Figure 1.
Front View of Laboratory
High Pressure Laboratory Designed f o r Safe Operation A. L. GLASEBROOIC AXD J. B . MOSTGOMERY Hercules Experiment Station, Hercules Powder Company, W'ilmington 99, Del.
T
HE use of high preshigh pressure laboratory designed for general exploraratory which would be tailorsures in chemical 8j-ntory work, sample preparation, and small scale developmade to its requirements for ment work is described. Safety and flexibility in the high pressure research. Emthesis dates back to the beginning of this century, but design of the building and control equipment are emphasis \vas giver1 t o ,i:iEety and developments in this field phasized. Barricading, remote controls, and aic tomatic flexitjility in the design of the have been accelerated greatly safety features are incorporated wherever tiecessar>- to jIuilding anti control equiponly during the past decade. reduce the probability of injury in this potentially hazardment to provide lllasiInum A nunilier of publications on 0"s type of work. protwtion for t h e operating high pressure laboratory depersonnel a n d adaptability of thc c~cjriipnic~iitt 11 :i v:iriety of problems. Construction was sign for specific applications have already appeared in the literaturc -for example, the descriptions of the high pressurc :ininioni:~ complt~tc~ti i i i I!N7 :mil thc 1abor:itory !vas ready for operation 1:tboratories of the Fixed Sitrogen Remirrh 1,;ibor:ir:irl>. i n 1 I11X. tory (5):ind the Du Pont Company (5), aiid the contributions 13~l11,1~1\(> L O C i T I O S t N I ) LAYOUT from the Fuel Research Station ( 2 ) and the I3ure:iu of 1Iinea Co;il The 1:it)or;itciry [Figure 1) is locntctl in :L re1:itivcly isohted Hydrogenation Laboratory ( 7 ) . The purpose of the prcatvit, ~ m p e r is to describe a high pressure laboratory, designed for genela1 vootieil :iw:i. T h c .sitlc o f the builciing housing t h e pressurc equipment f:irw ti r t c ~ ptiill :tntl all of the rcuctor a n d cornpressor J ' O ~ I I I S exploratory work, sample preparation, and small scale developmenf, work, which was constructed by Hercules Powder Conipariy have lightweight blonwut psnels nimetl a t thi. hill (Figure 2)> to protect, the surrountlings from Hying missiles \vhich might arise at, its Experiment Station near \\-ilmington, Del. For a number of years Hercules has been engaged in high presfrom equipment f:dure. The building is approximately 145 feet long and -10 feet, \vide sure ammonia synthesis and hydrogenation of rosin to Staybelite. Recently the manufacture of .&it01 (hydroabietyl alcoholj and and of concrete block construction. Approximately 60c; of the rosin amines has evolved from the laboratory to the plant space in the building is occupied by reactors, compressors, :ind their control instrunients (Figure 3), and the remainder of the stage. The increasing activity in high pressure research, and cerspace is occupied by laborat,ories and offices. T h e barric:ded tain deficiencies in the safety features of the existing laboratory cells, cornpressor rooms, and laboratories are installed with esplopointed up the need for more adequate facilities. Therefore, in sionproof Cluss 1 Group D electrical iviring and fixtures. The 1936 plans were drawn by the company for a high pressurt? 1al)o2368
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
October 1949
2369
square-inch storage tank is used, in conjunction with the cylinder manifold supply, t o prepare and starc gus niixi,ures. Three compressor rooms are located on tht: high pressure side of the 1ahoratoi.y (Figure 3). Thr. ire cwlosetl with 0.5-irlch steel plate on the d e s exposed to tho ii1tt:rior anti blowout p:uiols of light construction on the side f:tcilig the hill. Encll roo111 ir vrntiluted witti :I 1tK)O-cut)ic feet-per-rniuute 1rall e h t u s t t x i : the :itmospliere in these rooms i s d s o chccked b y :utom:itic y lyzers for coniliustible or toxic gases. Two prinxti,y eonipwsuors :tw :iv:~il:hlc-that is, coinpressors which opurnt L' at :ipprosini;ttcl?- atmospheric pressure UII tlu. suction sidc. Both of these :ire oi' t riaoritd type. Onc is L: f i n stage :dloy-steel compressor (.If ' I h k r 1IotIel 5 ) with :in intake of 6 cubic. feet per rninutc and :i mnsinium tlclivery priwure
Figure 2.
