SU877244A1

SU877244A1 - Draining apparatus

Info

Publication number: SU877244A1
Application number: SU802872392A
Authority: SU
Inventors: Владимир Федорович Плешаков; Владимир Иосифович Макеев; Борис Александрович Иванов; Анатолий Петрович Чугуев; Николай Васильевич Филин; Александр Александрович Родэ; Константин Захарович Тушабрамишвили; Игорь Евгеньевич Дудкин; Василий Степанович Сердюк; Юрий Владимирович Красовицкий; Игорь Васильевич Переездчиков; Владимир Гаврилович Кулаков; Лев Григорьевич Антоненко; Юрий Никитович Чернушкин
Original assignee: Предприятие П/Я А-3605
Priority date: 1980-01-16
Filing date: 1980-01-16
Publication date: 1981-10-30

Description

Изобретение относится к машино строению, преимущественно химическому, нефтехимическому и криогенному, и может быть использовано в любой отрасли) народного хозяйства, где возникает необходимость дренажа (т.е. организован-^* ного, упорядоченного сброса) больших количеств взрывоопасных, токсичных и других опасных газов (например водорода, метана, азота, кислорода, побочных продуктов химических производств), а также паров сжиженных криогенных продуктов (например жидких азота, кислорода, водорода, гелия и др.) в атмос феру.'The invention relates to a machine building, mainly chemical, petrochemical and cryogenic, and can be used in any industry) of the national economy, where there is a need for drainage (i.e., organized, orderly discharge) of large quantities of explosive, toxic and other dangerous gases (e.g. hydrogen, methane, nitrogen, oxygen, by-products of chemical industries), as well as vapors of liquefied cryogenic products (e.g. liquid nitrogen, oxygen, hydrogen, helium, etc.) into the atmosphere. '

В зависимости от вида выбрасываемого газа для обеспечения безопасности современных промышленных объектов и предотвращения загрязнения окружающей среды в настоящее время используются разнообразные дренажные устройства, работа которых основана на принципах самопроизвольного рассеивания газов под действием атмосферной турбулент2 ности, разбавления выбрасываемого опасного газа до предельно допустимых концентраций, сжигания выбрасываемого опасного газа, либо на их комбинации.Depending on the type of gas emitted, to ensure the safety of modern industrial facilities and to prevent environmental pollution, various drainage devices are currently being used, the operation of which is based on the principles of spontaneous gas dispersion under the influence of atmospheric turbulence, dilution of the hazardous gas emitted to the maximum permissible concentration, and combustion of the emitted dangerous gas, or a combination thereof.

Известны устройства для сброса газов, содержащие вертикально установленную дренажную трубу, по которой газ отводится на большую высоту и выбрасывается в атмосферу без дожигания либо с дожиганием, колпак, предназначенный для предотвращения загрязнения трубы от метеорологических осадков, песка,, пыли, либо огнепре·? градитель, предназначенный для предотвращения проскока пламени внутрь трубы при малых расходах выбрасываемого горючего газа £1].Known devices for the discharge of gases, containing a vertically installed drainage pipe, through which gas is discharged to a high height and released into the atmosphere without afterburning or afterburning, a cap designed to prevent pollution of the pipe from meteorological precipitation, sand, dust, or fire · a shredder designed to prevent flame penetration into the pipe at low flow rates of combustible gas emitted £ 1].

Недостатком известных устройств. является существование очень больших факелов или зон опасных концентраций при выбросе с помощью них газов в атмосферу, соответственно, с дожиганием или без дожигания. Так, длина факела при выбросе водорода, метана и : других горючих газов составляет 220250 диаметров дренажной трубы при турбулентном режиме выброса и может составлять при небольших диаметрах дренажных труб более 400 диаметром при ламинарных режимах выброса. Оценки длин зон опасных концентраций по известным закономерностям для случаев струйного выброса азота, кислорода и горючих газов без дожигания показывают, что длины зон опасных концентраций также могут достигать 200-400 диаметров дренажной трубы.A disadvantage of the known devices. there is the existence of very large flares or zones of hazardous concentrations when gases are released into the atmosphere, respectively, with or without afterburning. Thus, the length of the plume during the release of hydrogen, methane and: other combustible gases is 220,250 diameters of the drain pipe with a turbulent discharge mode and can be more than 400 diameters with small diameters of the drain pipes with laminar discharge modes. Estimates of the lengths of zones of hazardous concentrations according to well-known patterns for cases of jet emission of nitrogen, oxygen and combustible gases without afterburning show that the lengths of zones of hazardous concentrations can also reach 200-400 diameters of the drainage pipe.

