RU2131762C1 - Autoclave - Google Patents

Abstract

FIELD: apparatuses for carrying out physicochemical processes and filtering. SUBSTANCE: autoclave includes housing in which apparatus for agitating and discharging processed suspension is arranged. Apparatus also includes discharging chamber fluid-tightly joined with housing of autoclave and connected with discharging branch pipe of autoclave. Chamber includes convex removable cover with check valve. Multilayer filter forming cavity for filtrate connected with check valve is arranged in cover. Discharging chamber is connected by means of bypass pipeline with vapor-gas zone of autoclave. EFFECT: possibilities of filtering and discharging liquid product from apparatus at working values of pressure and temperature, keeping physicochemical properties of product and reducing its loss. 2 cl, 1 dwg

Description

 The technical solution relates to apparatus for carrying out physical and technical processes and filtering the product and can be used for processing substances in the form of dense suspensions or pulps at high pressure and temperature parameters, for example, in chemical industries, non-ferrous and rare metals hydrometallurgy.

 A reactor for carrying out physicochemical processes and filtering under atmospheric or overpressure is known, comprising a housing with a jacket, a mixing device with a drive, and a filter including a filter baffle located at the bottom of the reactor, a filtrate receiver, and a piston equipped with a pneumatic cylinder, while the piston is fixed in the piston reaction outlet fitting. When the reactor is operating in the mode of conducting physicochemical processes, the piston, being in the upper position in the filtrate receiver, is pressed to the filter baffle, blocking it, after the reaction is carried out and the solid phase precipitates, the piston is lowered, the reactor operates in the filtration mode (see certificate of the USSR N 1155288, class B 01 J 19/00, 1985).

 This reactor, designed to carry out processes under atmospheric or overpressure, cannot be used for conducting physicochemical processes and filtering under high pressure, including the processing of abrasive suspensions at high speeds of rotation of the mixing device. So, the filter baffle, which is in direct contact with the processed suspension, can be destroyed by abrasive grains at high speeds of rotation of the mixing device. When moving the piston from the filter baffle, both the baffle and the piston can be destroyed by pressure.

 A known autoclave for conducting physical and chemical processes under pressure, comprising a housing, a device for mixing and unloading the processed pulp located inside the housing, and a filtering device for sampling through it the liquid phase of the pulp, made in the form of a package of filter elements (rings) placed in bottom of the body. The device for moving and unloading the pulp is made in the form of a drive hollow shaft (rotor), on the outer surface of which blades are installed, and a pipe (stator), which is located inside the hollow shaft with the formation of an annular gap between it and the shaft (see US patent N 3902858, C. B 01 J 3/04, 1975).

 When using this autoclave for processing mineral concentrates of non-ferrous and rare metals, for example, for leaching mineral concentrates, the subsequent operations of separation of solid, liquid and gaseous substances are carried out in a chain of other apparatuses where the suspension (pulp) unloaded from the autoclave is transported. The disadvantage of this autoclave is the inability to filter and select the main liquid product directly in the apparatus while maintaining the temperature and pressure, which is necessary, in turn, to preserve the physicochemical properties of the product and avoid its losses, as well as to avoid overhead costs.

 The objective of the proposed technical solution is to carry out the processing of a substance in an autoclave at high pressure, temperature and rotation speeds of the mixing device and to ensure separate discharge of solid, liquid and gaseous substances from the autoclave at operating pressure and temperature.

 The problem is solved by providing filtration and selection of the main liquid product at the operating parameters of the apparatus. To accomplish the task, an autoclave containing a housing with a device for mixing and unloading the processed suspension placed inside the housing is equipped with an unloading chamber connected hermetically to the body and communicating with the unloading port of the device for unloading the processed suspension from the autoclave's body, while the unloading chamber has a convex removable cover with a shut-off a valve, a multilayer filter is installed in the lid, forming a filtrate chamber in communication with a shut-off valve, an unloading chamber is informed about aqueous duct with gas-vapor zone autoclave.

 The drawing shows the proposed autoclave intended for the processing of mineral concentrates, a vertical section.

 The autoclave includes a housing 1 with a removable cover 2, on which an electric drive and a mechanical seal (the latter are not shown in the drawing) of the shaft of the device for mixing and unloading the suspension processed in the autoclave are installed. On the cover 2 there is a hatch 3 for loading solid materials into the autoclave and a shut-off valve 4 for loading liquid and gaseous reagents under excessive pressure. A device for mixing and unloading the processed suspension consists of a hollow drive shaft 5 provided with blades 6 from the outside, and an unloading pipe 7, which enters the hollow drive shaft 5 with an annular gap, while the upper end of the pipe is located above the maximum suspension level in the autoclave. An unloading chamber 8, in communication with the autoclave nozzle 7, is hermetically connected to the bottom of the housing. The discharge chamber has a convex removable cover 9, equipped with a shut-off valve 10; a multilayer filter 11 is installed in the lid for fine cleaning of the solution, made of asbestos fiber and fine-porous material, such as porous ceramics or carbon graphite, which forms a filtrate chamber 12 in the lid, in communication with the shut-off valve 10. The discharge chamber is connected to the gas-vapor zone of the autoclave by a bypass pipe 13, equipped with a shut-off valve 14. A process valve 15 is also provided in the discharge chamber 8. The autocraw is equipped with a thermocouple 16.

 The autoclave operates as follows. Mineral concentrate is loaded into the autoclave through the hatch 3 in the form of a dense suspension (for example, when the solid to liquid mass ratio is 1: 3), the hatch is hermetically closed and the valve 14 is opened on the bypass pipe 13. The compressed inert gas is heated through the valve 4 under test pressure to check the integrity of the autoclave. After dropping the test pressure, the mixing device 6 and external heating of the autoclave (not shown in the drawing) are turned on and leaches for a predetermined time. At the end of leaching, close the valve 14 on the bypass pipe and open the valve 10 mounted on the lid of the discharge chamber. At operating parameters of pressure and shaft rotation frequency 5, the suspension is transferred from the autoclave to the discharge chamber to a multilayer fine filter 11 located in the cover 9. The filtered solution from the chamber 12 is transported through a pipe 17 to a sealed container of a given volume, after which the valve 10 is closed and unloaded through valve 4, the gas-vapor mixture is also in the corresponding sealed container (collectors are not shown in the drawing). The autoclave is cooled to normal temperature. Using valves 4 and 15, the reaction space is purged with inert gas to completely remove gaseous residues; open the cover 9 of the discharge chamber and by hydraulic pressure supplied through the valve 4, remove solid sediment from the discharge chamber 8. The autoclave is washed, the lid 9, the hatch 3 and all valves are sealed, the autoclave is ready for processing a new portion of the mineral concentrate.

Claims (2)

 1. An autoclave comprising a housing, a device for mixing and unloading the processed suspension placed in the housing, characterized in that the autoclave is equipped with an unloading chamber connected tightly to the autoclave body and communicated with the unloading port of the autoclave, the chamber has a convex removable lid with a shut-off valve in the lid a multilayer filter is installed, forming a chamber for the filtrate, in communication with a shut-off valve, while the discharge chamber is communicated by a bypass pipe with a steam-gas zone of the autoclave.  2. The autoclave according to claim 1, characterized in that the multilayer filter includes asbestos fiber and fine-porous material, such as porous ceramics or carbon graphite.