Rear \-iew of Laboratory
building is equipped ivith thc usual laboratory safety f:dities: safety s h o m r s , fire blankets, fire extinguishers. overhead sprinkler system, and gas masks. T h e portion of the building occupied bj- operat,ing personnel is heated \\ith forced-air heat with 1:trge fresh-air intakes to minimize the danger of build-up of toxic or explosive gases. COMPRESSOR ST.4TION
The gas-handling equipment x m s designed t o permit the compression of gases from comniercial cylinders either directly into the reactors or to high pressure storage cylinders for distribution to the reactors as needed. Facilities to accomplish this include provisions for storing the commercinl cylinders; reducing arid nianit'oltling the gas from the cylinders t o the conipressor : and coniprcssiny, storing, and distributing the high pressure gas t o the react 01's. .I26 X :38 feet cj.linder stor:ige shed of open Hanieproof \voorl coiistrurtioii is located npprosim:itelj. 7.3 ieet :1\7:iy froni the Isbor a t o i ~ j . . I t is proviclcd with pressure-reducing m:inifolds \vhich nre connected t)>- overheuci lines to the conipreswr minifolds in the m i i n 1al)oratory iFigure 4). -I~5000-g:illori,200-pound-l)er-
IO'
0
Figure 4.
Compressor 3Ianifold and Control Panel
20'
S C A L E4 - 1
Ilr'
f
II 11
L I
I
---Figure 3.
Floor Plan
2370
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Figure 5.
Vol. 41, No. 10
Compressor
or 15,000 pounds pel syun~.c-inch. The second is a grit) ITLJ stage duplex compressor (Sorwalk Company, T y p e SItwith zin intake of 30 cubic feet per minutr and :t xii:ixinirini ( t3i-j- pressure of 10,000 pounds per q u a r e inch (Figure 5 i . T h e compressors arc operntrd by controls located on t l i t , I'CiI'I'l-
troxii :i solid forging ( t h e Midvale Conipariy 1 t l J a %inch insitlc tli:imeter by an 11-inch outside diameter, ancl closed with a I)utt reas-tlire3deil plug qeatrJ on R copper gasket. An underground trenrli contains t lie high pressure lines connecting the ?tor:ige t:ink; {vith thf, high pr~:euw comprrwor m:inifolds and
lior n-all (Figwe 4). The giLst2:: entering tlic I)uililing 1'riitii tlir cylinder slieJ are nianifoltld t o the coniprew)r3 :in11r i ~ ~ I u c c J (Fisher Goveriior Compmiy, T ~ - p730) e from GO 10 :jl,l)ro\.itii:itc,l~ 2 pounds ])er squ:ire inch gage. The C O I ~ I ~ I ' ~ I S O :ire I ' . ~ pI'~Jl- pneuin:itic agitators i o elimiiuit e vanstruct ion joints and hone>-cwmhiny. Each IuIrric:idt, iiriit is struct ur:illy i~idependentof tiit. rC>t of the building t ( I r , ( v I i i r ( ~ the t r:iii.sniissioii of \-ilir:rtinii or shock. Similarly, t hv floow Lvithiii th(, rc'nct,or rooms :ire iiitiepcndrnt of tht, n.:tlls :it111 :trc 1:iitl or) s:ind Ixirkfill :il,ove the Footings. Figure 9 sho~vssome details of the inside of the ti;irrii;:iild 1'6'actor, l ~ y s .Services and high pressure gas supply lirics eritrr llic Imys through trenches. Reactor manifold v:ilvea are mount tvl on the n.:ill above the gas-distribution trench. Each room hns :i pivntiriy hoist support. I n the event t h a t it is desired t o \vatell t h c oper:ition of the equipment, r:rch cell is provided with :I pecxp holr coverivl ivitli 2-inch thick I,ulletproof glass. -41000-cul)icfeet-lmminut cx1i:iust. far1 is installed in the w:dl facing the hillsitle (Figure 2'). The fan circuit is interlocked with the reactor controls so that the fnn must k>running whenever the m w t o r is in operat ion.
Vol. 41, No. 10
pensates for changes iri the :imbient temperature, line voltage fluctuations, and heat of rcaction, and maintains the temperature of the autoclave contrnts within * 1O C. Several safety fe:itures arc incorporntetl in the heat control circuits. If the thermocouples tireak, the reactors are automatically shut down. If the autoclave temperature exceeds control limits set in the recording potentiometer, the heat is shut o f f ,water is automatic:illy admitted to cooling coils, the agitation may be turned off, arid the liquid feed pump ( i f involved in the operationj is turned off. Timers with a 60-hour span are incorporated in the ciiiitrol circuits to start or stop operntioris during periods wheii t h r laboratory is uIi:itteiided. JIost of the p i ' r s u r c meusurements are made ivith Dourtion gages ( : i i ~ m o r r ~c:~ser l with plastic fronts and .safety backs) loc:ited on the outside of t h txirricades. I n such cases pressure control is manual. 'Thc valvw ai'e opri,ated from the outside of t h e reactor bays hy I i i i x i s oi rxtension huritlles. JIowwer, scvcrul of the reactor b a ) arc ~ cquippctl Tvith .itcotr:iii prwsurc: transniitters :ind re(-ordtw ( 1 ) . I n this system the tip of :i I h u r d o n drives thc: core of a differential t u l x 1oc:iteti I)iJhintl the‘ 1~:irr~ieacie traiisfomier. Thv output of the tlansfornm is csrrieet for excessirc pi'essure rise tlJ tun1 off thc heat, :ithiit water to cooling coils, shut off t lie f w c l puiiips, :mil opor:ite :i \variiirig :ilai,iii.