Кроме того, при переменных расходах выбрасываемых газов указанные ра^-<5 меры факелов и зон опасных концентраций становятся неконтролируемыми, что приводит к необходимости при назначении пожарных разрывов и безопасных расстояний ориентироваться на максияальные значения указанных величин. Применение дренажных устройств подобного типа на современных промышленных объектах, где используются дренажные . трубы диаметром до 400 мм и более, при-₂₅водит к выборе безопасных расстояний к большим экономическим затратам, связанным с нерациональным использованием строительных площадей, а также расходами на проектирование и изготовление вспомогательных магистралей (трубопроводов, арматуры, каналов воздухозабора и т.п.).In addition, at variable discharge rates, the indicated sizes ^ - <5 measures of torches and zones of hazardous concentrations become uncontrollable, which leads to the need to focus on the maximum values of these values when assigning fire breaks and safe distances. The use of drainage devices of this type in modern industrial facilities where drainage is used. pipe diameters up to 400 mm and more, pri- ₂₅ leads to choosing safe distances large economic costs associated with inappropriate use of building space as well as the cost of designing and manufacturing auxiliary lines (piping, valves, and intake channels, etc.) .

Известны также устройства эжекторного тапа, основанные на способе ограничения зон опасных концентраций за счет разбавления струи выбрасываемого опасного газа нейтральным компонентом ^2].Ejector tapas are also known, based on the method of limiting hazardous concentration zones by diluting the jet of hazardous gas emitted with a neutral component ^ 2].

Недостаток подобных устройств состоит в необходимости запасов больших количеств нейтральных газов для разбавления выбрасываемых опасных газов.The disadvantage of such devices is the need to stockpile large quantities of neutral gases to dilute hazardous gases emitted.

Наиболее близким к предлагаемому является ультракинематический диффузор, предназначенный для выброса водорода с дожиганием. На конце вертикальной дренажной трубы диффузора укреплена тарелка с центральным круглым отверстием, диаметр которого равен диаметру дренажной трубы. Тарелка может быть выполнена как плоской, так и в виде усеченного конуса с углом раствора от 0 до 360°. Другим элементом, укрепленным на конце трубы,. является колпак в виде тела вращения. Колпак в нижней рабочей части имеет форму усеченного гиперболоида вращения, вершина которого обращена к тарелке, при чем диаметр колпака равен или несколько превышает внутренний диаметр дренажной трубы и много меньше диаметра тарелки. В рабочем состоянии оба элемента устройства - тарелка и колпак - образуют с дренажной трубой сужающийся в виде конфузора кольцевой канал. Минимальный зазор в канале выбирается в зависимости от числа Маха истекающей струи водорода и допустимых потерь давления. Для устойчивой работы устройства площадь наиболее узкой части кольцевого канала выбирается в 2 или более раз меньше площади поперечного сечения дренажной трубы.Closest to the proposed is an ultrakinematic diffuser designed to release hydrogen with afterburning. At the end of the vertical drainage pipe of the diffuser there is a plate with a central round hole, the diameter of which is equal to the diameter of the drainage pipe. The plate can be made both flat or in the form of a truncated cone with a solution angle from 0 to 360 °. Another element mounted on the end of the pipe. is a cap in the form of a body of revolution. The cap in the lower working part has the shape of a truncated rotation hyperboloid, the top of which faces the plate, with the diameter of the cap equal to or slightly greater than the inner diameter of the drain pipe and much smaller than the diameter of the plate. In working condition, both elements of the device — the plate and the cap — form an annular channel tapering in the form of a confuser with a drain pipe. The minimum gap in the channel is selected depending on the Mach number of the outgoing stream of hydrogen and the allowable pressure loss. For stable operation of the device, the area of the narrowest part of the annular channel is selected 2 or more times smaller than the cross-sectional area of the drainage pipe.

