SA111320736B1 - Method and Apparatus for Vaporizing Liquid Chlorine Containing Nitrogen Trichloride - Google Patents

Abstract

The present invention relates to a method for safely vaporizing liquid chlorine containing high concentrations of nitrogen trichloride from an industrial chloralkali plant. In a vertical mass flow vaporizer having an overflow direction, a stream of liquid chlorine containing nitrogen trichloride is received. A gas such as air, nitrogen gas or chlorine is introduced into the liquid stream prior to the boiling zone of the vaporizer to induce a flow system, eg annular flow or moisture flow, which prevents nitrogen trichloride mass build-up in the vaporizer. Liquid chlorine containing nitrogen trichloride is evaporated. The resulting gas stream can be processed to remove the nitrogen trichloride and recycled to the chlorine production train.

Description

- v = method and apparatus for evaporating liquid chlorine containing nitrogen trichloride

Method and apparatus for vaporizing liquid chlorine containing nitrogen trichloride Full description Background nitrogen containing liquid chlorine stream The present invention relates to the treatment of a liquid chlorine stream such as a chlorine production process from a chlorine production process trichloride A small amount of trichlorine is produced in the industrial production of chloralkali - the secondary chloralkali. In the chlor alkali production process the nitrogen trichloride© contained in the salt is fed to the process. to be continued Ammonia The amount formed is proportional to the amount of + chloralkali cell housegslall The chlorine product leaving the chlorine cell housing Nitrogen trichloride is an unstable compound that explodes when it reaches a critical concentration; Nitrogen trichloride is estimated to decompose to form nitrogen trichloride (aia) by weight, although it is about 0 in dangerous conditions at concentrations as low as 77 by weight. However; 0 must be present before it can be considered capable of damaging equipment. According to a report by nitrogen trichloride with a critical mass of fag of half Mu, a typical chlorine vessel having a wall thickness can be cracked “Chlorine Institute Inc. for and as a compound of Yanan 1,0 aC of 8 nitrogen trichloride using a liquid membrane of chlorine having a vapor pressure considerably lower than that of chlorine; It can be concentrated if the liquid chlorine is allowed to evaporate. Nitrogen trichloride is believed to be . Nitrogen trichloride containing liquid chlorine© 0 chloralkali is the cause of explosions and fatal injuries inside chlor-alkali production facilities.

blood chlorine product is supplied; stereotyped; in liquid form; But of course the end user vaporizes the liquid chlorine before use. Depending on how the chlorine is evaporated; This can lead to an increase in the concentration of “nitrogen trichloride” and thus; Jia is an important part of the chlorine production process in keeping the nitrogen trichloride concentration at a low level in the final chlorine product; typically at a few parts per million; This is to allow the end user to vaporize the liquid chlorine. In the chlor-alkali process, we » chloralkali, nitrogen trichloride is removed from the chlorine product through an absorption step; For example, in a chlorine scrubber ¢ unit before chlorine is compressed and liquefied. In the washing step, “nitrogen trichloride” is absorbed to obtain a clean and new chlorine product, then it is pushed to the bottom of the washing unit and into the holding tank 0 will be referred to as “aly” decomposition unit “nitrogen trichloride” containing carbon tetrachloride carbon tetrachloride or sometimes containing chloroform. in the decomposition unit; The solvent is kept at a temperature above the boiling point of chlorine. When liquid chlorine comes into contact with the warm solvent; It returns to the scrubber 1010:106©_while the nitrogen trichloride is absorbed by the solvent. The conditions in Jab the Yo decomposer are chosen so that the nitrogen trichloride decomposes slowly and safely. over time; Bitumen compounds and other impurities accumulate in the solvent; The solvent must be replaced periodically; Which generates a stream of waste that must be disposed of. and for reasons of regulatory and product quality constraints (ie, to reduce the content of organic compounds in the final chlorine product); It is preferable to avoid the use of solvents such as carbon tetrachloride, chloroform Ye, in the chlorine production train.

