Fire research furnaces at the National Research Council

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Fire Study (National Research Council of Canada. Division of Building Research), 1960-07-01

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Fire research furnaces at the National Research Council

Ser

I

; T H 9 l l l N27f ₅ no. 1 c . 2

1

EXDG-

NATIONAL RESEARCH COUNCIL CANADA

DIVISION OF BUILDING RESEARCH

FIRE EZESEARCH FTJRNACES AT THE NATIONAL RESEARCH COUNCIL

by

G.W. Shorter and

T.Z.

Harmathy

Fire Study No. 1

of the

Division of Building Research

rnTAWA

PREFACE

This i s t h e f i r s t number in _{a new s e r i e s of} p u b l i c a t i o n s t o be issued by t h e Division of Building Research, National Research Council. A s t h e i r t i t l e ,

"Fire Studies", suggests, t h e papers i n t h i s new

s e r i e s w i l l a l l be concerned with f i r e research. This

f i r s t paper i s a d e s c r i p t i o n of t h e s p e c i a l l a b o r a t o r y furnaces t h a t a r e now i n use i n t h e F i r e Research

Building of the Division. Future papers i n t h i s s e r i e s w i l 1 , i n c l u d e r e g u l a r r e p o r t s upon t h e t e s t s conducted i n these major r e s e a r c h f a c i l i t i e s .

m e Division i n t e n d s t o continue i t s s t a t e d policy of having a s many a s possible of the papers r e p o r t i n g i t s f i r e research work published through t h e medium of s c i e n t i f i c and engineering s o c i e t i e s

and i n t h e pages of e s t a b l i s h e d journals. Opportunities f o r such p u b l i c a t i o n i n t h e f i r e r e s e a r c h f i e l d , however, a r e r a t h e r l i m i t e d if only because of t h e r a t h e r s p e c i a l c h a r a c t e r of t h i s branch of building r e s e a r c h work.

It has t h e r e f o r e become c l e a r t h a t , i f t h e M v i s i o n i s t o make promptly a v a i l a b l e f o r t h e b e n e f i t of t h e people of Canada the r e s u l t s of work c a r r i e d out i n i t s F i r e Research Building, some supplement t o such p r i n t e d

p u b l i c a t i o n s i s necessary. !his s e r i e s has been designed t o f i l l t h i s gap.

Whenever possible, reference w i l l be made on t h e end covers of papers i n t h i s s e r i e s t o o t h e r

p u b l i c a t i o n s of t h e Division r e l a t i n g t o f i r e research. I n t h i s way those who r e c e i v e t h i s s e r i e s w i l l be

enabled t o keep i n touch conveniently with a l l t h e i n - formation a v a i l a b l e i n r e l a t i o n t o f i r e research from the Division. I n q u i r i e s regarding t h e f i r e research work of t h e M v i s i o n w i l l always be welcome. These

should be addressed d i r e c t l y t o Ilk. G. W. S h o r t e r , Head, F i r e Research Section, c/o M v i s i o n of Building Research, National Research Council, Ottawa 2.

Ottawa

J u l y 1960 Robert

F. Legget Director

FIRE RESEARCH l?UFU?ACES AT THE NATIONAL RESEARCH COUNCIL

G.W. S h o r t e r and T.Z. H a m a t h y

When a f i r e o c c u r s i n a b u i l d i n g , a t a n e a r l y s t a g e it i s g e n e r a l l y confined t o a s i n g l e compartment. A major d i s a s - t e r c a n t h e r e f o r e be avoided if t h e w a l l s , f l o o r , and o t h e r elements of t h i s compartment a r e s o designed as t o p r e v e n t t h e f i r e from s p r e a d i n g t o o t h e r compartments. The p r o p e r t y of

a c o n s t r u c t i o n t h a t d i r e c t l y r e l a t e s t o i t s a b i l i t y t o r e s t r a i n a f i r e w i t h i n a compartment i s c a l l e d i t s f i r e endurance; it i s measured i n h o u r s .

Test f a c i l i t i e s have been provided i n t h e new F i r e Research B u i l d i n g of t h e D i v i s i o n of B u i l d i n g Research of t h e N a t i o n a l Research Council, Ottawa, t o determine t h e f i r e en- durance p e r i o d of walls and f l o o r s . These f a c i l i t i e s have been designed t o a c h i e v e maximum f l e x i b i l i t y and u t i l i z a t i o n i n o r d e r t o r e n d e r a n e f f i c i e n t s e r v i c e t o Canadian i n d u s t r y and t o f u r t h e r knowledge i n t h e use of b u i l d i n g m a t e r i a l s f o r s t r u c t u r a l f i r e p r o t e c t i o n .