В основу работы ультракинематического диффузора заложены 2 принципа: пространственное осесимметричное разделение потока и прилипание истекающего потока к поверхности тарелки. Выбрасываемый газ на выходе из трубы распределяется по сужающемуся кольцевому каналу, ускоряется в нем до скоростей равных и более скорости звука и выбрасывается в виде горящего факела, при этом факел как бы прилипает к тарелке [3].The operation of the ultrakinematic diffuser is based on 2 principles: spatial axisymmetric separation of the flow and adhesion of the outflowing flow to the surface of the plate. The ejected gas at the outlet of the pipe is distributed along the tapering annular channel, accelerates in it to velocities equal to or more than the speed of sound and is ejected in the form of a burning torch, while the torch adheres to the plate [3].

Основным недостатком указанного устройства является необходимость поддержания для устойчивой работы достаточно высокого избыточного давления в трубопроводах газосброса для обеспечения выброса заданного расхода газа через узкую щель с площадью поперечного сечения, в несколько раз меньшей площади поперечного сечения трубы. В случае же, если площадь поперечного сечения кольцевой щели в самом узком месте при рекомендованных в данном устройстве размерах колпака равна или превышает площадь поперечного сёчения трубы, длина факела и опасной зоны сравнимы с подобными длинами для устройств, описанных выше. Кроме того, известное устройство не эффективно для случаев выброса низкотемпературных паров газов из испарителей и переохладителей, работающих при небольших избыточных давлениях (~0,05 ати) , а также при выбросе больших количеств газов из магистралей низкого давления. Устройство не защищено от воздействия атмосферных осадков, а при угле тарелки £ 180° возможно прямое попадание влаги, снега, песка и пыли в дренажную трубу. Применение в устройстве нижней тарелки, диаметр которой значительно превышает диаметр центрального тела вращения в виде колпака, увеличивает размеры зон опасных концентраций и пламени, поскольку смешение и разбавление турбулентной струи на выходе из щели до ⁵момента срыва с тарелки происходит только со стороны, противоположной ей. Цель изобретения - сокращение эон опасных концентраций и размеров факелов горючих газов.The main disadvantage of this device is the need to maintain for stable operation a sufficiently high excess pressure in the gas discharge pipelines to ensure the emission of a given gas flow through a narrow gap with a cross-sectional area several times smaller than the cross-sectional area of the pipe. If the cross-sectional area of the annular gap in the narrowest place at the cap sizes recommended in this device is equal to or greater than the cross-sectional area of the pipe, the length of the torch and the danger zone are comparable with similar lengths for the devices described above. In addition, the known device is not effective for cases of emission of low-temperature gas vapors from evaporators and supercoolers operating at low excess pressures (~ 0.05 atm), as well as when large quantities of gases are ejected from low-pressure lines. The device is not protected from the effects of atmospheric precipitation, and at a plate angle of £ 180 °, direct moisture, snow, sand and dust can directly enter the drainage pipe. The use of a lower plate in the device, the diameter of which significantly exceeds the diameter of the central body of revolution in the form of a cap, increases the size of the zones of hazardous concentrations and flame, since the mixing and dilution of the turbulent jet at the exit from the gap up to the ^5th moment of separation from the plate occurs only from the side opposite to it. The purpose of the invention is to reduce the eon of hazardous concentrations and sizes of flames of combustible gases.

Указанная цель достигается тем, что в устройстве, содержащем вертикальную трубу с укрепленными на ней тарелкой с отверстием, равным диаметру трубы, и колпаком в виде тела вра— щения, установленном с зазором относительно торца трубы и соосно с ней, (Колпак выполнен в виде полого усеченного прямого конуса, обращенного большим основанием к тарелке, причем диат 20 метр этого основания равен наружному диаметру тарелки, а зазор между конусом и тарелкой в периферийной зоне оп ределяется соотношением ⁼ ‘J ' ²⁵ где - величина зазора между большим основанием усеченного конуса и тарелкой в периферийной зоне;This goal is achieved by the fact that in a device containing a vertical pipe with a plate fixed on it with an opening equal to the diameter of the pipe, and a cap in the form of a body of revolution, installed with a gap relative to the pipe end and aligned with it (The cap is made in the form of a hollow a truncated straight cone facing a large base to the plate, with a diatom of 20 meters of this base equal to the outer diameter of the plate, and the gap between the cone and the plate in the peripheral zone is determined by the ratio ⁼ 'J' ²⁵ where is the gap between the large base a truncated cone and a plate in the peripheral zone;

“ величина зазора между мень- 30 шим основанием усеченного конуса й тарелкой;“The size of the gap between the smaller base of the truncated cone and plate;

D -диаметр большого основания конуса;D is the diameter of the large base of the cone;

cl - внутренний диаметр дренажной 35 трубы.cl is the inner diameter of the drainage pipe 35.