US Patent No. 794 of Ferguson et al. describes a method for eliminating nitrogen trichloride without the use of carbon tetrachloride or chloroform solvents. And in this way; The chlorine gas from the drying tower comes into contact with hydrochloric acid prior to the compression and liquefaction steps. However; The process produces an acidic waste stream that must be disposed of or used at the AT site in the method described in US Patent #36,768404 The chlorine is evaporated and recycled back into the process but only after the removal or disposal of the nitrogen content trichloride. In the industrial process used (Ulla), chlorine Und is evaporated and recycled to the process, but after absorbing nitrogen trichloride and obtaining carbon tetrachloride 0, chloroform, or other appropriate organic solvents. Chlorine fumigation is an important step in most of the proposed methods for removing nitrogen trichloride from the final chlorine product from the chioralkali + chlor alkali production facility, although it may be preferred to fumigate the liquid chlorine stream containing Je concentration from Nitrogen trichloride issued by the unit Jue Chlorine Quadl chlorine scrubber The use of Vo as a decomposing agent and organic solvents or the use of other chemicals that generate waste streams must be dealt with There are disadvantages of chlorine vaporizers used Ulla in the industrial field when Industrial chlorine evaporators are non-horizontal units Jie cole amg two-pin units or horizontal vaporizer units Jie reboiler-type units For convenience in the following discussion reference will be made to non-horizontal inclined units Positive as Ye units (CR) which means units of angle from the horizontal plane from 1/1 to 50 degrees. maybe

This means that the horizontal and vertical chlorine evaporators are of two types; namely: boil-tub evaporators and mass flow evaporators. in a boil-tub evaporator; such as a vertical two screw vaporizer or reboiler; Liquid chlorine evaporates out of the main body of liquid chlorine. Compounds with a vapor pressure lower than chlorine are concentrated in the main body of liquid chlorine as the chlorine evaporates. in the top flow evaporator; such as Hooker or tubular evaporator; Liquid chlorine evaporates as it moves through the evaporator. in the top flow evaporator; Based on the advanced flow system, compounds with a vapor pressure lower than chlorine can be locally concentrated within the unit; As will be seen below. Neither type of vaporizer is used to vaporize liquid chlorine containing a high concentration of nitrogen trichloride ¢ due to its hazardous concentration. Euro Chlor as by maintaining 0 concentration of nitrogen trichloride in liquid chlorine inside the daily re-boiling Ji of 0001 ppm in order to avoid overconcentration. There is a balance between the tendency to concentrate and the tendency to decompose nitrogen. trichloride which is complex and totally incomprehensible In a conventional vertical top flow vaporizer the chlorine flows the length of the unit through three distinct system zones Liquid chlorine is heated to its boiling point in the first zone 0 chlorine is vaporized in Aull) and in the third zone the chlorine gas produced is superheated The second zone, the boiling zone ¢ of the vertical top flow evaporator, is that zone where the nitrogen can be concentrated trichloride Led dangerously.with ella gla can cause liquid from boiling zone to preheating zone to concentrate.

In the boiling zone of a conventional vertical top flow vaporizer three flow regimes are generally encountered. The first flow regime occurs at the onset of boiling when LD forms from vapor and a 'shake' flow system develops. In an agitating flow system the vapor and liquid mix randomly and then are mixed again. Once a sufficient amount of Al is generated an AS flow system develops 0 where Lal flows through the center of the heat transfer confinement (a pipe, for example) forcing the liquid forward and towards the heat transfer wall. Finally enough vapor is generated to move the system into a "moisture" flow system, where the liquid breaks up into small droplets which mix randomly with the vapor as it moves forward through the boiling zone.The boiling zone in which the agitating flow system is located is that zone in which the nitrogen trichloride led can concentrate and accumulate mass.In this zone 0 the chlorine can mix liquid chlorine again and a vasa boil can develop. Once the annular flow system has developed within the boiling zone; The liquid is pushed forward by the steam generated »and mixed again; Thus the level of nitrogen trichloride accumulation is minimal. Mixing is again at the lowest level in the moisture flow system. When the fluid flows forward through annular flow and moisture flow systems; Liquid chlorine evolves faster than dissolved nitrogen trichloride. With “sll,” the mass of nitrogen trichloride in the liquid decreases and does not accumulate. In a conventional vertical top flow 0 chlorine evaporator it is difficult to ensure that nitrogen trichloride concentrations do not increase significantly in the area where the liquid and agitating systems are located; And before the formation of the annular flow system. As a result; This type of vaporizers, Sale, is not used in dealing with streams of liquid chlorine 00 rich in nitrogen trichloride +