FIRE ENDURANCE TESTS

Actual f i r e s v a r y s o g r e a t l y t h a t t h e f i r e endurances observed d u r i n g f i r e s a r e of l i t t l e v a l u e from t h e viewpoint of c l a s s i f y i n g d i f f e r e n t b u i l d i n g elements. Standard t e s t i n g methods f o r f i r e endurance have t h e r e f o r e been developed and a d o p t e d i n t h e United Kingdom (BS 476, 1932)

,

i n t h e United

S t a t e s (ASICM E-119, 1 9 3 3 ) , and i n many o t h e r c o u n t r i e s . A

s i g n i f i c a n t f e a t u r e of t h e s e s t a n d a r d s i s t h e d e f i n i t i o n of t h e s t a n d a r d f i r e exposure. Since t h e most c h a r a c t e r i s t i c q u a l i t y of a f i r e i s i t s t e m p e r a t u r e , t h e v a r i a t i o n of t h e t e m p e r a t u r e i n t h e f u r n a c e d u r i n g t h e t e s t i s p r e s c r i b e d . !Ibis temperature- time curve i s a l m o s t i d e n t i c a l i n t h e d i f f e r e n t s t a n d a r d s ; it

i s s i g n i f i c a n t f o r i t s r a p i d t e m p e r a t u r e r i s e d u r i n g t h e first t e n minutes ( F i g . 1). It i s assumed t h a t t h i s curve r e p r e s e n t s t h e development of a f a i r l y s e v e r e f i r e .

Three b a s i c t y p e s of f a i l u r e of t h e t e s t specimen a r e s p e c i f i e d i n t h e s t a n d a r d s : (a ) t e m p e r a t u r e r i s e ,more t h a n 250°F above t h e i n i t i a l t e m p e r a t u r e , on t h e s i d e of t h e specimen

which i s n o t exposed t o t h e t e s t f i r e ; ( b ) c o l l a p s e ; and ( c ) f o r - mation of wide c r a c k s . A n i m p o r t a n t r e g u l a t i o n i n t h e s t a n d a r d s

i s t h a t t h o s e elements, which i n p r a c t i c e a r e used as l o a d - b e a r i n g s t r u c t u r e s , s h o u l d be t e s t e d under d e s i g n l o a d , and t h a t t h e

non-load-bearing elements should be r e s t r a i n e d a g a i n s t t h e r m a l expansion. IChe minimum s i z e of t h e t e s t specimen, t h e method of measuring t h e f u r n a c e t e m p e r a t u r e , and t h e t e m p e r a t u r e of t h e s u r f a c e unexposed t o f i r e a s w e l l a s some m i s c e l l a n e o u s r e q u i r e m e n t s a r e a l s o s p e c i f i e d . D.B.R. T e s t F a c i l i t i e s Wall Furnace Before t h e d e s i g n of t h e NRC f a c i l i t i e s w a s begun, t h e e x i s t i n g f a c i l i t i e s i n o t h e r c o u n t r i e s were s t u d i e d c a r e f u l l y

as o c c a s i o n p e r m i t t e d throughout s e v e r a l y e a r s . Canadian needs f o r r e s e a r c h and t e s t i n g , b o t h c u r r e n t and f u t u r e , were t a k e n i n t o c o n s i d e r a t i o n . It was f i n a l l y d e c i d e d t o p r o v i d e f a c i l i t i e s f o r w a l l and f l o o r t e s t i n g , and t o omit, a t l e a s t f o r t h e p r e - s e n t , f a c i l i t i e s f o r t e s t i n g columns a n d beams. The main

equipment t h u s c o n s i s t s of two major u n i t s , one f o r c a r r y i n g o u t f i r e endurance s t u d i e s on w a l l s , and t h e o t h e r f o r s t u d i e s on f l o o r s and c e i l i n g s . Each of t h e s e u n i t s c a n f u r t h e r be d i v i d e d Fnto a f u r n a c e assembly, and a d e v i c e f o r l o a d i n g o r r e s t r a i n i n g t h e t e s t specimen i n accordance w i t h t h e t e s t s p e c i f i c a t i o n s .

A diagrammatic p i c t u r e of t h e w a l l t e s t i n g u n i t i s shown i n Fig. 2. It i s s e e n t h a t t h e f u r n a c e assembly i s mounted on a c a r r i a g e , and i s t h u s movable on t r a c k s . On t h e o t h e r hand,

- 3 -

t h e frame t h a t r e c e i v e s t h e specimen and t h e f l u e a r e f i x e d . !he ' s e c t i o n ' i n Fig. 2 shows t h e u n i t i n p o s i t i o n p r i o r t o t e s t i n g , immediately a f t e r t h e t e s t specimen has been l o c a t e d i n t h e frame. The combustion chamber i s t h e n completed by moving t h e f u r n a c e t o t h e specimen, a s shown i n d o t t e d l i n e .