Кроме того, устройство снабжено турбулизирукицим элементом, выполненным в виде кольцевой решетки, установленным между тарелкой и усеченным ко- 40 нусом.In addition, the device is equipped with a turbulizing element made in the form of an annular lattice installed between the plate and the truncated cone 40.

На чертеже изображено дренажное устройство, общий вид.The drawing shows a drainage device, General view.

Дренажное устройство состоит из нижней тарелки 1 и верхнего полого ₄₅усеченного прямого кругового конуса 2, концентрически расположенных и закрепленных на дренажной трубе 4. Между тарелкой и усеченным конусом по .всему периметру размещен турбулизирующйй элемент 3, выполненный в виде решетки, закрепленной на тарелке. Усеченный конус устанавливается над тарелкой с зазорами и ofy , выбранными из условия равенства площадей сечения $$ (дренажной трубы и кольцевой щели в концентрических сечениях между тарелкой и конусом на входе в кольцевое . > пространство и выходе из него. При размерах щели сЛ), Задаваемой приведенным соотношением, обеспечивается минимально допустимое избыточное давление в магистрали.The drainage device consists of the lower plate 1 and the upper hollow _{45 of the} truncated straight circular cone 2, concentrically located and fixed on the drainage pipe 4. Between the plate and the truncated cone, a turbulizing element 3 is made around the entire perimeter, made in the form of a lattice mounted on the plate. The truncated cone is installed over the plate with gaps and ofy selected from the condition that the $$ sectional area (drain pipe and annular gap in concentric sections between the plate and the cone are equal in the annulus.> Space and exit from it. When the slit dimensions are SL) the given ratio provides the minimum allowable overpressure in the line.

Величина диаметра нижней тарелки выбирается исходя из требуемого минимального размера длины факела или зоны опасных концентраций, которые имеют место выброса газа через кольцевую щель в развитом турбулентном режиме истечения.The diameter of the lower plate is selected based on the required minimum size of the length of the torch or zone of hazardous concentrations that occur when gas is released through the annular gap in the developed turbulent flow regime.

Устройство работает следующим образом.The device operates as follows.

Выбрасываемый газ по дренажной трубе 4 попадает в кольцевое пространство между тарелкой 1 и конусом 2, где меняет свое направление на 90° и, проходя через решетку 3 и кольцевую щель на выходе из устройства, выбрасывается наружу турбулизированным потоком. При необходимости дожигания горючего газа он поджигается одним из известных устройств.The ejected gas through the drain pipe 4 enters the annular space between the plate 1 and the cone 2, where it changes its direction by 90 ° and, passing through the grate 3 and the annular gap at the outlet of the device, is ejected outward by a turbulent flow. If necessary, the burning of combustible gas, it is ignited by one of the known devices.

Предлагаемое устройство отличается простотой и надежностью в условиях эксплуатации. - Оно пригодно для выброса любых газов и их паров из коммуникаций с любым заданным избыточным давлением как с дожиганием, так и без дожигания, обеспечивает минимальные безопасные расстояния от объекта сброса, независящие от расхода газа, защищает окружающую среду от вредного воздействия выбрасываемых продуктов.The proposed device is simple and reliable in operating conditions. - It is suitable for the discharge of any gases and their vapors from communications with any given overpressure, both with afterburning and without afterburning, provides minimum safe distances from the discharge object, independent of gas flow, and protects the environment from the harmful effects of the released products.

Анализ геометрических соотношений размеров факела, образующегося при выбросе из трубы круглого сечения и из предлагаемого устройства, и результаты испытаний показывают, что применение дренажного устройства позвол ляет уменьшить размер опасной зоны в 3-5 раз при соотношении ·«- = 3-5.An analysis of the geometric proportions of the size of the torch formed during ejection from a pipe of circular cross-section and from the proposed device, and the test results show that the use of a drainage device reduces the size of the danger zone by 3-5 times with the ratio · - - = 3-5.