(1
CONTROL SYSTEBl
Thv remote controls for reartor temperature, pres.sn~'c.and agitation are centralized 011 control panels in the operating corridor (Figuie 6). Automatic instrumentation is used where feasible to simplify and increase the safety of operation. The control pitncl:: are color-engineered for operating efficiency. The \)arkground color is coral, electrical controls are blue, and v:ilvc cxtensiori h:tndle,s are color-coded for different gases. T h e -4iiiericnn Standards Association color code is f o l l o n d for etantlard servici: lines and valves. Tht, temperature control s)-steni is designed t o overcoIue the inherent prohlenis of high heat capacity and temperatme lag due to thr heavy TTalls of the pressure vessels, and a t the s i m e time t o respond rapidly t o exothermic temperat,ure changes within the reactor. This is accomplished with a txo-potentiomerer control system (Figure 7 ) . One potentiometer, a Brown indicating-controller, is connected to a thermocouple installed adjacent to the heating element outside the bomb. T h e other potent'ionietcr. a Urom-Ti strip-chart, recorder, is connected t o a thermocouple placed i n a thermocouple n.ell within the autoclave. Both potentiometers have on-off switches mired in serics to operate a contnctor in t h e 44O-volt, power circuit to t,he heating elements. T h u s the outside thermocouple controls the temperature gradient through t h e autoclave walls and the inside thermocouple responds t,o esothermic temperature changes. This system automatically com-
Figure 9.
Five-Gallon .Autoclave and Barricade Interior
October 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
shown that the conventional arrangement whereby the safety head is connected t o the autoclave through several feet of high pressure tubing is inadequate. Rocking-type bombs (.American Instrument Company) are used for batch exploratory studies. Sizes range from 0.1 to 2 liters. Bombs or liners of carbon steel, chrome steel, various stainless steels, nickel, silver, copper, Everdur, Elastuf, glass, arid platinum are available. The standard he:rds have been redesigned to incorporate a wide diameter opening for :i safety head assembly :ind a liquid sampling port, in :tdclition t o the usual gas inlct port and therniocouple mil, Safety l i e d Siv:ills, :ind Uryson! Inc.) with 0.5-inch safety directly i n t o the liunib head. .Isa rcsult of agitation studies in glass models ( A ) , new bomb shakers have been designed and shop built to olitjiin optimum :igitation. The bonib henters for differCII t size l)oiiiL)s :ire ni:idc to be interchange:ilile and their heater 1r:tda :it,c :ittnc.hed to standard receptacle. t o f:icilitnte changcimately hall of the b:iya Figure 8 shon-s :i typical For rxplor:itor~-exothermic rcnctionr, :i spccial rocking-type 1)oinb is usrcl (designed in cooper:ition with Autoclave Engineers, In(%.).Onc cntii,c end comprises :I snt'ety he:d nsiemlily aceomniotlating 2-inch safety divks (Blnck, divalls, nncl Bryson, Inc.), Tlic closurc on the other end carries a cooling coil, :I thermocouple n-c,ll, gas 1)oi,ts,and :i 0.5-inch safety disk. Stiri,etl :iutoclaves mngirig in size from 3 qu:irts to 5 g:illons and eovcvitig the p i ' c ~ s u r e~ i i i g et o 15,000 pounds per squnre inch are availal)1c~for smiple prrpnmt ions. All of these nutoelaves are constructtd of either stainless steel or nirliel uncl have cooling coils and extra large rupture dislts. The 5-gnllon autochve shown in Figure 9 (Autoclnve Engineers, Iiic.) 2i:is :i 2-inch safety head assernlily in the top head. Two of the barricaded bays are equipped n-itli continuous flow units for the evaluation of high pressure r e x t i o n s on a continuous basis antl fur miall sc:ile process tlcvelopnient. .i nuniber of reactor tubes ranging in size from 27 inched long (0.75-1iter