I n

t h i s p o s i t i o n t h e opening on t o p of t h e f u r n a c e i s immedi- a t e l y under t h e f l u e t h r o u g h which t h e combustion p r o d u c t s l e a v e t h e u n i t .

Heat i s s u p p l i e d t h r o u g h propane g a s b u r n e r s l o c a t e d i n t h e r e a r w a l l of t h e f u r n a c e assembly. !Chey a r e a r r a n g e d I n t e n banks, w i t h t e n b u r n e r s i n each bank. !Ihe t h r o u g h p u t of each b u r n e r i s 50 s t a n d a r d cu

ft/hr

a t a nominal o p e r a t i n g g a s p r e s s u r e of 25 l b / s q i n . g a , !be n e t h e a t of combustion of propane i s a b o u t 2,400 ~ t u / c u f t . Thus t h e maximum t o t a l h e a t i n p u t a t 25 l b / s q i n . ga p r e s s u r e i s approximately 12,000,000

s t u b .

The high k i n e t i c energy of t h e propane f l o w i s used t o d r a w a i r i n t o t h e b u r n e r and t o mix it w i t h t h e gas i n t h e r e q u i r e d p r o p o r t i o n ; no p r e s s u r i z e d a i r system i s t h e r e f o r e r e q u i r e d f o r combustion. This makes it p o s s i b l e f o r t h e h e a t i n p u t t o be c o n t r o l l e d by c o n t r o l l i n g t h e propane p r e s s u r e a l o n e . C o n t r o l c a n t a k e p l a c e b o t h c e n t r a l l y , a s w i l l be l a t e r des-

c r i b e d , and i n d i v i d u a l l y a t each s e p a r a t e b u r n e r by manually a d j u s t i n g a r e g u l a t i n g v a l v e . Each b u r n e r i s equipped w i t h a

p r e s s u r e gauge, which i n d i c a t e s t h e p r e s s u r e r e s u l t i n g from t h e combined c e n t r a l and manual p r e s s u r e c o n t r o l .

Each b u r n e r i s s e t i n a s e p a r a t e c a s t - i r o n b u r n e r b l o c k which c a r r i e s , b e s i d e s t h e main b u r n e r , a small p i l o t b u r n e r .

These p i l o t b u r n e r s bypass t h e p r e s s u r e c o n t r o l l i n g v a l v e s , and . a r e d i r e c t l y connected w i t h .the main g a s l i n e by a s m a l l p i p e

system. The gas flow r a t e through t h e p i l o t b u r n e r s i s f a i r l y c o n s t a n t , b u t v e r y low because of t h e h i g h p r e s s u r e d r o p through t h e small l i n e .

Each p i l o t burner has a shut-off valve. A t t h e s t a r t of a t e s t , t h e s e valves a r e opened and t h e p i l o t burners

l i g h t e d with a t o r c h a few minutes before s t a r t i n g t h e gas flow through t h e main burners. The p i l o t f l a m e s i g n i t e t h e main gas flow n o t only a t t h e s t a r t of t h e t e s t , b u t a l s o during t h e t e s t , whenever t h e gas flow i s r e s t o r e d a f t e r a complete shut- o f f by t h e automatic c e n t r a l gas pressure c o n t r o l . Because t h e furnace assembly i s movable, a l l t h e gas, e l e c t r i c , and instrument connections t o t h e furnace a r e through f l e x i b l e conduits.

The f r o n t e l e v a t i o n i n Fig. 2 i s mainly a n i l l u s t r a t i o n of t h e loading device. !he components of t h i s device a r e a s t r o n g s t e e l frame, i n which t h e specimen i s placed, and a number of hydraulic jacks f i t t e d i n t o t h e frame. lChese jacks can be used e i t h e r f o r f i x i n g t h e specimen i n t h e frame (by applying only a s l i g h t pressure on t h e specimen), o r f o r simu- l a t i n g s t r u c t u r a l loads o r - r e s t r a i n i n g f o r c e s . m e r e a r e e i g h t jacks l o c a t e d on t h e t o p and on both s i d e s of t h e frame opening; a t t h e bottom t h e r e a r e s i x jacks, and two f i x e d supports. Each

jack i s capable of t r a n s f e r r i n g a load of 30,000 l b t o t h e speci- men, which corresponds t o a maximum load of about 1 0 tons/ft.