ЯI

Claims

(54) DRAINAGE DEVICE 1. The invention relates to mechanical engineering, mainly chemical petrochemical and cryogenic, and can be used in any branch of the national economy where there is a need for drainage (i.e., organized, ordered discharge) of large quantities of explosive, toxic and other dangerous gases (for example hydrogen, methane, nitrogen, oxygen, by-products of chemical production), and liquefied cryogenic vapor (for example liquid nitrogen, oxygen, hydrogen, gels, etc.) to the atmosphere pv. Depending on the type of emitted gas, various drainage devices are currently used to ensure the safety of modern industrial facilities and to prevent pollution of the environment. Their operation is based on the principles of spontaneous gas dispersion under the action of atmospheric turbulence, diluting the emitted hazardous gas to the maximum permissible concentrations, burning emitted hazardous gas, or on their combination. Gas discharge devices are known, which contain a vertically installed drain pipe through which gas is vented to a great height and released into the atmosphere without afterburning or with afterburning, a cap designed to prevent pipe pollution from meteorological precipitation, sand, dust, or fire- , a projectile designed to prevent flame from leaking into the pipe at low flow rates of the emitted combustible gas tl. The disadvantage of the known devices. is the existence of very large plumes or zones of hazardous concentrations when gases are emitted into the atmosphere with them, with or without afterburning, respectively. Thus, the length of the plume when emitting hydrogen, methane, and: other combustible gases is 220,250 diameters of the drainage pipe with a bulentiy discharge mode and may be more than 400 diameters with small diameters of the drainage pipes with small diameters of the drainage pipes. Estimates of the lengths of zones of hazardous concentrations according to known laws for cases of jet ejection of nitrogen, oxygen, and combustible gases without afterburning show that the lengths of zones of hazardous concentrations can also reach 200-400 diameters of the drainage pipe. In addition, with variable flow, .. i --- fr f--. When emitted gases are released, the indicated ranges of flares and zones of hazardous concentrations become uncontrollable, which makes it necessary to focus on the maximum values of the indicated values when assigning fire breaks and safe distances. The use of drainage devices of this type in modern industrial facilities, where drainage pipes with a diameter of up to 400 mm and more are used, leads to the choice of safe distances to large economic costs associated with the irrational use of construction areas, as well as the costs of designing and manufacturing auxiliary highways (pipelines, fittings, air intake channels, etc.). Injecting chip devices are also known, which are based on the method of limiting hazardous concentrations by diluting the jet of hazardous gas with a neutral component 2 ,. A disadvantage of such devices is the need to store large quantities of neutral gases in order to dilute the emitted hazardous gases. The closest to the proposed is an ultra-cinematic diffuser, designed to release hydrogen with post-combustion. At the end of the vertical drainage pipe of the diffuser, it was fixed on a plate with a central round hole, the diameter of which is equal to the diameter of the drainage pipe. The plate can be made both flat and in the form of a truncated cone with a solution angle from 0 to 360. Another element fixed at the end of the pipe. is a cap in the form of a body of rotation. The cap in the lower working part has the shape of a truncated hyperboloid of rotation, the top of which is facing the plate, the cap diameter being equal to or slightly greater than the internal diameter of the drainage pipe and much smaller than the diameter of the plate. In working condition, both elements of the device — a plate and a cap — form with the drainage pipe an annular channel narrowing in the form of a confuser. The minimum gap in the channel is selected depending on the Mach number of the flowing hydrogen stream and up to the allowable pressure loss. For stable operation of the device, the area of the narrowest part of the annular channel is selected 2 or more times smaller - the cross-sectional area of the drainage pipe. The operation of the ultra-kinematic diffuser is based on two principles: spatial axisymmetric separation of the flow and adherence of the outflowing flow to the surface of the plate. The emitted gas at the exit from the pipe is distributed along a narrowing annular channel, accelerated therein at speeds equal to or greater than the speed of sound AND is ejected as a burning torch, while the torch sticks to the plate as it were. The main disadvantage of this device is the need for maintaining sufficiently high overpressure in gas discharge pipelines for stable operation to ensure the discharge of a given gas flow through a narrow slit with a cross-sectional area several times smaller than the cross-sectional area of the pipe. In the case, if the cross-sectional area of the annular gap at the narrowest point at the size of the holpak recommended in this device is equal to or exceeds the cross-sectional area of the pipe, the length of the torch and the danger zone are comparable to similar lengths for the devices described by Bbmie. Besides. The