Title of Invention

A METHOD FOR SEALING QUICK-CLOSING DOORS FOR CYLINDRICAL PRESSURE VESSELS

Abstract

This invention relates to a method for sealing quick-closing doors for cylindrical pressure vessels for a safe use of these vessels even with an atmosphere of burnable gases (e.g. hydrogen) and with variable inner pressure, like un-derpressure, ambient pressure and overpressure, using two lip-gaskets (8, 21) between the flange (1) of the pressure vessel body (10) and the flange (2) of the door (4), which are mounted in two concentric grooves in the flange (1) of the pressure vessel (10) around it's longitudinal axis in a way, that the lips face each other, and by having a space (25) between the gaskets (8,21), which is designed as a third concentric groove, and which is connected to a nitrogen source (23), which supplies a pressure, which is 1.2-2.0 times so high as the maximum pressure in the vessel, in order to press the lips of the gaskets to the flange (2) of the door and giving tight sealing of the vessel independent of the inner pressure, and comprising a tightness-control system (22), by continuous measuring the overpressure between the gaskets (8,21) and giving a signal, if the pressure value is out of its tolerance, by which a supervisor-system brings the vessel automatically into safe mode, depending on the actual stage of the process in the vessel, which can mean purging with nitrogen or backfilling with nitrogen and/or stopping the process.