S t e e l pads, 5 i n . by

5

i n . , a r e i n c o n t a c t with t h e specimen, and a r e connected, with the p i s t o n , through a s p e c i a l l y designed linkage t o ensure t h e proper bearing of t h e pads o n . t h e specimen. Coiled s p r i n g s a t each corner of t h e pad keep t h e gide jacks

i n a more o r l e s s h o r i z o n t a l p o s i t i o n u n t i l they a r e brought up t o bear a g a i n s t t h e edge of t h e specimen. The jacks have a &in. s t r o k e . When they a r e i n r e t r a c t e d p o s i t i o n , t h e opening between t h e jack pads a c r o s s t h e frame i s s l i g h t l y more t h a n 1 4 f t .

!The two f i x e d supports a t t h e bottom of t h e frame opening serve t o c a r r y t h e specimen when it i s f i r s t placed i n t h e frame. A clamp, which i s shown i n Fig. 2, holds t h e

specimen i n p o s i t i o n u n t i l t h e j a c k s a r e p u t i n o p e r a t i o n . I h e j a c k s a r e a c t u a t e d from a c e n t r a l h y d r a u l i c power u n i t . This u n i t i s c a p a b l e of d e l i v e r i n g o i l t o t h e jack a t a maximum p r e s s u r e of 1500 l b / s q i n . ga. !be v e r t i c a l and h o r i z o n t a l

l o a d on t h e specimen c a n be c o n t r o l l e d s e p a r a t e l y .

When a l o a d - b e a r i n g w a l l i s t e s t e d , t h e p r e s s u r e on t h e v e r t i c a l j a c k s i s k e p t a t a c o n s t a n t v a l u e corresponding t o t h e d e s i g n l o a d . I n t h e c a s e of non-load-bearing w a l l s , b o t h t h e v e r t i c a l and h o r i z o n t a l j a c k s a r e used. The p r e s s u r e on a l l t h e j a c k s i s e q u a l , b u t i s v a r i e d i n o r d e r t o s i m u l a t e , t o t h e e x t e n t p o s s i b l e , f u l l r e s t r a i n t on t h e w a l l a g a i n s t thermal expansion. A s p e c i a l i n s t r u m e n t has been designed t o i n d i c a t e w i t h g r e a t a c c u r a c y , t h e v a r i a t i o n o f t h e w a l l l e n g t h . If t h e p o i n t e r of t h i s i n s t r u m e n t d e f l e c t s from t h e p o s i t i o n corresponding t o z e r o w a l l expansion, t h e p r e s s u r e on t h e j a c k s i s a d j u s t e d manually s o a s t o e l i m i n a t e t h e d e f l e c t i o n .

llhe s i z e of t h e f u r n a c e opening and t h e n e t c l e a r a n c e between t h e jacks were s e t by t h e d e s i r e t o be a b l e t o t e s t i n accordance w i t h b o t h t h e American and B r i t i s h s t a n d a r d s . 'Ilhe American s t a n d a r d s t i p u l a t e s t h a t t h e a r e a of t h e specimen ex- posed t o f i r e be n o t l e s s t h a n 100 s q f t w i t h n e i t h e r dimension l e s s t h a n 9 f t , whereas t h e B r i t i s h s t a n d a r d r e q u i r e s a specimen of 1 0 f t by 1 0 f t . Accordingly a f u r n a c e opening of 1 2 f t by 1 2 f t w a s s e l e c t e d . !The maximum opening between t h e jacks i s somewhat l a r g e r , 1 4 f t by 1 4 f t . This l a r g e r opening makes it p o s s i b l e f o r w a l l p a n e l s c o n s t r u c t e d in frames, o r equipped w i t h framing members, t o be f i t t e d i n t o t h e l o a d i n g frame w i t h o u t r e d u c i n g t h e a r e a of t h e p a n e l exposed t o f i r e . F l o o r Furnace

The f l o o r t e s t i n g u n i t , shovin i n Fig. 3 , i s similar t o t h e w a l l t e s t i n g u n i t i n many r e s p e c t s . The most s i g n i f i c a n t d i f f e r e n c e i s t h a t t h e f u r n a c e assembly ( i n c l u d i n g t h e f l u e )

i s a f i x e d i n s t a l l a t i o n , w h i l e t h e frame i n which t h e specimen i s l o c a t e d and t h e l o a d i n g d e v i c e a r e movable. The diagram shows t h e u n i t a s it a p p e a r s d u r i n g a t e s t . ! b e combustion chamber i s completed when t h e frame and specimen a r e p l a c e d on t o p of t h e f u r n a c e .

