RU2335691C2 - Method of filling vessels of smaller volumes with high-purity high-pressure nitrogen with monitoring of humidity and device for its implementation - Google Patents

Abstract

FIELD: technological processes; chemistry.

SUBSTANCE: in suggested method of vessels filling initial material is dried down to required norm of humidity by dew point at deep drying installation, gas pipeline of cryocompressor is blown with dried nitrogen until required norm of humidity is obtained, internal cavity of filled vessel prior to filling is subjected to multiple pressure "pulling-drop" (so called "rinsing") with system of electromagnet valves, pressure of dried gas is increased in cryocompressor, and required pressure is obtained in filled vessel of deeply dried gaseous nitrogen with guaranteed norm of humidity by dew point. Device for implementation of method for filling of small volume vessels with high-purity high-pressure nitrogen contains pressurised vessel, installation of deep drying, cryocompressor of flow type and protected filling device. Cryocompressor consists of designed airtight volume for required pressure at single defrosting, Dewar bottle with liquid nitrogen for condensation of dried nitrogen, systems of electromagnet valves intended for drying of internal cavity of filled vessel, high-precision manometers, stop valves, nitrogen flow meter and safety valves.

EFFECT: reduction of works cost and power inputs.

2 cl, 1 dwg

Description

The invention is of general industrial importance and will find application, for example, when charging cylinders with especially pure dry nitrogen with an overpressure of up to 100 MPa (1000 kgf / cm ² ) and a humidity norm at the dew point of not higher than minus 110 ° C. The quality of the refueling gas is ensured by 100% analytical control at all stages.

The closest analogue of the invention is the patent EP 0823584, F17C 5/06, 1998.02.11 "Method and equipment for filling gas", including filling nitrogen in a pressure vessel (HP) by connecting the end of the gas supply pipe to the filling pipe in a cleaned through compartment.

The composition of the installation for refueling with nitrogen VD includes:

- the first clean compartment, where the filling pipeline and the device for its cleaning with preserving highly pure gas are stored and connected to refueling cylinders [1].

- a second clean compartment having a through opening and closing hole for connecting the filling pipe to the supply pipe, as well as for cleaning it with preservative gas.

The disadvantages of this method and device are:

- the complexity of the design and high material costs,

- a complex and long piping system,

- lack of control of the humidity of the refueling gas.

The aim of the invention is: to reduce energy consumption when refueling VD vessels with clean dry nitrogen, reducing the cost of work and obtaining a guaranteed rate of humidity and gas pressure in a refilled vessel.

This goal is achieved by drying the feedstock (gaseous nitrogen GOST 9293-74) to a moisture norm of not higher than minus 110 ° C at the dew point and increasing the pressure of pure deeply dried gas to 100 MPa (1000 kgf / cm ² ) using a flow-type cryocompressor, principle whose work is based on the use of the physical properties of nitrogen [3, 4].

The proposed method of filling vessels with high-purity high-pressure nitrogen (HP), includes filling high-purity nitrogen gas into a high-pressure gas vessel and differs in that the source material, nitrogen gas, is dried to the required moisture norm at the dew point in a deep-drying unit. Then, the gas pipeline of the installation is purged to increase the pressure with dried nitrogen until the required humidity level is reached. Before filling, the internal cavity of the refueling vessel is subjected to repeated “set-release” of pressure (“rinsing”) by the system of electromagnetic valves of the installation to increase the pressure until the required humidity level is reached, and the pressure of the dried gas is increased by the cryocompressor until the required pressure of deeply dried nitrogen gas in the refueling vessel is guaranteed humidity standard for dew point.

A device for implementing a method for filling vessels with especially pure VD nitrogen is characterized in that it includes a deep nitrogen dehydration unit, a device for increasing the pressure of deeply dried nitrogen, and a protected refueling device. To obtain very pure dry VD dry nitrogen with a guaranteed rate of humidity and pressure, a pressure boosting system is used, consisting of a flow-type cryocompressor with a calculated tight volume for the required pressure at a single heating, a Dewar vessel with liquid nitrogen to condense dried nitrogen, a system of electromagnetic valves, designed for drying the internal cavity of the refueling vessel, high-precision pressure gauges, shut-off valves, hygrometer, pressure regulator, nitrogen flow meter and safety valve valves. The VD vessel is charged with especially pure nitrogen gas in a protected refueling device, which includes a filling nozzle and a device for cooling the VD vessel with a pipeline.

The drawing shows a diagram of a device for implementing the proposed method of refueling. The device consists of sources of feedstock 1 and 2 (gaseous nitrogen GOST 9293-74 in standard cylinders with a capacity of 40 l with a gas pressure of 15 MPa (150 kgf / cm ² )), shut-off valves 3 and 4, necessary to replace used cylinders without stopping the process dehydration, VD 7 gearbox with pressure gauges 5 and 6, deep dehydration units 8, installations for increasing the pressure of deeply dried nitrogen 28 and a protected refueling device 46.

The main elements of the deep-drying unit 8 are: shelf-type adsorption apparatuses 14 and 15, shut-off and control equipment 9, 10, 11, 12, 22, 23, 24, 25, thermostats 16 and 17, meter-regulators 18 and 19, pressure gauges 20 and 21, a rotameter 13, a filter for final cleaning of mechanical impurities 26 and a hygrometer 27 [5].

The main elements of the installation for increasing the pressure of deeply dried nitrogen 28 are: a flow-type cryocompressor 36 with a calculated hermetic volume for the required pressure at a single heating, a Dewar vessel 37 (thermos), shut-off valves 31, 33, 34, 38, 40, 41 and 43, safety valves 29, 30 and 32, pressure gauges 35 and 39, pressure regulator 44, rotameter 45 and hygrometer 42.

