increases the energy consumption of the pump pumping highly viscous products before they are heated in the heat exchanger.

The technical result of the invention is a significant reduction in the cost of the recirculation system, reducing the energy consumption of the system, improving the quality of the product, as well as increasing its environmental friendliness.

The technical result is achieved as follows. The heating and draining of highly viscous products, for example, from transport tanks, is carried out by taking the product from the tank, heating it in an external heating device, returning the heated product to the tank with product recirculation until the product is heated in the tank to the required temperature, after which the product is drained from the tank, moreover, the initial cycle of selection of a mixture of a cold product with a heated product is carried out using a pre-heated product, which before starting the heating and draining process filling a starting capacitance that is installed in a product recirculation system. The method differs from the known ones in that the initial selection cycle is carried out after filling the recirculation system pipeline with a heated product from the starting tank, the mixture of cold and heated product from the tank is taken into the receiving manifold via a low-temperature pipeline, through which the mixture is sent to a fired tube furnace, and the cold product they are heated in a fire tube furnace with a given speed of product passing through the pipes, and part of the heated product is returned to the tank by selecting it from a high temperature pipeline through the branch, pump, pressure header and high pressure pipe. In a recirculation system, for example, by creating the required vacuum, the amount of heated product entering the pressure header and high pressure pipe is controlled. In particular, the heated product is injected into the bottom of the tank through a high-pressure pipe located inside the intake pipe, they can additionally install the pump in the low-temperature pipe after the intake manifold to ensure the selection of the product from the container at a variable speed. In addition, the product can be drained from the tank by gravity after reaching heating of the product in the tank to the desired temperature. For example, a product can be drained from a container with a portion of the heated product taken into a recirculation system.

The proposed technical solution is illustrated in the drawing, which shows a functional diagram of a recirculation system.

The method is as follows. The recirculation system includes a starting tank (1) with a low-power heating device (2), a receiving manifold (3), into which a mixture of heated and cold product from the tank (4), a low-temperature pipeline (5), through which the mixture enters the fire a tube furnace (6), a high-temperature pipeline (7), a branch (8), a pump station (9) containing a pump (10) installed in front of the pressure header (11), and a pump (12) installed in the low-temperature pipe (5) and working if necessary. The pressure header (11) extends inside the intake manifold (3). From the furnace (6) with a high-temperature pipeline (7) using a pump (10) of a pump station (9), hot fuel oil is fed through a branch (8) to a pressure header-pipe (11) or through a tank (13) and a pressure header (11) into the container (4).

Heating and maintaining the required temperature of fuel oil in the tank (13) is carried out according to the cycle: entry from the high-temperature collector (7) into the tank (13) and exit from the tank (13) through the pump (10) of the pump station (9) to the pressure header (11) or directly through the pump (12) of the pump station (9) to the furnace (6).

Before heating and draining the product from the tank (4), the recirculation system is filled with pre-heated to a temperature 25 ° C below the flash point, for example, fuel oil, which in this case is a product from the starting tank (1), after which the pumps are switched on (10) , 12) pump station (9). The pumps (10, 12) turn on either simultaneously, or first turn on the pump (10), and then, if necessary, the pump (12).

The product from the intake manifold (3) through the pump (12) of the pump station (9) is fed into the furnace (6) through a low-temperature pipeline (5) with a given design flow rate.

After heating the product in the furnace (6) to a temperature 25 ° C below the flash point of the product through the high-temperature pipe (7) and pump (10) of the pump station (9), the product is fed to the pressure header (11) and then to the bottom of the tank (4 ) with adjustable pressure.