except in a mass flow vaporizer with a horizontal or downward slope; The chance that liquid chlorine will evaporate without being mixed with another $e (ie without concentration of nitrogen trichloride locally) is greatly increased for a vertical overhead flow unit. And in these units; Gravity forces the liquid chlorine to flow forward, taking the steam generated for more of the unit's volume. If appropriately designed; Say avoid the boiling zone by shaking completely. However; The concern with these types of units is that they can accidentally overflow; For example JU by exceeding its evaporation capacity (i.e. feeding more liquid chlorine). And once it overflows; Vaporization of liquid chlorine results in trough boiling rather than mass flow vaporization. This causes a concentration of nitrogen trichloride » which may lead to insecurity. 0 On the other hand; The vertical top flow vaporizer submerged in liquid chlorination is quickly drawn into the feed tank once sufficient amount of vapor chlorination has been generated again; To avoid boil-pelvic conditions. Briefly; The vertical, horizontal and bottom flow evaporators suffer from defects in dealing with liquid chlorine streams rich in nitrogen trichloride. And therefore; There is a need in the field to provide an improved method for evaporating chlorine streams containing a high concentration of nitrogen trichloride. It would also be preferable to provide a process for the disposal of nitrogen trichloride that was removed from the chlorine stream without using organic solvents such as carbon tetrachloride or carbon tetrachloride. chioroform » or other liquid chemicals. General description of the invention

M - The invention provides a method for vaporizing liquid chlorine containing nitrogen trichloride in a mass flow evaporator that is directed to a non-horizontal direction and has an upper flow direction. The method includes receiving a stream containing liquid chlorine containing nitrogen trichloride »and introducing Je into the liquid stream located before the boiling zone of the vaporizer in order to induce 58 the occurrence of a flow system in the liquid stream in order to prevent or reduce any agglomeration The masses of nitrogen trichloride J are in the boiling zone; vaporizing the liquid stream to produce a stream comprising chlorine gas and nitrogen trichloride + U, for some embodiments; The method includes treating the evaporated LA by removing the nitrogen trichloride present in the cay to produce a stream comprising chlorine gas with nitrogen gas) formed through the decomposition of nitrogen trichloride. The stream containing chlorine gas can be recycled together with nitrogen gas to the chlorine chain of the chlorine production process. The invention also provides Blea to implement the methods of the invention. The device includes a non-horizontally oriented mass flow chlorine evaporator with an overflow direction. The device includes an entrance to receive liquid chlorine stream jil.

Yo contains nitrogen trichloride inside the vaporizer + there is a boiling zone in the vaporizer after the liquid inlet. The device includes a gas inlet before the boiling zone, in order to enter the gas into the (JL) stream, and the gas, for example, is air, nitrogen gas, or chlorine, and therefore, the invention provides the Blea method. To safely vaporize a liquid chlorine stream rich in nitrogen trichloride Ye The chlorine vaporization process provides an effective means of avoiding a churning flow system within an evaporator boil zone

top flow chlorine; This provides a safe means for vaporizing liquid chlorine containing a Je concentration of nitrogen trichloride » for example greater than 0 ppm. Due to the vertical position of the evaporator; Accidental overflow of the evaporator does not cause boiling point; Which helps to avoid the possibility of increasing the concentration of nitrogen trichloride. The © process includes the introduction of Sle (steam); at any point prior to the boiling point of the chlorine evaporator; In an amount sufficient to drive the liquid chlorine feed stream into any flow system so as not to cause significant mixing again or a jal boiling zone of the vaporizer. The mass flow vaporizer can be oriented at any angle from 0.1 to 0 from the horizontal position. The gas introduced into the liquid stream can be any suitable Vo gas or vapor, nitrogen Jie, helium hydrogen 5 chlorine gas, oxygen and mixtures thereof. The liquid chlorine feed stream is forced into the vaporizer within a suitable flow system before it reaches the boiling zone of the vaporizer; allowing for the safe evaporation of liquid chlorine. These and other features of the invention will be evident from the following description Vo and the following drawings of the specified embodiments. Brief Explanation of the Drawings Figure 1 is a schematic form of a first model of the invention process. appearance ? It is a schematic diagram of a chlorine vaporizer.