Protected refueling device 46 consists of a filling nozzle 47 and a device for cooling the vessel 48 with the pipe 50.

The refueling method is implemented as follows.

Open the valve 3 and the gear 7 on the manometer 6 set the pressure of the drained gas to 1.0 MPa (10.0 kgf / cm ² ). Open the valve 9 or 10 and the gas pressure of 1.0 MPa (10.0 kgf / cm ² ), which is controlled by a pressure gauge 20 or 21, is sent for deep drying to one of the prepared adsorption apparatuses 14 or 15. Switching by valves 9, 10, 23 and 24. Drying is carried out at a gas operating pressure in the adsorption apparatus of 1.0 MPa (10.0 kgf / cm ² ), and regeneration is performed under pressure close to atmospheric and temperature (350-360) ° С. Gas for regeneration is supplied through valve 22 and discharged to a discharge, while the gas flow rate is controlled by flowmeter 13, the heating temperature of the thermostats is set and controlled by meter-regulators 18 and 19.

Dried and purified nitrogen is supplied from the installation through the valve 25 and the finish filter 26, while the flow passes through the measuring chamber of the hygrometer 27. Thus, the nitrogen is dried to achieve the required humidity level at the dew point [5].

Before refueling, the inner cavity of the vessel 49 is thoroughly cleaned by repeated washing with alcohol and purged with clean dry nitrogen. Then, they are installed in the protected filling device 46 and the filling fitting 47 is fixed. Cooling gas (air) is supplied to the cooling device 48 via a pipe 50 to the walls of the vessel 49 to prevent it from heating up during the filling with VD nitrogen.

Dried nitrogen with a pressure of 1.0 MPa (10 kgf / cm ² ), which is controlled by a manometer 35, is fed into a cryocompressor 36 through a valve 33 and a valve 34. The valve 41 is opened and the pressure regulator 44 sets the nitrogen flow rate to purge the path through the rotameter 45 The gas flow passes through the measuring chamber of the hygrometer 42. In order to maintain the sensor of the hygrometer 42, which is in the “dry” state in the measuring chamber, a bypass line for supplying dry nitrogen through the valve 43 is provided [6]. Next, the internal cavity of the filled vessel 49 is dried through the valve 38 by the method of "rinsing" using a system of electromagnetic valves 33 and 31, which allow for dialing and pressure relief operations by switching one toggle switch.

After drying the inner cavity of the vessel 49, the valves 38 and 43 are closed and the volume of the cryocompressor 36 is placed in a Dewar vessel 37 with liquid nitrogen to condense the dried nitrogen.

After drying the inner cavity of the vessel 49, the valves 38 and 43 are closed and the volume of the cryocompressor 36 is placed in a Dewar vessel 37 with liquid nitrogen to condense the dried nitrogen.

At the end of the condensation process, which is determined by the termination of the intense boiling of liquid nitrogen, the VZ valve and valve 33 are closed, the Dewar vessel is removed and the cryocompressor 36 is heated to positive temperatures by a fan. At the same time, an increase in pressure is monitored by pressure gauge 39. Safety valves 29 and 32 are designed to prevent overpressure of more than 1.5 MPa (15 kgf / cm ² ), and valve 30 - more than 40 MPa (400 kgf / cm ² ).

Upon reaching the required pressure in the cryocompressor 36, the valve B2 is smoothly opened and the vessel 49 is filled with clean, dry high-pressure nitrogen. Seal the vessel 49 with the filling nozzle 47 and release the pressure in the cryocompressor 36 by the valve 40 to zero.

Literature

1. Patent EP 0823584, F17C 5/06, 1998.02.11.

2. A.K. Mikhailov, V.P. Voroshilov. Compressor machines. - M.: Energoizdat, 1989.

3. R. Hefer. Cryovacuum technology. - M .: Energoizdat, 1983.

4. Magazine "New Industrial Technologies", 2/2006, p.19, Central Research Institute of Nuclear Technology, Department of Nuclear Ammunition Industry.

5. Installation of deep drying of nitrogen "UGOA-2.5 / 10". Operation manual KD 04-032102 OOZRE. - M.: NTA "Science", 2003.

6. Hygrometer "IVA-9". Operation manual KD 4-02.010 OM. - M.: NTA "Science", 2003.

Claims (2)

1. A method of filling vessels with especially pure high-pressure nitrogen (VD), including filling nitrogen into the VD vessel, characterized in that the source material is dried to the required humidity level at the dew point in a deep-drying unit, and the gas pipeline of the installation is purged to increase the pressure with dried nitrogen Before reaching the required humidity norm, the internal cavity of the refueling vessel is subjected to repeated “pressure set-up” (“rinsing”) by a system of electromagnetic valves before filling, increasing the pressure e dried gas in the cryocompressor and receive the necessary pressure in the refueling vessel of the deeply dried gaseous nitrogen with a guaranteed humidity level at the dew point. 2. A device for implementing the method of filling vessels with highly pure high-pressure nitrogen, characterized in that it is equipped with a deep-drying unit, a unit for increasing the pressure of deeply dried nitrogen and a protected refueling device, moreover, to obtain very pure dry nitrogen of the high pressure with a guaranteed norm of humidity and pressure use the installation to increase the pressure, which includes: a flow-type cryocompressor, with a calculated tight volume for the required pressure with a single heating, a vessel Dyuara with liquid nitrogen for condensation of dried nitrogen, a system of electromagnetic valves designed to dry the internal cavity of the refueling vessel, high-precision pressure gauges, locking equipment, hygrometer, pressure regulator, nitrogen flow meter and safety valves.