The b u r n e r s a r e l o c a t e d a l o n g t h e two l o n g e r s i d e s of t h e f u r n a c e . There a r e 1 5 b u r n e r s on each s i d e , a r r a n g e d i n groups of t h r e e . The throughput of t h e b u r n e r s i s 220 s t a n d a r d cu

ft/hr

a t 25 l b / s q i n . gas p r e s s u r e ; t h u s t h e t o t a l h e a t i n p u t a t t h i s p r e s s u r e i s a b o u t 16,000,000

~ t u / h r .

The b u r n e r s a r e similar t o t h o s e a l r e a d y d e s c r i b e d . The p i l o t b u r n e r s a r e connected d i r e c t l y t o t h e main g a s l i n e , and t h u s y i e l d f a i r l y uniform flame throughout t h e whole t e s t . On _{t h e o t h e r hand,}

t h e gas flow r a t e t h r o u g h t h e main b u r n e r s i s s u b j e c t e d t o a . c e n t r a l a u t o m a t i c and t o a n i n d i v i d u a l manual c o n t r o l .

The frame i t s e l f , i n which t h e f l o o r specimen i s l o c a t e d ,

i s o f simple design. It has been made from c a s t a b l e r e f r a c t o r y m a t e r i a l and does n o t have any movable p a r t . In c o n t r a s t t o

t h e frame f o r t h e w a l l t e s t i n g u n i t , t h i s frame c o n t a i n s t h e specimen n o t o n l y d u r i n g t h e t e s t , b u t c a r r i e s it from i t s con- s t r u c t i o n t o i t s d e s t r u c t i o n . To a l l o w f o r n e c e s s a r y c u r i n g t i m e , t h r e e frames have been c o n s t r u c t e d .

The specimen can be l o c a t e d i n t h e frame i n two ways. If t h e r e i s a narrow gap around t h e edges o f the specimen, as shown i n Pig. 3, t h e specimen i s t h e n n o t r e s t - r a i n e d a g a i n s t thermal expansion. I n t h e c a s e of f u l l r e s t r a i n t , t h e edges of t h e specimen a r e b u i l t t i g h t l y a g a i n s t t h e frame. There a r e f o u r s h a c k l e s on t h e t o p of t h e frame. The l e g s of a l o a d i n g d e v i c e a r e pinned t o t h e s e s h a c k l e s , a s shown i n Fig. 3 . B e . l o a d i n g d e v i c e c o n s i s t s of a s t e e l frame c a r r y i n g t h i r t y hy-

d r a u l i c j a c k s , each c a p a b l e of t r a n s f e r r i n g a l o a d of 3,000 l b t o t h e specimen t h r o u g h t h r e e pads a r r a n g e d i n t r i a n g u l a r shape. This l o a d r e p r e s e n t s a d i s t r i b u t e d l o a d of a b o u t 500 l b / s q f t .

The s t r o k e of t h e j a c k s i s 1 2 i n . These j a c k s a r e a c t u a t e d from t h e same h y d r a u l i c power u n i t a s t h o s e o f t h e w a l l t e s t i n g u n i t . !the o i l p r e s s u r e f o r t h e system i s c a p a b l e of b e i n g

v a r i e d between 0 and 750 l b / s q i n . ga.

The ASnf s t a n d a r d r e q u i r e s t h a t t h e a r e a of t h e speoimen exposed t o f i r e s h a l l be a t l e a s t 180 s q f t w i t h n e i t h e r dimen- s i o n l e s s t h a n 1 2 f t . Accordingly a 12- by 1 5 - f t f u r n a c e opening w a s s e l e c t e d . The B r i t i s h s t a n d a r d r e q u i r e s a f l o o r specimen w i t h dimensions n o t l e s s t h a n 10 f t by 1 0 f t , s o t h a t t h e B r i t i s h s p e c i f i c a t i o n s a r e a l s o met. Operation of Furnaces S i n c e t e s t s c a n be scheduled s o as t o a v o i d t h e s i m u l - t a n e o u s o p e r a t i o n o f t h e w a l l and f l o o r t e s t i n g u n i t s , t h e f u e l s u p p l y system, t h e f l u e system, the' c o n t r o l p a n e l , and i n s t r u - m e n t a t i o n a r e common f o r b o t h u n i t s . The d i s p o s i t i o n of t h e s e

i n s t a l l a t i o n s i s diagrammatically shown i n Pig. 4 . Valves, dampers, and s e l e c t , o r s w i t c h e s make it p o s s i b l e t o connect e i t h e r u n i t t o t h e p r o c e s s l i n e .