The initial cycle of heating the product to the required temperature is carried out using the filling product recirculation system from the starting tank (1). The product from the intake manifold (3) passes through a low-temperature pipeline (5) to a tubular fire furnace (6), through which it passes at a given design speed. After passing through the furnace (6), the product heats up and enters the high-temperature pipeline (7), from which through the outlet (8) the heated product enters the pressure header (11). During the initial cycle, the entire flow of the heated product enters the pressure manifold due to the adjustable power of the pump (10) of the pump station (9). In subsequent cycles of the recirculation system, the heated product passing through the furnace (6) partially enters the reservoir (13), and partially into the outlet (8). The amount of heated product returned to the container (4) is controlled by the vacuum created by the pump (10). The heated product through the pressure header (11) is injected under pressure into the bottom of the tank (4), providing mixing of the heated product and cold product from the tank. The pressure at which the injection is also regulated by the pump (10). Next, the mixture from the cold and heated product is taken from the tank (4) through the intake manifold (3) and enters the low-temperature pipeline (5), from which the mixture enters the tube fire by gravity or using the pump (12) of the pump station (9) a furnace (6) with the required characteristics for the heating temperature, through which the mixture flows at a given design speed. In the process of passing the product through the pipes through the furnace, the product is heated to the required temperature due to the heat transfer of the pipe walls passing through the flame of the furnace with the required characteristics of combustion intensity. In addition, the heating temperature of the product is also regulated by the rate of passage of the product through the pipes. Then, the heated product enters the high-temperature pipeline (7), from which it partially enters the reservoir (13), is partially withdrawn through the outlet (8), and the pump (10) into the pressure header (11). Next, the cycle is repeated again until the temperature of the product in the container (4) rises to the desired value. After that, the product is poured into the tank (13) through the intake manifold (3), a low-temperature pipeline (5), a furnace (6) and a high-temperature pipeline (7). The selection of the product in the branch (8) does not occur, because pump (10) is turned off. At the same time, the furnace is turned off if the temperature in the container (4) has reached the required value. If the product is completely drained from the tank (4), but there is a need to maintain the required product temperature in the tank (13), the product is removed from the tank (13) through the pumps (10, 12) of the pump station (9) and the low-temperature pipeline (5) to the furnace (6) in a closed ring, and then through a high-temperature pipeline (7), without selection in the outlet (8) of the product, return it to the tank (13).

The tubular fire-fired product heating furnace is designed and manufactured with all the necessary characteristics and has a sufficient control system for the temperature of the heated product and the furnace operation safety system.

Heating and maintaining the required temperature of the product in the tank (13) according to the above cycle is also carried out by the estimated consumption of the product and by controlling the operational characteristics of the furnace.

Thus, the proposed method of fire heating can significantly reduce the technological scheme of the entire installation, exclude from it a heat exchanger with a boiler room, which significantly reduces the cost of the installation and the process of draining the product from the tank.

In addition, the proposed method can significantly reduce the energy intensity of the pump, because pumping of the product by the pump is carried out after heating the product to a temperature of 40-50 ° C, and therefore, the energy consumption is reduced by 12 times compared with the operation of the pump pumping the product at a temperature of 25 ° C.

In addition, the proposed method significantly improves the environmental friendliness of the entire recycling system, because a heat exchanger is not used, in which water vapor is most often used as an agent.

Since it is not necessary to drain waste water that has impurities when servicing the system, the environment is not damaged.

The entire recirculation system is designed to operate in a closed cycle that prevents the product being pumped into the environment.

Claims (6)

1. The method of heating and draining highly viscous products from transport and stationary tanks, which consists in the selection of the product from the tank, heating it in an external fire heating device, returning the heated product to the tank with product recirculation until the product is heated in the tank to the required temperature, after which the product is drained from the tank, and the initial cycle of selection of a mixture of cold product with a heated product is carried out using a preheated product, which The start of the heating and draining process fills the starting tank installed in the product recirculation system, characterized in that the initial selection cycle is performed after filling the recirculation system pipeline with a heated product from the starting tank, the mixture of cold and heated product is taken from the tank into the receiving manifold via a low-temperature pipeline, through which the mixture is sent to a fired tube furnace, and the cold product is heated in a fired tube furnace with a given passage speed I am piping the product, and part of the heated product is returned to the tank by taking it from the high-temperature pipeline through an outlet, pump, pressure header and high-pressure pipeline. 2. The method of heating and draining according to claim 1, characterized in that by creating the required vacuum regulate the amount of heated product entering the pressure header and high pressure pipe. 3. The method of heating and draining according to claim 1, characterized in that the heated product is injected into the bottom of the tank through a high pressure pipe located inside the receiving pipe. 4. The method of heating and draining according to claim 1, characterized in that the pump is additionally installed in the low-temperature pipe after the intake manifold to ensure the selection of the product from the tank with an adjustable speed. 5. The method of heating and draining according to claim 1, characterized in that the draining of the product from the tank is carried out after reaching heating of the product in the tank to the desired temperature. 6. The method of heating and draining according to claim 1, characterized in that the product is drained from the tank with the selection of part of the heated product in the recirculation system.