tulles) u p t o 60 i n c h c long (:&liter tubes) ;ire :ivsilnl)le. Auxili:ir>- rc~uipnieiltfor use v i t h both thc continuous units antl the bat c h autoclaves includes feed pumps :ind pressure regulntors. The punips (Hills-lIcC:mnii C o i i i p m y ~nre of tile twin-feed piston type ~ v i t hj:iclicteil pistons :itid chrclis. They cover flon r:ites froin 0.1 gnllon per hour to 12.5 gilloris per hour :it presaiire3 up to 25,000 pountls pcr squ:ire inch. Hxitchcs :mtl st:inclusd receptaclrs : i w provitletl on most of the control pnnrls t o permit flesihility in the p1:icement of the ~ ) u n i p s , I'ressurr cwntrol on the continuous units is obtaiiicd with :L I)iicUmntic:ill?- operated control v n l v ~c:ipalile of hnnciling sniall f l o ~ (Fisher s ovcrnorCompany Gismo Type 530 llicro-Flo control valve). O t h e r misccll:ineous equipment includes nn oil lienting fur j:iclirtetl lines, n.cigh scales, a gnge trster, :~iida hydraulic punip for e l e i ~ ~ t epressures. d L.ABOR.ATORIES
The laboratory layout (Figure 3) provides space for product recovery, low pressure reactors, and catalyst preparation and evaluation. .Is shon-n in Figure 10, stantlard nietnl laboratory furniture with Alberene stone table tops and sinks is installed. Each labo1,atory has two large hooded units. T h e laboratories itre heated ivith forced air and are on a sep:ir:ite fresh-nir intake from the corridor. SAFETY
Although equipment design, barricading, automatic controls, and protrctive devices arc important, the most essential element of d r t y in high pressure operation is the personncl. This philosophy of safety has been presented elsewhere (6). Personnel responsible for inspection and maintenance of equipment are an
Figure 10.
2373
Typical Laboratory
integral part of the 1:ibor:ttory .st:Lff, \Tit11 responsibility lor inspection, nmintenuice, antl operation ceritr:dized to give close coordin:Ltion. 0prr:Lting manu:ils :we issued for the compressors, autoclaves, teiiiper:i.ture antl prrssure controls, :inti timers. Ilefinitc responsi1)ility is :issigned ior conipressoi. opwation antl m:iinten:mce anti the inspcction nncl m:iintcn:irice of iristrunicsnts :md equipment. Frequent inspection is c:irriccl out, on vnlvcs, fittingR, rupturc disks, thrends, nntl closut~cs01' t h e equipmcwt i n opernt ion. Designs of pressure vessels nro approved by the IIart ford Steam Boilcr Inqicction :ind Insurance Comp:my. Sew pressui'c? vesc tested, in the presrncc: of a rcprcscwtativc sels : ~ r h~drost:itically of this c-onip:triy. t o at Iwst onr arid o w h:tll' tinies the r:ited ircl sutlsrqucntly irisuretl. I'eworking presmrr, :ind the v( t h c nri.,l is intlic*:atc~ I. the :tutocl:ivcts are sul)ji:ctcll to further h>-Jr:iuli(~ tests, :ind r t ~ o r t l sof :Lutocl:tve tlinicnsions arc 1iept. Thi~oughthe eonibin:ation of nell tr:iinetl srii'cxty-conscious pcrsonncl :ind thc use of :itlequ:Ltr Ixirricndirig, runiote controls, : t i i d safety provisions in the cquipnic'nt, it is lielieved t h a t the p ~ . o l ) : ~ hility of injury from potentiall)- h:iz:~r~Ious high pressure rc:ictions has been r e h e e d to a levcl conqxtrable with t h e h:az:Lrds inhci,cnt in any ordinury 1:ibor:ttory work. 1
LITERATURE CITED
(1) Anon., Instruments, 21, 806 (1048). ( 2 ) Barher. A. T . , and T a y l o r . -i.H., Trans. Inst. .Ilech. Engrs., 128, 5 (1934). (3) Emst, F. A , , Reed, F. C . , and Iklwards, W. L., IND. EXG. CHEM.. 17, 781-83 (1926). (4) Hoffmnnn. A. N.. M o n t g o m e r y , J. B., arid Moore, J. K., Ibid., 40, 1705-10 (1948). ( 5 ) Killeffer. D . H., Ibid., 17, i 8 9 (1925). (6) Mooie, J. IC., .iutoclave E n g i n e e r s , Inc., E r i e , Pa., Catalog 100, p. 13-15 (1948). (7) Storch, H. H.. Hirst, L. L., Fisher. C. H., and S p r u n k , G. C., U. S . Bur. Mines Tech. Paper 622 (1941).
RECEIVED July 15, 1919.