The l i q u i d propane i s s t o r e d i n a 1750-gallon t a n k . Three v a p o u r i z e r s , each of 70 g a l h r c a p a c i t y s e r v e f o r v a p o u r i z i n g t h e l i q u i d f u e l . !the p r e s s u r e o f t h e gaseous

propane c a n be reduced t o any v a l u e between 30 and 60 lb/sq i n . ga by means of t h r e e r e g u l a t o r s on t h e o u t l e t s i d e o f t h e

v a p o u r i z e r s . The g a s i s piped underground t o t h e l a b o r a t o r y i n a 4-in. l i n e . I n s i d e t h e b u i l d i n g , it p a s s e s through a diaphragm c o n t r o l v a l v e , t h e n through one o f two s h u t - o f f

l e v e r - h a n d l e cocks which d i r e c t t h e gas flow t o e i t h e r t h e f l o o r o r t h e w a l l t e s t i n g u n i t .

The diaphragm v a l v e p r o v i d e s f o r t h e c e n t r a l c o n t r o l of t h e h e a t i n p u t i n t o t h e f u r n a c e . I t i s p n e u m a t i c a l l y p o s i t i o n e d by a p o t e n t i o m e t r i c program c o n t r o l l e r from t h e i n s t r u m e n t panel. %is i n s t r u m e n t r e c e i v e s d-c s i g n a l s from n i n e p a r a l l e l - c o n n e c t e d

thermocouples l o c a t e d i n t h e combustion chamber i n accordance

w i t h t h e s t a n d a r d s p e c i f i c a t i o n s . A cam, c u t f o r t h e p r e s c r i b e d temperature-time r e l a t i o n s h i p , i s p l a c e d i n s i d e t h e i n s t r u m e n t .

The pneumatic s i g n a l s e n t t o t h e diaphragm v a l v e c o r r e s p o n d s t o t h e d i f f e r e n c e between t h e a v e r a g e combustion chamber t e m p e r a t u r e and t h e p r e s c r i b e d f u r n a c e t e m p e r a t u r e . Thus t h e program con- t r o l l e r c a u s e s t h e combustion chamber t e m p e r a t u r e t o f o l l o m c l o s e l y t h e s t a n d a r d temperature-time curve.

The combustion p r o d u c t s l e a v e t h e f u r n a c e s through a f l u e system e n d a r e d i s c h a r g e d t o t h e a i r from a chimney. The h e i g h t of t h e chimney i s n o t enough t o induce t h e r e q u i r e d

d r a f t , s o t h a t a fan has been i n s e r t e d i n t h e du'ct. A pneu-

m a t i c draft c o n t r o l l e r , l o c a t e d on t h e i n s t r u m e n t p a n e l , p o s i t i o n s a f a n o u t l e t damper t o m a i n t a i n a s u b s t a n t i a l l y c o n s t a n t f u r -

nace d r a f t of 0.05 t o 0.1 i n . w a t e r ga. A t t h e p o i n t where t h e f a n i r l o c a t e d t h e t e m p e r a t u r e of t h e f l u e g a s e s may exceed 1000°F.

Since t h i s t e m p e r a t u r e would be harmful t o t h e f a n , p r o v i s i o n has been made t o p r o t e c t i t from e x c e s s i v e t e m p e r a t u r e s . A ,

system of t h r e e dampers i s i n s t a l l e d i n t h e passage n e a r t h e e n t r y p o r t of t h e f a n which open and a l l o w f r e s h a i r t o mix

w i t h t h e combustion g a s e s whenever t h e i r t e m p e r a t u r e exceeds 550°F. m e damper system i s a c t u a t e d pneumatically from a temperature c o n t r o l l e r on t h e i n s t r u m e n t p a n e l , a c c o r d i n g t o t h e s i g n a l s r e c e i v e d from a t e m p e r a t u r e probe i n s t a l l e d a t t h e e x i t p o r t of t h e f a n .

A n c i l l a r y F a c i l i t i e s and Laboratory

F a c i l i t i e s have been provided f o r p r e p a r i n g specimens f o r t e s t and a l s o f o r removing t h e specimens f o l l o w i n g a t e s t . These f a c i l i t i e s a r e housed, w i t h t h e t e s t i n g u n i t s , i n a l a r g e l a b o r a t o r y 120 f t l o n g , 40 f t wide and 40 f t h i g h ( F i g . 4 ) . !Phis . l a b o r a t o r y c a n be extended a n o t h e r 40 f t i n l e n g t h , if n e c e s s a r y ,

by expanding i n t o a n a r e a now used f o r model s t u d i e s . The i n t e r i o r s u r f a c e of t h e w a l l s i s covered w i t h g l a z e d t i l e s , which p r e s e n t

a smooth, dense s u r f a c e f o r e a s e of c l e a n i n g . Equipment has been i n s t a l l e d t o p r o v i d e 3000 t o 6000 cu ft/min f i l t e r e d and h e a t e d a i r t o r e p l e n i s h t h e a i r t a k e n from t h e l a b o r a t o r y by

combustion.