- 11 nitrogen trichloride is a schematic form of a second process model; in which the lychee is removed using an extruder heater. Nitrogen trichloride form; is a schematic representation of a third process model; where it is removed. catalytic bed using a catalytic bed Similar and corresponding elements will be indicated in the following description and figures with the same reference symbols. In a first embodiment of the process of the invention; shown in Figure 1; A YY series top flow mass flow evaporator (nitrogen trichloride stream) receives a stream of liquid chlorine containing vertical 00 industrial chloralkali located in the chlor alkali unit 7 4 chlorine production train 7 on a chlor-alkali cell house production train The production chain includes . Electrolysis of brine unit The liquid chiorine stream of chlorine gas released from the cell housing and receives a liquid chlorine stream 1 between the chlorine cell housing dale Figures show the operations of other units that exist; Feed stream 11. chlorine scrubber and chlorine washing unit 01 chloralkali cell house 0 alkali then liquefied from the scrubbing unit to compressor 14 gas chlorine stream liquid chlorine liquid chlorine is fed 117 holding tank (VY chlorine scrubber) and from the bottom of the chlorine washing unit are directed to a holding tank 13 (liquid nitrogen trichloride stream) can be fed liquid chlorine (Jing) Yo vaporizer YY stream

11 - - chlorine rich in nitrogen trichloride directly from scrubber 11 to evaporator 01 (stream (ha) without using any holding tank. Stream YY typically includes OR ppm or more of nitrogen trichloride + displays the Y-shape of the evaporator Ye is largely a Bah-orientated evaporator; but it can be oriented at any angle from the horizontal within a range of 0.1 to 0 means that the vaporizer is not horizontal, inclined upwards and has an upper flow direction.The 01 evaporator has body 1 and is heated by YA current from heating medium flowing through a heating jacket .0 The 010 evaporator has a YY heating zone at the inlet end (YE) where the liquid stream is heated and a YU boiling zone after the heating zone where 0 evaporates Liquid chlorine At the end of the outlet YA outlet end of the vaporizer »a stream of 50% of chlorine gas exits the vaporized nitrogen trichloride gas + a gas such as air, nitrogen or chlorine gas is entered chlorine gas or mixtures thereof from a gas source ey (stream ;;) in stream YY of liquid chlorine 5 nitrogen trichloride prior to the 1 boiling zone of the vaporizer . Gas stream 464 can be inserted into liquid 0 stream ?? before entering into the evaporator; Or it can be inserted directly into the YY heating area of the evaporator; As denoted by tees, selective currents and; b shown in the form of ?. Gas stream fed?; at a flow rate sufficient to drive the liquid chlorine feed stream into a flow system within the evaporator 01 which does not allow further mixing or pan boiling to occur within boiling zone 1? Evaporator | Examples given of flow systems mentioned include annular flow and 0 flow systems with moisture. The gas stream flow rate can fall ;; In a range from 100 to 100 kg of

- 11 to 0.07 kg; or 1 to 00 ; Or from liquid chlorine gas per kg of liquid chlorine. The effect of this is to preserve liquid chlorine.; kg of gas per kg of liquid chlorine V0 boiling zone of the basin and boiling zone of the evaporator Jala from the accumulation of nitrogen trichloride on nitrogen despite the increase in the concentration of . nitrogen trichloride 5 as the chlorine vaporizer due to the high vapor pressure of chlorine (lower point » boiling zone across the boiling zone of nitrogen trichloride © ALS); The induced flow system will limit excess concentration and build-up to levels that can be safely handled. vaporizer inside the vaporizer trichloride inside the chlorine gas vaporizer; A £4 stream comprising chlorine gas TA at an outlet end and the gas fed to the liquid stream is sent for treatment at the step nitrogen trichloride Syngas; where hydrochloric acid the current can be directed 0; to JU +;. Alternatively, . 000 can be absorbed. hydrochloric acid To prepare hydrogen, chlorine reacts with nitrogen to remove AT. An option is made. hypochlorite system in a hypochlorite system 80 gas stream ; As the chlorine production train to the chlorine production chain 50 and the trichloride stream recycling will be described below. 01 vaporizer in a second embodiment of the process of the invention; The gas mixture produced is directed to the Vo evaporator and the gas is recycled. nitrogen trichloride to one or more unit processes in order to remove the chlorine gas coming out of the removal step and thus; chloralkali again to the chlorine chain of the chlor-alkali process » nitrogen gas, the invention avoids generating a tailings stream or adding other chemicals or solvents to deal with in a variety of ways. For example nitrogen trichloride a removal step can be performed. nitrogen trichloride 0

