RU2501767C1 - Method of convective drying of ceramic products with regeneration of drying agent in tube by gasodynamic temperature stratification - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of drying includes regeneration of drying agent, which consists in fact, that drying agent is supplied into drying chamber towards subject of drying, with further drying and re-supply into drying chamber. Drying of drying agent is performed in tube of gasodynamic temperature stratification.

EFFECT: increased energy efficiency of drying process.

2 dwg

Description

The invention relates to processes for drying ceramic products.

It is known that the drying cycle is carried out mainly in convection-type drying plants and is characterized by its duration and energy consumption, which is associated with the need to ensure uniform volumetric heating and dehydration, as well as to exclude the appearance of microcracks and chips. In addition, up to 70% of thermal energy in convective-type drying plants is lost with the spent drying agent.

A known method (see RF patent No. 224227), comprising supplying a coolant, for example hot air, into the chamber towards the drying object and discharging the spent coolant with its subsequent recirculation to a specific area of the drying chamber or into the mixing chamber and supplying water vapor to the coolant to regulate the pressure water vapor in the coolant. The disadvantage of this method is that the use of water vapor provokes corrosion of the walls of the device, which reduces the life of the device. In addition, significant amounts of energy are required to prepare water vapor, which reduces the energy efficiency of the drying process.

A known method of temperature stratification in a supersonic dispersed stream (see RF patent No. 2334178), which consists in the fact that the supersonic pipe temperature stratification contains a separation chamber, an external subsonic channel, an internal supersonic channel, an outlet pipe of a supersonic channel, a supersonic diffuser, an output pipe of a subsonic channel , supersonic nozzle, device for swirling a supersonic dispersed flow in a supersonic channel. Using the method allows to increase the heat flux between subsonic and supersonic dispersed flows and to increase the efficiency of the method of temperature stratification.

The closest technical solution is the method (see RF patent No. 2187770), comprising contacting the drying agent with the material to be dried, separating moisture from the spent drying agent, heating it to a drying temperature, and subsequent recycling. Moisture is separated from the spent drying agent by its direct contact with a liquid absorber, the temperature of which is controlled by changing the flow rate of the latter depending on the amount of spent drying agent and its moisture, after which it is additionally drained by pumping it through a regenerative heat exchanger made in the form of a heat pipe, and then through a regenerative heat exchanger, made in the form of a heat pump. The disadvantage of this method is the high energy intensity and duration of the regeneration cycle of the spent drying agent.

A common feature of the prototype and the proposed method is the contacting of the drying agent with the dried material, the separation of moisture from the spent drying agent and the subsequent recycling of the drying agent.

The technical result of the proposed method is to increase the energy efficiency of the drying process due to the regeneration of the spent drying agent in the gas-dynamic temperature stratification pipe.

The technical result is achieved by the fact that the drying agent is fed into the drying chamber towards the drying object, then it is dried and again fed into the drying chamber,

A feature is that the drying agent is drained in a gas-dynamic temperature stratification pipe.

The essence of the proposed method is illustrated by drawings, which depict a flow chart of drying with the regeneration of a drying agent in a gas-dynamic temperature stratification pipe (Fig. 1) and a gas-dynamic temperature stratification pipe device (Fig. 2).

The proposed method consists in the fact that the spent drying agent (OCA) from the drying chamber 1 is fed into the separation chamber 2 of the gas dynamic temperature stratification pipe 3, where it is divided into two streams that are sent to the external subsonic channel 4 and the internal supersonic channel 5, where its drainage and heating, the centers of condensation are dispersed particles fed towards the flow of a drying agent (CA). Next, the drying agent in the inner supersonic channel 5 passes through a supersonic diffuser 6 and is sent to the output pipe 7 of the internal supersonic channel 5. In turn, the subsonic dispersed stream passing through the external subsonic channel 4 is directed to the output pipe of the external subsonic channel 8. a dispersed stream passing through a supersonic nozzle 9 acquires a speed exceeding the speed of sound. Next, the supersonic dispersed stream is twisted, passing a device 10 for swirling a supersonic dispersed stream located in the internal supersonic channel 5. In the swirling dispersed supersonic stream, the dispersed particles inertially fall onto the wall of the internal supersonic channel 5. The dried drying agent (OCA) is taken from of the internal supersonic channel 5 of the pipe 3 of gas-dynamic temperature stratification, pass through a dust collector 11, where the wet dispersed phase. The drying agent (PCA) thus regenerated through the device 12 for preparing and distributing the drying agent into the zones of the drying chamber 1 is returned to the drying chamber 1.

Claims (1)

The drying method, including the regeneration of the drying agent, namely, that the drying agent is fed into the drying chamber towards the drying object, then dried and again fed into the drying chamber, characterized in that the drying agent is dried in a gas-dynamic temperature stratification pipe.

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