The r i g i d b u i l d i n g frames c a , r r y t h e g i r d e r s and r a i l s f o r a 30-ton c r a n e , which c a n r u n t h e f u l l l e n g t h of t h e l a b o r a - t o r y w i t h 2 8 - f t c l e a r a n c e from t h e f l o o r t o t h e maximum e l e v a - t i o n of t h e hook.

A 40- by 20- by 2 7 - f t space a t one end of t h e l a b o r a t o r y i s used f o r s t o r i n g and c u r i n g t h e specimens. This space w i l l be e n c l o s e d l a t e r with some form of l i g h t movable c o n s t r u c t i o n , t h u s making it p o s s i b l e t o m a i n t a i n s p e c i a l t e m p e r a t u r e and humidity c o n d i t i o n s i n o r d e r t o s h o r t e n t h e c u r i n g p e r i o d .

The c u r i n g space i s d i v i d e d i n t o two bays, each a b o u t 20 f t s q u a r e . One of t h e bays i s h o r i z o n t a l l y d i v i d e d a t a h e i g h t of 11 f t . The bottom chamber c o n s t i t u t e s t h e s p a c e where t h e a i r - c o n d i t i o n i n g equipment f o r t h e c u r i n g chambers w i l l be i n s t a l l e d . On _{t h e t o p o f t h i s chamber, t h e f l o o r}

specimens a r e s t o r e d i n h o r i z o n t a l p o s i t i o n w h i l e t h e w a l l specimens a r e s t o r e d v e r t i c a l l y i n t h e o t h e r bay. In s p i t e of t h e l i m i t e d l a b o r a t o r y s t o r a g e accommodation, a t l e a s t f o u r w a l l and t h r e e f l o o r specimens c a n be cured a t one time. A d d i t i o n a l

specimens, n o t r e q u i r i n g c a r e f u l c u r i n g , can be s t o r e d i n t h e o u t d o o r work a r e a .

S p e c i a l equipment has been designed t o f a c i l i t a t e t h e movements of t h e specimens. This i n c l u d e s a l i g h t s t e e l frame f o r s u p p o r t i n g f r a g i l e w a l l specimens, and a heavy s t e e l frame i n which t h e specimen and t h e embracing frame a r e f a s t e n e d 'while t h e y a r e moved by t h e c r a n e . Another s t r u c t u r a l s t e e l

d e d c e s e r v e s a s a l i f t i n g t a c k l e f o r t h e f l o o r specimen and i t s c o n c r e t e frame w h i l e t h e y a r e t r a n s f e r r e d from t h e c u r i n g a r e a t o t h e t e s t i n g u n i t , o r when, a f t e r t h e t e s t , t h e used specimen i s being moved t o t h e d i s p o s a l a r e a .

!be main i n s t r u m e n t p a n e l i s i n s t a l l e d i n a small c o n t r o l room 25 by 1 3 f t , a d j a c e n t t o t h e b i g t e s t l a b o r a t o r y . I n a d d i - t i o n t o t h e p o t e n t i o m e t r i c program c o n t r o l l e r , f a n d r a f t con- t r o l l e r , and f l u e t e m p e r a t u r e c o n t r o l l e r , a number of s w i t c h e s ,

a f u e l flow r e c o r d e r and i n t e g r a t o r , and a m u l t i p o i n t tempera- t u r e r e c o r d e r a r e l o c a t e d on t h e panel. The l a s t - m e n t i o n e d i n s t r u m e n t r e c o r d s t h e t e m p e r a t u r e s b o t h i n t h e combustion

chamber and on t h e s u r f a c e of t h e specimen n o t exposed t o f i r e . Trenches and d u c t s have been l a i d i n t h e f l o o r t o c a r r y t h e e l e c t r i c w i r i n g , thermocouple l e a d s , and t h e p i p e s of t h e pneu- m a t i c system, e t c . between t h e i n s t r u m e n t p a n e l and t h e t e s t i n g u n i t s .

Outdoor Working Area

An outdoor working a r e a 120 f t s q u a r e a d j o i n s t h e t e s t l a b o r a t o r y . This y a r d has been developed p r i m a r i l y t o provide a d d i t i o n a l space f o r t h e c o n s t r u c t i o n of specimens b u t a l s o f o r t h e s t o r a g e of specimens and a s s o c i a t e d frames. It h a s been l e v e l l e d , equipped w i t h a g r i d system of s t a n d a r d gauge r a i l w a y t r a c k a g e , and paved. A t r a c k which e x t e n d s i n t o t h e t e s t

l a b o r a t o r y through a n 18- by 2 4 - f t s t e e l door a n d r u n s t o t h e f a r s i d e of t h e y a r d , s e r v e s a s t h e main t r a n s f e r l i n e . !three s t e e l c a r s made by welding s u i t a b l e frames t o s a l v a g e d s t r e e t - c a r truclrs have been provided t o handle l o a d s up t o 30 t o n s on t h i s t r a c k .