Q1 example; The gas mixture vaporized in the vaporizer can be fed into a superheater; which may be part of the evaporator unit. Displays a Y-shape for that; Where the Ye evaporator has a superheater zone 71? After the LY boiling zone The operating conditions inside the superheater are selected such that the nearly complete destruction of 0. nitrogen trichloride can © The average operating temperature of the super heater ranges from 700 to 7000 °C, the operating pressure ranges from 1.5 to 100 bar, and the holding time ranges from 1.5 seconds to © minutes . Alternatively, the average operating temperature can range from TO 750 C to 750 C; The operating pressure ranges from atmospheric pressure to 90 bar and the holding time ranges from 1 second to ? minutes. The gas stream oY leaving the superheater is recycled; Which includes chlorine gas 0 with nitrogen gas ¢ to the chlorine production train Xi 7 of the chloralkali process. As an alternative to using a super heater; As shown in Figure , the vaporized gas in the 01 vaporizer can be directed to a catalytic bed 4© where 0 is removed. nitrogen trichloride catalytic layer can contain; JU) on Monel (registered trademark) as catalyst AY nitrogen trichloride 10 . The catalytic bed can be operated at temperatures in the range from minus 0 to 7700°C, pressure rates in the range from 1.5 to 100 bar, and retention times in the range from 1 Al to ¾ minutes. Gas stream 57 exiting the catalytic bed is recycled; Which includes chlorine gas and nitrogen gas ¢ back to the Y¢ chlorine production train or can be routed to other 0|unit operations.

1 - - can optionally use ileal; SIS superheater and catalytic bed for nitrogen trichloride removal. The catalytic bed can be located within the superheater area of the vaporizer « Yu than it is a separate unit. maybe; optionally; gas routing from the “nitrogen trichloride” removal step eg o superheater or catalytic bed; To the temperature conditioning step: 87 before being recycled to the chlorine chain (stream (Te) as shown in Figures ? and 4. This reduces the temperature of the gas stream resulting from the nitrogen trichloride removal step, which may be at a temperature ranging from about 0°C to 171°C until a lower temperature in order to include it in the chlorine series, which may be at a temperature of about minus #7°C. It will become clear to those skilled in the field that there are many modifications that fall within the scope of the invention, and the scope of the invention is determined by the following elements of protection.

Claims (1)