Full Text

QUICK - CLOSING POOR FOR PRESSURE VESSELS Background of the invention This kind of door is well known, e.g, it is used for hot-air-autoclaves, autoclaves for steam curing and for heat treatment of metals under protective atmosphere in overpressure- and underpressure ranges of -1/+20 or more bar. As long as the protective atmosphere is inert, it is no problem to vary the process pressure during operation from underpressure to overpressure and visa versa. In case, that the protective atmosphere is burnable or explosive when it is mixed with oxygen, safety questions have to be considered. The quick-closing doors are equipped with a special gasket, which ensures safe operation when the vessel is on overpressure as well as when it is at underpressure. A risk is seen at ambient pressure in the vessel, when no pressure - difference is sealing the gasket. For sale use of the pressure vessels with quick-closing doors, in case of variable, inner pressure from underpressure to ovcrprcssure and with burnable atmosphere, e.g. hydrogen, measurements have to be found, which avoid a leakage at ambient pressure, and which gave alarm, when a leakage should occur. Brief summary of the invention The aim of the present invention is to propose a sealing system for quick closing doors for pressure vessels, enabling the disadvantages described above to overcome. Two different ways were found for safe sealing also for the use of hydrogen atmosphere in the pressure vessel. The first method is to use underpressure from both sides of the gasket to avoid penetration of hydrogen to the ambient air, or of air into the pressure vessel. The second method is to use overpressure between two special gaskets, which keeps the sealing tight, independent of the pressure in the vessel. In both cases the function of the scaling will be continuously measured, and a signal of any malfunction would bring the pressure vessel into a safe mode. Brief description of the drawings Fig. 1 is a cross section along the center line of the quick-closing door of a pressure vessel in the existing design. Fig. 2 is showing the sealing area in a larger scale. Fig. 3 is a cross section along the center line of the quick-closing door of a pressure vessel with underpressure design. Fig. 4 is showing the sealing area of Fig. 3 in a larger scale. Fig. 5 is a cross section along the center line of the quick-closing door of a pressure vessel with overpressure design. Fig. 6 is showing the sealing area of Fig. 5 in a larger scale. Fig. 7 is a front view of a quick-closing door of a pressure vessel. Detailed description of the invention In the various figures, the same reference numbers designate identical elements, e.g. number 1 designates always the flange of the pressure vessel, even when the .flange has different design in the figures 1-7. The invention relates to a method of sealing quick-closing doors 2, 4, 5, 6, 7, 9 for pressure vessels 1, 10, 11 which arc locked by a turnable ring 3 and sealed with a lip-gasket 8, and waterjackct all around 12, 13. The inner space 30 of the vessel contains the load which has to he treated, devices for heating, cooling thermal isolation, an atmosphere of protection-, or reaction-gas, gas circulating and gas guiding systems. Compared with the ambient atmosphere 3.1., the inner pressure can be underpressure, overpressure, or as well ambient pressure. When the inner pressure is at underpressure, the ambient pressure presses the door towards the gasket and makes it tight. When the inner pressure is at overpressure, this pressure presses the lip of the gasket to the doorflange 2, and also makes it tight. When the inner pressure is at ambient pressure, the sealing in undefined and this can create danger, if the atmosphere consists of burnable gas, e.g. hydrogen. According to the invention, a first method is suggested to get a safe sealing by using two gaskets 8, 21, and an overpressure space 24, 25, with a fitting 23 for a connection to a nitrogen source, which supplies a pressure in space 25, which is 1,2 to 2,0 times so high, as the maximum pressure in the vessel 30. The pressure in space 25 will press the lips of the gaskets to the flange 2 of the door, and will give tight sealing of the pressure vessel independent of the inner pressure. The pressure in space 25 will be continuously controlled during the whole process in the vessel, by connecting the pressure space via a fitting 22 with a pressure controller with alarm switch. In case of any malfunction the vessel will be brought into safe mode, depending on the actual stage of the process in the vessel, which can mean purging with nitrogen or backfilling with nitrogen and/or stopping the process. A second method is suggested to get safe sealing by having an underpressure space 15, 1(5, 1.8 around the gasket 8 on the flange 1 of the pressure vessel, and an underpressure space 26,14, 17 around the gasket on the flange 2 of the door. This underpressure space will be connected by flanges 19, 20 with a suction pump, and the pressure will be in the range of 1 - 50 mbar, and will be continuously controlled. In case of a leakage at the gasket, the underpressure controller will give a signal to bring the vessel in safe mode, depending on the actual stage of the process in the vessel. For loading and unloading, the door can be opened after bringing the inner pressure and the overpressure or underpressure spaces at the gaskets to ambient pressure, turning the locking ring 3 with a hydraulic cylinder 41, till the clamping teeth 44 are in the gaps 43, by pulling the handle 42 and turning the door around the hinge 40. WE CLAIM 1. A method for sealing quick-closing doors for cylindrical pressure vessels for a safe use of these vessels even with an atmosphere of burnable gases (e.g. hydrogen) and with variable inner pressure, like un-derpressure, ambient pressure and overpressure, characterized by using two lip-gaskets (8, 21) between the flange (1) of the pressure vessel body (10) and the flange (2) of the door (4), which are mounted in two concentric grooves in the flange (1) of the pressure vessel (10) around it's longitudinal axis in a way, that the lips face each other, and by having a space (25) between the gaskets (8,21), which is designed as a third concentric groove, and which is connected to a nitrogen source (23), which supplies a pressure, which is 1.2-2.0 times so high as the maximum pressure in the vessel, in order to press the lips of the gaskets to the flange (2) of the door and giving tight sealing of the vessel independent of the inner pressure, and comprising a tightness-control system (22), by continuous measuring the overpressure between the gaskets (8,21) and giving a signal, if the pressure value is out of its tolerance, by which a supervisor-system brings the vessel automatically into safe mode, depending on the actual stage of the process in the vessel, which can mean purging with nitrogen or backfilling with nitrogen and/or stopping the process. This invention relates to a method for sealing quick-closing doors for cylindrical pressure vessels for a safe use of these vessels even with an atmosphere of burnable gases (e.g. hydrogen) and with variable inner pressure, like un-derpressure, ambient pressure and overpressure, using two lip-gaskets (8, 21) between the flange (1) of the pressure vessel body (10) and the flange (2) of the door (4), which are mounted in two concentric grooves in the flange (1) of the pressure vessel (10) around it's longitudinal axis in a way, that the lips face each other, and by having a space (25) between the gaskets (8,21), which is designed as a third concentric groove, and which is connected to a nitrogen source (23), which supplies a pressure, which is 1.2-2.0 times so high as the maximum pressure in the vessel, in order to press the lips of the gaskets to the flange (2) of the door and giving tight sealing of the vessel independent of the inner pressure, and comprising a tightness-control system (22), by continuous measuring the overpressure between the gaskets (8,21) and giving a signal, if the pressure value is out of its tolerance, by which a supervisor-system brings the vessel automatically into safe mode, depending on the actual stage of the process in the vessel, which can mean purging with nitrogen or backfilling with nitrogen and/or stopping the process.

Documents:

2160-KOLNP-2005-CORRESPONDENCE 1.1.pdf

2160-kolnp-2005-granted-abstract.pdf

2160-kolnp-2005-granted-claims.pdf

2160-kolnp-2005-granted-correspondence.pdf

2160-kolnp-2005-granted-description (complete).pdf

2160-kolnp-2005-granted-drawings.pdf

2160-kolnp-2005-granted-examination report.pdf

2160-kolnp-2005-granted-form 1.pdf

2160-kolnp-2005-granted-form 18.pdf

2160-kolnp-2005-granted-form 2.pdf

2160-kolnp-2005-granted-form 26.pdf

2160-kolnp-2005-granted-form 3.pdf

2160-kolnp-2005-granted-reply to examination report.pdf

2160-kolnp-2005-granted-specification.pdf

2160-kolnp-2005-granted-translated copy of priority document.pdf

2160-KOLNP-2005-OTHERS 1.1.pdf