!Three t r a c k s c r o s s t h e main l i n e a t right a n g l e s . Tho of t h e s e c r o s s - t r a c k s connect t h e main l i n e w i t h f o u r c o n s t r u c - t i o n a r e a s . ! b e r e a r e t h r e e c a r s on each of t h e s e l i n e s . The t h i r d c r o s s - t r a c k t e r m i n a t e s a t a r e t a i n i n g w a l l , o v e r which m a t e r i a l s t o be d i s c a r d e d a r e dumped. A 5000-lb c a r p u l l e r

i n s t a l l e d n e a r t h e c e n t r e of t h e y a r d and a system of p u l l e y b l o c k s have been provided f o r moving t h e c a r s .

Each c a r i s equippe'd w i t h a removable s t e e l frame. When a l o a d is t r a n s f e r r e d from a c r o s s l i n e t o t h e main l i n e ,

o r v i c e v e r s a , t h e l o a d - c a r r y i n g c a r i s drawn t o t h e i n t e r s e c t i o n of t h e t r a c k s , and t h e s t e e l frame, t o g e t h e r w i t h t h e l o a d , i s r a i s e d on f o u r p o r t a b l e h y d r a u l i c jacks. The c a r i s t h e n r e p l a c e d by a second c a r r u n i n a t r i g h t a n g l e s and t h e l o a d e d frame i s

lowered on t o it. Another means of t r a n s f e r r i n g t h e 1 o a d . i ~ a l s o p o s s i b l e a t one i n t e r s e c t i o n . A 2 1 - f t - h i g h frame of 3 2 - f t s p a n h a s been e r e c t e d a t a 4.5' a n g l e t o t h e t r a c k s . I t i s

equipped w i t h a n overhead 5-ton e l e c t r i c h o i s t and 24-ton c h a i n h o i s t . The primary purpose of t h i s assembly i s , however, t o unload l a r g e l o a d s d e l i v e r e d by motor t r a n s p o r t on t o t h e c a r s , t h u s augmenting t h e b u i l d i n g crane.

Conclusion

!Re f a c i l i t i e s d e s c r i b e d w i l l enable t h e F i r e S e c t i o n t o c a r r y o u t a comprehensive f i r e r e s e a r c h and t e s t program.

Research s t u d i e s a r e b e i n g planned t o o b t a i n a b e t t e r u n d e r s t a n d i n g of t h e behaviour of b u i l d i n g c o n s t r u c t i o n s when exposed t o f i r e . One major s t u d y w i l l be t o evolve a r e l i a b l e method of p r e d i c t i o n of f i r e endurance p e r i o d s i n o r d e r t o reduce t h e number of ex- pensive l a r g e - s c a l e t e s t s . !This i s a complex problem and Ohe

f i r s t approach w i l l be t o work o u t i n t e r p o l a t i o n formulae t h a t w i l l a l l o w f o r some r e d u c t i o n i n t h e number of t e s t s . The immediate problems t h a t a r e now b e i n g s t u d i e d i n c l u d e t h e i n - f l u e n c e of l o a d , r e s t r a i n t , and m o i s t u r e c o n t e n t on t h e f i r e endurance p e r i o d , and t h e c o r r e l a t i o n between t h e American and B r i t i s h f i r e endurance d a t a .

Acknonle dgments

!The l a b o r a t o r y b u i l d i n g w a s designed by &Teadowcroft and MacKay, A r c h i t e c t s , of Montreal, and c o n s t r u c t e d by t h e Thomas

F u l l e r C o n s t r u c t i o n Co. Ltd., of O t t a w a a s g e n e r a l c o n t r a c t o r s , The f u r n a c e s were d e s i g n e d by Ebvbank and P a r t n e r s (Canada) Ltd., p r i n c i p a l c o n t r a c t o r s b e i n g Amco Furnaces oron onto)

.

D r . N.B. Hutcheon, A s s i s t a n t D i r e c t o r of t h e Division of Building .Research, was d i r e c t l y responsible, with t h e s e n i o r author, for t h e i n i t i a l general planning and d e s i m and for l i a i s o n with the professional consultants.

TIME (HOURSI

FIGURE

1

I=?

LOADING DEVICE MOVABLE FRAME

FLOOR ELEV.

FIGURE 3

P4RKING

MAlH TRACK

PLAN

SECTION A-A

FIGURE 4

PLAN OF LABORATORY

a

OUTSIDE WORK AREA