and 1 - protections nitrogen trichloride containing vaporizing liquid chlorine method for vaporizing liquid chlorine 1-1 in a mass flow evaporator that is oriented in a non-horizontal direction and has an overflow direction; The method includes the following steps: ¢ nitrogen trichloride with liquid chlorine 00) receiving a boiling stream (b) introducing a gas into the stream mentioned in step (a) located before the evaporator's boiling zone oe and zone of the vaporizer 1 resulting from nitrogen trichloride containing liquid chlorine vaporizing liquid chlorine (z) Vv 0 nitrogen trichloride and chlorine gas step (b) to produce a stream containing chlorine gas 1 ?- method according to claim 6) wherein step (b) induces a flux regime in the ¥ stream of step (a) which reduces any agglomeration of nitrogen trichloride in the boiling zone | Y . 1 *- A method according to protection element 1 or oF in which the step stream (7) is received from the Y chlorine production train 01110106 of the chlorine production plant ¥. 01 ¢—Gig method for any of the above claims; where step current (1) is received from the unit ,- chlorine scrubber, ¥ 1 0 - a method pursuant to any of the foregoing claims; Where the gas includes air or nitrogen or Chlorine vapor or mixtures thereof. 1 +- method according to any of claims 1 to of where the gas comprises air, nitrogen Y, hydrogen 0 chlorine vapor, helium, or oxygen 0 mixtures of Jew YX 1 #- the Gay method of any of the above claims; Where the gas comprises a flow rate of 0.00 to 01 kg of gas per kg of liquid chlorine + A - 1 way Ey for any of the 1 to oF protections Where the gas comprises a flow rate of 00 to 1 kg of gas per kg of liquid chlorine + 1 *4- method according to any of the claims 1 to . gas at a Y flow rate of 7 to 05 kg of gas per kg of liquid chlorine 0 - 1 Sy method of any of the above protections where the vaporizer is directed At an XY angle against the horizontal in the range from 1.1 to 500 degrees.-11 1 Gd method, for any of protections 1 to 95; wherein the vaporizer is Significantly vertical 7. 1 1 - EP method for any of the foregoing claims wherein the flow regime mentioned in step YX (b) is annular flow and moisture flow. — and 0 —- -1”1 method pursuant to any of the foregoing claims; where the flow system in Step 0 (b) reduces the boiling point of liquid chlorine in the boiling zone. -14 1 method according to which RELL the flow system in Step 0 reduces (b) From mixing again the liquid chlorine in the boiling zone + -11-1 method in accordance with any of the foregoing claims; where the stream reported in step (a) Y includes a concentration of nitrogen trichloride greater than 0 © ppm. -11 1 method according to any of Claims 1 to 106 wherein the stream mentioned in ¥ step 0 has a concentration of nitrogen trichloride greater than You ppm. -11 1 method a, of any of the preceding claims; where (lS after step (z) ¢ includes (iii) treating the step (c) stream by removing its nitrogen trichloride to produce a ¥ stream comprising chlorine gas and 0 nitrogen gas —YA 1 Gy method of protection VY where step (d) involves heating the current of step (c) Up to a temperature ranging from YY 700 C at a pressure ranging from 1.5 to 001 ob until a time T Hold ranges from 0 seconds to * minutes. -19 1 By way of protection element OA where da temperature ranges from You LTO m and ranges from Y The holding time is from 1 second to 1 minute. - A - Y 0 1 0 method according to claim and '1 or 1 A or 3 1' where bal & step (2) is done in a superheater .superheater ~~ Y -71 1 way Gy of protection oY where the super heater includes heating zone Y super from 0 vaporizer 01 ?7- way Gy of claim 000 or 17, wherein the superheater contains a catalytic bed Y for a catalytic containing a catalyst that eliminates nitrogen trichloride + 01 ?7?- method according to claim VY where Step (d) involves introducing the current of step (c) into a Y catalytic bed containing a catalyst eliminating nitrogen trichloride + 4 01 ?- method Gy of claim 17 or YY where The catalytic bed operates at temperatures ranging from -0° to 7000°C and pressures from 1.5 to 100 bar for a retention time of oy seconds to © minutes. 1©#?- method Wy for any of the claims 11 through (YE) where after step (d) it also includes dug the temperature of the current of step (d). -71 1 method according to any of Claims 17 to Yo which also includes sale) ¥ circulating step current (d) to the chlorine production train located in the industrial chlorine production unit ov chlorine production plant + 01-77 A method of claim YT wherein the method is free from any production of tailings streams “and any addition of process chemicals 0 nitrogen trichloride — 1 YA vaporizing liquid chlorine containing nitrogen trichloride oY where the device comprises: » - (a) a non-Vall mass flow chlorine vaporizer with an overhead flow direction; vaporizer; (z) 1 boiling zone in the vaporizer after element inlet (b) ¢ 1 (3) gas inlet before boiling zone to introduce gas into the liquid stream. 1 4- An EP device for the Sus (YA) protection element. The inlet of element (B) is effectively connected to the z-chain chlorine production train located in the chlorine-©0-©0 1 device. 1-*1 Apparatus of claim 78 or YA where the gas includes air, nitrogen, chlorine vapor, or mixtures thereof, of claim 78 or YA where the gas includes air or Nitrogen or “chlorine vapor” Hydrogen any helium or oxygen Mixtures Age 1 ?1*- Gy device for any of the protection elements from YA to FV It also includes a means to remove nitrogen trichloride Je after the boiling zone + — nor - 0 **- device of claim FY where the removal method includes a superheater -superheater v 01 0 ?*- device Gy of claim FY where the superheater includes on the “heating zone |” super in the vaporizer. 1 ©#5 - device according to protection Con FY The removal medium includes a catalytic bed ¥. la, Olea - Y 1 1 for claim Y a $ wherein the J removal method includes JS from a superheater and a Y catalytic bed. 1 7©#- Device pursuant to any of YA claims through 7; It also includes the ¥Y source of the gas. 1 *8*- Ey device for any of the YY YA protections where the vaporizer is "orientated" at an angle to the horizontal within the range of 1.01 to 90 degrees. 1 4 ©*- Apparatus of any of claims YA to FV where the vaporizer is more or less vertical 1 0 56?- Apparatus of claim FY which also includes means of recycling A stream of ¥ chlorine gas and nitrogen gas from the ¥ nitrogen trichloride removal device to a chlorine production chain in a chlorine plant.