known device is not effective for cases of emission of low-temperature gas vapors from evaporators and subcoolers operating at small excessive pressures (-0.05 atm), as well as when emitting large quantities of gases from low-pressure pipelines. The device is not protected from the effects of precipitation, and when the angle of the i180 ° plate is possible, direct ingress of moisture, snow, sand and dust into the drainage pipe is possible. The use of a lower plate in the device, the diameter of which significantly exceeds the diameter of the central body of rotation in the form of a cap, increases the size of the zones of dangerous concentrations and flames, since mixing and dilution of the turbulent jet at the exit from the slot until the plate is removed only from the side opposite to it. the invention is the reduction of zones of dangerous concentrations and torch sizes of flammable gases. This goal is achieved by the fact that in a device containing a vertical pipe with a plate fixed to it with a hole equal to the diameter of the pipe, and a cap in the form of a rotating body, installed with a gap relative to the end of the pipe and coaxial with it, the cap is made in the form of a hollow truncated The diameter of this base is equal to the outer diameter of the plate, and the gap between the cone and the plate in the peripheral zone is defined by the ratio SL. where a) is the size of the gap between the large base of the truncated to nus and the plate in the peripheral zone; L - the size of the gap between the smaller base of the truncated to the nus and the plate; D is the diameter of the large base of the cone; d - internal diameter of the drainage pipe. In addition, the device is equipped with a turbulence element, made in the form of an annular lattice, installed between the plate and a truncated cone. The drawing shows a drainage device, general view. The drainage device consists of the bottom plate 1 and the upper hollow truncated straight circular cone concentrically located and fastened on the drain pipe 4. Between the plate and the truncated cone along the entire perimeter there is an element of turbulization 3, made in the form of sieves :: nd fixed to the plate. The truncated cone is set above the plate with gaps of f. and, selected from the condition of equality of the cross-sectional areas of the drainage pipe and the annular gap in concentric cross sections between the plate and the cone at the entrance to and out of the annular space. At the size of the gap (L), given by the ratio given, the minimum allowable overpressure in the line is ensured. The diameter of the bottom plate is selected on the basis of the required yutnimal size of the flare length or the zone of hazardous concentrations, which take place through the annular gap in the developed turbulent flow regime. The device works as follows. The emitted gas through the drain pipe 4 enters the annular space between the plate 1 and the cone 2, where it changes its direction by 90 and the passage through the grill 3 and the annular gap fl, at the outlet of the device, is thrown out by a turbulent flow. If necessary, the after-burning of the combustible gas is ignited by one of the known devices. The proposed device is characterized by simplicity and reliability in operating conditions. - It is suitable for discharging any gases and their vapors from communications with any given overpressure, both with and without afterburning, provides minimal safe distances from the discharge object, independent of the gas flow rate, and protects the environment from the harmful effects of the discharged products. An analysis of the geometric relationships between the dimensions of the plume formed during ejection from a circular pipe and from the proposed device, and the test results show that the use of a drainage device can reduce the size of the danger zone by a factor of 3-5 when the ratio of Invention 1. Drainage device for ejection of toxic or hazardous gases and vapors of liquefied cryogenic products containing a vertical pipe with a plate fixed to it with a hole equal to the diameter of the pipe and a cap in the form of a body of rotation, with a gap relative to the end of the pipe and coaxially with it, characterized in that, in order to reduce zones of dangerous concentrations and sizes of flames of flammable gases, the cap is made in the form of a hollow truncated straight cone, facing a large base to the plate, and the base diameter is equal to the outer diameter plate, and the gap between the cone and the plate in the peripheral zone is determined by the ratio.

.l | where the value of the gap between the large base of the truncated cone and the plate in the peripheral zone;

with the maximum gap between the smaller base of the truncated cone and the plate; diameter of large base

D cone;

o1 is the inner diameter of the pipe; 2. The device according to p. 1, I distinguish it with the fact that it is equipped with a turbulizing element in the form of an annular lattice installed between the plate and a truncated cone.

Sources of information taken into account in the examination 1. Baev V. K., Yasakov V. A. Combustion and explosion physics. 1974, p. 835.

2. For the application of the Federal Republic of Germany No. 1900763, cl. 81 with 139, published. 1969.

3. Investigation of the conditions for reducing the safe distance during hydrogen drainage. GIPH Report No. 1775, 1975.